WorldWideScience

Sample records for sequester carbon reduce

  1. Can greening of aquaculture sequester blue carbon?

    Science.gov (United States)

    Ahmed, Nesar; Bunting, Stuart W; Glaser, Marion; Flaherty, Mark S; Diana, James S

    2017-05-01

    Globally, blue carbon (i.e., carbon in coastal and marine ecosystems) emissions have been seriously augmented due to the devastating effects of anthropogenic pressures on coastal ecosystems including mangrove swamps, salt marshes, and seagrass meadows. The greening of aquaculture, however, including an ecosystem approach to Integrated Aquaculture-Agriculture (IAA) and Integrated Multi-Trophic Aquaculture (IMTA) could play a significant role in reversing this trend, enhancing coastal ecosystems, and sequestering blue carbon. Ponds within IAA farming systems sequester more carbon per unit area than conventional fish ponds, natural lakes, and inland seas. The translocation of shrimp culture from mangrove swamps to offshore IMTA could reduce mangrove loss, reverse blue carbon emissions, and in turn increase storage of blue carbon through restoration of mangroves. Moreover, offshore IMTA may create a barrier to trawl fishing which in turn could help restore seagrasses and further enhance blue carbon sequestration. Seaweed and shellfish culture within IMTA could also help to sequester more blue carbon. The greening of aquaculture could face several challenges that need to be addressed in order to realize substantial benefits from enhanced blue carbon sequestration and eventually contribute to global climate change mitigation.

  2. Apparatus for extracting and sequestering carbon dioxide

    Science.gov (United States)

    Rau, Gregory H [Castro Valley, CA; Caldeira, Kenneth G [Livermore, CA

    2010-02-02

    An apparatus and method associated therewith to extract and sequester carbon dioxide (CO.sub.2) from a stream or volume of gas wherein said apparatus hydrates CO.sub.2 and reacts the resulting carbonic acid with carbonate. Suitable carbonates include, but are not limited to, carbonates of alkali metals and alkaline earth metals, preferably carbonates of calcium and magnesium. Waste products are metal cations and bicarbonate in solution or dehydrated metal salts, which when disposed of in a large body of water provide an effective way of sequestering CO.sub.2 from a gaseous environment.

  3. Method for Extracting and Sequestering Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Rau, Gregory H.; Caldeira, Kenneth G.

    2005-05-10

    A method and apparatus to extract and sequester carbon dioxide (CO2) from a stream or volume of gas wherein said method and apparatus hydrates CO2, and reacts the resulting carbonic acid with carbonate. Suitable carbonates include, but are not limited to, carbonates of alkali metals and alkaline earth metals, preferably carbonates of calcium and magnesium. Waste products are metal cations and bicarbonate in solution or dehydrated metal salts, which when disposed of in a large body of water provide an effective way of sequestering CO2 from a gaseous environment.

  4. Economic Analysis of Sequestering Carbon in Green Ash Forests in the Lower Mississippi River Valley

    Directory of Open Access Journals (Sweden)

    Ching-Hsun Huang

    2003-01-01

    Full Text Available Since the U.S. is the largest emitter of carbon dioxide (CO2, it has become crucial to develop options that are both cost effective and supportive of sustainable development to reduce atmospheric CO2. Electric utility companies have the options of reducing their use of fossil fuels, switching to alternative energy sources, increasing efficiency, or offsetting carbon emissions. This study determined the cost and profitability of sequestering carbon in green ash plantations, and the number of tons of carbon that can be sequestered. The profitability of green ash is $2,342 and $3,645 per acre on site indices (measurement of soil quality 65 and 105 land, respectively, calculated with a 2.5% alternative rate of return (ARR. These figures shift to –$248 and –$240 calculated with a 15.0% ARR. If landowners who have an ARR of 2.5% can sell carbon credits for $10 per ton of carbon, profits will increase by $107 per acre on poor sites and $242 on good sites. Over one rotation (cutting cycle, 38.56 net tons of carbon can be sequestered on an acre of poor quality land and 51.35 tons on good quality land. The cost of sequestering carbon, without including revenues from timber production and carbon credits, ranges from a high of $15.20 per ton on poor sites to $14.41 on good sites, calculated with a 2.5% ARR; to a high of $8.51 per ton on poor sites to $7.63 on good sites, calculated with a 15.0% ARR. The cost of storing carbon can be reduced significantly if the trees can be sold for wood products.

  5. Process for sequestering carbon dioxide and sulfur dioxide

    Science.gov (United States)

    Maroto-Valer, M Mercedes [State College, PA; Zhang, Yinzhi [State College, PA; Kuchta, Matthew E [State College, PA; Andresen, John M [State College, PA; Fauth, Dan J [Pittsburgh, PA

    2009-10-20

    A process for sequestering carbon dioxide, which includes reacting a silicate based material with an acid to form a suspension, and combining the suspension with carbon dioxide to create active carbonation of the silicate-based material, and thereafter producing a metal salt, silica and regenerating the acid in the liquid phase of the suspension.

  6. Models for estimation of carbon sequestered by Cupressus ...

    African Journals Online (AJOL)

    This study compared models for estimating carbon sequestered aboveground in Cupressus lusitanica plantation stands at Wondo Genet College of Forestry and Natural Resources, Ethiopia. Relationships of carbon storage with tree component and stand age were also investigated. Thirty trees of three different ages (5, ...

  7. Potential to sequester carbon in Canadian forests: Some economic considerations

    International Nuclear Information System (INIS)

    Kooten, G.C. van; Arthur, L.M.; Wilson, W.R.

    1992-01-01

    The potential role of reforestation policies in reducing Canada's contribution to atmospheric CO 2 is examined. The results indicate sequestering carbon by reforestation of forest lands may be a cost-effective means for Canada to offset domestic emissions of CO 2 from other sources, and that planting forests on marginal agricultural lands also warrants consideration. But these policies need to be compared with alternatives for reducing CO 2 emissions to determine their relative cost-effectiveness. It is found that reforestation is more costly than policies to increase the fuel efficiency of automobiles, but economically more efficient than converting vehicles to natural gas. Forestation can make an important contribution to reduced atmospheric accumulation of carbon after the more cost-effective strategy, replacing less fuel-efficient automobiles, is exhausted (i.e. when the marginal costs of automobile emissions increase beyond those of forestation alternatives). Finally, it is demonstrated that, because of its vast forests, Canada is a net carbon sink. 26 refs., 2 figs., 4 tabs

  8. Comparing black carbon types in sequestering polybrominated diphenyl ethers (PBDEs) in sediments

    International Nuclear Information System (INIS)

    Jia, Fang; Gan, Jay

    2014-01-01

    Polybrominated diphenyl ethers (PBDEs) are widely found in sediments, especially congeners from the penta-BDE formula. Due to their strong affinity for black carbon (BC), bioavailability of PBDEs may be decreased in BC-amended sediments. In this study, we used a matrix-SPME method to measure the freely dissolved concentration (C free ) of PBDEs as a parameter of their potential bioavailability and evaluated the differences among biochar, charcoal, and activated carbon. Activated carbon displayed a substantially greater sequestration capacity than biochar or charcoal. At 1% amendment rate in sediment with low organic carbon (OC) content (0.12%), C free of six PBDEs was reduced by 47.5–78.0%, 47.3–77.5%, and 94.1–98.3% with biochar, charcoal, and activated carbon, respectively, while the sequestration was more limited in sediment with high OC content (0.87%). Therefore, it is important to consider the type and properties of the BC and the sediment in BC-based remediation or mitigation. -- Highlights: • A matrix-SPME method was developed for measuring C free of PBDEs in sediment porewater. • Different black carbon types differed greatly in their ability to decrease C free of PBDEs in sediments. • Activated carbon was much more efficient in sequestering PBDEs than biochar or charcoal. • The effect of black carbon was more pronounced in sediment with lower indigenous OC content. -- Biochar, charcoal, and activated carbon have been compared for their efficacy in sequestering PBDEs in sediments by using a matrix-SPME method

  9. Carbon Sequestered, Carbon Displaced and the Kyoto Context

    International Nuclear Information System (INIS)

    Marland, G.; Schlamadinger, B.

    1999-01-01

    The integrated system that embraces forest management, forest products, and land-use change impacts the global carbon cycle - and hence the net emission of the greenhouse gas carbon dioxide - in four fundamental ways. Carbon is stored in living and dead biomass, carbon is stored in wood products and landfills, forest products substitute in the market place for products made from other materials, and forest harvests can be used wholly or partially to displace fossil fuels in the energy sector. Implementation of the Kyoto Protocol to the United Nations Framework Convention on Climate Change would result in the creation of international markets for carbon dioxide emissions credits, but the current Kyoto text does not treat all carbon identically. We have developed a carbon accounting model, GORCAM, to examine a variety of scenarios for land management and the production of forest products. In this paper we explore, for two simple scenarios of forest management, the carbon flows that occur and how these might be accounted for under the Kyoto text. The Kyoto protocol raises questions about what activities can result in emissions credits, which carbon reservoirs will be counted, who will receive the credits, and how much credit will be available? The Kyoto Protocol would sometimes give credits for carbon sequestered, but it would always give credits when fossil-fuel carbon dioxide emissions are displaced

  10. Urban warming reduces aboveground carbon storage

    DEFF Research Database (Denmark)

    Meineke, Emily; Youngsteadt, Elsa; Dunn, Robert Roberdeau

    2016-01-01

    sequestration (carbon stored per year) of mature trees. Urban warming increased herbivorous arthropod abundance on trees, but these herbivores had negligible effects on tree carbon sequestration. Instead, urban warming was associated with an estimated 12% loss of carbon sequestration, in part because...... photosynthesis was reduced at hotter sites. Ecosystem service assessments that do not consider urban conditions may overestimate urban tree carbon storage. Because urban and global warming are becoming more intense, our results suggest that urban trees will sequester even less carbon in the future....

  11. Genome Sequence of Carbon Dioxide-Sequestering Serratia sp. Strain ISTD04 Isolated from Marble Mining Rocks

    OpenAIRE

    Kumar, Manish; Gazara, Rajesh Kumar; Verma, Sandhya; Kumar, Madan; Verma, Praveen Kumar; Thakur, Indu Shekhar

    2016-01-01

    The Serratia sp. strain ISTD04 has been identified as a carbon dioxide (CO2)-sequestering bacterium isolated from marble mining rocks in the Umra area, Rajasthan, India. This strain grows chemolithotrophically on media that contain sodium bicarbonate (NaHCO3) as the sole carbon source. Here, we report the genome sequence of 5.07?Mb Serratia sp. ISTD04.

  12. Genome Sequence of Carbon Dioxide-Sequestering Serratia sp. Strain ISTD04 Isolated from Marble Mining Rocks.

    Science.gov (United States)

    Kumar, Manish; Gazara, Rajesh Kumar; Verma, Sandhya; Kumar, Madan; Verma, Praveen Kumar; Thakur, Indu Shekhar

    2016-10-20

    The Serratia sp. strain ISTD04 has been identified as a carbon dioxide (CO 2 )-sequestering bacterium isolated from marble mining rocks in the Umra area, Rajasthan, India. This strain grows chemolithotrophically on media that contain sodium bicarbonate (NaHCO 3 ) as the sole carbon source. Here, we report the genome sequence of 5.07 Mb Serratia sp. ISTD04. Copyright © 2016 Kumar et al.

  13. The carbon balance of reducing wildfire risk and restoring process: an analysis of 10-year post-treatment carbon dynamics in a mixed-conifer forest

    Science.gov (United States)

    Morgan L. Wiechmann; Matthew D. Hurteau; Malcolm P. North; George W. Koch; Lucie Jerabkova

    2015-01-01

    Forests sequester carbon from the atmosphere, helping mitigate climate change. In fire-prone forests, burn events result in direct and indirect emissions of carbon. High fire-induced tree mortality can cause a transition from a carbon sink to source, but thinning and prescribed burning can reduce fire severity and carbon loss when wildfire occurs. However, treatment...

  14. Ex-situ and in-situ mineral carbonation as a means to sequester carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Gerdemann, Stephen J.; Dahlin, David C.; O' Connor, William K.; Penner, Larry R.; Rush, G.E.

    2004-01-01

    The U. S. Department of Energy's Albany Research Center is investigating mineral carbonation as a method of sequestering CO2 from coal-fired-power plants. Magnesium-silicate minerals such as serpentine [Mg3Si2O5(OH)4] and olivine (Mg2SiO4) react with CO2 to produce magnesite (MgCO3), and the calcium-silicate mineral, wollastonite (CaSiO3), reacts to form calcite (CaCO3). It is possible to carry out these reactions either ex situ (above ground in a traditional chemical processing plant) or in situ (storage underground and subsequent reaction with the host rock to trap CO2 as carbonate minerals). For ex situ mineral carbonation to be economically attractive, the reaction must proceed quickly to near completion. The reaction rate is accelerated by raising the activity of CO2 in solution, heat (but not too much), reducing the particle size, high-intensity grinding to disrupt the crystal structure, and, in the case of serpentine, heat-treatment to remove the chemically bound water. All of these carry energy/economic penalties. An economic study illustrates the impact of mineral availability and process parameters on the cost of ex situ carbon sequestration. In situ carbonation offers economic advantages over ex situ processes, because no chemical plant is required. Knowledge gained from the ex situ work was applied to long-term experiments designed to simulate in situ CO2 storage conditions. The Columbia River Basalt Group (CRBG), a multi-layered basaltic lava formation, has potentially favorable mineralogy (up to 25% combined concentration of Ca, Fe2+, and Mg cations) for storage of CO2. However, more information about the interaction of CO2 with aquifers and the host rock is needed. Core samples from the CRBG, as well as samples of olivine, serpentine, and sandstone, were reacted in an autoclave for up to 2000 hours at elevated temperatures and pressures. Changes in core porosity, secondary mineralizations, and both solution and solid chemistry were measured.

  15. Nutrient amendment does not increase mineralisation of sequestered carbon during incubation of a nitrogen limited mangrove soil

    KAUST Repository

    Keuskamp, Joost A.

    2013-02-01

    Mangrove forests are sites of intense carbon and nutrient cycling, which result in soil carbon sequestration on a global scale. Currently, mangrove forests receive increasing quantities of exogenous nutrients due to coastal development. The present paper quantifies the effects of nutrient loading on microbial growth rates and the mineralisation of soil organic carbon (SOC) in two mangrove soils contrasting in carbon content. An increase in SOC mineralisation rates would lead to the loss of historically sequestered carbon and an enhanced CO2 release from these mangrove soils.In an incubation experiment we enriched soils from Avicennia and Rhizophora mangrove forests bordering the Red Sea with different combinations of nitrogen, phosphorus and glucose to mimic the effects of wastewater influx. We measured microbial growth rates as well as carbon mineralisation rates in the natural situation and after enrichment. The results show that microbial growth is energy limited in both soils, with nitrogen as a secondary limitation. Nitrogen amendment increased the rate at which labile organic carbon was decomposed, while it decreased SOC mineralisation rates. Such an inhibitory effect on SOC mineralisation was not found for phosphorus enrichment.Our data confirm the negative effect of nitrogen enrichment on the mineralisation of recalcitrant carbon compounds found in other systems. Based on our results it is not to be expected that nutrient enrichment by itself will cause degradation of historically sequestered soil organic carbon in nitrogen limited mangrove forests. © 2012 Elsevier Ltd.

  16. Methane production by Methanothermobacter thermautotrophicus to recover energy from carbon dioxide sequestered in geological reservoirs.

    Science.gov (United States)

    Kawaguchi, Hideo; Sakuma, Takahiro; Nakata, Yuiko; Kobayashi, Hajime; Endo, Keita; Sato, Kozo

    2010-07-01

    To recover energy from carbon dioxide sequestered in geological reservoirs, the geochemical effects of acidic and substrate- and nutrient-limiting conditions on methane production by the hydrogenotrophic methanogen Methanothermobacter thermautotrophicus were investigated in a simulated deep saline aquifer environment using formation water media retrieved from petroleum reservoirs. 2009 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  17. Comparative Status of Sequestered Carbon Stock of Azadirachta indica and Conocarpus erectus at the University of Karachi Campus, Pakistan

    OpenAIRE

    Amber Ajani; Zafar Iqbal Shams

    2016-01-01

    Carbon sequestration by trees is one of the most cost-effective and efficient methods to remove carbon dioxide from atmosphere since trees remove and store carbon at higher rates compared to other land covers. Carbon storage by trees typically ranges from 1 to 8 MgC ha-1 yr-1.The carbon is sequestered in different parts of the trees as biomass. The measurements of biomass provide reasonably accurate estimate of the amount of carbon that was removed from lower troposphere over the years. There...

  18. THE POTENTIAL OF RECLAIMED LANDS TO SEQUESTER CARBON AND MITIGATE THE GREENHOUSE EFFECT

    Energy Technology Data Exchange (ETDEWEB)

    Terry Brown; Song Jin

    2006-05-01

    Reclaimed mine lands have the potential to sequester carbon. The use of amendments to increase fertility and overall soil quality is encouraging. Waste amendments such as sewage sludge and clarifier sludge, as well as commercial compost were tested to determine their effects on carbon sequestration and humic acid formation in reclaimed mine lands. Sewage sludge and clarifier sludge have the potential to work as reclaimed mine lands amendments. C:N ratios need to be understood to determine probability of nutrient leaching and water contamination. Microbial activity on the humic acid fraction of sludge is directed toward the readily degradable constituents containing single chain functional groups. This finding indicate that amendments with lower molecular constituents such as aliphatic compounds are more amenable to microbial degradation, therefore serves as better nutrient sources to enhance the formation of vegetation in mine lands and leads to more efficient carbon sequestration.

  19. A conceptual framework for the evaluation of cost-effectiveness of projects to reduce GHG emissions and sequester carbon

    International Nuclear Information System (INIS)

    Sathaye, J.; Norgaard, R.; Makundi, W.

    1993-07-01

    This paper proposes a conceptual framework for evaluating the cost of projects to reduce atmospheric greenhouse gases (GHGs). The evaluation of cost-effectiveness should account for both the timing of carbon emissions and the damage caused by the atmospheric stock of carbon. We develop a conceptual basis to estimate the cost-effectiveness of projects in terms of the cost of reducing atmospheric carbon (CRAC) and other GHGs. CRAC accounts for the economic discount rate, alternative functional forms of the shadow price, the residence period of carbon in the atmosphere, and the multiple monetary benefits of projects. The last item is of particular importance to the developing countries

  20. Sequestering in string theory

    International Nuclear Information System (INIS)

    Kachru, Shamit; McAllister, Liam; Sundrum, Raman

    2007-01-01

    We study sequestering, a prerequisite for flavor-blind supersymmetry breaking in several high-scale mediation mechanisms, in compactifications of type IIB string theory. We find that although sequestering is typically absent in unwarped backgrounds, strongly warped compactifications do readily sequester. The AdS/CFT dual description in terms of conformal sequestering plays an important role in our analysis, and we establish how sequestering works both on the gravity side and on the gauge theory side. We pay special attention to subtle compactification effects that can disrupt sequestering. Our result is a step toward realizing an appealing pattern of soft terms in a KKLT compactification

  1. Mitigating climate change by sequestering carbon soils: A hypertext-based scientific assessment

    International Nuclear Information System (INIS)

    Rauscher, H.M.; Alban, D.H.; Johnson, D.W.

    1992-01-01

    The general objective of this project is the development of a hypertext-based scientific assessment on the subject of mitigating climate change by sequestering carbon in soils. Specifically, the authors want to (1) translate the scientific knowledge base on soil carbon cycling into a form meaningful for policy makers by using the theory of issue-based hypertext for problem solving using the argumentative approach developed by the late Horst Rittel, professor of planning and design at the University of California, Berkeley; (2) provide an organized and evaluated scientific knowledge base on soil carbon dynamics for research scientists to aid in the rapid and economical review and understanding of the subfield of science; and (3) test this new hybrid hypertext and AI methodology for use as a tool for program managers to help them evaluate a research domain to find knowledge gaps, to prioritize these knowledge gaps, to channel available research funding to these projects aimed at filling the most promising knowledge gaps in order to have the greatest possible impact on the entire knowledge base of the field, and to help explicitly measure scientific progress in terms that funding sources can understand. The authors began this project in fall 1991 and expect to complete it by fall 1993

  2. Improving farming practices reduces the carbon footprint of spring wheat production.

    Science.gov (United States)

    Gan, Yantai; Liang, Chang; Chai, Qiang; Lemke, Reynald L; Campbell, Con A; Zentner, Robert P

    2014-11-18

    Wheat is one of the world's most favoured food sources, reaching millions of people on a daily basis. However, its production has climatic consequences. Fuel, inorganic fertilizers and pesticides used in wheat production emit greenhouse gases that can contribute negatively to climate change. It is unknown whether adopting alternative farming practices will increase crop yield while reducing carbon emissions. Here we quantify the carbon footprint of alternative wheat production systems suited to semiarid environments. We find that integrating improved farming practices (that is, fertilizing crops based on soil tests, reducing summerfallow frequencies and rotating cereals with grain legumes) lowers wheat carbon footprint effectively, averaging -256 kg CO2 eq ha(-1) per year. For each kg of wheat grain produced, a net 0.027-0.377 kg CO2 eq is sequestered into the soil. With the suite of improved farming practices, wheat takes up more CO2 from the atmosphere than is actually emitted during its production.

  3. Fossil fuel derivatives with reduced carbon. Phase I final report

    Energy Technology Data Exchange (ETDEWEB)

    Kennel, E.B.; Zondlo, J.W.; Cessna, T.J.

    1999-06-30

    This project involves the simultaneous production of clean fossil fuel derivatives with reduced carbon and sulfur, along with value-added carbon nanofibers. This can be accomplished because the nanofiber production process removes carbon via a catalyzed pyrolysis reaction, which also has the effect of removing 99.9% of the sulfur, which is trapped in the nanofibers. The reaction is mildly endothermic, meaning that net energy production with real reductions in greenhouse emissions are possible. In Phase I research, the feasibility of generating clean fossil fuel derivatives with reduced carbon was demonstrated by the successful design, construction and operation of a facility capable of utilizing coal as well as natural gas as an inlet feedstock. In the case of coal, for example, reductions in CO{sub 2} emissions can be as much as 70% (normalized according to kilowatts produced), with the majority of carbon safely sequestered in the form of carbon nanofibers or coke. Both of these products are value-added commodities, indicating that low-emission coal fuel can be done at a profit rather than a loss as is the case with most clean-up schemes. The main results of this project were as follows: (1) It was shown that the nanofiber production process produces hydrogen as a byproduct. (2) The hydrogen, or hydrogen-rich hydrocarbon mixture can be consumed with net release of enthalpy. (3) The greenhouse gas emissions from both coal and natural gas are significantly reduced. Because coal consumption also creates coke, the carbon emission can be reduced by 75% per kilowatt-hour of power produced.

  4. Native Soil Charcoal as a Model for Designing Biochar for Carbon Sequestration

    Science.gov (United States)

    Under changing climate a variety of mechanisms for removing carbon from the atmosphere and sequestering it elsewhere are being considered to reduce the forcing of the atmosphere. Amending soils with biochar has been proposed as one long-term means of sequestering carbon originat...

  5. Forest managment options for sequestering carbon in Mexico

    International Nuclear Information System (INIS)

    Masera, O.R.; Bellon, M.R.; Segura, G.

    1995-01-01

    This paper identifies and examines economic response options to avoid carbon emissions and increase carbon sequestration in Mexican forests. A ''Policy'' scenario covering the years 2000, 2010 and 2030 and a ''Technical Potential'' scenario (year 2030) are developed to examine the potential carbon sequestration and costs of each response option. Benefit-cost analyses for three case studies, including management of a pulpwood plantation, a native temperate forest and a native tropical evergreen forest are presented and discussed. The study suggests that a large potential for reducing carbon emissions and increasing carbon sequestration exists in Mexican forests. However, the achievement of this potential will require important reforms to the current institutional setting of the forest sector. The management of native temperate and tropical forests offers the most promising alternatives for carbon sequestration. The cost effectiveness of commercial plantations critically depends on very high site productivity. Restoration of degraded forest lands; particularly through the establishment of energy plantations, also shows a large carbon sequestration potential. (Author)

  6. An Integrated, Low Temperature Process to Capture and Sequester Carbon Dioxide from Industrial Emissions

    Science.gov (United States)

    Wendlandt, R. F.; Foremski, J. J.

    2013-12-01

    Laboratory experiments show that it is possible to integrate (1) the chemistry of serpentine dissolution, (2) capture of CO2 gas from the combustion of natural gas and coal-fired power plants using aqueous amine-based solvents, (3) long-term CO2 sequestration via solid phase carbonate precipitation, and (4) capture solvent regeneration with acid recycling in a single, continuous process. In our process, magnesium is released from serpentine at 300°C via heat treatment with ammonium sulfate salts or at temperatures as low as 50°C via reaction with sulfuric acid. We have also demonstrated that various solid carbonate phases can be precipitated directly from aqueous amine-based (NH3, MEA, DMEA) CO2 capture solvent solutions at room temperature. Direct precipitation from the capture solvent enables regenerating CO2 capture solvent without the need for heat and without the need to compress the CO2 off gas. We propose that known low-temperature electrochemical methods can be integrated with this process to regenerate the aqueous amine capture solvent and recycle acid for dissolution of magnesium-bearing mineral feedstocks and magnesium release. Although the direct precipitation of magnesite at ambient conditions remains elusive, experimental results demonstrate that at temperatures ranging from 20°C to 60°C, either nesquehonite Mg(HCO3)(OH)●2H2O or a double salt with the formula [NH4]2Mg(CO3)2●4H2O or an amorphous magnesium carbonate precipitate directly from the capture solvent. These phases are less desirable for CO2 sequestration than magnesite because they potentially remove constituents (water, ammonia) from the reaction system, reducing the overall efficiency of the sequestration process. Accordingly, the integrated process can be accomplished with minimal energy consumption and loss of CO2 capture and acid solvents, and a net generation of 1 to 4 moles of H2O/6 moles of CO2 sequestered (depending on the solid carbonate precipitate and amount of produced H2

  7. Conformal sequestering simplified

    International Nuclear Information System (INIS)

    Schmaltz, Martin; Sundrum, Raman

    2006-01-01

    Sequestering is important for obtaining flavor-universal soft masses in models where supersymmetry breaking is mediated at high scales. We construct a simple and robust class of hidden sector models which sequester themselves from the visible sector due to strong and conformally invariant hidden dynamics. Masses for hidden matter eventually break the conformal symmetry and lead to supersymmetry breaking by the mechanism recently discovered by Intriligator, Seiberg and Shih. We give a unified treatment of subtleties due to global symmetries of the CFT. There is enough review for the paper to constitute a self-contained account of conformal sequestering

  8. Carbon sequestration in forests as a national policy issue

    Science.gov (United States)

    Linda S. Heath; Linda A. Joyce

    1997-01-01

    The United States' 1993 Climate Change Action Plan called upon the forestry sector to sequester an additional 10 million metric tons/yr by the year 2000. Forests are currently sequestering carbon and may provide opportunities to mitigate fossil fuel emissions in the near-term until fossil fuel emissions can be reduced. Using the analysis of carbon budgets based on...

  9. The potential for reducing atmospheric carbon by large-scale afforestation in China and related cost/benefit analysis

    International Nuclear Information System (INIS)

    Deying Xu

    1995-01-01

    In this paper, the amount of carbon sequestered through large-scale afforestation and related costs and benefits are calculated, assuming that the forests are managed in perpetual rotations. Based on land availability for afforestation, 20 cases are identified in five suitable regions in China. The least expensive way of developing forests for the purpose of sequestering carbon emissions is the case of Pinus massoniana from the initial investment point of view, and then Spruce. The cases of open forest management are relatively less expensive options because of their low initial investment and long rotations, although their annual wood increments are low. Some less productive tree species have higher net costs for carbon sequestering. For most of the agroforestry systems the net costs are low, especially in the south, the southwest, and the north of China, though their initial investments are high. If the total land available is afforested, the net carbon sequestering will be about 9.7 billion tons under perpetual rotations, amounting to 16.3 times the total industrial carbon release in 1988 in China, and the total initial cost for such a programme is estimated at 19.3 billion US$. Some hindrances in developing forests in China are discussed. (Author)

  10. Induction of systemic resistance in plants by biochar, a soil-applied carbon sequestering agent.

    Science.gov (United States)

    Elad, Yigal; David, Dalia Rav; Harel, Yael Meller; Borenshtein, Menahem; Kalifa, Hananel Ben; Silber, Avner; Graber, Ellen R

    2010-09-01

    Biochar is the solid coproduct of biomass pyrolysis, a technique used for carbon-negative production of second-generation biofuels. The biochar can be applied as a soil amendment, where it permanently sequesters carbon from the atmosphere as well as improves soil tilth, nutrient retention, and crop productivity. In addition to its other benefits in soil, we found that soil-applied biochar induces systemic resistance to the foliar fungal pathogens Botrytis cinerea (gray mold) and Leveillula taurica (powdery mildew) on pepper and tomato and to the broad mite pest (Polyphagotarsonemus latus Banks) on pepper. Levels of 1 to 5% biochar in a soil and a coconut fiber-tuff potting medium were found to be significantly effective at suppressing both diseases in leaves of different ages. In long-term tests (105 days), pepper powdery mildew was significantly less severe in the biochar-treated plants than in the plants from the unamended controls although, during the final 25 days, the rate of disease development in the treatments and controls was similar. Possible biochar-related elicitors of systemic induced resistance are discussed.

  11. Reducing carbon transaction costs in community based forest management

    NARCIS (Netherlands)

    Skutsch, Margaret

    The paper considers the potential for community based forest management (of existing forests) in developing countries, as a future CDM strategy, to sequester carbon and claim credits in future commitment periods. This kind of forestry is cost effective, and should bring many more benefits to local

  12. Spatial Associations and Chemical Composition of Organic Carbon Sequestered in Fe, Ca, and Organic Carbon Ternary Systems.

    Science.gov (United States)

    Sowers, Tyler D; Adhikari, Dinesh; Wang, Jian; Yang, Yu; Sparks, Donald L

    2018-05-25

    Organo-mineral associations of organic carbon (OC) with iron (Fe) oxides play a major role in environmental OC sequestration, a process crucial to mitigating climate change. Calcium has been found to have high coassociation with OC in soils containing high Fe content, increase OC sorption extent to poorly crystalline Fe oxides, and has long been suspected to form bridging complexes with Fe and OC. Due to the growing realization that Ca may be an important component of C cycling, we launched a scanning transmission X-ray microscopy (STXM) investigation, paired with near-edge X-ray absorption fine structure (NEXAFS) spectroscopy, in order to spatially resolve Fe, Ca, and OC relationships and probe the effect of Ca on sorbed OC speciation. We performed STXM-NEXAFS analysis on 2-line ferrihydrite reacted with leaf litter-extractable dissolved OC and citric acid in the absence and presence of Ca. Organic carbon was found to highly associate with Ca ( R 2 = 0.91). Carboxylic acid moieties were dominantly sequestered; however, Ca facilitated the additional sequestration of aromatic and phenolic moieties. Also, C NEXAFS revealed polyvalent metal ion complexation. Our results provide evidence for the presence of Fe-Ca-OC ternary complexation, which has the potential to significantly impact how organo-mineral associations are modeled.

  13. Preliminary investigations on the carbon dioxide sequestering potential of the ultramafic rock

    Energy Technology Data Exchange (ETDEWEB)

    Goff, F.; Guthrie, G.; Counce, D.; Kluk, E.; Bergfeld, D.; Snow, M.

    1997-08-01

    Fossil fuels continue to provide major sources of energy to the modern world even though global emissions of CO{sub 2} are presently at levels of 19 Gt/yr. Future antipollution measures may include sequestering of waste CO{sub 2} as magnesite (MgCO{sub 3}) by processing ultramafic rocks to obtain reactable Mg. Huge ultramafic deposits consisting of relatively pure Mg-rich silicates exist throughout much of the world in ophiolites and layered intrusions. Peridotites (especially dunites) and serpentinites comprise the best ores because they contain the most Mg by weight and are relatively reactive to hot acids such as HCl. Although mining such deposits on a large scale would have environmental impacts, the sequestering process could provide Cr, Ni, and other metals as byproducts and could dispose of existing waste (white) asbestos. Small ultramafic bodies ({approximately} 1 km{sup 3}) can potentially sequester about 1 Gt of CO{sub 2} or about 20% of annual US emissions. A single large deposit of dunite ({approximately} 30 km{sup 3}) could dispose of about 20 yr of current US CO{sub 2} emissions. The cost and environmental impact of mining these deposits must be weighed against the increased costs of energy and benefits to the atmosphere and climate.

  14. A Spatio-Temporal Based Estimation of Sequestered Carbon in the ...

    African Journals Online (AJOL)

    Michael

    2015-06-01

    Jun 1, 2015 ... reduction in carbon emissions due to deforestation and forest ... global initiatives to reduce global warming, and the management of ... using a process-based equilibrium terrestrial. *Manuscript ..... aboveground biomass limits modeled for African lowland ... replacement of vegetation biomass carbon from.

  15. Sequestering of Fe and Pb ions from Wastewater by Canarium ...

    African Journals Online (AJOL)

    In this paper agricultural waste; Canarium schweinfurthii was explored for the sequestering of Fe and Pb ions from wastewater solution after carbonization and chemical treatment at 400oC. Optimum time of 30 and 150 min with percentage removal of 95 and 98% at optimum pH of 2 and 6 was obtained for Fe and Pb ions.

  16. Spent coffee grounds-based activated carbon preparation for sequestering of malachite green

    Science.gov (United States)

    Lim, Jun-Wei; Lam, Keat-Ying; Bashir, Mohammed J. K.; Yeong, Yin-Fong; Lam, Man-Kee; Ho, Yeek-Chia

    2016-11-01

    The key of reported work was to optimize the fabricating factors of spent coffee grounds-based activated carbon (SCG-bAC) used to sequester Malachite Green (MG) form aqueous solution via adsorption process. The fabricating factors of impregnation ratio with ortho-phosphoric acid, activation temperature and activation time were simultaneously optimized by central composite design (CCD) of response surface methodology (RSM) targeting on maximum removal of MG. At the optimum condition, 96.3% of MG was successfully removed by SCG-bAC at the impregnation ratio with ortho-phosphoric acid of 0.50, activation temperature of 554°C and activation time of 31.4 min. Statistical model that could predict the MG removal percentage was also derived and had been statistically confirmed to be significant. Subsequently, the MG adsorption equilibrium data was found well-fitted to Langmuir isotherm model, indicating the predominance of monolayer adsorption of MG on SCG-bAC surface. To conclude, the findings from the this study unveil the potential of spent coffee grounds as an alternative precursor in fabricating low-cost AC for the treatment of wastewater loaded with MG pollutant.

  17. Carbon Dioxide Sequestering Using Microalgal Systems

    Energy Technology Data Exchange (ETDEWEB)

    Daniel J. Stepan; Richard E. Shockey; Thomas A. Moe; Ryan Dorn

    2002-02-01

    This project evaluated key design criteria, the technical feasibility, and the preliminary economic viability of a CO{sub 2}-sequestering system integrated with a coal-fired power plant based on microalgae biofixation. A review of relevant literature was conducted, and a bench-scale algal-based sequestration system was constructed and operated to verify algal growth capabilities using a simulated flue gas stream. The bench-scale system was a 20-gallon glass aquarium with a 16-gallon operating volume and was direct-sparged with a simulated flue gas. The flue gas composition was based on flue gas analyses for a 550-MW Coal Creek Power Station boiler in Underwood, North Dakota, which averaged 12.1% CO{sub 2}, 5.5% O{sub 2}, 423 ppm SO{sub 2}, 124 ppm NO{sub x}, and an estimated 50 mg/m{sup 3} fly ash loading. The algae were grown in Bold's basal growth medium. Lighting was provided using a two-tube fluorescent ''grow-light'' bulb fixture mounted directly above the tank. Algal growth appeared to be inhibited in the presence of SO{sub 2} using mixed cultures of green and blue-green cultures of algae. Samples of Monoraphidium strain MONOR02 and Nannochloropsis NANNO02 algal samples were obtained from the University of Hawaii Culture Collection. These samples did not exhibit inhibited growth in the presence of all the simulated flue gas constituents, but growth rates were somewhat lower than those expected, based on the review of literature. Samples of harvested algae were analyzed for protein, lipid, and carbohydrate content. A lipid content of 26% appeared to be fairly normal for algae, and it did not appear that large amounts of nitrogen were being fixed and promoting growth, nor were the algae starved for nitrogen. Proteins made up 41% of the total mass, and carbohydrates were assumed to be 33% (by difference). A preliminary economic analysis showed the costs of an integrated system based on microalgae biofixation to sequester 25% of the CO

  18. Comparative Status of Sequestered Carbon Stock of Azadirachta indica and Conocarpus erectus at the University of Karachi Campus, Pakistan

    Directory of Open Access Journals (Sweden)

    Amber Ajani

    2016-05-01

    Full Text Available Carbon sequestration by trees is one of the most cost-effective and efficient methods to remove carbon dioxide from atmosphere since trees remove and store carbon at higher rates compared to other land covers. Carbon storage by trees typically ranges from 1 to 8 MgC ha-1 yr-1.The carbon is sequestered in different parts of the trees as biomass. The measurements of biomass provide reasonably accurate estimate of the amount of carbon that was removed from lower troposphere over the years. Therefore, the present study investigates and compares the carbon stock of native Azadirachta indica and exotic Conocarpus erectus, which are extensively cultivated in the campus of the University of Karachi, Pakistan. The above-ground and below-ground biomass of 327 trees of A. indica and 253 trees of C. erectus were estimated by using non-destructive method. The average carbon content of A. indica is calculated to be 662.32 + 1144.81 Kg while that of C. erectus is 192.70 + 322.60 Kg. The independent t-test analysis showed significant difference (p < 0.001 between the means of the carbon content of both the species. The carbon contents of two different species were also correlated with bole’s diameter at breast height (DBH and tree’s height. The analysis demonstrated greater correlation between the carbon content and the DBH of both the species compared to that with their height. The study will help to understand the carbon sequestration potential of two different types of species for planting particularly in urban area of the world.INTERNATIONAL JOURNAL OF ENVIRONMENTVolume-5, Issue-2, March-May 2016, Page: 89-97

  19. Method of detecting leakage from geologic formations used to sequester CO.sub.2

    Science.gov (United States)

    White, Curt [Pittsburgh, PA; Wells, Arthur [Bridgeville, PA; Diehl, J Rodney [Pittsburgh, PA; Strazisar, Brian [Venetia, PA

    2010-04-27

    The invention provides methods for the measurement of carbon dioxide leakage from sequestration reservoirs. Tracer moieties are injected along with carbon dioxide into geological formations. Leakage is monitored by gas chromatographic analyses of absorbents. The invention also provides a process for the early leak detection of possible carbon dioxide leakage from sequestration reservoirs by measuring methane (CH.sub.4), ethane (C.sub.2H.sub.6), propane (C.sub.3H.sub.8), and/or radon (Rn) leakage rates from the reservoirs. The invention further provides a method for branding sequestered carbon dioxide using perfluorcarbon tracers (PFTs) to show ownership.

  20. Carbon recovery rates following different wildfire risk mitigation treatments

    Science.gov (United States)

    M. Hurteau; M. North

    2010-01-01

    Sequestered forest carbon can provide a climate change mitigation benefit, but in dry temperate forests, wildfire poses a reversal risk to carbon offset projects. Reducing wildfire risk requires a reduction in and redistribution of carbon stocks, the benefit of which is only realized when wildfire occurs. To estimate the time needed to recover carbon removed and...

  1. Atmospheric carbon reduction by urban trees

    International Nuclear Information System (INIS)

    Nowak, D.J.

    1993-01-01

    Trees, because they sequester atmospheric carbon through their growth process and conserve energy in urban areas, have been suggested as one means to combat increasing levels of atmospheric carbon. Analysis of the urban forest in Oakland, California (21% tree cover), reveals a tree carbon storage level of 11·0 metric tons/hectare. Trees in the area of the 1991 fire in Oakland stored approximately 14,500 metric tons of carbon, 10% of the total amount stored by Oakland's urban forest. National urban forest carbon storage in the United States (28% tree cover) is estimated at between 350 and 750 million metric tons. Establishment of 10 million urban trees annually over the next 10 years is estimated to sequester and offset the production of 363 million metric tons of carbon over the next 50 years-less than 1% of the estimated carbon emissions in the United States over the same time period. Advantages and limitations of managing urban trees to reduce atmospheric carbon are discussed. 36 refs., 2 figs., 3 tabs

  2. Red mud as a carbon sink: variability, affecting factors and environmental significance.

    Science.gov (United States)

    Si, Chunhua; Ma, Yingqun; Lin, Chuxia

    2013-01-15

    The capacity of red mud to sequester CO(2) varied markedly due to differences in bauxite type, processing and disposal methods. Calcium carbonates were the dominant mineral phases responsible for the carbon sequestration in the investigated red mud types. The carbon sequestration capacity of red mud was not fully exploited due to shortages of soluble divalent cations for formation of stable carbonate minerals. Titanate and silicate ions were the two major oxyanions that appeared to strongly compete with carbonate ions for the available soluble Ca. Supply of additional soluble Ca and Mg could be a viable pathway for maximizing carbon sequestration in red mud and simultaneously reducing the causticity of red mud. It is roughly estimated that over 100 million tonnes of CO(2) have been unintentionally sequestered in red mud around the world to date through the natural weathering of historically produced red mud. Based on the current production rate of red mud, it is likely that some 6 million tonnes of CO(2) will be sequestered annually through atmospheric carbonation. If appropriate technologies are in place for incorporating binding cations into red mud, approximately 6 million tonnes of additional CO(2) can be captured and stored in the red mud while the hazardousness of red mud is simultaneously reduced. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Sequestering CO2 in the Built Environment

    Science.gov (United States)

    Constantz, B. R.

    2009-12-01

    Calera’s Carbonate Mineralization by Aqueous Precipitation (CMAP) technology with beneficial reuse has been called, “game-changing” by Carl Pope, Director of the Sierra Club. Calera offers a solution to the scale of the carbon problem. By capturing carbon into the built environment through carbonate mineralization, Calera provides a sound and cost-effective alternative to Geologic Sequestration and Terrestrial Sequestration. The CMAP technology permanently converts carbon dioxide into a mineral form that can be stored above ground, or used as a building material. The process produces a suite of carbonate-containing minerals of various polymorphic forms. Calera product can be substituted into blends with ordinary Portland cements and used as aggregate to produce concrete with reduced carbon, carbon neutral, or carbon negative footprints. For each ton of product produced, approximately half a ton of carbon dioxide can be sequestered using the Calera process. Coal and natural gas are composed of predominately istopically light carbon, as the carbon in the fuel is plant-derived. Thus, power plant CO2 emissions have relatively low δ13C values.The carbon species throughout the CMAP process are identified through measuring the inorganic carbon content, δ13C values of the dissolved carbonate species, and the product carbonate minerals. Measuring δ13C allows for tracking the flue gas CO2 throughout the capture process. Initial analysis of the capture of propane flue gas (δ13C ˜ -25 ‰) with seawater (δ13C ˜ -10 ‰) and industrial brucite tailings from a retired magnesium oxide plant in Moss Landing, CA (δ13C ˜ -7 ‰ from residual calcite) produced carbonate mineral products with a δ13C value of ˜ -20 ‰. This isotopically light carbon, transformed from flue gas to stable carbonate minerals, can be transferred and tracked through the capture process, and finally to the built environment. CMAP provides an economical solution to global warming by producing

  4. Forest carbon benefits, costs and leakage effects of carbon reserve scenarios in the United States

    Science.gov (United States)

    Prakash Nepal; Peter J. Ince; Kenneth E. Skog; Sun J. Chang

    2013-01-01

    This study evaluated the potential effectiveness of future carbon reserve scenarios, where U.S. forest landowners would hypothetically be paid to sequester carbon on their timberland and forego timber harvests for 100 years. Scenarios featured direct payments to landowners of $0 (baseline), $5, $10, or $15 per metric ton of additional forest carbon sequestered on the...

  5. SUSY Unparticle and Conformal Sequestering

    Energy Technology Data Exchange (ETDEWEB)

    Nakayama, Yu; Nakayama, Yu

    2007-07-17

    We investigate unparticle physics with supersymmetry (SUSY). The SUSY breaking effects due to the gravity mediation induce soft masses for the SUSY unparticles and hence break the conformal invariance. The unparticle physics observable in near future experiments is only consistent if the SUSY breakingeffects from the hidden sector to the standard model sector are dominated by the gauge mediation, or if the SUSY breaking effects to the unparticle sector are sufficiently sequestered. We argue that the natural realization of the latter possibility is the conformal sequestering scenario.

  6. Do we need to sequester carbon dioxide?

    International Nuclear Information System (INIS)

    Delbecq, D.

    2011-01-01

    Carbon sequestration may be the solution to face our difficulty to cut down the use of fossil energies. CO 2 has to be separated from other gases released by thermal power plants before being stored in deep geological layers, there it can stay as a gas, or it can be dissolved in a fluid phase, or it can react with minerals and be integrated to a solid phase. Oil fields and deep saline water reservoirs are natural candidates for carbon sequestration. Carbon sequestration implies the installation of a network of pipelines to transport CO 2 from the place of production to the place of sequestration. The high cost of carbon sequestration implies the implementation of financial incentives from governments. Some economists foresee a raise of the electricity cost up to 50% if carbon sequestration is used. Other economists see a contradiction: sequestration techniques will not be available in a short term range while numerous thermal power plants are planned to be built in the decade. So carbon sequestration may arrive too late and at a cost that may be not competitive with some renewable energies like off-shore wind energy or thermal solar energy which will be full-grown at that time. (A.C.)

  7. The potential role of alcohol fuels in reducing carbon dioxide emissions

    International Nuclear Information System (INIS)

    Duff, S.J.B.

    1991-01-01

    Atmospheric concentrations of CO 2 have increased from 280 to 350 mg/l over the past two hundred years. One of the principal causes has been the increased reliance on combustion of fossil fuels to generate energy. Higher CO 2 levels have been historically correlated with warming of the earth. While attempts have been made to quantify and model the relationships between carbon dioxide emissions, atmospheric CO 2 concentrations, and global climate changes, the state of the current knowledge base is such that large uncertainties persist. It is precisely these uncertainties which has evoked justifiable concern among the scientific community. The use of biomass fuels such as alcohols can provide a partial solution to the problem of increasing emissions of CO 2 . Combustion of biomass fuels releases carbon previously sequestered from the atmosphere during growth. There is a cycling of carbon, with net additions to the atmosphere resulting only from losses, or the use of fossil fuels for process energy. Alcohol fuels can make their biggest impact in the transportation sector, which, in industrial nations, contributes up to 32% of CO 2 emissions. While not the complete answer, alcohol fuels can make a significant impact, and will no doubt be one factor in a multidimensional approach to reducing CO 2 emissions. 17 refs., 4 figs., 10 tabs

  8. Pasture Management Strategies for Sequestering Soil Carbon - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Franzluebbers, Alan J.

    2006-03-15

    management indicated that soil organic carbon and nitrogen storage were greater with than without endophyte only under high soil fertility. This extra carbon and nitrogen in soil due to the presence of the endophyte was further found to be located in intermediately sized soil aggregates, which are important for reducing water runoff and improving water quality. These results suggest that well-fertilized tall fescue pastures with a high percentage of plants infected with the endophyte have the potential to help offset the rising carbon dioxide in the atmosphere. This research has also shown positive ecological implications of tall fescue-endophyte association.

  9. Enabling food security by verifying agricultural carbon

    DEFF Research Database (Denmark)

    Kahiluoto, H; Smith, P; Moran, D

    2014-01-01

    Rewarding smallholders for sequestering carbon in agricultural land can improve food security while mitigating climate change. Verification of carbon offsets in food-insecure regions is possible and achievable through rigorously controlled monitoring......Rewarding smallholders for sequestering carbon in agricultural land can improve food security while mitigating climate change. Verification of carbon offsets in food-insecure regions is possible and achievable through rigorously controlled monitoring...

  10. POSSIBILITIES OF CARBON DIOXIDE FIXATION BY MICROALGAE IN REFINERY

    OpenAIRE

    Šingliar, Michal; Mikulec, Jozef; Kušnir, Patrik; Polakovičova, Gabriela

    2013-01-01

    Capture and sequestration of carbon dioxide is one of the most critical challenges today for businesses and governments worldwide. Thousands of emitting power plants and industries worldwide face this costly challenge – reduce the CO2 emissions or pay penalties. One possibility for carbon dioxide sequestration is its fixation in microalgae. Microalgae can sequester CO2 from flue gases emitted from fossil fuel-fired refinery plants and units, thereby reducing emissions of a major greenhouse ga...

  11. Biochar, compost and biochar-compost blend as options to recover nutrients and sequester carbon.

    Science.gov (United States)

    Oldfield, Thomas L; Sikirica, Nataša; Mondini, Claudio; López, Guadalupe; Kuikman, Peter J; Holden, Nicholas M

    2018-07-15

    This work assessed the potential environmental impact of recycling organic materials in agriculture via pyrolysis (biochar) and composting (compost), as well its combination (biochar-compost blend) versus business-as-usual represented by mineral fertiliser. Life cycle assessment methodology was applied using data sourced from experiments (FP7 project Fertiplus) in three countries (Spain, Italy and Belgium), and considering three environmental impact categories, (i) global warming; (ii) acidification and (iii) eutrophication. The novelty of this analysis is the inclusion of the biochar-compost blend with a focus on multiple European countries, and the inclusion of the acidification and eutrophication impact categories. Biochar, compost and biochar-compost blend all resulted in lower environmental impacts than mineral fertiliser from a systems perspective. Regional differences were found between biochar, compost and biochar-compost blend. The biochar-compost blend offered benefits related to available nutrients and sequestered C. It also produced yields of similar magnitude to mineral fertiliser, which makes its acceptance by farmers more likely whilst reducing environmental impacts. However, careful consideration of feedstock is required. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Global carbon impacts of using forest harvest residues for district heating in Vermont

    International Nuclear Information System (INIS)

    McLain, H.A.

    1998-01-01

    Forests in Vermont are selectively logged periodically to generate wood products and useful energy. Carbon remains stored in the wood products during their lifetime and in fossil fuel displaced by using these products in place of energy-intensive products. Additional carbon is sequestered by new forest growth, and the forest inventory is sustained using this procedure. A significant portion of the harvest residue can be used as biofuel in central plants to generate electricity and thermal energy, which also displaces the use of fossil fuels. The impact of this action on the global carbon balance was analyzed using a model derived from the Graz/Oak Ridge Carbon Accounting Model (GORCAM). The analysis showed that when forests are harvested only to manufacture wood products, more than 100 years are required to match the sequestered carbon present if the forest is left undisturbed. If part of the harvest residue is collected and used as biofuel in place of oil or natural gas, it is possible to reduce this time to about 90 years, but it is usually longer. Given that harvesting the forest for products will continue, carbon emission benefits relative to this practice can start within 10 to 70 years if part of the harvest residue is used as biofuel. This time is usually higher for electric generation plants, but it can be reduced substantially by converting to cogeneration operation. Cogeneration makes possible a ratio of carbon emission reduction for district heating to carbon emission increase for electricity generation in the range of 3 to 5. Additional sequestering benefits can be realized by using discarded wood products as biofuels

  13. Phenomenology of supersymmetry with scalar sequestering

    International Nuclear Information System (INIS)

    Perez, Gilad; Roy, Tuhin S.; Schmaltz, Martin

    2009-01-01

    The defining feature of scalar sequestering is that the minimal supersymmetric standard model squark and slepton masses as well as all entries of the scalar Higgs mass matrix vanish at some high scale. This ultraviolet boundary condition--scalar masses vanish while gaugino and Higgsino masses are unsuppressed--is independent of the supersymmetry breaking mediation mechanism. It is the result of renormalization group scaling from approximately conformal strong dynamics in the hidden sector. We review the mechanism of scalar sequestering and prove that the same dynamics which suppresses scalar soft masses and the B μ term also drives the Higgs soft masses to -|μ| 2 . Thus the supersymmetric contribution to the Higgs mass matrix from the μ term is exactly canceled by the soft masses. Scalar sequestering has two tell-tale predictions for the superpartner spectrum in addition to the usual gaugino mediation predictions: Higgsinos are much heavier (μ > or approx. TeV) than scalar Higgses (m A ∼few hundred GeV), and third generation scalar masses are enhanced because of new positive contributions from Higgs loops.

  14. Meeting global policy commitments carbon sequestration and southern pine forests

    Science.gov (United States)

    Kurt H. Johnsen; David N. Wear; R. Oren; R.O. Teskey; Felipe Sanchez; Rodney E. Will; John Butnor; D. Markewitz; D. Richter; T. Rials; H.L. Allen; J. Seiler; D. Ellsworth; Christopher Maier; G. Katul; P.M. Dougherty

    2001-01-01

    In managed forests, the amount of carbon further sequestered will be determined by (1) the increased amount of carbon in standing biomass (resulting from land-use changes and increased productivity); (2) the amount of recalcitrant carbon remaining below ground at the end of rotations; and (3) the amount of carbon sequestered in products created from harvested wood....

  15. Assessing ocean alkalinity for carbon sequestration

    Science.gov (United States)

    Renforth, Phil; Henderson, Gideon

    2017-09-01

    Over the coming century humanity may need to find reservoirs to store several trillions of tons of carbon dioxide (CO2) emitted from fossil fuel combustion, which would otherwise cause dangerous climate change if it were left in the atmosphere. Carbon storage in the ocean as bicarbonate ions (by increasing ocean alkalinity) has received very little attention. Yet recent work suggests sufficient capacity to sequester copious quantities of CO2. It may be possible to sequester hundreds of billions to trillions of tons of C without surpassing postindustrial average carbonate saturation states in the surface ocean. When globally distributed, the impact of elevated alkalinity is potentially small and may help ameliorate the effects of ocean acidification. However, the local impact around addition sites may be more acute but is specific to the mineral and technology. The alkalinity of the ocean increases naturally because of rock weathering in which >1.5 mol of carbon are removed from the atmosphere for every mole of magnesium or calcium dissolved from silicate minerals (e.g., wollastonite, olivine, and anorthite) and 0.5 mol for carbonate minerals (e.g., calcite and dolomite). These processes are responsible for naturally sequestering 0.5 billion tons of CO2 per year. Alkalinity is reduced in the ocean through carbonate mineral precipitation, which is almost exclusively formed from biological activity. Most of the previous work on the biological response to changes in carbonate chemistry have focused on acidifying conditions. More research is required to understand carbonate precipitation at elevated alkalinity to constrain the longevity of carbon storage. A range of technologies have been proposed to increase ocean alkalinity (accelerated weathering of limestone, enhanced weathering, electrochemical promoted weathering, and ocean liming), the cost of which may be comparable to alternative carbon sequestration proposals (e.g., $20-100 tCO2-1). There are still many

  16. Progress Toward Sequestering Carbon Nanotubes in PmPV

    Science.gov (United States)

    Bley, Richard A.

    2009-01-01

    Sequestration of single-walled carbon nanotubes (SWNTs) in molecules of poly(m-phenylenevinylene-co-2,5-diocty-loxy-p-phenylenevinylene) [PmPV] is a candidate means of promoting dissolution of single-walled carbon nanotubes (SWNTs) into epoxies for making strong, lightweight epoxy-matrix/carbon-fiber composite materials. Bare SWNTs cannot be incorporated because they are not soluble in epoxies. In the present approach, one exploits the tendency of PmPV molecules to wrap themselves around SWNTs without chemically bonding to them.

  17. Aggregation of ALS-linked FUS mutant sequesters RNA binding proteins and impairs RNA granules formation

    Energy Technology Data Exchange (ETDEWEB)

    Takanashi, Keisuke; Yamaguchi, Atsushi, E-mail: atsyama@restaff.chiba-u.jp

    2014-09-26

    Highlights: • Aggregation of ALS-linked FUS mutant sequesters ALS-associated RNA-binding proteins (FUS wt, hnRNP A1, and hnRNP A2). • Aggregation of ALS-linked FUS mutant sequesters SMN1 in the detergent-insoluble fraction. • Aggregation of ALS-linked FUS mutant reduced the number of speckles in the nucleus. • Overproduced ALS-linked FUS mutant reduced the number of processing-bodies (PBs). - Abstract: Protein aggregate/inclusion is one of hallmarks for neurodegenerative disorders including amyotrophic lateral sclerosis (ALS). FUS/TLS, one of causative genes for familial ALS, encodes a multifunctional DNA/RNA binding protein predominantly localized in the nucleus. C-terminal mutations in FUS/TLS cause the retention and the inclusion of FUS/TLS mutants in the cytoplasm. In the present study, we examined the effects of ALS-linked FUS mutants on ALS-associated RNA binding proteins and RNA granules. FUS C-terminal mutants were diffusely mislocalized in the cytoplasm as small granules in transiently transfected SH-SY5Y cells, whereas large aggregates were spontaneously formed in ∼10% of those cells. hnRNP A1, hnRNP A2, and SMN1 as well as FUS wild type were assembled into stress granules under stress conditions, and these were also recruited to FUS mutant-derived spontaneous aggregates in the cytoplasm. These aggregates stalled poly(A) mRNAs and sequestered SMN1 in the detergent insoluble fraction, which also reduced the number of nuclear oligo(dT)-positive foci (speckles) in FISH (fluorescence in situ hybridization) assay. In addition, the number of P-bodies was decreased in cells harboring cytoplasmic granules of FUS P525L. These findings raise the possibility that ALS-linked C-terminal FUS mutants could sequester a variety of RNA binding proteins and mRNAs in the cytoplasmic aggregates, which could disrupt various aspects of RNA equilibrium and biogenesis.

  18. Two small RNAs, CrcY and CrcZ, act in concert to sequester the Crc global regulator in Pseudomonas putida, modulating catabolite repression.

    Science.gov (United States)

    Moreno, Renata; Fonseca, Pilar; Rojo, Fernando

    2012-01-01

    The Crc protein is a translational repressor that recognizes a specific target at some mRNAs, controlling catabolite repression and co-ordinating carbon metabolism in pseudomonads. In Pseudomonas aeruginosa, the levels of free Crc protein are controlled by CrcZ, a sRNA that sequesters Crc, acting as an antagonist. We show that, in Pseudomonas putida, the levels of free Crc are controlled by CrcZ and by a novel 368 nt sRNA named CrcY. CrcZ and CrcY, which contain six potential targets for Crc, were able to bind Crc specifically in vitro. The levels of CrcZ and CrcY were low under conditions generating a strong catabolite repression, and increased strongly when catabolite repression was absent. Deletion of either crcZ or crcY had no effect on catabolite repression, but the simultaneous absence of both sRNAs led to constitutive catabolite repression that compromised growth on some carbon sources. Overproduction of CrcZ or CrcY significantly reduced repression. We propose that CrcZ and CrcY act in concert, sequestering and modulating the levels of free Crc according to metabolic conditions. The CbrA/CbrB two-component system activated crcZ transcription, but had little effect on crcY. CrcY was detected in P. putida, Pseudomonas fluorescens and Pseudomonas syringae, but not in P. aeruginosa. © 2011 Blackwell Publishing Ltd.

  19. The value of carbon sequestration and storage in coastal habitats

    Science.gov (United States)

    Beaumont, N. J.; Jones, L.; Garbutt, A.; Hansom, J. D.; Toberman, M.

    2014-01-01

    Coastal margin habitats are globally significant in terms of their capacity to sequester and store carbon, but their continuing decline, due to environmental change and human land use decisions, is reducing their capacity to provide this ecosystem service. In this paper the UK is used as a case study area to develop methodologies to quantify and value the ecosystem service of blue carbon sequestration and storage in coastal margin habitats. Changes in UK coastal habitat area between 1900 and 2060 are documented, the long term stocks of carbon stored by these habitats are calculated, and the capacity of these habitats to sequester CO2 is detailed. Changes in value of the carbon sequestration service of coastal habitats are then projected for 2000-2060 under two scenarios, the maintenance of the current state of the habitat and the continuation of current trends of habitat loss. If coastal habitats are maintained at their current extent, their sequestration capacity over the period 2000-2060 is valued to be in the region of £1 billion UK sterling (3.5% discount rate). However, if current trends of habitat loss continue, the capacity of the coastal habitats both to sequester and store CO2 will be significantly reduced, with a reduction in value of around £0.25 billion UK sterling (2000-2060; 3.5% discount rate). If loss-trends due to sea level rise or land reclamation worsen, this loss in value will be greater. This case study provides valuable site specific information, but also highlights global issues regarding the quantification and valuation of carbon sequestration and storage. Whilst our ability to value ecosystem services is improving, considerable uncertainty remains. If such ecosystem valuations are to be incorporated with confidence into national and global policy and legislative frameworks, it is necessary to address this uncertainty. Recommendations to achieve this are outlined.

  20. Micellized sequestered silver atoms and small silver clusters

    International Nuclear Information System (INIS)

    Borgarello, E.; Lawless, D.; Serpone, N.; Pelizzetti, E.; Meisel, D.

    1990-01-01

    Pulse radiolysis was used to examine the nature of the silver species obtained when an aqueous solution containing sequestered Ag + ions was reduced by hydrated electrons in the presence of a surfactant macrocyclic crown ether, labeled L, and/or a maltoside surfactant. The initially formed product is the Ag 0 (L) species which rapidly loses its ligand (half-life ≤5 μs) and reacts with another Ag + (L) ion to form Ag 2 + (L). The latter species decays by a bimolecular process to form the Ag 4 2+ (L) n species at a faster rate than its ligand free analogue. Ultimately, colloidal metallic silver, (Ag) n , forms which is stabilized by the surfactant moieties. No long-term stability to the reduced monomolecular species could be obtained

  1. Substantial role of macroalgae in marine carbon sequestration

    KAUST Repository

    Krause-Jensen, Dorte; Duarte, Carlos M.

    2016-01-01

    Vegetated coastal habitats have been identified as important carbon sinks. In contrast to angiosperm-based habitats such as seagrass meadows, salt marshes and mangroves, marine macroalgae have largely been excluded from discussions of marine carbon sinks. Macroalgae are the dominant primary producers in the coastal zone, but they typically do not grow in habitats that are considered to accumulate large stocks of organic carbon. However, the presence of macroalgal carbon in the deep sea and sediments, where it is effectively sequestered from the atmosphere, has been reported. A synthesis of these data suggests that macroalgae could represent an important source of the carbon sequestered in marine sediments and the deep ocean. We propose two main modes for the transport of macroalgae to the deep ocean and sediments: macroalgal material drifting through submarine canyons, and the sinking of negatively buoyant macroalgal detritus. A rough estimate suggests that macroalgae could sequester about 173 TgC yr â '1 (with a range of 61-268 TgC yr â '1) globally. About 90% of this sequestration occurs through export to the deep sea, and the rest through burial in coastal sediments. This estimate exceeds that for carbon sequestered in angiosperm-based coastal habitats.

  2. Substantial role of macroalgae in marine carbon sequestration

    KAUST Repository

    Krause-Jensen, Dorte

    2016-09-12

    Vegetated coastal habitats have been identified as important carbon sinks. In contrast to angiosperm-based habitats such as seagrass meadows, salt marshes and mangroves, marine macroalgae have largely been excluded from discussions of marine carbon sinks. Macroalgae are the dominant primary producers in the coastal zone, but they typically do not grow in habitats that are considered to accumulate large stocks of organic carbon. However, the presence of macroalgal carbon in the deep sea and sediments, where it is effectively sequestered from the atmosphere, has been reported. A synthesis of these data suggests that macroalgae could represent an important source of the carbon sequestered in marine sediments and the deep ocean. We propose two main modes for the transport of macroalgae to the deep ocean and sediments: macroalgal material drifting through submarine canyons, and the sinking of negatively buoyant macroalgal detritus. A rough estimate suggests that macroalgae could sequester about 173 TgC yr â \\'1 (with a range of 61-268 TgC yr â \\'1) globally. About 90% of this sequestration occurs through export to the deep sea, and the rest through burial in coastal sediments. This estimate exceeds that for carbon sequestered in angiosperm-based coastal habitats.

  3. Monitoring soil carbon will prepare growers for a carbon trading system

    Directory of Open Access Journals (Sweden)

    Emma C. Suddick

    2013-07-01

    Full Text Available California growers could reap financial benefits from the low-carbon economy and cap-and-trade system envisioned by the state's AB 32 law, which seeks to lower greenhouse gas emissions statewide. Growers could gain carbon credits by reducing greenhouse gas emissions and sequestering carbon through reduced tillage and increased biomass residue incorporation. First, however, baseline stocks of soil carbon need to be assessed for various cropping systems and management practices. We designed and set up a pilot soil carbon and land-use monitoring network at several perennial cropping systems in Northern California. We compared soil carbon content in two vineyards and two orchards (walnut and almond, looking at conventional and conservation management practices, as well as in native grassland and oak woodland. We then calculated baseline estimates of the total carbon in almond, wine grape and walnut acreages statewide. The organic walnut orchard had the highest total soil carbon, and no-till vineyards had 27% more carbon in the surface soil than tilled vineyards. We estimated wine grape vineyards are storing significantly more soil carbon per acre than almond and walnut orchards. The data can be used to provide accurate information about soil carbon stocks in perennial cropping systems for a future carbon trading system.

  4. Carbon sequestration.

    Science.gov (United States)

    Lal, Rattan

    2008-02-27

    Developing technologies to reduce the rate of increase of atmospheric concentration of carbon dioxide (CO2) from annual emissions of 8.6PgCyr-1 from energy, process industry, land-use conversion and soil cultivation is an important issue of the twenty-first century. Of the three options of reducing the global energy use, developing low or no-carbon fuel and sequestering emissions, this manuscript describes processes for carbon (CO2) sequestration and discusses abiotic and biotic technologies. Carbon sequestration implies transfer of atmospheric CO2 into other long-lived global pools including oceanic, pedologic, biotic and geological strata to reduce the net rate of increase in atmospheric CO2. Engineering techniques of CO2 injection in deep ocean, geological strata, old coal mines and oil wells, and saline aquifers along with mineral carbonation of CO2 constitute abiotic techniques. These techniques have a large potential of thousands of Pg, are expensive, have leakage risks and may be available for routine use by 2025 and beyond. In comparison, biotic techniques are natural and cost-effective processes, have numerous ancillary benefits, are immediately applicable but have finite sink capacity. Biotic and abiotic C sequestration options have specific nitches, are complementary, and have potential to mitigate the climate change risks.

  5. The Efficacy and Potential of Renewable Energy from Carbon Dioxide that is Sequestered in Sedimentary Basin Geothermal Resources

    Science.gov (United States)

    Bielicki, J. M.; Adams, B. M.; Choi, H.; Saar, M. O.; Taff, S. J.; Jamiyansuren, B.; Buscheck, T. A.; Ogland-Hand, J.

    2015-12-01

    Mitigating climate change requires increasing the amount of electricity that is generated from renewable energy technologies and while simultaneously reducing the amount of carbon dioxide (CO2) that is emitted to the atmosphere from present energy and industrial facilities. We investigated the efficacy of generating electricity using renewable geothermal heat that is extracted by CO2 that is sequestered in sedimentary basins. To determine the efficacy of CO2-Geothermal power production in the United States, we conducted a geospatial resource assessment of the combination of subsurface CO2 storage capacity and heat flow in sedimentary basins and developed an integrated systems model that combines reservoir modeling with power plant modeling and economic costs. The geospatial resource assessment estimates the potential resource base for CO2-Geothermal power plants, and the integrated systems model estimates the physical (e.g., net power) and economic (e.g., levelized cost of electricity, capital cost) performance of an individual CO2-Geothermal power plant for a range of reservoir characteristics (permeability, depth, geothermal temperature gradient). Using coupled inverted five-spot injection patterns that are common in CO2-enhanced oil recovery operations, we determined the well pattern size that best leveraged physical and economic economies of scale for the integrated system. Our results indicate that CO2-Geothermal plants can be cost-effectively deployed in a much larger region of the United States than typical approaches to geothermal electricity production. These cost-effective CO2-Geothermal electricity facilities can also be capacity-competitive with many existing baseload and renewable energy technologies over a range of reservoir parameters. For example, our results suggest that, given the right combination of reservoir parameters, LCOEs can be as low as $25/MWh and capacities can be as high as a few hundred MW.

  6. Forest management for fixing and sequestering carbon

    International Nuclear Information System (INIS)

    Marland, G.; Dale, V.; Graham, R.; Luxmoore, R.; Marland, S.; McLaughlin, S.; Norby, R.; Post, W.M.; Tschaplinski, T.; Tuskan, J.; Wright, L.

    1993-01-01

    The concept of planting trees as part of a strategy to confront the possibility of global climate change is now widely accepted. As trees grow they remove CO 2 from the atmosphere and thus slow the atmospheric build-up of CO 2 , an important greenhouse gas. Within the global-climate-change context, there are two fundamental problems with managing trees to store carbon. First, the magnitude of fossil-fuel related emissions of CO 2 is so large, 6 billion metric tons of carbon per year that it takes very large areas of tree planting to make a significant impact. Second, as trees mature their rate of growth, and hence rate of net carbon uptake, declines. lie large demand on land area suggests that there is a limit to the fraction of total CO 2 emissions that we might reasonably expect to offset with growing trees. The ultimate maturation of forests suggests that there is a limit on the length of time over which offsets are feasible and that we need to ask what to do as the rate of C uptake declines. Acknowledging a that the availability of land will constrain the ability of tree planting to offset industrial emissions of CO 2 , we consider how the land which is available can be used most effectively. This report speculates on how much land might be available for a forest management strategy motivated (at least partially) by concerns about climate change, but our principal focus is on how a given land area can be best used to minimize net emissions of CO 2 and how much might be achieved on a unit of land. We do not suggest that carbon management should be the principal criteria for land management, but we discuss the implications if it were. Confronting global and local changes in climate will be one of many objectives in land management and we explore for the most effective strategy for pursuing this objective

  7. Deployable micro-traps to sequester motile bacteria

    Science.gov (United States)

    di Giacomo, Raffaele; Krödel, Sebastian; Maresca, Bruno; Benzoni, Patrizia; Rusconi, Roberto; Stocker, Roman; Daraio, Chiara

    2017-04-01

    The development of strategies to reduce the load of unwanted bacteria is a fundamental challenge in industrial processing, environmental sciences and medical applications. Here, we report a new method to sequester motile bacteria from a liquid, based on passive, deployable micro-traps that confine bacteria using micro-funnels that open into trapping chambers. Even in low concentrations, micro-traps afford a 70% reduction in the amount of bacteria in a liquid sample, with a potential to reach >90% as shown by modelling improved geometries. This work introduces a new approach to contain the growth of bacteria without chemical means, an advantage of particular importance given the alarming growth of pan-drug-resistant bacteria.

  8. In-Situ Microbial Conversion of Sequestered Greenhouse Gases

    Energy Technology Data Exchange (ETDEWEB)

    Scott, A R; Mukhopadhyay, M; Balin, D F

    2012-09-06

    The objectives of the project are to use microbiological in situ bioconversion technology to convert sequestered or naturally-occurring greenhouse gases, including carbon dioxide and carbon monoxide, into methane and other useful organic compounds. The key factors affecting coal bioconversion identified in this research include (1) coal properties, (2) thermal maturation and coalification process, (3) microbial population dynamics, (4) hydrodynamics (5) reservoir conditions, and (6) the methodology of getting the nutrients into the coal seams. While nearly all cultures produced methane, we were unable to confirm sustained methane production from the enrichments. We believe that the methane generation may have been derived from readily metabolized organic matter in the coal samples and/or biosoluble organic material in the coal formation water. This raises the intriguing possibility that pretreatment of the coal in the subsurface to bioactivate the coal prior to the injection of microbes and nutrients might be possible. We determined that it would be more cost effective to inject nutrients into coal seams to stimulate indigenous microbes in the coal seams, than to grow microbes in fermentation vats and transport them to the well site. If the coal bioconversion process can be developed on a larger scale, then the cost to generate methane could be less than $1 per Mcf

  9. Trading forest carbon - OSU

    Science.gov (United States)

    Issues associate with trading carbon sequestered in forests are discussed. Scientific uncertainties associated with carbon measurement are discussed with respect to proposed accounting procedures. Major issues include: (1) Establishing baselines. (2) Determining additivity from f...

  10. Post-harvest carbon emissions and sequestration in southern United States forest industries

    Energy Technology Data Exchange (ETDEWEB)

    Row, C.

    1997-12-31

    Whether the forest industries in the southern United States are net emitters or sequesters of carbon from the atmosphere depends on one`s viewpoint. In the short-term, the solid-wood industries-lumber, plywood, and panels--appear to sequester more carbon than is in the fossil fuels they use for processing. The paper industries, however, emit more carbon from fossil fuels than they sequester in the pulp and paper they manufacture. This viewpoint is quite limited. If one considers the life-cycles of solid-wood and paper products from seedlings to landfill, these industries sequester more carbon than they emit from burning fossil fuels. These industries also generate large amounts of energy by replacing fossil fuels with biofuels from processing residues, and wood-based products produce more energy from incineration and landfill gases. Use of the carbon in these biofuels in effect keeps fossil fuel carbon in the ground, considering that at least that amount of carbon would be emitted in producing alternative materials. Another way of looking the emission balances is that wood-based materials, pound for pound or use for use, are the most {open_quotes}carbon efficient{close_quotes} group of major industrial materials. 5 refs., 12 figs.

  11. How costly are carbon offsets : a meta-analysis of forest carbon sinks

    International Nuclear Information System (INIS)

    Van Kooten, G.C.; Eagle, A.J.; Manley, J.; Smolak, T.M.

    2004-01-01

    Carbon terrestrial sinks are one of the many proposed mitigation responses to climate change. Carbon sinks are considered to be a low-cost alternative to fuel switching and reduced fossil fuel consumption for reducing atmospheric carbon dioxide emissions. This study examined the costs of sequestering carbon in terrestrial ecosystems via forestry activities. A meta-regression analysis was used to determine which factors influence the costs of carbon sequestration via forest activities. Important concerns about how the Kyoto Protocol may be implemented were also addressed. The meta-regression analysis was used to examine 981 estimates from 55 studies on the cost of creating carbon offsets using forestry. Baseline cost estimates are US$46.62 to 260.29 per tC. Tree planting and agroforestry increases costs by more than 200 per cent. Costs are lowest when post-harvest storage of carbon in wood products is considered, or when biomass is substituted for fossil fuels in energy production. The meta-analysis also considered land use, land-use change and forestry (LULUCF) policies that increase the carbon sink functions of terrestrial ecosystems. The main motive for using sinks in the accounting process is that they avoid the use of expensive controls for the emission of carbon dioxide and other greenhouse gases. refs., tabs

  12. Use of hydrate for sequestering CO{sub 2} in the deep ocean

    Energy Technology Data Exchange (ETDEWEB)

    North, W.J.; Morgan, J.J. [California Inst. of Technology, Pasadena, CA (United States); Spencer, D.F. [Electric Power Research Inst., Palo Alto, CA (United States)] [and others

    1993-12-31

    Tremendous amounts of CO{sub 2} are accumulating annually in the atmosphere (ca 3 gigatons of carbon per year at present). Prevention or significant amelioration of this atmospheric buildup will obviously require a grand scale corrective activity. A potential solution to the problem might involve sequestering CO{sub 2} in an alternate reservoir. The ocean immediately comes to mind as a reservoir of appropriate magnitude to accommodate the huge quantities of CO{sub 2} involved. Presumably there would be a trade-off: we would achieve a semi-clean atmosphere for an as- yet-to-be-determined impact in the ocean. Minimizing any oceanic impacts would enhance attractiveness of the trade-off.

  13. Sequestering HMGB1 via DNA-Conjugated Beads Ameliorates Murine Colitis

    Science.gov (United States)

    Antoine, Daniel J.; Dancho, Meghan; Tsaava, Teá; Li, Jianhua; Lu, Ben; Levine, Yaakov A.; Stiegler, Andrew; Tamari, Yehuda; Al-Abed, Yousef; Roth, Jesse; Tracey, Kevin J.; Yang, Huan

    2014-01-01

    Inflammatory bowel disease (IBD) is chronic inflammation of the gastrointestinal tract that affects millions of people worldwide. Although the etiology of IBD is not clear, it is known that products from stressed cells and enteric microbes promote intestinal inflammation. High mobility group box 1 (HMGB1), originally identified as a nuclear DNA binding protein, is a cytokine-like protein mediator implicated in infection, sterile injury, autoimmune disease, and IBD. Elevated levels of HMGB1 have been detected in inflamed human intestinal tissues and in feces of IBD patients and mouse models of colitis. Neutralizing HMGB1 activity by administration of anti-HMGB1 antibodies or HMGB1-specific antagonist improves clinical outcomes in animal models of colitis. Since HMGB1 binds to DNA with high affinity, here we developed a novel strategy to sequester HMGB1 using DNA immobilized on sepharose beads. Screening of DNA-bead constructs revealed that B2 beads, one linear form of DNA conjugated beads, bind HMGB1 with high affinity, capture HMGB1 ex vivo from endotoxin-stimulated RAW 264.7 cell supernatant and from feces of mice with colitis. Oral administration of B2 DNA beads significantly improved body weight, reduced colon injury, and suppressed colonic and circulating cytokine levels in mice with spontaneous colitis (IL-10 knockout) and with dextran sulfate sodium-induced colitis. Thus, DNA beads reduce inflammation by sequestering HMGB1 and may have therapeutic potential for the treatment of IBD. PMID:25127031

  14. Specific sequestering agents for the actinides: Pt. 10

    International Nuclear Information System (INIS)

    Ren Hongyu; Wang Huicai

    1991-01-01

    In this article, ten new and four known polyaminocarboxy-licphenolic sequestering agents have been synthesized. The result of animal screening of ten of these sequestering agents indicates: six of all, at a dose of 50 μmol/kg can excrete liver Am·Va (N, N'-di(2-hydroxybenzyl)-diethylenetriamine-N 1 , N 4 , N 7 -triacetic acid) is the most effective, it can excrete liver Am, skeleten Am and kidney Am. But all are less effective than DTPA. The structure-activity relationship has been discussed, ligand with more aminocarboxylic acid groups showed a better result than the ligand with more phenolic groups

  15. Black carbon sequestration as an alternative to bioenergy

    International Nuclear Information System (INIS)

    Fowles, Malcolm

    2007-01-01

    Most policy and much research concerning the application of biomass to reduce global warming gas emissions has concentrated either on increasing the Earth's reservoir of biomass or on substituting biomass for fossil fuels, with or without CO 2 sequestration. Suggested approaches entail varied risks of impermanence, delay, high costs, and unknowable side-effects. An under-researched alternative approach is to extract from biomass black (elemental) carbon, which can be permanently sequestered as mineral geomass and may be relatively advantageous in terms of those risks. This paper reviews salient features of black carbon sequestration and uses a high-level quantitative model to compare the approach with the alternative use of biomass to displace fossil fuels. Black carbon has been demonstrated to produce significant benefits when sequestered in agricultural soil, apparently without bad side-effects. Black carbon sequestration appears to be more efficient in general than energy generation, in terms of atmospheric carbon saved per unit of biomass; an exception is where biomass can efficiently displace coal-fired generation. Black carbon sequestration can reasonably be expected to be relatively quick and cheap to apply due to its short value chain and known technology. However, the model is sensitive to several input variables, whose values depend heavily on local conditions. Because characteristics of black carbon sequestration are only known from limited geographical contexts, its worldwide potential will not be known without multiple streams of research, replicated in other contexts. (author)

  16. Nongovernmental valorization of carbon dioxide

    International Nuclear Information System (INIS)

    Petersen, Gene; Viviani, Donn; Magrini-Bair, Kim; Kelley, Stephen; Moens, Luc; Shepherd, Phil; DuBois, Dan

    2005-01-01

    Carbon dioxide (CO 2 ) is considered the largest contributor to the greenhouse gas effect. Most attempts to manage the flow of CO 2 or carbon into our environment involve reducing net emissions or sequestering the gas into long-lived sinks. Using CO 2 as a chemical feedstock has a long history, but using it on scales that might impact the net emissions of CO 2 into the atmosphere has not generally been considered seriously. There is also a growing interest in employing our natural biomes of carbon such as trees, vegetation, and soils as storage media. Some amelioration of the net carbon emissions into the atmosphere could be achieved by concomitant large withdrawals of carbon. This report surveys the potential and limitations in employing carbon as a resource for organic chemicals, fuels, inorganic materials, and in using the biome to manage carbon. The outlook for each of these opportunities is also described

  17. Making carbon dioxide sequestration feasible: Toward federal regulation of CO2 sequestration pipelines

    International Nuclear Information System (INIS)

    Mack, Joel; Endemann, Buck

    2010-01-01

    As the United States moves closer to a national climate change policy, it will have to focus on a variety of factors affecting the manner in which the country moves toward a future with a substantially lower carbon footprint. In addition to encouraging renewable energy, smart grid, clean fuels and other technologies, the United States will need to make substantial infrastructure investments in a variety of industries. Among the significant contributors to the current carbon footprint in the United States is the use of coal as a major fuel for the generation of electricity. One of the most important technologies that the United States can employ to reduce its carbon footprint is to sequester the carbon dioxide ('CO 2 ') from coal-fired power plants. This article focuses on the legal and policy issues surrounding a critical piece of the necessary sequestration infrastructure: CO 2 pipelines that will carry CO 2 from where it is removed from fuel or waste gas streams to where it will be sequestered. Ultimately, this article recommends developing a federally regulated CO 2 pipeline program to foster the implementation of carbon sequestration technology.

  18. Arbuscular mycorrhizal fungi increase organic carbon decomposition under elevated carbon dioxide

    Science.gov (United States)

    A major goal of climate change research is to understand whether and how terrestrial ecosystems can sequester more carbon to mitigate rising atmospheric carbon dioxide (CO2) levels. The stimulation of arbuscular mycorrhizal fungi (AMF) by elevated atmospheric CO2 has been assumed to be a major mecha...

  19. Tropical Wetlands as Carbon Sinks

    Science.gov (United States)

    Jones, M. B.; Saunders, M.

    2007-12-01

    This presentation focuses on the tropical wetlands of sub-Saharan Africa. These are an understudied ecosystem in which large emergent grasses and sedges normally dominate and which have the potential to sequester significant amounts of carbon. Measurements of Net Primary Production of these wetlands show that they are some of the highest values recorded for any ecosystem. We have used eddy covariance to measure Net Ecosystem Exchange of pristine and disturbed wetlands and show that pristine systems can have sink strengths as strong as tropical forests while disturbed systems that have been reclaimed for agricultural purposes have a very much reduced carbon sink activity and may be net carbon sources. The management issues surrounding the use of these wetlands illustrate a direct conflict between the production of food crops for the local population and the maintenance of carbon sequestration as an ecosystem service.

  20. Producing energy while sequestering carbon? The relationship between biochar and agricultural productivity

    International Nuclear Information System (INIS)

    Kauffman, Nathan; Dumortier, Jerome; Hayes, Dermot J.; Brown, Robert C.; Laird, David A.

    2014-01-01

    A partial solution to problems associated with anthropogenic greenhouse gas (GHG) emissions could be the development and deployment of carbon-negative technologies, i.e., producing energy while reducing atmospheric carbon dioxide levels. Biofuels have been considered a possibility but have faced limitations due to competition with food production and GHG emissions through indirect land-use change (ILUC). In this article, we show how emissions from ILUC can potentially be reduced by producing food and bioenergy from biochar amended soils. The possibility of yield improvements from biochar would reduce the land requirement for crop production and thus, lead to a reduction in emissions from ILUC. In our application, biochar and bio-oil are produced via fast pyrolysis of corn stover. Bio-oil is subsequently upgraded into a fuel suitable for use in internal combustion engines. Applying the U.S. regulatory method used to determine biofuel life cycle emissions, our results show that a biochar-induced yield improvement in the U.S. Midwest ranging from 1% to 8% above trend can lead to an ILUC credit between 1.65 and 14.79 t CO 2 -equivalent ha −1  year −1 when future emissions are assessed over the next 30 years. The model is generalizable to other feedstocks and locations and illustrates the relationship between biochar and crop production. - Highlights: • If biochar leads to higher crop yields, a land-use change (LUC) credit applies. • Indirect LUC credit is applied to biofuel if biochar is produced as a by-product. • 1.65 to 14.79 t CO 2 -e ha −1  year −1 credit for 1%–8% yield increase in U.S. Midwest. • Life cycle analysis generalizable to other locations and feedstock

  1. Managing Commercial Tree Species for Timber Production and Carbon Sequestration: Management Guidelines and Financial Returns

    Energy Technology Data Exchange (ETDEWEB)

    Gary D. Kronrad

    2006-09-19

    A carbon credit market is developing in the United States. Information is needed by buyers and sellers of carbon credits so that the market functions equitably and efficiently. Analyses have been conducted to determine the optimal forest management regime to employ for each of the major commercial tree species so that profitability of timber production only or the combination of timber production and carbon sequestration is maximized. Because the potential of a forest ecosystem to sequester carbon depends on the tree species, site quality and management regimes utilized, analyses have determined how to optimize carbon sequestration by determining how to optimally manage each species, given a range of site qualities, discount rates, prices of carbon credits and other economic variables. The effects of a carbon credit market on the method and profitability of forest management, the cost of sequestering carbon, the amount of carbon that can be sequestered, and the amount of timber products produced has been determined.

  2. A Modeled Carbon Emission Analysis Of Rampal Power Plant In Bangladesh And A Review Of Carbon Reduction Technologies

    Directory of Open Access Journals (Sweden)

    Gour Chand Mazumder

    2015-08-01

    Full Text Available todays most important concern of Bangladesh is power generation. Government has planned a 1320 MW coal-fired power station at Rampal near Sundarbans. Environmentalists have indicated that this plant will face environmental issues. So we tried finding the capability of Sundarbans to face carbon emissions. We figured out approximate carbon emission of that power plant using an arbitrary operational model. We found 3.16MKg of carbon emission daily. We used mangroves carbon sequestration rate to calculate the carbon tolerance level of Sundarbans and found approximately 4.2 MKg of carbon per day.The amount of emission we found here is marginal with the ability of Sundarbans as it is already contributing to sequester carbon from other sources. We studied and showed technology wise carbon reductions. It is possible to reduce 90 to 95 carbon emissioby using these technologies. We recommend these advanced technologies to ensure sundarbans environmental safety.

  3. Integrating Algae with Bioenergy Carbon Capture and Storage (ABECCS) Increases Sustainability

    Science.gov (United States)

    Beal, Colin M.; Archibald, Ian; Huntley, Mark E.; Greene, Charles H.; Johnson, Zackary I.

    2018-03-01

    Bioenergy carbon capture and storage (BECCS) has been proposed to reduce atmospheric CO2 concentrations, but concerns remain about competition for arable land and freshwater. The synergistic integration of algae production, which does not require arable land or freshwater, with BECCS (called "ABECCS") can reduce CO2 emissions without competing with agriculture. This study presents a technoeconomic and life-cycle assessment for colocating a 121-ha algae facility with a 2,680-ha eucalyptus forest for BECCS. The eucalyptus biomass fuels combined heat and power (CHP) generation with subsequent amine-based carbon capture and storage (CCS). A portion of the captured CO2 is used for growing algae and the remainder is sequestered. Biomass combustion supplies CO2, heat, and electricity, thus increasing the range of sites suitable for algae cultivation. Economic, energetic, and environmental impacts are considered. The system yields as much protein as soybeans while generating 61.5 TJ of electricity and sequestering 29,600 t of CO2 per year. More energy is generated than consumed and the freshwater footprint is roughly equal to that for soybeans. Financial break-even is achieved for product value combinations that include 1) algal biomass sold for 1,400/t (fishmeal replacement) with a 68/t carbon credit and 2) algal biomass sold for 600/t (soymeal replacement) with a 278/t carbon credit. Sensitivity analysis shows significant reductions to the cost of carbon sequestration are possible. The ABECCS system represents a unique technology for negative emissions without reducing protein production or increasing water demand, and should therefore be included in the suite of technologies being considered to address global sustainability.

  4. Nature of Reduced Carbon in Martian Meteorites

    Science.gov (United States)

    Gibson, Everett K., Jr.; McKay, D. S.; Thomas-Keprta, K. L.; Clemett, S. J.; White, L. M.

    2012-01-01

    Martian meteorites provide important information on the nature of reduced carbon components present on Mars throughout its history. The first in situ analyses for carbon on the surface of Mars by the Viking landers yielded disappointing results. With the recognition of Martian meteorites on Earth, investigations have shown carbon-bearing phases exist on Mars. Studies have yielded presence of reduced carbon, carbonates and inferred graphitic carbon phases. Samples ranging in age from the first approximately 4 Ga of Mars history [e.g. ALH84001] to nakhlites with a crystallization age of 1.3 Ga [e.g. Nakhla] with aqueous alteration processes occurring 0.5-0.7 Ga after crystallizaton. Shergottites demonstrate formation ages around 165-500 Ma with younger aqueous alterations events. Only a limited number of the Martian meteorites do not show evidence of significance terrestrial alterations. Selected areas within ALH84001, Nakhla, Yamato 000593 and possibly Tissint are suitable for study of their indigenous reduced carbon bearing phases. Nakhla possesses discrete, well-defined carbonaceous phases present within iddingsite alteration zones. Based upon both isotopic measurements and analysis of Nakhla's organic phases the presence of pre-terrestrial organics is now recognized. The reduced carbon-bearing phases appear to have been deposited during preterrestrial aqueous alteration events that produced clays. In addition, the microcrystalline layers of Nakhla's iddingsite have discrete units of salt crystals suggestive of evaporation processes. While we can only speculate on the origin of these unique carbonaceous structures, we note that the significance of such observations is that it may allow us to understand the role of Martian carbon as seen in the Martian meteorites with obvious implications for astrobiology and the pre-biotic evolution of Mars. In any case, our observations strongly suggest that reduced organic carbon exists as micrometer- size, discrete structures

  5. How to estimate carbon sequestration on small forest tracts estimate carbon sequestration on small forest tracts

    Science.gov (United States)

    Coeli M. Hoover; Richard A. Birdsey; Linda S. Heath; Susan L. Stout

    2000-01-01

    International climate change agreements may allow carbon stored as a result of afforestation and reforestation to be used to offset CO2 emissions. Monitoring the carbon sequestered or released through forest management activities thus becomes important. Estimating forest carbon storage is feasible even for nonindustrial private forestland (NIPF)...

  6. Reducing carbon dioxide to products

    Science.gov (United States)

    Cole, Emily Barton; Sivasankar, Narayanappa; Parajuli, Rishi; Keets, Kate A

    2014-09-30

    A method reducing carbon dioxide to one or more products may include steps (A) to (C). Step (A) may bubble said carbon dioxide into a solution of an electrolyte and a catalyst in a divided electrochemical cell. The divided electrochemical cell may include an anode in a first cell compartment and a cathode in a second cell compartment. The cathode may reduce said carbon dioxide into said products. Step (B) may adjust one or more of (a) a cathode material, (b) a surface morphology of said cathode, (c) said electrolyte, (d) a manner in which said carbon dioxide is bubbled, (e), a pH level of said solution, and (f) an electrical potential of said divided electrochemical cell, to vary at least one of (i) which of said products is produced and (ii) a faradaic yield of said products. Step (C) may separate said products from said solution.

  7. Geological Sequestration of CO2 by Hydrous Carbonate Formation with Reclaimed Slag

    Energy Technology Data Exchange (ETDEWEB)

    Von L. Richards; Kent Peaslee; Jeffrey Smith

    2008-02-06

    The concept of this project is to develop a process that improves the kinetics of the hydrous carbonate formation reaction enabling steelmakers to directly remove CO2 from their furnace exhaust gas. It is proposed to bring the furnace exhaust stream containing CO2 in contact with reclaimed steelmaking slag in a reactor that has an environment near the unit activity of water resulting in the production of carbonates. The CO2 emissions from the plant would be reduced by the amount sequestered in the formation of carbonates. The main raw materials for the process are furnace exhaust gases and specially prepared slag.

  8. High resolution remote sensing for reducing uncertainties in urban forest carbon offset life cycle assessments.

    Science.gov (United States)

    Tigges, Jan; Lakes, Tobia

    2017-10-04

    Urban forests reduce greenhouse gas emissions by storing and sequestering considerable amounts of carbon. However, few studies have considered the local scale of urban forests to effectively evaluate their potential long-term carbon offset. The lack of precise, consistent and up-to-date forest details is challenging for long-term prognoses. Therefore, this review aims to identify uncertainties in urban forest carbon offset assessment and discuss the extent to which such uncertainties can be reduced by recent progress in high resolution remote sensing. We do this by performing an extensive literature review and a case study combining remote sensing and life cycle assessment of urban forest carbon offset in Berlin, Germany. Recent progress in high resolution remote sensing and methods is adequate for delivering more precise details on the urban tree canopy, individual tree metrics, species, and age structures compared to conventional land use/cover class approaches. These area-wide consistent details can update life cycle inventories for more precise future prognoses. Additional improvements in classification accuracy can be achieved by a higher number of features derived from remote sensing data of increasing resolution, but first studies on this subject indicated that a smart selection of features already provides sufficient data that avoids redundancies and enables more efficient data processing. Our case study from Berlin could use remotely sensed individual tree species as consistent inventory of a life cycle assessment. However, a lack of growth, mortality and planting data forced us to make assumptions, therefore creating uncertainty in the long-term prognoses. Regarding temporal changes and reliable long-term estimates, more attention is required to detect changes of gradual growth, pruning and abrupt changes in tree planting and mortality. As such, precise long-term urban ecological monitoring using high resolution remote sensing should be intensified

  9. An etude on global vacuum energy sequester

    International Nuclear Information System (INIS)

    D'Amico, Guido; Kaloper, Nemanja; Padilla, Antonio; Stefanyszyn, David; Westphal, Alexander; Zahariade, George

    2017-01-01

    Recently two of the authors proposed a mechanism of vacuum energy sequester as a means of protecting the observable cosmological constant from quantum radiative corrections. The original proposal was based on using global Lagrange multipliers, but later a local formulation was provided. Subsequently other interesting claims of a different non-local approach to the cosmological constant problem were made, based again on global Lagrange multipliers. We examine some of these proposals and find their mutual relationship. We explain that the proposals which do not treat the cosmological constant counterterm as a dynamical variable require fine tunings to have acceptable solutions. Furthermore, the counterterm often needs to be retuned at every order in the loop expansion to cancel the radiative corrections to the cosmological constant, just like in standard GR. These observations are an important reminder of just how the proposal of vacuum energy sequester avoids such problems.

  10. An etude on global vacuum energy sequester

    Energy Technology Data Exchange (ETDEWEB)

    D' Amico, Guido [CERN, Geneva (Switzerland). Theoretical Physics Dept.; Kaloper, Nemanja [California Univ., Davis, CA (United States). Dept. of Physics; Padilla, Antonio [Nottingham Univ. (United Kingdom). School of Physics and Astronomy; Stefanyszyn, David [Groningen Univ. (Netherlands). Van Swinderen Inst. for Particle Physics and Gravity; Westphal, Alexander [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group; Zahariade, George [Arizona State Univ., Tempe, AZ (United States). Dept. of Physics

    2017-05-24

    Recently two of the authors proposed a mechanism of vacuum energy sequester as a means of protecting the observable cosmological constant from quantum radiative corrections. The original proposal was based on using global Lagrange multipliers, but later a local formulation was provided. Subsequently other interesting claims of a different non-local approach to the cosmological constant problem were made, based again on global Lagrange multipliers. We examine some of these proposals and find their mutual relationship. We explain that the proposals which do not treat the cosmological constant counterterm as a dynamical variable require fine tunings to have acceptable solutions. Furthermore, the counterterm often needs to be retuned at every order in the loop expansion to cancel the radiative corrections to the cosmological constant, just like in standard GR. These observations are an important reminder of just how the proposal of vacuum energy sequester avoids such problems.

  11. Dynamically sequestered F-term uplifting in extra dimension

    International Nuclear Information System (INIS)

    Abe, Hiroyuki; Higaki, Tetsutaro; Kobayashi, Tatsuo; Omura, Yuji

    2008-01-01

    We study moduli stabilization, the dynamical supersymmetry (SUSY) breaking, the uplifting of SUSY anti-de Sitter (AdS) vacuum and the sequestering of hidden sector in a five-dimensional supergravity model, where all modes of the visible sector and the hidden sector are originated from bulk fields. We clarify couplings between the visible and hidden sectors. The expressions for the visible sector soft SUSY breaking terms as well as the hidden sector potential are shown explicitly in our model. The sequestering is achieved dynamically by a wavefunction localization in extra dimension. We find that the tree-level soft scalar mass and the A-term can be suppressed at a SUSY breaking Minkowski minimum where the radius modulus is stabilized, while gaugino masses would be a mirage type

  12. Activated carbon amendment to sequester PAHs in contaminated soil: a lysimeter field trial.

    Science.gov (United States)

    Hale, Sarah E; Elmquist, Marie; Brändli, Rahel; Hartnik, Thomas; Jakob, Lena; Henriksen, Thomas; Werner, David; Cornelissen, Gerard

    2012-04-01

    Activated carbon (AC) amendment is an innovative method for the in situ remediation of contaminated soils. A field-scale AC amendment of either 2% powder or granular AC (PAC and GAC) to a PAH contaminated soil was carried out in Norway. The PAH concentration in drainage water from the field plot was measured with a direct solvent extraction and by deploying polyoxymethylene (POM) passive samplers. In addition, POM samplers were dug directly in the AC amended and unamended soil in order to monitor the reduction in free aqueous PAH concentrations in the soil pore water. The total PAH concentration in the drainage water, measured by direct solvent extraction of the water, was reduced by 14% for the PAC amendment and by 59% for GAC, 12 months after amendment. Measurements carried out with POM showed a reduction of 93% for PAC and 56% for GAC. The free aqueous PAH concentration in soil pore water was reduced 93% and 76%, 17 and 28 months after PAC amendment, compared to 84% and 69% for GAC. PAC, in contrast to GAC, was more effective for reducing freely dissolved concentrations than total dissolved ones. This could tentatively be explained by leaching of microscopic AC particles from PAC. Secondary chemical effects of the AC amendment were monitored by considering concentration changes in dissolved organic carbon (DOC) and nutrients. DOC was bound by AC, while the concentrations of nutrients (NO(3), NO(2), NH(4), PO(4), P-total, K, Ca and Mg) were variable and likely affected by external environmental factors. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Why the CDM can reduce carbon leakage

    International Nuclear Information System (INIS)

    Kallbekken, S.

    2006-04-01

    Carbon leakage is an important concern because it can reduce the environmental effectiveness of the Kyoto Protocol. The Clean Development Mechanism, one of the flexibility mechanisms allowed under the protocol, has the potential to reduce carbon leakage significantly because it reduces the relative competitive disadvantage to Annex B countries of restricting greenhouse gas emissions. The economic intuition behind this mechanism is explored in a theoretical analysis. It is then analyzed numerically using a CGE model. The results indicate that, assuming appropriate accounting for leakage and under realistic assumptions on CDM activity, the CDM has the potential to reduce the magnitude of carbon leakage by around three fifths

  14. Economic feasibility of no-tillage and manure for soil carbon sequestration in corn production in northeastern Kansas.

    Science.gov (United States)

    Pendell, Dustin L; Williams, Jeffery R; Rice, Charles W; Nelson, Richard G; Boyles, Scott B

    2006-01-01

    This study examined the economic potential of no-tillage versus conventional tillage to sequester soil carbon by using two rates of commercial N fertilizer or beef cattle manure for continuous corn (Zea mays L.) production. Yields, input rates, field operations, and prices from an experiment were used to simulate a distribution of net returns for eight production systems. Carbon release values from direct, embodied, and feedstock energies were estimated for each system, and were used with soil carbon sequestration rates from soil tests to determine the amount of net carbon sequestered by each system. The values of carbon credits that provide an incentive for managers to adopt production systems that sequester carbon at greater rates were derived. No-till systems had greater annual soil carbon gains, net carbon gains, and net returns than conventional tillage systems. Systems that used beef cattle manure had greater soil carbon gains and net carbon gains, but lower net returns, than systems that used commercial N fertilizer. Carbon credits would be needed to encourage the use of manure-fertilized cropping systems.

  15. The carbon-sequestration potential of a global afforestation program

    International Nuclear Information System (INIS)

    Nilsson, S.; Schopfhauser, W.

    1995-01-01

    The authors analyzed the changes in the carbon cycle that could be achieved with a global large-scale afforestation program that is economically, politically and technically feasible. They estimated that of the areas regarded as suitable for large-scale plantations, only about 345 million ha would actually be available for plantations and agroforestry for the sole purpose of sequestering carbon. The maximum annual rate of carbon fixation (1.48 Gt/yr) would only be achieved 60 years after the establishment of the plantation - 1.14 Gt by above-ground biomass and 0.34 Gt by below-ground biomass. Over the periods from 1995 to 2095, a total of 104 Gt of carbon would be sequestered. This is substantially lower than the amount of carbon required to offset current carbon emissions (3.8 Gt/yr) in order to stabilize the carbon content of the atmosphere. 108 refs., 1 fig., 14 tabs

  16. Sequestering CO2 by mineralization into useful nesquehonite-based products

    Directory of Open Access Journals (Sweden)

    Fredrik Paul Glasser

    2016-02-01

    Full Text Available The precipitation of magnesium hydroxy-carbonate hydrates has been suggested as a route to sequester CO2 into solids. We report the development of self-cementing compositions based on nesquehonite, MgCO3·3H2O, that are made from CO2-containing gas streams, the CO2 being separated from other gases by its high solubility in alkaline water, while magnesium is typically provided by waste desalination brines. Precipitation conditions are adjusted to optimize the formation of nesquehonite and the crystalline solid can readily be washed free of chloride. Products can be prepared to achieve self-cementation following two routes: (i thermal activation of the nesquehonite then rehydration of the precursor or (ii direct curing of a slurry of nesquehonite. The products thus obtained contain ~ 30 wt% CO2 and could form the basis for a new generation of lightweight, thermally insulating boards, blocks and panels, with sufficient strength for general construction.

  17. Soil carbon sequestration is a climate stabilization wedge: comments on Sommer and Bossio (2014).

    Science.gov (United States)

    Lassaletta, Luis; Aguilera, Eduardo

    2015-04-15

    Sommer and Bossio (2014) model the potential soil organic carbon (SOC) sequestration in agricultural soils (croplands and grasslands) during the next 87 years, concluding that this process cannot be considered as a climate stabilization wedge. We argue, however, that the amounts of SOC potentially sequestered in both scenarios (pessimistic and optimistic) fulfil the requirements for being considered as wedge because in both cases at least 25 GtC would be sequestered during the next 50 years. We consider that it is precisely in the near future, and meanwhile other solutions are developed, when this stabilization effort is most urgent even if after some decades the sequestration rate is significantly reduced. Indirect effects of SOC sequestration on mitigation could reinforce the potential of this solution. We conclude that the sequestration of organic carbon in agricultural soils as a climate change mitigation tool still deserves important attention for scientists, managers and policy makers. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Production of precipitated calcium carbonate from calcium silicates and carbon dioxide

    International Nuclear Information System (INIS)

    Teir, Sebastian; Eloneva, Sanni; Zevenhoven, Ron

    2005-01-01

    The possibilities for reducing carbon dioxide emissions from the pulp and paper industry by calcium carbonation are presented. The current precipitated calcium carbonate (PCC) production uses mined, crushed calcium carbonate as raw materials. If calcium silicates were used instead, carbon dioxide emissions from the calcination of carbonates would be eliminated. In Finland, there could, thus, be a potential for eliminating 200 kt of carbon dioxide emissions per year, considering only the PCC used in the pulp and paper industry. A preliminary investigation of the feasibility to produce PCC from calcium silicates and the potential to replace calcium carbonate as the raw material was made. Calcium carbonate can be manufactured from calcium silicates by various methods, but only a few have been experimentally verified. The possibility and feasibility of these methods as a replacement for the current PCC production process was studied by thermodynamic equilibrium calculations using HSC software and process modelling using Aspen Plus[reg]. The results from the process modelling showed that a process that uses acetic acid for extraction of the calcium ions is a high potential option for sequestering carbon dioxide by mineral carbonation. The main obstacle seems to be the limited availability and relatively high price of wollastonite, which is a mineral with high calcium silicate content. An alternative is to use the more common, but also more complex, basalt rock instead

  19. Cooperative water network system to reduce carbon footprint.

    Science.gov (United States)

    Lim, Seong-Rin; Park, Jong Moon

    2008-08-15

    Much effort has been made in reducing the carbon footprint to mitigate climate change. However, water network synthesis has been focused on reducing the consumption and cost of freshwater within each industrial plant. The objective of this study is to illustrate the necessity of the cooperation of industrial plants to reduce the total carbon footprint of their water supply systems. A mathematical optimization model to minimize global warming potentials is developed to synthesize (1) a cooperative water network system (WNS) integrated over two plants and (2) an individual WNS consisting of two WNSs separated for each plant. The cooperative WNS is compared to the individual WNS. The cooperation reduces their carbon footprint and is economically feasible and profitable. A strategy for implementing the cooperation is suggested for the fair distribution of costs and benefits. As a consequence, industrial plants should cooperate with their neighbor plants to further reduce the carbon footprint.

  20. Soil carbon stocks in Sarawak, Malaysia.

    Science.gov (United States)

    Padmanabhan, E; Eswaran, H; Reich, P F

    2013-11-01

    The relationship between greenhouse gas emission and climate change has led to research to identify and manage the natural sources and sinks of the gases. CO2, CH4, and N2O have an anthropic source and of these CO2 is the least effective in trapping long wave radiation. Soil carbon sequestration can best be described as a process of removing carbon dioxide from the atmosphere and relocating into soils in a form that is not readily released back into the atmosphere. The purpose of this study is to estimate carbon stocks available under current conditions in Sarawak, Malaysia. SOC estimates are made for a standard depth of 100 cm unless the soil by definition is less than this depth, as in the case of lithic subgroups. Among the mineral soils, Inceptisols tend to generally have the highest carbon contents (about 25 kg m(-2) m(-1)), while Oxisols and Ultisols rate second (about 10-15 kg m(-2) m(-1)). The Oxisols store a good amount of carbon because of an appreciable time-frame to sequester carbon and possibly lower decomposition rates for the organic carbon that is found at 1m depths. Wet soils such as peatlands tend to store significant amounts of carbon. The highest values estimated for such soils are about 114 kg m(-2) m(-1). Such appreciable amounts can also be found in the Aquepts. In conclusion, it is pertinent to recognize that degradation of the carbon pool, just like desertification, is a real process and that this irreversible process must be addressed immediately. Therefore, appropriate soil management practices should be instituted to sequester large masses of soil carbon on an annual basis. This knowledge can be used effectively to formulate strategies to prevent forest fires and clearing: two processes that can quickly release sequestered carbon to the atmosphere in an almost irreversible manner. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Carbonate stability in the reduced lower mantle

    Science.gov (United States)

    Dorfman, Susannah M.; Badro, James; Nabiei, Farhang; Prakapenka, Vitali B.; Cantoni, Marco; Gillet, Philippe

    2018-05-01

    Carbonate minerals are important hosts of carbon in the crust and mantle with a key role in the transport and storage of carbon in Earth's deep interior over the history of the planet. Whether subducted carbonates efficiently melt and break down due to interactions with reduced phases or are preserved to great depths and ultimately reach the core-mantle boundary remains controversial. In this study, experiments in the laser-heated diamond anvil cell (LHDAC) on layered samples of dolomite (Mg, Ca)CO3 and iron at pressure and temperature conditions reaching those of the deep lower mantle show that carbon-iron redox interactions destabilize the MgCO3 component, producing a mixture of diamond, Fe7C3, and (Mg, Fe)O. However, CaCO3 is preserved, supporting its relative stability in carbonate-rich lithologies under reducing lower mantle conditions. These results constrain the thermodynamic stability of redox-driven breakdown of carbonates and demonstrate progress towards multiphase mantle petrology in the LHDAC at conditions of the lowermost mantle.

  2. Low carbon renewable natural gas production from coalbeds and implications for carbon capture and storage.

    Science.gov (United States)

    Huang, Zaixing; Sednek, Christine; Urynowicz, Michael A; Guo, Hongguang; Wang, Qiurong; Fallgren, Paul; Jin, Song; Jin, Yan; Igwe, Uche; Li, Shengpin

    2017-09-18

    Isotopic studies have shown that many of the world's coalbed natural gas plays are secondary biogenic in origin, suggesting a potential for gas regeneration through enhanced microbial activities. The generation of biogas through biostimulation and bioaugmentation is limited to the bioavailability of coal-derived compounds and is considered carbon positive. Here we show that plant-derived carbohydrates can be used as alternative substrates for gas generation by the indigenous coal seam microorganisms. The results suggest that coalbeds can act as natural geobioreactors to produce low carbon renewable natural gas, which can be considered carbon neutral, or perhaps even carbon negative depending on the amount of carbon sequestered within the coal. In addition, coal bioavailability is no longer a limiting factor. This approach has the potential of bridging the gap between fossil fuels and renewable energy by utilizing existing coalbed natural gas infrastructure to produce low carbon renewable natural gas and reducing global warming.Coalbeds produce natural gas, which has been observed to be enhanced by in situ microbes. Here, the authors add plant-derived carbohydrates (monosaccharides) to coal seams to be converted by indigenous microbes into natural gas, thus demonstrating a potential low carbon renewable natural gas resource.

  3. Forest carbon calculators: a review for managers, policymakers, and educators

    Science.gov (United States)

    Harold S.J. Zald; Thomas A. Spies; Mark E. Harmon; Mark J. Twery

    2016-01-01

    Forests play a critical role sequestering atmospheric carbon dioxide, partially offsetting greenhouse gas emissions, and thereby mitigating climate change. Forest management, natural disturbances, and the fate of carbon in wood products strongly influence carbon sequestration and emissions in the forest sector. Government policies, carbon offset and trading programs,...

  4. Agroforestry: a sustainable environmental practice for carbon sequestration under the climate change scenarios-a review.

    Science.gov (United States)

    Abbas, Farhat; Hammad, Hafiz Mohkum; Fahad, Shah; Cerdà, Artemi; Rizwan, Muhammad; Farhad, Wajid; Ehsan, Sana; Bakhat, Hafiz Faiq

    2017-04-01

    Agroforestry is a sustainable land use system with a promising potential to sequester atmospheric carbon into soil. This system of land use distinguishes itself from the other systems, such as sole crop cultivation and afforestation on croplands only through its potential to sequester higher amounts of carbon (in the above- and belowground tree biomass) than the aforementioned two systems. According to Kyoto protocol, agroforestry is recognized as an afforestation activity that, in addition to sequestering carbon dioxide (CO 2 ) to soil, conserves biodiversity, protects cropland, works as a windbreak, and provides food and feed to human and livestock, pollen for honey bees, wood for fuel, and timber for shelters construction. Agroforestry is more attractive as a land use practice for the farming community worldwide instead of cropland and forestland management systems. This practice is a win-win situation for the farming community and for the environmental sustainability. This review presents agroforestry potential to counter the increasing concentration of atmospheric CO 2 by sequestering it in above- and belowground biomass. The role of agroforestry in climate change mitigation worldwide might be recognized to its full potential by overcoming various financial, technical, and institutional barriers. Carbon sequestration in soil by various agricultural systems can be simulated by various models but literature lacks reports on validated models to quantify the agroforestry potential for carbon sequestration.

  5. Biomass and carbon pools of disturbed riparian forests

    Science.gov (United States)

    Laura A. B. Giese; W. M. Aust; Randall K. Kolka; Carl C. Trettin

    2003-01-01

    Quantification of carbon pools as affected by forest age/development can facilitate riparian restoration and increase awareness of the potential for forests to sequester global carbon. Riparian forest biomass and carbon pools were quantified for four riparian forests representing different seral stages in the South Carolina Upper Coastal Plain. Three of the riparian...

  6. Sequestering CO{sub 2} by Mineralization into Useful Nesquehonite-Based Products

    Energy Technology Data Exchange (ETDEWEB)

    Glasser, Fredrik Paul, E-mail: f.p.glasser@abdn.ac.uk; Jauffret, Guillaume; Morrison, Jennie [Department of Chemistry, University of Aberdeen, Aberdeen (United Kingdom); Galvez-Martos, Jose-Luis; Patterson, Naomi; Imbabi, Mohammed Salah-Eldin [School of Engineering, University of Aberdeen, Aberdeen (United Kingdom)

    2016-02-11

    The precipitation of magnesium hydroxy-carbonate hydrates has been suggested as a route to sequester CO{sub 2} into solids. We report the development of self-cementing compositions based on nesquehonite, MgCO{sub 3}⋅3H{sub 2}O, that are made from CO{sub 2}-containing gas streams, the CO{sub 2} being separated from other gases by its high solubility in alkaline water, while magnesium is typically provided by waste desalination brines. Precipitation conditions are adjusted to optimize the formation of nesquehonite and the crystalline solid can readily be washed free of chloride. Products can be prepared to achieve self-cementation following two routes: (i) thermal activation of the nesquehonite then rehydration of the precursor or (ii) direct curing of a slurry of nesquehonite. The products thus obtained contain ~30 wt% CO{sub 2} and could form the basis for a new generation of lightweight, thermally insulating boards, blocks, and panels, with sufficient strength for general construction.

  7. Where is the carbon? Carbon sequestration potential from private forestland in the Southern United States

    Science.gov (United States)

    Christopher S. Galik; Brian C. Murray; D. Evan Mercer

    2013-01-01

    Uncertainty surrounding the future supply of timber in the southern United States prompted the question, “Where is all the wood?” (Cubbage et al. 1995). We ask a similar question about the potential of southern forests to mitigate greenhouse gas (GHG) emissions by sequestering carbon. Because significant carbon sequestration potential occurs on individual nonindustrial...

  8. Soil carbon stocks in Sarawak, Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Padmanabhan, E., E-mail: Eswaran_padmanabhan@petronas.com.my [Department of Geosciences, Faculty of Geosciences and Petroleum Engineering, Universiti Teknologi PETRONAS, Tronoh, 31750, Perak (Malaysia); Eswaran, H.; Reich, P.F. [USDA-Natural Resources Conservation Service, Washington, DC 20250 (United States)

    2013-11-01

    The relationship between greenhouse gas emission and climate change has led to research to identify and manage the natural sources and sinks of the gases. CO{sub 2}, CH{sub 4}, and N{sub 2}O have an anthropic source and of these CO{sub 2} is the least effective in trapping long wave radiation. Soil carbon sequestration can best be described as a process of removing carbon dioxide from the atmosphere and relocating into soils in a form that is not readily released back into the atmosphere. The purpose of this study is to estimate carbon stocks available under current conditions in Sarawak, Malaysia. SOC estimates are made for a standard depth of 100 cm unless the soil by definition is less than this depth, as in the case of lithic subgroups. Among the mineral soils, Inceptisols tend to generally have the highest carbon contents (about 25 kg m{sup −2} m{sup −1}), while Oxisols and Ultisols rate second (about 10–15 kg m{sup −2} m{sup −1}). The Oxisols store a good amount of carbon because of an appreciable time-frame to sequester carbon and possibly lower decomposition rates for the organic carbon that is found at 1 m depths. Wet soils such as peatlands tend to store significant amounts of carbon. The highest values estimated for such soils are about 114 kg m{sup −2} m{sup −1}. Such appreciable amounts can also be found in the Aquepts. In conclusion, it is pertinent to recognize that degradation of the carbon pool, just like desertification, is a real process and that this irreversible process must be addressed immediately. Therefore, appropriate soil management practices should be instituted to sequester large masses of soil carbon on an annual basis. This knowledge can be used effectively to formulate strategies to prevent forest fires and clearing: two processes that can quickly release sequestered carbon to the atmosphere in an almost irreversible manner. - Highlights: • Soil carbon stocks in different soils in Sarawak • In depth discussion of

  9. Soil carbon stocks in Sarawak, Malaysia

    International Nuclear Information System (INIS)

    Padmanabhan, E.; Eswaran, H.; Reich, P.F.

    2013-01-01

    The relationship between greenhouse gas emission and climate change has led to research to identify and manage the natural sources and sinks of the gases. CO 2 , CH 4 , and N 2 O have an anthropic source and of these CO 2 is the least effective in trapping long wave radiation. Soil carbon sequestration can best be described as a process of removing carbon dioxide from the atmosphere and relocating into soils in a form that is not readily released back into the atmosphere. The purpose of this study is to estimate carbon stocks available under current conditions in Sarawak, Malaysia. SOC estimates are made for a standard depth of 100 cm unless the soil by definition is less than this depth, as in the case of lithic subgroups. Among the mineral soils, Inceptisols tend to generally have the highest carbon contents (about 25 kg m −2 m −1 ), while Oxisols and Ultisols rate second (about 10–15 kg m −2 m −1 ). The Oxisols store a good amount of carbon because of an appreciable time-frame to sequester carbon and possibly lower decomposition rates for the organic carbon that is found at 1 m depths. Wet soils such as peatlands tend to store significant amounts of carbon. The highest values estimated for such soils are about 114 kg m −2 m −1 . Such appreciable amounts can also be found in the Aquepts. In conclusion, it is pertinent to recognize that degradation of the carbon pool, just like desertification, is a real process and that this irreversible process must be addressed immediately. Therefore, appropriate soil management practices should be instituted to sequester large masses of soil carbon on an annual basis. This knowledge can be used effectively to formulate strategies to prevent forest fires and clearing: two processes that can quickly release sequestered carbon to the atmosphere in an almost irreversible manner. - Highlights: • Soil carbon stocks in different soils in Sarawak • In depth discussion of soil carbon pools in Histosols • Strategies

  10. Carbon Sequestration in Arable Soils is Likely to Increase Nitrous Oxide Emissions, Offsetting Reductions in Climate Radiative Forcing

    International Nuclear Information System (INIS)

    Li, Changsheng Li; Frolking, S.; Butterbach-Bahl, K.

    2005-01-01

    Strategies for mitigating the increasing concentration of carbon dioxide (CO2) in the atmosphere include sequestering carbon (C) in soils and vegetation of terrestrial ecosystems. Carbon and nitrogen (N) move through terrestrial ecosystems in coupled biogeochemical cycles, and increasing C stocks in soils and vegetation will have an impact on the N cycle. We conducted simulations with a biogeochemical model to evaluate the impact of different cropland management strategies on the coupled cycles of C and N, with special emphasis on C-sequestration and emission of the greenhouse gases methane (CH4) and nitrous oxide (N2O). Reduced tillage, enhanced crop residue incorporation, and farmyard manure application each increased soil C-sequestration, increased N2O emissions, and had little effect on CH4 uptake. Over 20 years, increases in N2O emissions, which were converted into CO2-equivalent emissions with 100-year global warming potential multipliers, offset 75-310% of the carbon sequestered, depending on the scenario. Quantification of these types of biogeochemical interactions must be incorporated into assessment frameworks and trading mechanisms to accurately evaluate the value of agricultural systems in strategies for climate protection

  11. Toward Reducing Uncertainties in Biospheric Carbon Uptake in the American West: An Atmospheric Perspective

    Science.gov (United States)

    Lin, J. C.; Stephens, B. B.; Mallia, D.; Wu, D.; Jacobson, A. R.

    2015-12-01

    Despite the need for an understanding of terrestrial biospheric carbon fluxes to account for carbon cycle feedbacks and predict future CO2 concentrations, knowledge of such fluxes at the regional scale remains poor. This is particularly true in mountainous areas, where lack of observations combined with difficulties in their interpretation lead to significant uncertainties. Yet mountainous regions are also where significant forest cover and biomass are found—areas that have the potential to serve as carbon sinks. In particular, understanding carbon fluxes in the American West is of critical importance for the U.S. carbon budget, as the large area and biomass indicate potential for carbon sequestration. However, disturbances such as drought, insect outbreak, and wildfires in this region can introduce significant perturbations to the carbon cycle and thereby affect the amount of carbon sequestered by vegetation in the Rockies. To date, there have been few atmospheric CO2 observations in the American Rockies due to a combination of difficulties associated with logistics and interpretation of the measurements in the midst of complex terrain. Among the few sites are those associated with NCAR's Regional Atmospheric Continuous CO2 Network in the Rocky Mountains (Rocky RACCOON). As CO2 observations in mountainous areas increase in the future, it is imperative that they can be properly interpreted to yield information about biospheric carbon fluxes. In this paper, we will present CO2 observations from RACCOON, along with atmospheric simulations that attempt to extract information about biospheric carbon fluxes in the Western U.S. from these observations. We show that atmospheric models can significantly misinterpret the CO2 observations, leading to large errors in the retrieved biospheric fluxes, due to erroneous atmospheric flows. Recommendations for ways to minimize such errors and properly link the CO2 concentrations to biospheric fluxes are discussed.

  12. Spatio-temporal study of carbon sequestration through piscicultural practice at East Kolkata Wetland.

    Science.gov (United States)

    Pal, Sudin; Chattopadhyay, Buddhadeb; Mukhopadhyay, Subhra Kumar

    2016-09-01

    The present study focus the variation of carbon concentrations within three trophic level i.e., primary producer (phytoplankton), primary consumers (zooplankton) and secondary consumers (fish) in three selected ponds at East Kolkata Wetland area. Depending on the amount and frequency of wastewater input, physico-chemical characteristics of pond, species richness, predator-prey interactions and pond wise different piscicultural practices, the amount of carbon sequestration varied spatially. Significant temporal variations were also observed in each trophic level of these three selected East Kolkata Wetland pond ecosystems. On average primary producers were sequestered 2038.6 ± 244.8mg C m-3 d-1 whereas 307 ± 19.3 mg C m-3 and 11531.4 ± 318.2mg C m-3 was sequestered by primary and secondary consumers, respectively. In Kolkata and its nearby districts over 90% of the production was marked from the East Kolkata Wetland area. Consequently, a significant amount of sequestered carbon was exported from the East Kolkata Wetland ecosystem in the form of fish and this continuous system might increase the carbon sequestration efficiency of the aquatic ecosystem.

  13. Estimating sequestered parasite population dynamics in cerebral malaria

    NARCIS (Netherlands)

    Gravenor, M. B.; van Hensbroek, M. B.; Kwiatkowski, D.

    1998-01-01

    Clinical investigation of malaria is hampered by the lack of a method for estimating the number of parasites that are sequestered in the tissues, for it is these parasites that are thought to be crucial to the pathogenesis of life-threatening complications such as cerebral malaria. We present a

  14. Old-growth forests as global carbon sinks

    NARCIS (Netherlands)

    Luyssaert, S; Schulze, E.D.; Börner, A.

    2008-01-01

    Old- growth forests remove carbon dioxide from the atmosphere(1,2) at rates that vary with climate and nitrogen deposition(3). The sequestered carbon dioxide is stored in live woody tissues and slowly decomposing organic matter in litter and soil(4). Old- growth forests therefore serve as a global

  15. Self-Cleaning Boudouard Reactor for Full Oxygen Recovery from Carbon Dioxide

    Science.gov (United States)

    Coutts, Janelle; Hintze, Paul E.; Muscatello, Anthony C.; Gibson, Tracy L.; Captain, James G.; Lunn, Griffin M.; Devor, Robert W.; Bauer, Brint; Parks, Steve

    2016-01-01

    Oxygen recovery from respiratory carbon dioxide is an important aspect of human spaceflight. Methods exist to sequester the carbon dioxide, but production of oxygen needs further development. The current International Space Station Carbon Dioxide Reduction System (CRS) uses the Sabatier reaction to produce water (and ultimately breathing air). Oxygen recovery is limited to 50 because half of the hydrogen used in the Sabatier reactor is lost as methane, which is vented overboard. The Bosch reaction, which converts carbon dioxide to oxygen and solid carbon is capable of recovering all the oxygen from carbon dioxide, and is the only real alternative to the Sabatier reaction. However, the last reaction in the cycle, the Boudouard reaction, produces solid carbon and the resulting carbon buildup will eventually foul the nickel or iron catalyst, reducing reactor life and increasing consumables. To minimize this fouling and increase efficiency, a number of self-cleaning catalyst designs have been created. This paper will describe recent results evaluating one of the designs.

  16. Carbon sequestration in depleted oil shale deposits

    Science.gov (United States)

    Burnham, Alan K; Carroll, Susan A

    2014-12-02

    A method and apparatus are described for sequestering carbon dioxide underground by mineralizing the carbon dioxide with coinjected fluids and minerals remaining from the extraction shale oil. In one embodiment, the oil shale of an illite-rich oil shale is heated to pyrolyze the shale underground, and carbon dioxide is provided to the remaining depleted oil shale while at an elevated temperature. Conditions are sufficient to mineralize the carbon dioxide.

  17. Global assessment of promising forest management practices for sequestration of carbon

    International Nuclear Information System (INIS)

    Winjum, J.K.; Dixon, R.K.; Schroeder, P.E.

    1991-01-01

    In the 1980s, forests covered an estimated 4.08 billion hectares and contained a carbon pool of 1,400 gigatonnes, or 64% of the total terrestrial pool. Forest biomass productivity per unit of land can be enhanced by proper management practices and it is suggested that by implementing such practices, forests could store more carbon globally and thereby slow the increase in atmospheric CO 2 . Currently, only about 10% of world forests are managed at an active level. An assessment is presented of the amount of carbon that could be sequestered globally by implementing the practices of reforestation, afforestation, natural regeneration, silviculture, and agroforestry. The assessment is based on the development of a global database on managed forest and agroforestry systems. For each of the above five practices, the database contains information on carbon sequestered per hectare, implementation costs, and estimates of the amount of land technically suitable for such practices throughout the world. Results are presented for each practice in the boreal, temperate, and tropical regions. Preliminary estimates show that promising forestry and agroforestry practices could sequester, over a 50-y period, ca 50-100 gigatonnes of carbon at a cost of $170-340 million. This would be a significant contribution as a mitigating measure regarding atmospheric CO 2 buildup and projections for global warming, at present rates of anthropogenic carbon emissions (300-400 gigatonnes carbon over 50 y). 19 refs., 2 figs., 4 tabs

  18. Preservation of Reduced Carbon on Mars: Implications for Understanding Habitability

    Science.gov (United States)

    Conrad, Pamela; Fogel, Marilyn; Steele, Andrew; Summons, Roger E.

    2007-01-01

    Upcoming Mars missions (e.g., Mars Science Laboratory, ExoMars, Astrobiology Field Laboratory, and Mars Sample Return) will search for evidence of extant and fossil microbial habitats and the potential for future habitation. Understanding the distribution and composition of reduced carbon (or organic carbon) is critical for unraveling the Martian carbon cycle, potential for life, and possible biosignature record. Reduced carbon may be produced from biological, geochemical, or interstellar processes; however, evidence for reduced carbon on Mars is lacking with the exception of parts per billion of atmospheric methane. In contrast, abundant atmospheric carbon dioxide may reflect surface oxidation of reduced carbon and accumulation over geological timescales. This suggests that there is an undetected or lost pool of reduced carbon - a pool that may host molecular biosignatures, a characteristic of extant or extinct habitability. In this presentation, we will evaluate factors influencing the preservation potential for organic molecules in rocks on Earth and Martian. We,draw examples from organic molecules in sulfates, basalts, and ancient shales from Mars-analog settings to show how the distribution of organics and their structural patterns will aid Mars habitability studies.

  19. Seasonal copepod lipid pump promotes carbon sequestration in the deep North Atlantic.

    Science.gov (United States)

    Jónasdóttir, Sigrún Huld; Visser, André W; Richardson, Katherine; Heath, Michael R

    2015-09-29

    Estimates of carbon flux to the deep oceans are essential for our understanding of global carbon budgets. Sinking of detrital material ("biological pump") is usually thought to be the main biological component of this flux. Here, we identify an additional biological mechanism, the seasonal "lipid pump," which is highly efficient at sequestering carbon into the deep ocean. It involves the vertical transport and metabolism of carbon rich lipids by overwintering zooplankton. We show that one species, the copepod Calanus finmarchicus overwintering in the North Atlantic, sequesters an amount of carbon equivalent to the sinking flux of detrital material. The efficiency of the lipid pump derives from a near-complete decoupling between nutrient and carbon cycling—a "lipid shunt," and its direct transport of carbon through the mesopelagic zone to below the permanent thermocline with very little attenuation. Inclusion of the lipid pump almost doubles the previous estimates of deep-ocean carbon sequestration by biological processes in the North Atlantic.

  20. Anthropogenic perturbation of the carbon fluxes from land to ocean

    KAUST Repository

    Regnier, Pierre; Friedlingstein, Pierre; Ciais, Philippe; Mackenzie, Fred T.; Gruber, Nicolas; Janssens, Ivan A.; Laruelle, Goulven G.; Lauerwald, Ronny; Luyssaert, Sebastiaan; Andersson, Andreas J.; Arndt, Sandra; Arnosti, Carol; Borges, Alberto V.; Dale, Andrew W.; Gallego-Sala, Angela; Goddé ris, Yves; Goossens, Nicolas; Hartmann, Jens; Heinze, Christoph; Ilyina, Tatiana; Joos, Fortunat; LaRowe, Douglas E.; Leifeld, Jens; Meysman, Filip J. R.; Munhoven, Guy; Raymond, Peter A.; Spahni, Renato; Suntharalingam, Parvadha; Thullner, Martin

    2013-01-01

    to enhanced carbon export from soils. Most of this additional carbon input to upstream rivers is either emitted back to the atmosphere as carbon dioxide (∼0.4 Pg C yr -1) or sequestered in sediments (∼0.5 Pg C yr -1) along the continuum of freshwater bodies

  1. FINAL TOPICAL REPORT FOR NOVEL SYSTEMS SEQUESTERING AND UTILIZATION OF CO2

    Energy Technology Data Exchange (ETDEWEB)

    Edwin S. Olson

    1999-04-30

    Atmospheric CO{sub 2} concentrations are increasing by about 0.5% each year, and there is serious concern that this will cause adverse climate change via the ''greenhouse effect.'' The principal sources of the increase are the utilization of fossil fuels and the deforestation of land. The capture of CO{sub 2} from flue gas or process streams has been demonstrated using chemical absorption with an ethanolamine solvent. However, the cost of releasing the CO{sub 2} by thermal stripping and recovering the solvent is very high, resulting in an energy penalty of 27% to 37 %, depending on the type of power plant (1). Alternatives that would result in energy penalties of 15% have been investigated. Sequestering schemes for CO{sub 2} produced from fossil fuels conversion to energy in utility plants could instead yield useful polymer products. Relatively concentrated CO{sub 2} by-product streams from fermentation of cellulose to fuel ethanol will also be available for conversion to useful polymers. As shown in Figure 1, this project offers two opportunities for mitigating the emission of CO{sub 2} to the atmosphere, depending on the source configuration and economic feasibility of the proposed processes: CO{sub 2} in a conventional utility-produced flue gas could be sequestered to form a reactive monomer using an amine (such as ethanolamine) that reacts with an aldehyde to form an amine intermediate, which subsequently copolymerizes with the CO{sub 2} to give a copolyurethane. Using a tertiary amine to trap the CO{sub 2} is also proposed. In this case the tertiary ammonium carbonate is reacted with the aldehyde to form the copolycarbonate, regenerating the tertiary amine. In an alternate scheme, a concentrated CO{sub 2} stream from an advanced energy system could be directly polymerized with aldehyde and catalyst to Polymer 2. Sources of concentrated CO{sub 2} include the water-gas shift reaction in an IGCC (integrated gasification combined-cycle) device

  2. Aquatic carbon cycling in the conterminous United States and implications for terrestrial carbon accounting.

    Science.gov (United States)

    Butman, David; Stackpoole, Sarah; Stets, Edward; McDonald, Cory P; Clow, David W; Striegl, Robert G

    2016-01-05

    Inland water ecosystems dynamically process, transport, and sequester carbon. However, the transport of carbon through aquatic environments has not been quantitatively integrated in the context of terrestrial ecosystems. Here, we present the first integrated assessment, to our knowledge, of freshwater carbon fluxes for the conterminous United States, where 106 (range: 71-149) teragrams of carbon per year (TgC⋅y(-1)) is exported downstream or emitted to the atmosphere and sedimentation stores 21 (range: 9-65) TgC⋅y(-1) in lakes and reservoirs. We show that there is significant regional variation in aquatic carbon flux, but verify that emission across stream and river surfaces represents the dominant flux at 69 (range: 36-110) TgC⋅y(-1) or 65% of the total aquatic carbon flux for the conterminous United States. Comparing our results with the output of a suite of terrestrial biosphere models (TBMs), we suggest that within the current modeling framework, calculations of net ecosystem production (NEP) defined as terrestrial only may be overestimated by as much as 27%. However, the internal production and mineralization of carbon in freshwaters remain to be quantified and would reduce the effect of including aquatic carbon fluxes within calculations of terrestrial NEP. Reconciliation of carbon mass-flux interactions between terrestrial and aquatic carbon sources and sinks will require significant additional research and modeling capacity.

  3. Aquatic carbon cycling in the conterminous United States and implications for terrestrial carbon accounting

    Science.gov (United States)

    Butman, David; Stackpoole, Sarah; Stets, Edward; McDonald, Cory P.; Clow, David W.; Striegl, Robert G.

    2016-01-01

    Inland water ecosystems dynamically process, transport, and sequester carbon. However, the transport of carbon through aquatic environments has not been quantitatively integrated in the context of terrestrial ecosystems. Here, we present the first integrated assessment, to our knowledge, of freshwater carbon fluxes for the conterminous United States, where 106 (range: 71–149) teragrams of carbon per year (TgC⋅y−1) is exported downstream or emitted to the atmosphere and sedimentation stores 21 (range: 9–65) TgC⋅y−1 in lakes and reservoirs. We show that there is significant regional variation in aquatic carbon flux, but verify that emission across stream and river surfaces represents the dominant flux at 69 (range: 36–110) TgC⋅y−1 or 65% of the total aquatic carbon flux for the conterminous United States. Comparing our results with the output of a suite of terrestrial biosphere models (TBMs), we suggest that within the current modeling framework, calculations of net ecosystem production (NEP) defined as terrestrial only may be overestimated by as much as 27%. However, the internal production and mineralization of carbon in freshwaters remain to be quantified and would reduce the effect of including aquatic carbon fluxes within calculations of terrestrial NEP. Reconciliation of carbon mass–flux interactions between terrestrial and aquatic carbon sources and sinks will require significant additional research and modeling capacity. PMID:26699473

  4. Transformation of carbon tetrachloride under sulfate reducing conditions

    NARCIS (Netherlands)

    Best, Jappe H. de; Salminen, E.; Doddema, Hans J.; Janssen, Dick B.; Harder, Wim

    1998-01-01

    The removal of carbon tetrachloride under sulfate reducing conditions was studied in an anaerobic packed-bed reactor. Carbon tetrachloride, up to a concentration of 30 µM, was completely converted. Chloroform and dichloromethane were the main transformation products, but part of the carbon

  5. Transformation of carbon tetrachloride under sulfate reducing conditions

    NARCIS (Netherlands)

    de Best, JH; Salminen, E; Doddema, HJ; Janssen, DB; Harder, W

    1997-01-01

    The removal of carbon tetrachloride under sulfate reducing conditions was studied in an anaerobic packed-bed reactor. Carbon tetrachloride, up to a concentration of 30 mu M, was completely converted. Chloroform and dichloromethane were the main transformation products, but part of the carbon

  6. Forest carbon response to management scenarios intended to mitigate GHG emissions and reduce fire impacts in the US West Coast region

    Science.gov (United States)

    Hudiburg, T. W.; Law, B. E.; Thornton, P. E.; Luyssaert, S.

    2012-12-01

    US West coast forests are among the most carbon dense biomes in the world and the potential for biomass accumulation in mesic coastal forests is the highest recorded (Waring and Franklin 1979, Hudiburg et al. 2009). Greenhouse gas (GHG) mitigation strategies have recently expanded to include forest woody biomass as bioenergy, with the expectation that this will also reduce forest mortality. We examined forest carbon response and life cycle assessment (LCA) of net carbon emissions following varying combinations of bioenergy management scenarios in Pacific Northwest forests for the period from 2010-2100. We use the NCAR CLM4 model combined with a regional atmospheric forcing dataset and account for future environmental change using the IPCC RCP4.5 and RCP 8.5 scenarios. Bioenergy management strategies include a repeated thinning harvest, a repeated clearcut harvest, and a single salvage harvest in areas with projected insect-related mortality. None of the bioenergy management scenarios reduce net emissions to the atmosphere compared to continued business-as-usual harvest (BAU) by the end of the 21st century. Forest regrowth and reduced fire emissions are not large enough to balance the wood removals from harvest. Moreover, the substitution of wood for fossil fuel energy and products is not large enough to offset the wood losses through decomposition and combustion. However, in some ecoregions (Blue Mountains and East Cascades), emissions from the thinning harvests begin to improve over BAU at the end of the century and could lead to net reductions in those ecoregions over a longer time period (> 100 years). For salvage logging, there is no change compared to BAU emissions by the end of the 21st century because the treatment area is minimal compared to the other treatments and only performed once. These results suggest that managing forests for carbon sequestration will need to include a variety of approaches accounting for forest baseline conditions and in some

  7. Springer An étude on global vacuum energy sequester

    CERN Document Server

    D'Amico, Guido; Padilla, Antonio; Stefanyszyn, David; Westphal, Alexander; Zahariade, George

    2017-09-18

    Recently two of the authors proposed a mechanism of vacuum energy sequester as a means of protecting the observable cosmological constant from quantum radiative corrections. The original proposal was based on using global Lagrange multipliers, but later a local formulation was provided. Subsequently other interesting claims of a different non-local approach to the cosmological constant problem were made, based again on global Lagrange multipliers. We examine some of these proposals and find their mutual relationship. We explain that the proposals which do not treat the cosmological constant counterterm as a dynamical variable require fine tunings to have acceptable solutions. Furthermore, the counterterm often needs to be retuned at every order in the loop expansion to cancel the radiative corrections to the cosmological constant, just like in standard GR. These observations are an important reminder of just how the proposal of vacuum energy sequester avoids such problems.

  8. Boreal Forests Sequester Large Amounts of Mercury over Millennial Time Scales in the Absence of Wildfire.

    Science.gov (United States)

    Giesler, Reiner; Clemmensen, Karina E; Wardle, David A; Klaminder, Jonatan; Bindler, Richard

    2017-03-07

    Alterations in fire activity due to climate change and fire suppression may have profound effects on the balance between storage and release of carbon (C) and associated volatile elements. Stored soil mercury (Hg) is known to volatilize due to wildfires and this could substantially affect the land-air exchange of Hg; conversely the absence of fires and human disturbance may increase the time period over which Hg is sequestered. Here we show for a wildfire chronosequence spanning over more than 5000 years in boreal forest in northern Sweden that belowground inventories of total Hg are strongly related to soil humus C accumulation (R 2 = 0.94, p millennial time scales in the prolonged absence of fire.

  9. Federal land management, carbon sequestration, and climate change in the Southeastern U.S.: a case study with fort benning

    Science.gov (United States)

    Zhao, S.; Liu, S.; Li, Z.; Sohl, Terry L.

    2010-01-01

    Land use activities can have a major impact on the temporal trendsandspatialpatternsofregionalland-atmosphereexchange of carbon. Federal lands generally have substantially different land management strategies from surrounding areas, and the carbon consequences have rarely been quantified and assessed. Using the Fort Benning Installation as a case study, we used the General Ensemble biogeochemical Modeling System (GEMS) to simulate and compare ecosystem carbon sequestration between the U.S. Army's Fort Benning and surrounding areas from 1992 to 2050. Our results indicate that the military installation sequestered more carbon than surrounding areas from 1992 to 2007 (76.7 vs 18.5 g C m-2 yr-1), and is projected to continue sequestering more carbon from 2008 to 2050 (75.7 vs 25.6 g C m-2 yr-1), mostly because of the proactive management approaches adopted on military training lands. Our results suggest that federal lands might play a positive and important role in sequestering and conserving atmospheric carbon because some anthropogenic disturbances (e.g., urbanization, forest harvesting, and agriculture) can be minimized or prevented on federal lands

  10. Carbon Sequestration in Olivine and Basalt Powder Packed Beds.

    Science.gov (United States)

    Xiong, Wei; Wells, Rachel K; Giammar, Daniel E

    2017-02-21

    Fractures and pores in basalt could provide substantial pore volume and surface area of reactive minerals for carbonate mineral formation in geologic carbon sequestration. In many fractures solute transport will be limited to diffusion, and opposing chemical gradients that form as a result of concentration differences can lead to spatial distribution of silicate mineral dissolution and carbonate mineral precipitation. Glass tubes packed with grains of olivine or basalt with different grain sizes and compositions were used to explore the identity and spatial distribution of carbonate minerals that form in dead-end one-dimensional diffusion-limited zones that are connected to a larger reservoir of water in equilibrium with 100 bar CO 2 at 100 °C. Magnesite formed in experiments with olivine, and Mg- and Ca-bearing siderite formed in experiments with flood basalt. The spatial distribution of carbonates varied between powder packed beds with different powder sizes. Packed beds of basalt powder with large specific surface areas sequestered more carbon per unit basalt mass than powder with low surface area. The spatial location and extent of carbonate mineral formation can influence the overall ability of fractured basalt to sequester carbon.

  11. Biochar carbon stability and effect on greenhouse gas emissions

    DEFF Research Database (Denmark)

    Bruun, Esben Wilson; Cross, Andrew; Hammond, Jim

    2016-01-01

    As demonstrated by several scientific studies there is no doubt that biochar in general is very recalcitrant compared to other organic matter additions and soil organic matter fractions and also that it is possible to sequester carbon at a climate change relevant time scale (~100 years or more......) by soil application of biochar. However, the carbon stability of biochar in soil is strongly correlated with the degree of thermal alteration of the original feedstock (the lower the temperature, the larger the labile fraction) and in depth understanding of the technology used and its effect...... on the biochar quality is necessary in order to produce the most beneficial biochars for soil application. Beside carbon sequestration in soil biochar may improve the GHG balance by reducing N2O and CH4 soil emissions, although contrasting results are found in the literature. The mechanisms behind...

  12. Lianas reduce carbon accumulation and storage in tropical forests.

    Science.gov (United States)

    van der Heijden, Geertje M F; Powers, Jennifer S; Schnitzer, Stefan A

    2015-10-27

    Tropical forests store vast quantities of carbon, account for one-third of the carbon fixed by photosynthesis, and are a major sink in the global carbon cycle. Recent evidence suggests that competition between lianas (woody vines) and trees may reduce forest-wide carbon uptake; however, estimates of the impact of lianas on carbon dynamics of tropical forests are crucially lacking. Here we used a large-scale liana removal experiment and found that, at 3 y after liana removal, lianas reduced net above-ground carbon uptake (growth and recruitment minus mortality) by ∼76% per year, mostly by reducing tree growth. The loss of carbon uptake due to liana-induced mortality was four times greater in the control plots in which lianas were present, but high variation among plots prevented a significant difference among the treatments. Lianas altered how aboveground carbon was stored. In forests where lianas were present, the partitioning of forest aboveground net primary production was dominated by leaves (53.2%, compared with 39.2% in liana-free forests) at the expense of woody stems (from 28.9%, compared with 43.9%), resulting in a more rapid return of fixed carbon to the atmosphere. After 3 y of experimental liana removal, our results clearly demonstrate large differences in carbon cycling between forests with and without lianas. Combined with the recently reported increases in liana abundance, these results indicate that lianas are an important and increasing agent of change in the carbon dynamics of tropical forests.

  13. Criterion 5: Maintenance of forest contributions to global carbon cycles

    Science.gov (United States)

    Stephen R. Shifley; Francisco X. Aguilar; Nianfu Song; Susan I. Stewart; David J. Nowak; Dale D. Gormanson; W. Keith Moser; Sherri Wormstead; Eric J. Greenfield

    2012-01-01

    Northern forests cover more than 42 percent of the region and are enormous reservoirs of carbon. Through photosynthesis, live trees emit oxygen in exchange for carbon dioxide they pull from the atmosphere. As a tree grows it stores carbon in wood above and below ground, and sequestered carbon comprises about half of its dry weight. Dead trees and down logs are also...

  14. Possibilities for carbon sequestration by the forestry sector in Hungary. COST E21 Workshop. Contribution of forests and forestry to mitigate greenhouse effects. Joensuu (Finland. 28-30 Sep 2000

    Directory of Open Access Journals (Sweden)

    Somogyi Z.

    2000-01-01

    Full Text Available In Hungary, gross emissions of carbon amount to some 17.6 millions t C per year. Forestry, the only sector which can offset emissions, seems to be a net sink of 1.6 Mt C per year. Afforesting large areas could substantially increase the carbon fixing capacity of the Hungarian forests. To assess the possibilities of sequestering carbon by afforestation, the CASFOR model, an adaptation of the COMAP model, was developed for Hungarian conditions. The technical potential scenario showed that, by afforesting 773,000 ha of former agricultural land by 2050, some 46 millions t C could be sequestered. The specific costs of sequestering carbon by afforestation are pretty low.

  15. Consequences of co-benefits for the efficient design of carbon sequestration programs

    International Nuclear Information System (INIS)

    Feng, H.; Kling, C.L.

    2005-01-01

    The social efficiency of private carbon markets that also included trading in agricultural soil carbon sequestration with significant associated co-benefits were considered. Three topics related to the presence of co-benefits that sequester carbon were examined: (1) the consequences of co-benefits from carbon sinks and carbon abatement technology on the efficiency of carbon markets; (2) the efficient supply of carbon sequestration and co-benefits when there is spatial heterogeneity; and (3) the consequences of the presence of a carbon market when there is also a government supported conservation program. Co-benefits from carbon sinks and abatement were considered in relation to the socially efficient level of sequestration. The supply of carbon sequestration and co-benefits were then considered when fields differed in their potential to provide carbon and other environmental benefits. An empirical example of the economic characteristics of carbon sequestration and co-benefits in the Upper Mississippi River Basin was presented, in which the sequestration practice of land retirement with planting of perennial grasses was examined. Two sets of figures were used to illustrate the relationship between the cost of carbon sequestration and its marginal co-benefits: the marginal cost and the marginal co-benefits of carbon sequestration in a carbon market; and the marginal cost of carbon sequestration under a policy designed to maximize a bundle of environmental benefits. It was demonstrated that the relationship between carbon and its associated co-benefits will affect the efficiency of policy instruments designed for carbon sequestration. It was recommended that policy-makers consider that there are already a multitude of existing conservation programmes that result in significant carbon sequestration in many countries, and that nascent carbon markets are emerging in countries that have not ratified the Kyoto Protocol. The efficient level and location of carbon

  16. Does grazing management matter for soil carbon sequestration in shortgrass steppe?

    Science.gov (United States)

    Considerable uncertainty remains regarding the potential of grazing management on semiarid rangelands to sequester soil carbon. Short-term (less than 1 decade) studies have determined that grazing management potentially influences fluxes of carbon, but such studies are strongly influenced by prevail...

  17. A General Methodology for Evaluation of Carbon Sequestration Activities and Carbon Credits

    Energy Technology Data Exchange (ETDEWEB)

    Klasson, KT

    2002-12-23

    A general methodology was developed for evaluation of carbon sequestration technologies. In this document, we provide a method that is quantitative, but is structured to give qualitative comparisons despite changes in detailed method parameters, i.e., it does not matter what ''grade'' a sequestration technology gets but a ''better'' technology should receive a better grade. To meet these objectives, we developed and elaborate on the following concepts: (1) All resources used in a sequestration activity should be reviewed by estimating the amount of greenhouse gas emissions for which they historically are responsible. We have done this by introducing a quantifier we term Full-Cycle Carbon Emissions, which is tied to the resource. (2) The future fate of sequestered carbon should be included in technology evaluations. We have addressed this by introducing a variable called Time-adjusted Value of Carbon Sequestration to weigh potential future releases of carbon, escaping the sequestered form. (3) The Figure of Merit of a sequestration technology should address the entire life-cycle of an activity. The figures of merit we have developed relate the investment made (carbon release during the construction phase) to the life-time sequestration capacity of the activity. To account for carbon flows that occur during different times of an activity we incorporate the Time Value of Carbon Flows. The methodology we have developed can be expanded to include financial, social, and long-term environmental aspects of a sequestration technology implementation. It does not rely on global atmospheric modeling efforts but is consistent with these efforts and could be combined with them.

  18. Deciphering ocean carbon in a changing world

    Energy Technology Data Exchange (ETDEWEB)

    Moran, Mary Ann; Kujawinski, Elizabeth B.; Stubbins, Aron; Fatland, Rob; Aluwihare, Lihini I.; Buchan, Alison; Crump, Byron C.; Dorrestein, Pieter C.; Dyhrman, Sonya T.; Hess, Nancy J.; Howe, Bill; Longnecker, Krista; Medeiros, Patricia M.; Niggemann, Jutta; Obernosterer, Ingrid; Repeta, Daniel J.; Waldbauer, Jacob R.

    2016-03-07

    Dissolved organic matter (DOM) in the oceans is one of the largest pools of reduced carbon on Earth, comparable in size to the atmospheric CO2 reservoir. The cycling of DOM over short and long time scales has profound impacts on the quantity of carbon sequestered in the oceans and the foundations of the food webs that support ocean life. At the heart of this cycle lie molecular-level relationships between the individual molecules in DOM and the members of the ocean microbiome that produce and consume them. In the past, these connections have defied clear definition and study because both DOM and microbial communities consist of many thousands of individual components. Emerging tools in analytical chemistry, microbiology and informatics are breaking down the barriers to a fuller appreciation of these connections. Here we highlight questions that are being addressed using this new toolkit and consider how these advances are transforming our understanding of some of the most important reactions of the marine carbon cycle.

  19. MR imaging findings of a sequestered disc in the lumbar spine: a comparison with an extruded disc

    International Nuclear Information System (INIS)

    Sim, Su Youn; Park, Ji Seon; Ryu, Kyung Nam; Jin, Wook

    2007-01-01

    To compare the MR findings of a sequestered disc with an extruded disc. MR images of 28 patients with a sequestered disc and 18 patients with an extruded disc were retrospectively reviewed. Patients with sequestered discs were divided into two groups whether definite separation from the parent disc was or was not seen. In the latter group (definite separation not seen) and the extruded disc group of patients, the signal intensities of the herniated discs were compared with the signal intensities of the parent discs and were evaluated on T1-and T2-weighted images. We also assessed the presence of a notch within the herniated disc. In the sequestered disc group of patients (28 discs), only 5 discs (18%) showed obvious separation from the parent disc. Among the remaining 23 discs with indefinite separation, the notch was visible in 14 discs (61%) and 9 discs (39%) had no notch. In the extruded disc group (18 discs), the notch was visible in 2 (11%) discs and the difference between the two groups was statistically significant (ρ 0.0002). The signal intensities of the herniated discs on T1-weighted images were isointense in both the sequestered and extruded discs. The difference of incidence of high signal intensities on T2-weighted images was not statistically significant (ρ = 0.125). It is necessary to consider the possibility of the presence of a sequestered disc when a herniated disc material shows a notch

  20. Carbonate-H₂O₂ leaching for sequestering uranium from seawater.

    Science.gov (United States)

    Pan, Horng-Bin; Liao, Weisheng; Wai, Chien M; Oyola, Yatsandra; Janke, Christopher J; Tian, Guoxin; Rao, Linfeng

    2014-07-28

    Uranium adsorbed on amidoxime-based polyethylene fiber in simulated seawater can be quantitatively eluted at room temperature using 1 M Na2CO3 containing 0.1 M H2O2. This efficient elution process is probably due to the formation of an extremely stable uranyl-peroxo-carbonato complex in the carbonate solution. After washing with water, the sorbent can be reused with minimal loss of uranium loading capacity. Possible existence of this stable uranyl species in ocean water is also discussed.

  1. Growing common plantation tree species in Kenya for sale of carbon ...

    African Journals Online (AJOL)

    The introduction of carbon finance as an incentive in forestry farming has a potential of increasing the amount of carbon sequestered. However, this has created a daunting task among investors in forestry to optimise the joint production of wood and carbon sequestration. For instance, investors might find it profitable to give ...

  2. Reducing CO2 flux by decreasing tillage in Ohio: overcoming conjecture with data

    Science.gov (United States)

    Soil could become an important sink for atmospheric carbon dioxide (CO2) as global agricultural greenhouse gas emissions continue to grow, but data to support this conjecture are few. Sequestering soil carbon (C) depends upon many factors including soil type, climate, crop, tillage, nitrogen fertili...

  3. Phytosequestration: Carbon biosequestration by plants and the prospects of genetic engineering

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, C.; Wullschleger, S.D.; Kalluri, U.C.; Tuskan, G.A.

    2010-07-15

    Photosynthetic assimilation of atmospheric carbon dioxide by land plants offers the underpinnings for terrestrial carbon (C) sequestration. A proportion of the C captured in plant biomass is partitioned to roots, where it enters the pools of soil organic C and soil inorganic C and can be sequestered for millennia. Bioenergy crops serve the dual role of providing biofuel that offsets fossil-fuel greenhouse gas (GHG) emissions and sequestering C in the soil through extensive root systems. Carbon captured in plant biomass can also contribute to C sequestration through the deliberate addition of biochar to soil, wood burial, or the use of durable plant products. Increasing our understanding of plant, microbial, and soil biology, and harnessing the benefits of traditional genetics and genetic engineering, will help us fully realize the GHG mitigation potential of phytosequestration.

  4. Effects of single-walled carbon nanotubes on the bioavailability of PCBs in field-contaminated sediments

    Science.gov (United States)

    Adsorption of hydrophobic organic contaminants (HOCs) to black carbon is a well studied phenomenon. One emerging class of engineered black carbon materials are single-walled carbon nanotubes (SWNT). Little research has investigated the potential of SWNT to adsorb and sequester HO...

  5. Sequestering carbon dioxide in industrial polymers: Building materials for the 21st century

    Energy Technology Data Exchange (ETDEWEB)

    Molton, P.M.; Nelson, D.A.

    1993-06-01

    This study was undertaken to determine the possibility of developing beneficial uses for carbon dioxide as a key component for a large-volume building product. Such a use may provide an alternative to storing the gas in oceanic sinks or clathrates as a way to slow the rate of global warming. The authors investigated the concept that carbon dioxide might be used with other chemicals to make carbon-dioxide-based polymers which would be lightweight, strong, and economical alternatives to some types of wood and silica-based building materials. As a construction-grade material, carbon dioxide would be fixed in a solid, useful form where it would not contribute to global warming. With the probable imposition of a fuel carbon tax in industrialized countries, this alternative would allow beneficial use of the carbon dioxide and could remove it from the tax basis if legislation were structured appropriately. Hence, there would be an economic driver towards the use of carbon-dioxide-based polymers which would enhance their future applications. Information was obtained through literature searches and personal contacts on carbon dioxide polymers which showed that the concept (1) is technically feasible, (2) is economically defensible, and (3) has an existing industrial infrastructure which could logically develop it. The technology exists for production of building materials which are strong enough for use by industry and which contain up to 90% by weight of carbon dioxide, both chemically and physically bound. A significant side-benefit of using this material would be that it is self-extinguishing in case of fire. This report is the first stage in the investigation. Further work being proposed will provide details on costs, specific applications and volumes, and potential impacts of this technology.

  6. A Spatio-Temporal Based Estimation of Sequestered Carbon in the ...

    African Journals Online (AJOL)

    The vegetation in the Tarkwa Mining Area (TMA) has experienced changes as a result of population growth, urbanization, mining activities and illegal chainsaw operations and this has led to an increase in temperature over the past years. Therefore, studying its forest biomass carbon (C) stock and its spatio-temporal ...

  7. Institute a modest carbon tax to reduce carbon emissions, finance clean energy technology development, cut taxes, and reduce the deficit

    Energy Technology Data Exchange (ETDEWEB)

    Muro, Mark; Rothwell, Jonathan

    2012-11-15

    The nation should institute a modest carbon tax in order to help clean up the economy and stabilize the nation’s finances. Specifically, Congress and the president should implement a $20 per ton, steadily increasing carbon excise fee that would discourage carbon dioxide emissions while shifting taxation onto pollution, financing energy efficiency (EE) and clean technology development, and providing opportunities to cut taxes or reduce the deficit. The net effect of these policies would be to curb harmful carbon emissions, improve the nation’s balance sheet, and stimulate job-creation and economic renewal.

  8. Comparing climate policies to reduce carbon emissions in China

    International Nuclear Information System (INIS)

    Li, Aijun; Lin, Boqiang

    2013-01-01

    Currently, China is the largest carbon emitter mainly due to growing consumption of fossil fuels. In 2009, the Chinese government committed itself to reducing domestic carbon emissions per unit of GDP by 40–45% by 2020 compared to 2005 levels. Therefore, it is a top priority for the Chinese government to adopt efficient policy instruments to reduce its carbon intensity. Against this background, this paper develops a general equilibrium model and seeks to provide empirical contributions by comparing the potential impacts of several different policy options to reduce China's carbon emissions. The main findings are as follows. Firstly, these climate policies would affect the structure of economy and contribute to carbon emissions reduction and carbon intensity reduction. Secondly, there would be significant differences in the economic and environmental effects among different climate policies and hence, the government would trade-off among different economic objectives to overcome any potential resistances. Thirdly, there would be considerable differences in the emissions effects of absolute and intensity-based carbon emissions controls, implying that the government might adopt different climate policies for absolute or intensity-based carbon emissions controls. Looking ahead, the government should trade-off among different objectives when designing climate reforms. - Highlights: • We develop a static general equilibrium model to simulate the impacts of climate policies. • We compare the potential impacts of various climate policies in China. • We discuss how to design these policies to make them more effective

  9. Sequestering agents for the removal of actinides from waste streams

    Energy Technology Data Exchange (ETDEWEB)

    Raymond, K.N.; White, D.J.; Xu, Jide; Mohs, T.R. [Univ. of California, Berkeley, CA (United States)

    1997-10-01

    The goal of this project is to take a biomimetic approach toward developing new separation technologies for the removal of radioactive elements from contaminated DOE sites. To achieve this objective, the authors are investigating the fundamental chemistry of naturally occurring, highly specific metal ion sequestering agents and developing them into liquid/liquid and solid supported actinide extraction agents. Nature produces sideophores (e.g., Enterobactin and Desferrioxamine B) to selectivity sequester Lewis acidic metal ions, in particular Fe(III), from its surroundings. These chelating agents typically use multiple catechols or hydroxamic acids to form polydentate ligands that chelate the metal ion forming very stable complexes. The authors are investigating and developing analogous molecules into selective chelators targeting actinide(IV) ions, which display similar properties to Fe(III). By taking advantage of differences in charge, preferred coordination number, and pH stability range, the transition from nature to actinide sequestering agents has been applied to the development of new and highly selective actinide extraction technologies. Additionally, the authors have shown that these chelating ligands are versatile ligands for chelating U(VI). In particular, they have been studying their coordination chemistry and fundamental interactions with the uranyl ion [UO{sub 2}]{sup 2+}, the dominant form of uranium found in aqueous media. With an understanding of this chemistry, and results obtained from in vivo uranium sequestration studies, it should be possible to apply these actinide(IV) extraction technologies to the development of new extraction agents for the removal of uranium from waste streams.

  10. Carbon Sequestration in Terrestrial Ecosystems: A Status Report on R and D Progress

    International Nuclear Information System (INIS)

    Jacobs, G.K.

    2001-01-01

    Sequestration of carbon in terrestrial ecosystems is a low-cost option that may be available in the near-term to mitigate increasing atmospheric CO(sub 2) concentrations, while providing additional benefits. Storing carbon in terrestrial ecosystems can be achieved through maintenance of standing aboveground biomass, utilization of aboveground biomass in long-lived products, or protection of carbon (organic and inorganic) compounds present in soils. There are potential co-benefits from efforts to sequester carbon in terrestrial ecosystems. For example, long-lived valuable products (wood) are produced, erosion would be reduced, soil productivity could be improved through increased capacity to retain water and nutrients, and marginal lands could be improved and riparian ecosystems restored. Another unique feature of the terrestrial sequestration option is that it is the only option that is ''reversible'' should it become desirable or permissible. For example, forests that are created are thus investments which could be harvested should CO(sub 2) emissions be reduced in other ways to acceptable levels 50-100 years from now

  11. Carbon payments and low-cost conservation.

    Science.gov (United States)

    Crossman, Neville D; Bryan, Brett A; Summers, David M

    2011-08-01

    A price on carbon is expected to generate demand for carbon offset schemes. This demand could drive investment in tree-based monocultures that provide higher carbon yields than diverse plantings of native tree and shrub species, which sequester less carbon but provide greater variation in vegetation structure and composition. Economic instruments such as species conservation banking, the creation and trading of credits that represent biological-diversity values on private land, could close the financial gap between monocultures and more diverse plantings by providing payments to individuals who plant diverse species in locations that contribute to conservation and restoration goals. We studied a highly modified agricultural system in southern Australia that is typical of many temperate agriculture zones globally (i.e., has a high proportion of endangered species, high levels of habitat fragmentation, and presence of non-native species). We quantified the economic returns from agriculture and from carbon plantings (monoculture and mixed tree and shrubs) under six carbon-price scenarios. We also identified high-priority locations for restoration of cleared landscapes with mixed tree and shrub carbon plantings. Depending on the price of carbon, direct annual payments to landowners of AU$7/ha/year to $125/ha/year (US$6-120/ha/year) may be sufficient to augment economic returns from a carbon market and encourage tree plantings that contribute more to the restoration of natural systems and endangered species habitats than monocultures. Thus, areas of high priority for conservation and restoration may be restored relatively cheaply in the presence of a carbon market. Overall, however, less carbon is sequestered by mixed native tree and shrub plantings. © 2011 Society for Conservation Biology.

  12. Modeling carbon dioxide sequestration in saline aquifers: Significance of elevated pressures and salinities

    International Nuclear Information System (INIS)

    Allen, D.E.; Strazisar, B.R.; Soong, Y.; Hedges, S.W.

    2005-01-01

    The ultimate capacity of saline formations to sequester carbon dioxide by solubility and mineral trapping must be determined by simulating sequestration with geochemical models. These models, however, are only as reliable as the data and reaction scheme on which they are based. Several models have been used to make estimates of carbon dioxide solubility and mineral formation as a function of pressure and fluid composition. Intercomparison of modeling results indicates that failure to adjust all equilibrium constants to account for elevated carbon dioxide pressures results in significant errors in both solubility and mineral formation estimates. Absence of experimental data at high carbon dioxide pressures and high salinities make verification of model results difficult. Results indicate standalone solubility models that do not take mineral reactions into account will underestimate the total capacity of aquifers to sequester carbon dioxide in the long term through enhanced solubility and mineral trapping mechanisms. Overall, it is difficult to confidently predict the ultimate sequestration capacity of deep saline aquifers using geochemical models. (author)

  13. Life Cycle Analysis of Carbon Flow and Carbon Footprint of Harvested Wood Products of Larix principis-rupprechtii in China

    Directory of Open Access Journals (Sweden)

    Fei Lun

    2016-03-01

    Full Text Available Larix principis-rupprechtii is a native tree species in North China with a large distribution; and its harvested timbers can be used for producing wood products. This study focused on estimating and comparing carbon flows and carbon footprints of different harvested wood products (HWPs from Larix principis-ruppechtii based on the life cycle analysis (from seedling cultivation to HWP final disposal. Based on our interviews and surveys, the system boundary in this study was divided into three processes: the forestry process, the manufacturing process, and the use and disposal process. By tracking carbon flows of HWPs along the entire life cycle, we found that, for one forest rotation period, a total of 26.81 tC/ha sequestered carbon was transferred into these HWPs, 66.2% of which were still stored in the HWP when the rotation period had ended; however, the HWP carbon storage decreased to 0.25 tC/ha (only 0.9% left in the 100th year after forest plantation. The manufacturing process contributed more than 90% of the total HWP carbon footprint, but it was still smaller than the HWP carbon storage. In terms of the carbon storage and the carbon footprint, construction products had the largest net positive carbon balance compared to furniture and panel products. In addition, HWP are known to have a positive impact on global carbon mitigation because they can store parts of the sequestered carbon for a certain period of time and they have a substitution effect on carbon mitigation. Furthermore, there still exist great opportunities for carbon mitigation from HWPs through the use of cleaner energy and increasing the utilization efficiency of wood fuel.

  14. Wind farms on undegraded peatlands are unlikely to reduce future carbon emissions

    International Nuclear Information System (INIS)

    Smith, Jo; Nayak, Dali Rani; Smith, Pete

    2014-01-01

    Onshore wind energy is a key component of the renewable energies used by governments to reduce carbon emissions from electricity production, but will carbon emissions be reduced when wind farms are located on carbon-rich peatands? Wind farms are often located in uplands because most are of low agricultural value, are distant from residential areas, and are windy. Many UK uplands are peatlands, with layers of accumulated peat that represent a large stock of soil carbon. When peatlands are drained for construction there is a higher risk of net carbon loss than for mineral soils. Previous work suggests that wind farms sited on peatlands can reduce net carbon emissions if strictly managed for maximum retention of carbon. Here we show that, whereas in 2010, most sites had potential to provide net carbon savings, by 2040 most sites will not reduce carbon emissions even with careful management. This is due to projected changes in the proportion of fossil fuels used to generate electricity. The results suggest future policy should avoid constructing wind farms on undegraded peatlands unless drainage of peat is minimal and the volume excavated in foundations can be significantly reduced compared to energy output. - Highlights: • Future wind farms located on undegraded peats will not reduce carbon emissions. • This is due to projected changes in fossil fuels used to generate electricity. • Future policy should avoid constructing wind farms on undegraded peats

  15. Energy consumption and net CO2 sequestration of aqueous mineral carbonation

    International Nuclear Information System (INIS)

    Huijgen, W.J.J.; Ruijg, G.J.; Comans, R.N.J.; Witkamp, G.J.

    2006-12-01

    Aqueous mineral carbonation is a potentially attractive sequestration technology to reduce CO2 emissions. The energy consumption of this technology, however, reduces the net amount of CO2 sequestered. Therefore, the energetic CO2 sequestration efficiency of aqueous mineral carbonation was studied in dependence of various process variables using either wollastonite (CaSiO3) or steel slag as feedstock. For wollastonite, the maximum energetic CO2 sequestration efficiency within the ranges of process conditions studied was 75% at 200C, 20 bar CO2, and a particle size of <38μm. The main energy-consuming process steps were the grinding of the feedstock and the compression of the CO2 feed. At these process conditions, a significantly lower efficiency was determined for steel slag (69%), mainly because of the lower Ca content of the feedstock. The CO2 sequestration efficiency might be improved substantially for both types of feedstock by, e.g., reducing the amount of process water applied and further grinding of the feedstock. The calculated energetic efficiencies warrant a further assessment of the (energetic) feasibility of CO2 sequestration by aqueous mineral carbonation on the basis of a pilot-scale process

  16. Sequestration of Carbon in Mycorrhizal Fungi Under Nitrogen Fertilization

    Science.gov (United States)

    Treseder, K. K.; Turner, K. M.

    2005-12-01

    Mycorrhizal fungi are root symbionts that facilitate plant uptake of soil nutrients in exchange for plant carbohydrates. They grow in almost every terrestrial ecosystem on earth, form relationships with about 80% of plant species, and receive 10 to 20% of the carbon fixed by their host plants. As such, they could potentially sequester a significant amount of carbon in ecosystems. We hypothesized that nitrogen fertilization would decrease carbon storage in mycorrhizal fungi, because plants should reduce investment of carbon in mycorrhizal fungi when nitrogen availability is high. We measured the abundance of two major groups of mycorrhizal fungi, arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) fungi, in control and nitrogen-fertilized plots within three boreal ecosystems of inland Alaska. The ecosystems represented different recovery stages following severe fire, and comprised a young site dominated by AM fungi, an old site dominated by ECM fungi, and an intermediate site co-dominated by both groups. Pools of mycorrhizal carbon included root-associated AM and ECM structures, soil-associated AM hyphae, and soil-associated glomalin. Glomalin is a glycoprotein produced only by AM fungi. It is present in the cell walls of AM hyphae, and then is deposited in the soil as the hyphae senesce. Nitrogen significantly altered total mycorrhizal carbon pools, but its effect varied by site (site * N interaction, P = 0.05). Under nitrogen fertilization, mycorrhizal carbon was reduced from 99 to 50 g C m2 in the youngest site, was increased from 124 to 203 g C m2 in the intermediate-aged site, and remained at 35 g C m2 in the oldest site. The changes in total mycorrhizal carbon stocks were driven mostly by changes in glomalin (site * N interaction, P = 0.05), and glomalin stocks were strongly correlated with AM hyphal abundance (P stocks within root-associated AM structures increased significantly with nitrogen fertilization across all sites (P = 0.001), as did root

  17. Degassing of reduced carbon from planetary basalts.

    Science.gov (United States)

    Wetzel, Diane T; Rutherford, Malcolm J; Jacobsen, Steven D; Hauri, Erik H; Saal, Alberto E

    2013-05-14

    Degassing of planetary interiors through surface volcanism plays an important role in the evolution of planetary bodies and atmospheres. On Earth, carbon dioxide and water are the primary volatile species in magmas. However, little is known about the speciation and degassing of carbon in magmas formed on other planets (i.e., Moon, Mars, Mercury), where the mantle oxidation state [oxygen fugacity (fO2)] is different from that of the Earth. Using experiments on a lunar basalt composition, we confirm that carbon dissolves as carbonate at an fO2 higher than -0.55 relative to the iron wustite oxygen buffer (IW-0.55), whereas at a lower fO2, we discover that carbon is present mainly as iron pentacarbonyl and in smaller amounts as methane in the melt. The transition of carbon speciation in mantle-derived melts at fO2 less than IW-0.55 is associated with a decrease in carbon solubility by a factor of 2. Thus, the fO2 controls carbon speciation and solubility in mantle-derived melts even more than previous data indicate, and the degassing of reduced carbon from Fe-rich basalts on planetary bodies would produce methane-bearing, CO-rich early atmospheres with a strong greenhouse potential.

  18. Evaluation of Southern Quebec asbestos residues for CO2 sequestration by mineral carbonation

    Energy Technology Data Exchange (ETDEWEB)

    Beaudoin, G.; Hebert, R.; Constantin, M. [Laval Univ., Quebec City, PQ (Canada); Bonin, G. [LAB Chrysotile Inc., Black Lake, PQ (Canada); Dipple, G. [British Columbia Univ., Vancouver, BC (Canada)

    2003-08-01

    One alternative to help reduce carbon dioxide (CO{sub 2}) levels in the atmosphere is to sequester CO{sub 2} by mineral carbonation using ultramafic rock-hosted magnesian silicates (serpentine, olivine, talc). The carbonation process produces magnesite, which is a geologically stable and an environmentally safe magnesium carbonate. Three CO{sub 2} sinks exist in southern Quebec use such silicates. They are: (1) asbestos mill residues, (2) associated mine waste, and (3) ultramafic bedrock. Extraction of asbestos in the region has been accomplished from serpentinized harzburgite located in the Thetford Mines and Asbestos ophiolitic massifs and also from the highly sheared Pennington Sheet. The physical and chemical properties of magnesium silicate deposits greatly determine their carbonation potential. A wide range of properties was observed in samples obtained from almost all asbestos mill residues and waste. The reaction which takes place depends on the mineral content. The kinetics of the reactions are influenced by humidity and grain size.

  19. Pseudomonas putida growing at low temperature shows increased levels of CrcZ and CrcY sRNAs, leading to reduced Crc-dependent catabolite repression.

    Science.gov (United States)

    Fonseca, Pilar; Moreno, Renata; Rojo, Fernando

    2013-01-01

    The Crc protein of Pseudomonas inhibits the expression of genes involved in the transport and assimilation of a number of non-preferred carbon sources when preferred substrates are available, thus coordinating carbon metabolism. Crc acts by binding to target mRNAs, inhibiting their translation. In Pseudomonas putida, the amount of free Crc available is controlled by two sRNAs, CrcY and CrcZ, which bind to and sequester Crc. The levels of these sRNAs vary according to metabolic conditions. Pseudomonas putida grows optimally at 30°C, but can also thrive at 10°C. The present work shows that when cells grow exponentially at 10°C, the repressive effect of Crc on many genes is significantly reduced compared with that seen at 30°C. Total Crc levels were similar at both temperatures, but those of CrcZ and CrcY were significantly higher at 10°C. Therefore, Crc-mediated repression may, at least in part, be reduced at 10°C because the fraction of Crc protein sequestered by CrcZ and CrcY is larger, reducing the amount of free Crc available to bind its targets. This may help P. putida to face cold stress. The results reported might help understanding the behaviour of this bacterium in bioremediation or rhizoremediation strategies at low temperatures. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  20. Carbono secuestrado en ecosistemas agropecuarios cubanos y su valoración económica.: Estudio de caso Carbon sequestered in Cuban livestock production ecosystems and its economic assessment.: Case study

    Directory of Open Access Journals (Sweden)

    Taymer Miranda

    2007-11-01

    Full Text Available Los sistemas agroforestales representan importantes sumideros de carbono; sin embargo, en Cuba no han sido considerados en este sentido debido fundamentalmente a la ausencia de información cuantificada sobre su potencialidad de almacenamiento y fijación. La presente investigación muestra los resultados comparativos de una finca con un pastizal natural y otra convertida en un sistema agroforestal, con 11 años de explotación. El carbono almacenado por el sistema silvopastoril fue mayor que el secuestrado en el sistema de pasto natural. El carbono forestal y el retenido en los pastos y en el suelo alcanzó valores de 64, 38 y 24 t/ha, respectivamente. El sistema silvopatoril secuestró126 t de carbono, a diferencia del sistema de pasto natural que solo alcanzó 32 t/ha en el año de evaluación. El sistema agroforestal superó sustancialmente al sistema de pasto natural, por su alta contribución ambiental y económica, cuyo valor se aproximó a los 1 300 dólares (USD por año. Esta valoración económica es un elemento fundamental para lograr una utilización sostenible del ecosistema y, aunque no constituye el instrumento a tener presente para todas las decisiones, representa uno de los aspectos que intervienen en el proceso decisorio, junto con otras importantes consideraciones políticas, sociales y culturales. Los resultados confirman que los sistemas agroforestales son una alternativa para el desarrollo sostenible de los sistemas en el sector agropecuario.Agroforestry systems represent important carbon sinks; nevertheless, in Cuba they have not been considered in that sense due, mainly, to the absence of quantified information about their storage and fixation potential. This study shows the comparative results of a farm with a natural pasture and another turned into an agroforestry system with 11 years of exploitation. The carbon stored by the silvopastoral system was higher than that sequestered in the system of natural pasture. The

  1. An Optimal Centralized Carbon Dioxide Repository for Florida, USA

    Directory of Open Access Journals (Sweden)

    Brandon Poiencot

    2011-03-01

    Full Text Available For over a decade, the United States Department of Energy, and engineers, geologists, and scientists from all over the world have investigated the potential for reducing atmospheric carbon emissions through carbon sequestration. Numerous reports exist analyzing the potential for sequestering carbon dioxide at various sites around the globe, but none have identified the potential for a statewide system in Florida, USA. In 2005, 83% of Florida’s electrical energy was produced by natural gas, coal, or oil (e.g., fossil fuels, from power plants spread across the state. In addition, only limited research has been completed on evaluating optimal pipeline transportation networks to centralized carbon dioxide repositories. This paper describes the feasibility and preliminary locations for an optimal centralized Florida-wide carbon sequestration repository. Linear programming optimization modeling is used to plan and route an idealized pipeline network to existing Florida power plants. Further analysis of the subsurface geology in these general locations will provide insight into the suitability of the subsurface conditions and the available capacity for carbon sequestration at selected possible repository sites. The identification of the most favorable site(s is also presented.

  2. Terrestrial Carbon Sequestration in National Parks: Values for the Conterminous United States

    Science.gov (United States)

    Richardson, Leslie A.; Huber, Christopher; Zhu, Zhi-Liang; Koontz, Lynne

    2015-01-01

    Lands managed by the National Park Service (NPS) provide a wide range of beneficial services to the American public. This study quantifies the ecosystem service value of carbon sequestration in terrestrial ecosystems within NPS units in the conterminous United States for which data were available. Combining annual net carbon balance data with spatially explicit NPS land unit boundaries and social cost of carbon estimates, this study calculates the net metric tons of carbon dioxide sequestered annually by park unit under baseline conditions, as well as the associated economic value to society. Results show that, in aggregate, NPS lands in the conterminous United States are a net carbon sink, sequestering more than 14.8 million metric tons of carbon dioxide annually. The associated societal value of this service is estimated at approximately $582.5 million per year. While this analysis provides a broad overview of the annual value of carbon sequestration on NPS lands averaged over a five year baseline period, it should be noted that carbon fluxes fluctuate from year to year, and there can be considerable variation in net carbon balance and its associated value within a given park unit. Future research could look in-depth at the spatial heterogeneity of carbon flux within specific NPS land units.

  3. Effects of nutrient ratios and carbon dioxide bio-sequestration on biomass growth of Chlorella sp. in bubble column photobioreactor.

    Science.gov (United States)

    Vo, Hoang-Nhat-Phong; Bui, Xuan-Thanh; Nguyen, Thanh-Tin; Nguyen, Dinh Duc; Dao, Thanh-Son; Cao, Ngoc-Dan-Thanh; Vo, Thi-Kim-Quyen

    2018-08-01

    Photobioreactor technology, especially bubble column configuration, employing microalgae cultivation (e.g., Chlorella sp.), is an ideal man-made environment to achieve sufficient microalgae biomass through its strictly operational control. Nutrients, typically N and P, are necessary elements in the cultivation process, which determine biomass yield and productivity. Specifically, N:P ratios have certain effects on microalgae's biomass growth. It is also attractive that microalgae can sequester CO 2 by using that carbon source for photosynthesis and, subsequently, reducing CO 2 emission. Therefore, this study aims to investigate the effect of N:P ratios on Chlorella sp.'s growth, and to study the dynamic of CO 2 fixation in the bubble column photobioreactor. According to our results, N:P ratio of 15:1 could produce the highest biomass yield (3568 ± 158 mg L -1 ). The maximum algae concentration was 105 × 10 6  cells mL -1 , receiving after 92 h. Chlorella sp. was also able to sequester CO 2 at 28 ± 1.2%, while the specific growth rate and carbon fixation rate were observed at 0.064 h -1 and 68.9 ± 1.91 mg L -1  h -1 , respectively. The types of carbon sources (e.g., organic and inorganic carbon) possessed potential impact on microalgae's cultivation. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. The fate of the tropical forest. Carbon or cattle?

    International Nuclear Information System (INIS)

    Coomes, Oliver T.; Grimard, Franque; Potvin, Catherin; Sima, Philip

    2008-01-01

    Small-scale afforestation/reforestation projects under the Clean Development Mechanism (CDM) of the Kyoto Protocol will sequester atmospheric carbon and facilitate carbon trading but they face significant implementation challenges among the rural poor households and communities that are meant to adopt and benefit from them. Avoiding deforestation - a controversial carbon reduction option now under climate policy discussion - shows promise though for both forest conservation and poverty alleviation among indigenous forest peoples. (author)

  5. Carbon changes in conterminous US forests associated with growth and major disturbances: 1992-2001

    International Nuclear Information System (INIS)

    Zheng Daolan; Ducey, Mark J; Heath, Linda S; Smith, James E

    2011-01-01

    We estimated forest area and carbon changes in the conterminous United States using a remote sensing based land cover change map, forest fire data from the Monitoring Trends in Burn Severity program, and forest growth and harvest data from the USDA Forest Service, Forest Inventory and Analysis Program. Natural and human-associated disturbances reduced the forest ecosystems' carbon sink by 36% from 1992 to 2001, compared to that without disturbances in the 48 states. Among the three identified disturbances, forest-related land cover change contributed 33% of the total effect in reducing the forest carbon potential sink, while harvests and fires accounted for 63% and 4% of the total effect, respectively. The nation's forests sequestered 1.6 ± 0.1 Pg (10 15 petagram) carbon during the period, or 0.18 Pg C yr -1 , with substantial regional variation. The southern region of the United States was a small net carbon source whereas the greater Pacific Northwest region was a strong net sink. Results of the approach fit reasonably well at an aggregate level with other related estimates of the current forest US greenhouse gas inventory, suggesting that further research using this approach is warranted.

  6. Chemiluminescence behavior of the carbon dots and the reduced state carbon dots

    Energy Technology Data Exchange (ETDEWEB)

    Teng, Ping [Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Xie, Jianxin [College of Resources and Environment, Yuxi Normal University, Yuxi, Yunnan 653100 (China); Long, Yijuan; Huang, Xiaoxiao; Zhu, Rui; Wang, Xiliang; Liang, Liping [Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Huang, Yuming, E-mail: ymhuang@swu.edu.cn [Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Zheng, Huzhi, E-mail: zhenghz@swu.edu.cn [Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China)

    2014-02-15

    Potassium permanganate (KMnO{sub 4}) can react with two different carbon nanoparticles, i.e., carbon dots (CDs) and reduced state carbon dots (r-CDs), in a strong acid medium to generate chemiluminescence (CL). Furthermore, the different CL intensities and CL behaviors due to the different surface groups on these two kinds of carbon nanoparticles were confirmed. CL spectra, fluorescence spectra, UV–vis absorption spectra, and electron paramagnanetic resonance spectra were applied to investigate the CL mechanism. The main reaction pathways were proposed as follows: for the CL reaction between CDs and KMnO{sub 4}, the excited states of CDs (CDs{sup ⁎}) and Mn(II) (Mn(II){sup ⁎}) emerged as KMnO{sub 4} could inject holes into CDs, then, the CDs{sup ⁎} and Mn(II){sup ⁎} acted as luminophors to yield CL; in the r-CDs-KMnO{sub 4} system, r-CDs were oxidized by KMnO{sub 4} directly, and CDs{sup ⁎} and Mn(II){sup ⁎} were produced, at the same time, CL occurred. What is more interesting is that the CL intensity of the r-CD system is stronger than that of the CD system, which confirms that functional groups have strong effect on the CL behavior. It inspired us that new carbon nanoparticles with excellent luminous performance can be designed by tuning their surface groups. -- Highlights: • Carbon dots (CDs) and reduced state carbon dots (r-CDs) can react with potassium permanganate (KMnO{sub 4}) in a strong acid to generate chemiluminescence (CL). • With different surface groups, the CL intensity of r-CDs-KMnO{sub 4} system is different from that of CDs-KMnO{sub 4} system. • The CL mechanisms of the two systems were investigated.

  7. Impact of elevated CO_2 concentrations on carbonate mineral precipitation ability of sulfate-reducing bacteria and implications for CO_2 sequestration

    International Nuclear Information System (INIS)

    Paul, Varun G.; Wronkiewicz, David J.; Mormile, Melanie R.

    2017-01-01

    Interest in anthropogenic CO_2 release and associated global climatic change has prompted numerous laboratory-scale and commercial efforts focused on capturing, sequestering or utilizing CO_2 in the subsurface. Known carbonate mineral precipitating microorganisms, such as the anaerobic sulfate-reducing bacteria (SRB), could enhance the rate of conversion of CO_2 into solid minerals and thereby improve long-term storage of captured gasses. The ability of SRB to induce carbonate mineral precipitation, when exposed to atmospheric and elevated pCO_2, was investigated in laboratory scale tests with bacteria from organic-rich sediments collected from hypersaline Lake Estancia, New Mexico. The enriched SRB culture was inoculated in continuous gas flow and batch reactors under variable headspace pCO_2 (0.0059 psi to 20 psi). Solution pH, redox conditions, sulfide, calcium and magnesium concentrations were monitored in the reactors. Those reactors containing SRB that were exposed to pCO_2 of 14.7 psi or less showed Mg-calcite precipitation. Reactors exposed to 20 psi pCO_2 did not exhibit any carbonate mineralization, likely due to the inhibition of bacterial metabolism caused by the high levels of CO_2. Hydrogen, lactate and formate served as suitable electron donors for the SRB metabolism and related carbonate mineralization. Carbon isotopic studies confirmed that ∼53% of carbon in the precipitated carbonate minerals was derived from the CO_2 headspace, with the remaining carbon being derived from the organic electron donors, and the bicarbonate ions available in the liquid medium. The ability of halotolerant SRB to induce the precipitation of carbonate minerals can potentially be applied to the long-term storage of anthropogenic CO_2 in saline aquifers and other ideal subsurface rock units by converting the gas into solid immobile phases. - Highlights: • SRB under study are capable of precipitating calcite up to 14.7 psi pCO_2. • At 20 psi pCO_2, bacterial activity

  8. CARBON SEQUESTRATION IN PASTURES WITH TREES, TREELESS PASTURES AND DECIDUOUS FOREST FROM HUATUSCO, VERACRUZ

    Directory of Open Access Journals (Sweden)

    José Antonio Torres-Rivera

    2011-11-01

    Full Text Available It was compared the amount of carbon (C sequestered in a pasture with trees (P+Ar and in conventional treeless pastures (P and deciduous forest (BC, typical of the region of Huatusco, Veracruz, Mexico. Total C sequestered by the systems evaluated was 49.9, 63.0 and 469.8 ton ha-1 for P, P+Ar and BC, respectively. The system with the highest amount of C sequestered was BC, with almost equal proportions in the aerial (268.4 ton ha-1 and belowground parts (201.4 ton ha-1. The amount of C sequestered in the livestock systems represented about one tenth of that sequestered in BC, being higher the proportion obtained in P+Ar (13.4 % compared to P (10.6 %. In both livestock systems, a significantly greater amount of C was sequestered in the soil organic matter than in the aerial biomass, with 59.7 and 3.29 ton ha-1 in P+Ar, and with 48.2 and 1.78 ton ha-1 in P, respectively. It is expected that as trees of the P+Ar system gain volume, C sequestration will increase, especially in the aerial biomass.

  9. Assessment of policy impacts on carbon capture and sequestration and bioenergy for U.S.' coal and natural gas power plants

    Science.gov (United States)

    Spokas, K.; Patrizio, P.; Leduc, S.; Mesfun, S.; Kraxner, F.

    2017-12-01

    Reducing electricity-sector emissions relies heavily on countries' abilities to either transition away from carbon-intensive energy generation or to sequester its resultant emissions with carbon capture and storage (CCS) technologies. The use of biomass energy technologies in conjunction with carbon capture and sequestration (BECCS) presents the opportunity for net reductions in atmospheric carbon dioxide. In this study, we investigate the limitations of several common policy mechanisms to incentivize the deployment of BECCS using the techno-economic spatial optimization model BeWhere (www.iiasa.ac.at/bewhere). We consider a set of coal and natural gas power plants in the United States (U.S.) selected using a screening process that considers capacity, boiler age, and capacity factor for electricity-generation units from the EPA 2014 eGRID database. The set makes up 470 GW of generation, and produces 8,400 PJ and 2.07 GtCO2 annually. Co-firing up to 15% for coal power plants is considered, using woody-biomass residues sourced from certified and managed U.S. forests obtained from the G4M (www.iiasa.ac.at/g4m) and GeoWiki (www.geo-wiki.org) database. Geologic storage is considered with injectivity and geomechanical limitations to ensure safe storage. Costs are minimized under two policy mechanisms: a carbon tax and geologic carbon sequestration credits, such as the Q45 credits. Results show that the carbon tax scenario incentivizes co-firing at low to medium carbon taxes, but is replaced by CCS at higher tax values. Carbon taxes do not strongly incentivize BECCS, as negative emissions associated with sequestering carbon content are not accounted as revenue. On the other hand, carbon credit scenarios result in significant CCS deployment, but lack any incentive for co-firing.

  10. Forest carbon sink: A potential forest investment

    Science.gov (United States)

    Zheng, Chaocheng; Zhang, Yi; Cheng, Dongxiang

    2017-01-01

    A major problem being confronted to our human society currently is that the global temperature is undoubtedly considered to be rising significantly year by year due to abundant human factors releasing carbon dioxide to around atmosphere. The problem of increasing atmospheric carbon dioxide can be addressed in a number of ways. One of these is forestry and forest management. Hence, this paper investigates a number of current issues related to mitigating the global warming problem from the point of forestry view previous to discussion on ongoing real-world activities utilizing forestry specifically to sequester carbon.

  11. A synthesis of the science on forests and carbon for U.S. Forests

    Science.gov (United States)

    Michael G. Ryan; Mark E. Harmon; Richard A. Birdsey; Christian P. Giardina; Linda S. Heath; Richard A. Houghton; Robert B. Jackson; Duncan C. McKinley; James F. Morrison; Brian C. Murray; Diane E. Pataki; Kenneth E. Skog

    2010-01-01

    Forests play an important role in the U.S. and global carbon cycle, and carbon sequestered by U.S. forest growth and harvested wood products currently offsets 12-19% of U.S. fossil fuel emissions. The cycle of forest growth, death, and regeneration and the use of wood removed from the forest complicate efforts to understand and measure forest carbon pools and flows....

  12. Field windbreaks for bioenergy production and carbon sequestration

    Science.gov (United States)

    Tree windbreaks are a multi-benefit land use with the ability to mitigate climate change by modifying the local microclimate for improved crop growth and sequestering carbon in soil and biomass. Agroforestry practices are also being considered for bioenergy production by direct combustion or produci...

  13. The provenance, formation, and implications of reduced carbon phases in Martian meteorites

    Science.gov (United States)

    Steele, Andrew; McCubbin, Francis M.; Fries, Marc D.

    2016-11-01

    This review is intended to summarize the current observations of reduced carbon in Martian meteorites, differentiating between terrestrial contamination and carbon that is indigenous to Mars. Indeed, the identification of Martian organic matter is among the highest priority targets for robotic spacecraft missions in the next decade, including the Mars Science Laboratory and Mars 2020. Organic carbon compounds are essential building blocks of terrestrial life, so the occurrence and origin (biotic or abiotic) of organic compounds on Mars is of great significance; however, not all forms of reduced carbon are conducive to biological systems. This paper discusses the significance of reduced organic carbon (including methane) in Martian geological and astrobiological systems. Specifically, it summarizes current thinking on the nature, sources, and sinks of Martian organic carbon, a key component to Martian habitability. Based on this compilation, reduced organic carbon on Mars, including detections of methane in the Martian atmosphere, is best described through a combination of abiotic organic synthesis on Mars and infall of extraterrestrial carbonaceous material. Although conclusive signs of Martian life have yet to be revealed, we have developed a strategy for life detection on Mars that can be utilized in future life-detection studies.

  14. Synthesis of reduced carbon nitride at the reduction by hydroquinone of water-soluble carbon nitride oxide (g-C{sub 3}N{sub 4})O

    Energy Technology Data Exchange (ETDEWEB)

    Kharlamov, Alexey [Frantsevich Institute for Problems of Materials Science of NASU, Krzhyzhanovsky St. 3, 03680 Kiev (Ukraine); Bondarenko, Marina, E-mail: mebondarenko@ukr.net [Frantsevich Institute for Problems of Materials Science of NASU, Krzhyzhanovsky St. 3, 03680 Kiev (Ukraine); Kharlamova, Ganna [Taras Shevchenko National University of Kiev, Volodymyrs' ka St. 64, 01601 Kiev (Ukraine); Fomenko, Veniamin [Frantsevich Institute for Problems of Materials Science of NASU, Krzhyzhanovsky St. 3, 03680 Kiev (Ukraine)

    2016-09-15

    For the first time at the reduction by hydroquinone of water-soluble carbon nitride oxide (g-C{sub 3}N{sub 4})O reduced carbon nitride (or reduced multi-layer azagraphene) is obtained. It is differed from usually synthesized carbon nitride by a significantly large (on 0.09 nm) interplanar distance is. At the same time, the chemical bonds between atoms in a heteroatomic plane of reduced carbon nitride correspond to the bonds in a synthesized g-C{sub 3}N{sub 4}. The samples of water-soluble carbon nitride oxide were synthesized under the special reactionary conditions of a pyrolysis of melamine and urea. We believe that reduced carbon nitride consists of weakly connected carbon-nitrogen monosheets (azagraphene sheets) as well as reduced (from graphene oxide) graphene contains weakly connected graphene sheets. - Graphical abstract: XRD pattern and schematic atomic model of one layer of reduced carbon nitride, carbon nitride oxide and synthesized carbon nitride. For the first time at the reduction by hydroquinone of the water-soluble carbon nitride oxide (g-C{sub 3}N{sub 4})O is obtained the reduced carbon nitride (or reduced multi-layer azagraphene). Display Omitted - Highlights: • First the reduced carbon nitride (RCN) at the reduction of the carbon nitride oxide was obtained. • Water-soluble carbon nitride oxide was reduced by hydroquinone. • The chemical bonds in a heteroatomic plane of RCN correspond to the bonds in a synthesized g-C{sub 3}N{sub 4}. • Reduced carbon nitride consists of poorly connected heteroatomic azagraphene layers.

  15. Potential biodiversity benefits from international programs to reduce carbon emissions from deforestation.

    Science.gov (United States)

    Siikamäki, Juha; Newbold, Stephen C

    2012-01-01

    Deforestation is the second largest anthropogenic source of carbon dioxide emissions and options for its reduction are integral to climate policy. In addition to providing potentially low cost and near-term options for reducing global carbon emissions, reducing deforestation also could support biodiversity conservation. However, current understanding of the potential benefits to biodiversity from forest carbon offset programs is limited. We compile spatial data on global forest carbon, biodiversity, deforestation rates, and the opportunity cost of land to examine biodiversity conservation benefits from an international program to reduce carbon emissions from deforestation. Our results indicate limited geographic overlap between the least-cost areas for retaining forest carbon and protecting biodiversity. Therefore, carbon-focused policies will likely generate substantially lower benefits to biodiversity than a more biodiversity-focused policy could achieve. These results highlight the need to systematically consider co-benefits, such as biodiversity in the design and implementation of forest conservation programs to support international climate policy.

  16. Using CaO- and MgO-rich industrial waste streams for carbon sequestration

    International Nuclear Information System (INIS)

    Stolaroff, Joshuah K.; Lowry, Gregory V.; Keith, David W.

    2005-01-01

    To prevent rapid climate change, it will be necessary to reduce net anthropogenic CO 2 emissions drastically. This likely will require imposition of a tax or tradable permit scheme that creates a subsidy for negative emissions. Here, we examine possible niche markets in the cement and steel industries where it is possible to generate a limited supply of negative emissions (carbon storage or sequestration) cost-effectively. Ca(OH) 2 and CaO from steel slag or concrete waste can be dissolved in water and reacted with CO 2 in ambient air to capture and store carbon safely and permanently in the form of stable carbonate minerals (CaCO 3 ). The kinetics of Ca dissolution for various particle size fractions of ground steel slag and concrete were measured in batch experiments. The majority of available Ca was found to dissolve on a time scale of hours, which was taken to be sufficiently fast for use in an industrial process. An overview of the management options for steel slag and concrete waste is presented, which indicates how their use for carbon sequestration might be integrated into existing industrial processes. Use of the materials in a carbon sequestration scheme does not preclude subsequent use and is likely to add value by removing the undesirable qualities of water absorption and expansion from the products. Finally, an example scheme is presented which could be built and operated with current technology to sequester CO 2 with steel slag or concrete waste. Numerical models and simple calculations are used to establish the feasibility and estimate the operating parameters of the scheme. The operating cost is estimated to be US$8/t-CO 2 sequestered. The scheme would be important as an early application of technology for capturing CO 2 directly from ambient air

  17. Limits on carbon sequestration in arid blue carbon ecosystems.

    Science.gov (United States)

    Schile, Lisa M; Kauffman, J Boone; Crooks, Stephen; Fourqurean, James W; Glavan, Jane; Megonigal, J Patrick

    2017-04-01

    Coastal ecosystems produce and sequester significant amounts of carbon ("blue carbon"), which has been well documented in humid and semi-humid regions of temperate and tropical climates but less so in arid regions where mangroves, marshes, and seagrasses exist near the limit of their tolerance for extreme temperature and salinity. To better understand these unique systems, we measured whole-ecosystem carbon stocks in 58 sites across the United Arab Emirates (UAE) in natural and planted mangroves, salt marshes, seagrass beds, microbial mats, and coastal sabkha (inter- and supratidal unvegetated salt flats). Natural mangroves held significantly more carbon in above- and belowground biomass than other vegetated ecosystems. Planted mangrove carbon stocks increased with age, but there were large differences for sites of similar age. Soil carbon varied widely across sites (2-367 Mg C/ha), with ecosystem averages that ranged from 49 to 156 Mg C/ha. For the first time, microbial mats were documented to contain soil carbon pools comparable to vascular plant-dominated ecosystems, and could arguably be recognized as a unique blue carbon ecosystem. Total ecosystem carbon stocks ranged widely from 2 to 515 Mg C/ha (seagrass bed and mangrove, respectively). Seagrass beds had the lowest carbon stock per unit area, but the largest stock per total area due to their large spatial coverage. Compared to similar ecosystems globally, mangroves and marshes in the UAE have lower plant and soil carbon stocks; however, the difference in soil stocks is far larger than with plant stocks. This incongruent difference between stocks is likely due to poor carbon preservation under conditions of weakly reduced soils (200-350 mV), coarse-grained sediments, and active shoreline migration. This work represents the first attempt to produce a country-wide coastal ecosystem carbon accounting using a uniform sampling protocol, and was motivated by specific policy goals identified by the Abu Dhabi Global

  18. Cumulative emission budgets and their implications: the case for SAFE carbon

    Science.gov (United States)

    Allen, Myles; Bowerman, Niel; Frame, David; Mason, Charles

    2010-05-01

    The risk of dangerous long-term climate change due to anthropogenic carbon dioxide emissions is predominantly determined by cumulative emissions over all time, not the rate of emission in any given year or commitment period. This has profound implications for climate mitigation policy: emission targets for specific years such as 2020 or 2050 provide no guarantee of meeting any overall cumulative emission budget. By focusing attention on short-term measures to reduce the flow of emissions, they may even exacerbate the overall long-term stock. Here we consider how climate policies might be designed explicitly to limit cumulative emissions to, for example, one trillion tonnes of carbon, a figure that has been estimated to give a most likely warming of two degrees above pre-industrial, with a likely range of 1.6-2.6 degrees. Three approaches are considered: tradable emission permits with the possibility of indefinite emission banking, carbon taxes explicitly linked to cumulative emissions and mandatory carbon sequestration. Framing mitigation policy around cumulative targets alleviates the apparent tension between climate protection and short-term consumption that bedevils any attempt to forge global agreement. We argue that the simplest and hence potentially the most effective approach might be a mandatory requirement on the fossil fuel industry to ensure that a steadily increasing fraction of fossil carbon extracted from the ground is artificially removed from the active carbon cycle through some form of sequestration. We define Sequestered Adequate Fraction of Extracted (SAFE) carbon as a source in which this sequestered fraction is anchored to cumulative emissions, increasing smoothly to reach 100% before we release the trillionth tonne. While adopting the use of SAFE carbon would increase the cost of fossil energy much as a system of emission permits or carbon taxes would, it could do so with much less explicit government intervention. We contrast this proposal

  19. Carbon Capture and Water Emissions Treatment System (CCWESTRS) at Fossil-Fueled Electric Generating Plants

    Energy Technology Data Exchange (ETDEWEB)

    P. Alan Mays; Bert R. Bock; Gregory A. Brodie; L. Suzanne Fisher; J. Devereux Joslin; Donald L. Kachelman; Jimmy J. Maddox; N. S. Nicholas; Larry E. Shelton; Nick Taylor; Mark H. Wolfe; Dennis H. Yankee; John Goodrich-Mahoney

    2005-08-30

    The Tennessee Valley Authority (TVA), the Electric Power Research Institute (EPRI), and the Department of Energy-National Energy Technologies Laboratory (DOE-NETL) are evaluating and demonstrating integration of terrestrial carbon sequestration techniques at a coal-fired electric power plant through the use of Flue Gas Desulfurization (FGD) system gypsum as a soil amendment and mulch, and coal fly ash pond process water for periodic irrigation. From January to March 2002, the Project Team initiated the construction of a 40 ha Carbon Capture and Water Emissions Treatment System (CCWESTRS) near TVA's Paradise Fossil Plant on marginally reclaimed surface coal mine lands in Kentucky. The CCWESTRS is growing commercial grade trees and cover crops and is expected to sequester 1.5-2.0 MT/ha carbon per year over a 20-year period. The concept could be used to meet a portion of the timber industry's needs while simultaneously sequestering carbon in lands which would otherwise remain non-productive. The CCWESTRS includes a constructed wetland to enhance the ability to sequester carbon and to remove any nutrients and metals present in the coal fly ash process water runoff. The CCWESTRS project is a cooperative effort between TVA, EPRI, and DOE-NETL, with a total budget of $1,574,000. The proposed demonstration project began in October 2000 and has continued through December 2005. Additional funding is being sought in order to extend the project. The primary goal of the project is to determine if integrating power plant processes with carbon sequestration techniques will enhance carbon sequestration cost-effectively. This goal is consistent with DOE objectives to provide economically competitive and environmentally safe options to offset projected growth in U.S. baseline emissions of greenhouse gases after 2010, achieve the long-term goal of $10/ton of avoided net costs for carbon sequestration, and provide half of the required reductions in global greenhouse gases by

  20. Elution of Uranium and Transition Metals from Amidoxime-Based Polymer Adsorbents for Sequestering Uranium from Seawater

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Horng-Bin; Kuo, Li-Jung; Wai, Chien M.; Miyamoto, Naomi; Joshi, Ruma; Wood, Jordana R.; Strivens, Jonathan E.; Janke, Christopher J.; Oyola, Yatsandra; Das, Sadananda; Mayes, Richard T.; Gill, Gary A.

    2015-11-30

    High-surface-area amidoxime and carboxylic acid grafted polymer adsorbents developed at Oak Ridge National Laboratory were tested for sequestering uranium in a flowing seawater flume system at the PNNL-Marine Sciences Laboratory. FTIR spectra indicate that a KOH conditioning process is necessary to remove the proton from the carboxylic acid and make the sorbent effective for sequestering uranium from seawater. The alkaline conditioning process also converts the amidoxime groups to carboxylate groups in the adsorbent. Both Na2CO3-H2O2 and hydrochloric acid elution methods can remove ~95% of the uranium sequestered by the adsorbent after 42 days of exposure in real seawater. The Na2CO3-H2O2 elution method is more selective for uranium than conventional acid elution. Iron and vanadium are the two major transition metals competing with uranium for adsorption to the amidoxime-based adsorbents in real seawater.

  1. Social and cultural influences on management for carbon sequestration on US family forestlands: a literature synthesis

    Science.gov (United States)

    A. Paige Fischer; Susan. Charnley

    2010-01-01

    Nonindustrial private—or "family"—forests hold great potential for sequestering carbon and have received much attention in discussions about forestry-based climate change mitigation. However, little is known about social and cultural influences on owners' willingness to manage for carbon and respond to policies designed to encourage carbon-oriented...

  2. RISING ATMOSPHERIC CO2 AND CARBON SEQUESTRATION IN FORESTS

    Science.gov (United States)

    Rising CO2 concentrations in the Earth's atmosphere could alter Earth's climate system, but it is thought that higher concentrations may improve plant growth by way of the fertilization effect. Forests, an important part of the Earth's carbon cycle, are postulated to sequester a...

  3. The 'Risk' of Implementing New Regulations on Game-Changing Technology: Sequestering CO2 in the Built Environment.

    Science.gov (United States)

    Constantz, B.

    2009-05-01

    Calera's Carbon Capture and Conversion (CCC) technology with beneficial reuse has been called, "game- changing" by Carl Pope, Director of the Sierra Club. Calera offers a solution to the scale of the carbon problem. By capturing carbon into the built environment, Calera provides a sound and cost-effective alternative to Geologic Sequestration and Terrestrial Sequestration. By chemically bonding carbon dioxide into carbonate minerals, this CCC technology permanently converts CO2 into a mineral form which can be stored above- ground, on the floor of the ocean, or used as a building material. The process produces a suite of carbonate containing minerals of various polymorphic forms and crystallographic characteristics, which can be substituted into blends with portland cements to produce concretes with reduced carbon, carbon neutral, and negative carbon footprints. For each ton of product produced, approximately half a ton of carbon dioxide is sequestered using the Calera process. A number of different technologies have been proposed for trapping CO2 into a permanent mineral form. One such process utilizes flue gas from power plants, cement plants, foundries, etc. as a feedstock for production of carbonate mineral forms which can be used as cements and aggregates for making concrete. The carbonate materials produced are essentially forms of limestone, which have morphologies which allow them to glue themselves together when mixed with water, just as conventional portland cement does. The result is a cemented limestone product, which has the permanent structure and stability of the limestone, which forms 10% of the earth's crust. A significant advantage of this process is that it does not require the separation of CO2 from the flue gas, a highly cost and energy intensive step. By producing a usable product, CCC also provides an economical solution to global warming. While the cost of this process may, in some cases, exceed the selling price of the resultant materials

  4. The U.S. forest carbon accounting framework: stocks and stock change, 1990-2016

    Science.gov (United States)

    Christopher W. Woodall; John W. Coulston; Grant M. Domke; Brian F. Walters; David N. Wear; James E. Smith; Hans-Erik Andersen; Brian J. Clough; Warren B. Cohen; Douglas M. Griffith; Stephen C. Hagen; Ian S. Hanou; Michael C. Nichols; Charles H. (Hobie) Perry; Matthew B. Russell; Jim Westfall; Barry T. (Ty) Wilson

    2015-01-01

    As a signatory to the United Nations Framework Convention on Climate Change, the United States annually prepares an inventory of carbon that has been emitted and sequestered among sectors (e.g., energy, agriculture, and forests). For many years, the United States developed an inventory of forest carbon by comparing contemporary forest inventories to inventories that...

  5. Investigation of the potential of coal combustion fly ash for mineral sequestration of CO2 by accelerated carbonation

    International Nuclear Information System (INIS)

    Ukwattage, N.L.; Ranjith, P.G.; Wang, S.H.

    2013-01-01

    Mineral carbonation of alkaline waste materials is being studied extensively for its potential as a way of reducing the increased level of CO 2 in the atmosphere. Carbonation converts CO 2 into minerals which are stable over geological time scales. This process occurs naturally but slowly, and needs to be accelerated to offset the present rate of emissions from power plants and other emission sources. The present study attempts to identify the potential of coal fly ash as a source for carbon storage (sequestration) through ex-situ accelerated mineral carbonation. In the study, two operational parameters that could affect the reaction process were tested to investigate their effect on mineralization. Coal fly ash was mixed with water to different water-to-solid ratios and samples were carbonated in a pressure vessel at different initial CO 2 pressures. Temperature was kept constant at 40 °C. According to the results, one ton of Hazelwood fly ash could sequester 7.66 kg of CO 2 . The pressure of CO 2 inside the vessel has an effect on the rate of CO 2 uptake and the water-to-solid ratio affects the weight gain after the carbonation of fly ash. The results confirm the possibility of the manipulation of process parameters in enhancing the carbonation reaction. - Highlights: ► Mineral sequestration CO 2 by of coal fly ash is a slow process under ambient conditions. ► It can be accelerated by manipulating the process parameters inside a reactor. ► Initial CO 2 pressure and water to solid mixing ratio inside the reactor are two of those operational parameters. ► According to the test results higher CO 2 initial pressure gives higher on rates of CO 2 sequestration. ► Water to fly ash mixing ratio effect on amount of CO 2 sequestered into fly ash

  6. Species diversity, biomass, and carbon stock assessments of a natural mangrove forest in palawan, philippines

    International Nuclear Information System (INIS)

    Abino, A.C.; Lee, Y.J.; Castillo, J.A.A

    2014-01-01

    Philippines claims international recognition for its mangrove-rich ecosystem which play significant functions from the viewpoint of ecosystem services and climate change mitigation. In this study, we assessed the species diversity of the natural mangrove forest of Bahile, Puerto Princesa City, Palawan and evaluated its potential to sequester and store carbon. Sixteen plots with a size of 10 m * 10 m were established using quadrat sampling technique to identify, record, and measure the trees. Diversity index and allometric equations were utilized to determine species diversity, and biomass and carbon stocks. Sediment samples in undisturbed portions using a 30 cm high and 5 cm diameter corer were collected in all plots to determine near-surface sediment carbon. The diversity index (H = 0.9918) was very low having a total of five true mangrove species identified dominated by Rhizophora apiculata Bl. with an importance value index of 148.1%. Among the stands, 74% of the total biomass was attributed to the above-ground (561.2 t ha-1) while 26% was credited to the roots (196.5 t ha-1). The total carbon sequestered and stored in the above-ground and root biomass were 263.8 t C ha-1 (50%) and 92.3 t C ha-1 (17%), respectively. Sediments contained 33% (173.75 t C ha-1) of the mangrove C-stocks. Stored carbon was equivalent to 1944.5 t CO/sub 2/ ha-1. These values suggest that Bahile natural mangrove forest has a potential to sequester and store substantial amounts of atmospheric carbon, hence the need for sustainable management and protection of this important coastal ecosystem. (author)

  7. The use of Powdered Activated Carbon in reducing the Doc in water treatment plants

    International Nuclear Information System (INIS)

    Nikravesh, S. H.; Etemad-Shahidi, A.; Razeghi, N.

    2003-01-01

    Today as the technology improves and the application of energy and chemicals enhances, the organic pollutants increases in surface waters in which waste waters are discharged into. In order to reduce water-born diseases, necessary actions should be taken to decrease the pollutants. Common methods of surface water treatment are not sufficient anymore. Therefore complementary methods like using activated carbon, aeration, oxidation and reverse osmosis should be used. In this paper the use of powdered activated carbon, Total organic carbon test and jar test in reducing the concentration of organic carbons in water treatment is investigated. Initial experimental results showed large errors in total organic carbon evaluation so dissolved organic carbon was measured instead. The results showed that using the powdered activated carbon in addition to conventional treatment method using ferric chloride, greatly reduces organic pollutants. Adding about 60 mg/lit of powdered activated carbon may reduce dissolved organic carbon up to 90% in optimum conditions. However, different factors like the quality of surface water, experimental errors, instrumental errors and tool errors can influence the experimental results

  8. The research on reactivity of alternative carbon reducers

    OpenAIRE

    Łabaj, J.; Słowikowski, M.; Żymła, W.; Lipart, J.

    2013-01-01

    The research involved measuring of the speed of zinc oxide with carbon reducers. Samples weighing between 60 and 100 mg were tested with the use of thermogravimetric analysis within the range of temperatures up to 1 100 °C in nitrogen atmosphere. The speed of heating was 20 deg min-1. The research involved also reducers normally used in reduction processes. The results obtained prove that some of the alternative reducers may be used for industrial purposes.

  9. Reducing biomass recalcitrance via mild sodium carbonate pretreatment.

    Science.gov (United States)

    Mirmohamadsadeghi, Safoora; Chen, Zhu; Wan, Caixia

    2016-06-01

    This study examined the effects of mild sodium carbonate (Na2CO3) pretreatment on enzymatic hydrolysis of different feedstocks (i.e., corn stover, Miscanthus, and switchgrass). The results showed that sodium carbonate pretreatment markedly enhanced the sugar yields of the tested biomass feedstocks. The pretreated corn stover, Miscanthus, and switchgrass gave the glucose yields of 95.1%, 62.3%, and 81.3%, respectively, after enzymatic hydrolysis. The above glucose yields of pretreated feedstocks were 2-4 times that of untreated ones. The pretreatment also enhanced the xylose yields, 4 times for corn stover and 20 times for both Miscanthus and switchgrass. Sodium carbonate pretreatment removed 40-59% lignin from the tested feedstocks while preserving most of cellulose (sodium carbonate pretreatment was effective for reducing biomass recalcitrance and subsequently improving the digestibility of lignocellulosic biomass. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Forest and grassland carbon in North America: A short course for land managers

    Science.gov (United States)

    Chris Swanston; Michael J. Furniss; Kristen Schmitt; Jeffrey Guntle; Maria Janowiak; Sarah Hines

    2012-01-01

    This multimedia short-course presents a range of information on the science, management and policy of forest and grassland carbon. Forests and grasslands worldwide play a critical role in storing carbon and sequestering greenhouse gases from the atmosphere. The U.S. Forest Service, which manages 193 million acres of forests and grasslands, emphasizes the need for...

  11. SEQUESTERING AGENTS FOR ACTIVE CAPS - REMEDIATION OF METALS AND ORGANICS

    Energy Technology Data Exchange (ETDEWEB)

    Knox, A; Michael Paller, M; Danny D. Reible, D; Xingmao Ma, X; Ioana G. Petrisor, I

    2007-05-10

    This research evaluated organoclays, zeolites, phosphates, and a biopolymer as sequestering agents for inorganic and organic contaminants. Batch experiments were conducted to identify amendments and mixtures of amendments for metal and organic contaminants removal and retention. Contaminant removal was evaluated by calculating partitioning coefficients. Metal retention was evaluated by desorption studies in which residue from the removal studies was extracted with 1 M MgCl{sub 2} solution. The results indicated that phosphate amendments, some organoclays, and the biopolymer, chitosan, were very effective sequestering agents for metals in fresh and salt water. Organoclays were very effective sorbents for phenanthrene, pyrene, and benzo(a)pyrene. Partitioning coefficients for the organoclays were 3000-3500 ml g{sup -1} for benzo(a)pyrene, 400-450 ml g{sup -1} for pyrene, and 50-70 ml g{sup -1} for phenanthrene. Remediation of sites with a mixture of contaminants is more difficult than sites with a single contaminant because metals and organic contaminants have different fate and transport mechanisms in sediment and water. Mixtures of amendments (e.g., organoclay and rock phosphate) have high potential for remediating both organic and inorganic contaminants under a broad range of environmental conditions, and have promise as components in active caps for sediment remediation.

  12. An economic evaluation of carbon emission and carbon sequestration for the forestry sector in Malaysia

    International Nuclear Information System (INIS)

    Ismail, R.

    1995-01-01

    Forestry is an important sector in Malaysia. The long term development of the forestry sector will definitely affect the future amounts of carbon sequestration and emission of the country. This paper evaluates various forestry economic options that contribute to the reduction of carbon dioxide in the atmosphere. The analysis shows that, although forest plantation could sequester the highest amount of carbon per unit area, natural forests which are managed for sustainable timber production are the cheapest option for per-unit area carbon sequestrated. In evaluating forest options to address the issues of carbon sequestration and emission, the paper proposes that it should be assessed as an integral part of overall long term forestry development of the country which takes into account the future demands for forestry goods and services, financial resources, technology and human resource development. (Author)

  13. Carbon sequestration and natural longleaf pine ecosystems

    Science.gov (United States)

    Ralph S. Meldahl; John S. Kush

    2006-01-01

    A fire-maintained longleaf pine (Pinus palustris Mill.) ecosystem may offer the best option for carbon (C) sequestration among the southern pines. Longleaf is the longest living of the southern pines, and products from longleaf pine will sequester C longer than most since they are likely to be solid wood products such as structural lumber and poles....

  14. The World Banks' BioCarbon Fund

    Energy Technology Data Exchange (ETDEWEB)

    Noble, I.

    2003-03-01

    In November 2002 the World Bank launched the BioCarbon Fund, a public/private initiative to provide finance to projects that store carbon in vegetation and soils ('sinks') while helping to reverse land degradation, conserve biodiversity and improve the livelihoods of local communities. The Fund will seek projects to sequester or conserve carbon in non-Annex I countries and in countries in transition. Sinks may be the only option for poor nations with small energy to benefit from the carbon finance business. The Fund will include a portion of assets based on reductions in emissions such as substitution of biofuels for fossil fuels. The author Ian Noble of the World Bank, is chairman of the BioCarbon Fund Technical Advisory Committee.

  15. The research on reactivity of alternative carbon reducers

    Directory of Open Access Journals (Sweden)

    J. Lipart

    2013-01-01

    Full Text Available The research involved measuring of the speed of zinc oxide with carbon reducers. Samples weighing between 60 and 100 mg were tested with the use of thermogravimetric analysis within the range of temperatures up to 1 100 °C in nitrogen atmosphere. The speed of heating was 20 deg min-1. The research involved also reducers normally used in reduction processes. The results obtained prove that some of the alternative reducers may be used for industrial purposes.

  16. Rivers of Carbon: Carbon Fluxes in a Watershed Context

    Science.gov (United States)

    Wohl, E.; Tom, B.; Hovius, N.

    2017-12-01

    Research within the past decade has identified the roles of diverse terrestrial processes in mobilizing terrestrial carbon from bedrock, soil, and vegetation and in redistributing this carbon among the atmosphere, biota, geosphere, and oceans. Rivers are central to carbon redistribution, serving as the primary initial receptor of mobilized terrestrial carbon, as well as governing the proportions of carbon sequestered within sediment, transported to oceans, or released to the atmosphere. We use a riverine carbon budget to examine how key questions regarding carbon dynamics can be addressed across diverse spatial and temporal scales from sub-meter areas over a few hours on a single gravel bar to thousands of square kilometers over millions of years across an entire large river network. The portion of the budget applying to the active channel(s) takes the form of ,in which Cs is organic carbon storage over time t. Inputs are surface and subsurface fluxes from uplands (CIupl) and the floodplain (CIfp), including fossil, soil, and biospheric organic carbon; surface and subsurface fluxes of carbon dioxide to the channel (CICO2); and net primary productivity in the channel (CINPP). Outputs occur via respiration within the channel and carbon dioxide emissions (COgas) and fluxes of dissolved and particulate organic carbon to the floodplain and downstream portions of the river network (COriver). The analogous budget for the floodplain portion of a river corridor is .

  17. Forest carbon trends in the Southern United States

    Science.gov (United States)

    Robert A. Mickler; James E. Smith; Linda S. Heath

    2004-01-01

    Forest, agricultural, rangeland, wetland, and urban landscapes have different rates of carbon (C) sequestration and total C sequestration potential under alternative management options. Future changes in the proportion and spatial distribution of land use could increase or decrease the capacity of areas to sequester C in terrestrial ecosystems. As the ecosystems within...

  18. Long-term simulations of forest management impacts on carbon storage from loblolly pine plantations in the Southern U.S.

    Science.gov (United States)

    Huei-Jin Wang; Philip J. Radtke; Stephen P. Prisley

    2012-01-01

    Accounting for forest components in carbon accounting systems may be insufficient when substantial amounts of sequestered carbon are harvested and converted to wood products in use and in landfill. The potential of forest offset – in-woods aboveground carbon storage, carbon stored in harvested wood, and energy offset by burning harvested wood – from loblolly pine...

  19. Site productivity and forest carbon stocks in the United States: Analysis and implications for forest offset project planning

    Science.gov (United States)

    Coeli M. Hoover; James E. Smith

    2012-01-01

    The documented role of United States forests in sequestering carbon, the relatively low cost of forest-based mitigation, and the many co-benefits of increasing forest carbon stocks all contribute to the ongoing trend in the establishment of forest-based carbon offset projects. We present a broad analysis of forest inventory data using site quality indicators to provide...

  20. An Integrated Tool for Calculating and Reducing Institution Carbon and Nitrogen Footprints

    Science.gov (United States)

    Galloway, James N.; Castner, Elizabeth A.; Andrews, Jennifer; Leary, Neil; Aber, John D.

    2017-01-01

    Abstract The development of nitrogen footprint tools has allowed a range of entities to calculate and reduce their contribution to nitrogen pollution, but these tools represent just one aspect of environmental pollution. For example, institutions have been calculating their carbon footprints to track and manage their greenhouse gas emissions for over a decade. This article introduces an integrated tool that institutions can use to calculate, track, and manage their nitrogen and carbon footprints together. It presents the methodology for the combined tool, describes several metrics for comparing institution nitrogen and carbon footprint results, and discusses management strategies that reduce both the nitrogen and carbon footprints. The data requirements for the two tools overlap substantially, although integrating the two tools does necessitate the calculation of the carbon footprint of food. Comparison results for five institutions suggest that the institution nitrogen and carbon footprints correlate strongly, especially in the utilities and food sectors. Scenario analyses indicate benefits to both footprints from a range of utilities and food footprint reduction strategies. Integrating these two footprints into a single tool will account for a broader range of environmental impacts, reduce data entry and analysis, and promote integrated management of institutional sustainability. PMID:29350217

  1. Reduced Future Precipitation Makes Permanence of Amazonian Carbon Sinks Questionable

    Science.gov (United States)

    Arora, V.

    2011-12-01

    The tropical forests of the Amazon, considered as a tipping element in Earth's climate system, provide several ecosystem services including the maintenance of favourable regional climatic conditions in the region and storage of large amounts of carbon in their above- and below-ground pools. While it is nearly impossible, at present, to put a dollar value on these ecosystem services, the developed countries have started paying large sums of money to developing countries in the tropics to reduce deforestation. Norway recently committed up to $1 billion to the Amazon fund. The United Nations' Reducing Emissions from Deforestation and forest Degradation (REDD) program also financially supports national activities of 13 countries worldwide. The primary assumption inherent in paying for avoiding deforestation is that avoided land use change emissions contribute towards climate change mitigation. In addition, the standing forests that are spared deforestation contribute towards additional carbon sinks associated with the CO2 fertilization effect. Implicit in this reasoning is the understanding that the carbon sinks provided by avoided deforestation have some "permanence" associated with them, at least in the order of 50-100 years. Clearly, if "avoided deforestation" is essentially "delayed deforestation" then the benefits will not be long lasting. More importantly, changes in climate have the potential to adversely affect the permanence of carbon sinks, whether they are being paid for or not. This presentation will address the question of "permanence" by analyzing simulations of the second generation Canadian Earth system model (CanESM2) that are contributing results to the upcoming fifth Coupled Modeled Intercomparison Project (CMIP5). CanESM2 results for the future RCP 2.6, 4.5 and 8.5 scenarios show, that due to reduced future precipitation, the Amazonian region remains a net source of carbon over the 21st century in all scenarios. The carbon losses during the recent

  2. Aboveground tree growth varies with belowground carbon allocation in a tropical rainforest environment

    Science.gov (United States)

    J.W. Raich; D.A. Clark; L. Schwendenmann; Tana Wood

    2014-01-01

    Young secondary forests and plantations in the moist tropics often have rapid rates of biomass accumulation and thus sequester large amounts of carbon. Here, we compare results from mature forest and nearby 15–20 year old tree plantations in lowland Costa Rica to evaluate differences in allocation of carbon to aboveground production and root systems. We found that the...

  3. Forest Carbon Sequestration Subsidy and Carbon Tax as Part of China’s Forestry Policies

    Directory of Open Access Journals (Sweden)

    Jinhua Liu

    2017-02-01

    Full Text Available Forestry is an effective strategy for climate change mitigation. However, forestry activities not only sequester carbon but also release CO2. It is therefore important to formulate carbon subsidy and carbon taxation policies on the basis of the price of carbon. In this study, a forestry-based Computable General Equilibrium (CGE model was built by using input-output data of China in 2014 to construct a Social Accounting Matrix (SAM. The model simulates different carbon price scenarios and was used to explore the effects of carbon subsidy and carbon taxation policies on the forestry economy. The main results can be summarized as follows: When the carbon price is low, the implementation of the policy increases forestry output and causes forest product prices to rise. When the carbon price is high, the carbon tax will produce an inhibitory effect, and output and prices will decline. With the constant rise of the carbon price, value addition will decrease, with flow to other industries. For the carbon sequestration policy, there is a reasonable carbon price range bound. In light of these results, relevant policies are proposed.

  4. The effect of ocean acidification on carbon storage and sequestration in seagrass beds; a global and UK context.

    Science.gov (United States)

    Garrard, Samantha L; Beaumont, Nicola J

    2014-09-15

    Ocean acidification will have many negative consequences for marine organisms and ecosystems, leading to a decline in many ecosystem services provided by the marine environment. This study reviews the effect of ocean acidification (OA) on seagrasses, assessing how this may affect their capacity to sequester carbon in the future and providing an economic valuation of these changes. If ocean acidification leads to a significant increase in above- and below-ground biomass, the capacity of seagrass to sequester carbon will be significantly increased. The associated value of this increase in sequestration capacity is approximately £500 and 600 billion globally between 2010 and 2100. A proportionally similar increase in carbon sequestration value was found for the UK. This study highlights one of the few positive stories for ocean acidification and underlines that sustainable management of seagrasses is critical to avoid their continued degradation and loss of carbon sequestration capacity. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Northern Latitude Afforestation: Quantifying Trade Offs Between Carbon Sequestration and Solar Forcing

    Science.gov (United States)

    Mykleby, P.; Snyder, P. K.; Twine, T. E.

    2012-12-01

    The planting of trees and forests has long been accepted as a practical and efficient method to sequester carbon dioxide from the atmosphere. Drastic measures are now needed to ensure that atmospheric levels of carbon dioxide (CO2) do not continue to rise and cause further planetary warming. However, recent studies have identified unintended biophysical feedbacks associated with land cover changes, especially in higher northern latitudes. The changes in surface reflectivity that occur when converting a lighter, more reflective surface, such as a grassland or bare soil, into a darker conifer forest, can result in surface warming due to the forest absorbing more shortwave radiation. This warming counteracts the cooling effect resulting from a reduction in atmospheric CO2 with increased vegetation productivity. This effect is further exacerbated in the higher northern latitudes where snow cover is prevalent during the long winter; the planting of trees can significantly decrease the reflectivity compared with white snow. The goal of this study is to determine whether the amount of carbon sequestered exceeds the carbon equivalent of the radiative forcing due to the change in surface reflectivity. Factors determining the net effect of these two competing forces are the local climate, the age of the forest, the amount of fractional cover and tree spacing within the forest, and the species of the forest. Previous modeling studies have attempted to determine the magnitude of these effects, but these studies have used coarse resolution climate models and unrealistic forest structure and dynamics. This study attempts to resolve these previous inaccuracies by incorporating a higher resolution model and more accurate representation of carbon dynamics in northern latitude forests. Here we present simulation results from the IBIS model, a dynamic global vegetation model, used to simulate the potential planting of large-area tree plantations in the northern United States and

  6. An optimal control model for reducing and trading of carbon emissions

    Science.gov (United States)

    Guo, Huaying; Liang, Jin

    2016-03-01

    A stochastic optimal control model of reducing and trading for carbon emissions is established in this paper. With considerations of reducing the carbon emission growth and the price of the allowances in the market, an optimal policy is searched to have the minimum total costs to achieve the agreement of emission reduction targets. The model turns to a two-dimension HJB equation problem. By the methods of reducing dimension and Cole-Hopf transformation, a semi-closed form solution of the corresponding HJB problem under some assumptions is obtained. For more general cases, the numerical calculations, analysis and comparisons are presented.

  7. A model for estimating windbreak carbon within COMET-Farm™

    Science.gov (United States)

    Justin ​Ziegler; Mark Easter; Amy Swan; James Brandle; William Ballesteros; Grant Domke; Adam Chambers; Marlen Eve; Keith. Paustian

    2016-01-01

    Agroforestry as a land management practice presents a method for partially offsetting greenhouse gas emissions from agricultural land. Of all agroforestry practices in the United States, windbreaks in particular are used throughout the United States providing a useful starting point for deriving a modelling systemwhich could quantify the amount of carbon sequestered on...

  8. Reducing emissions from deforestation and degradation: What contribution from carbon markets?

    OpenAIRE

    Bellassen , Valentin; Crassous , R.; Dietzsch , L.; Schwartzman , S.

    2008-01-01

    Tropical deforestation is responsible for 15-20% of total man-made emissions of greenhouse gases. In December 2007, at the international conference of Bali, the United Nations acknowledged that a viable solution to climate change must include a mechanism to limit deforestation and forest degradation. Today, the most widely used economic tool to reduce emissions is carbon markets: caps on emitters, and trade allowed between emitters and reducers, drive a price signal on carbon and provide ince...

  9. Microalgal CO2 sequestering – Modeling microalgae production costs

    International Nuclear Information System (INIS)

    Bilanovic, Dragoljub; Holland, Mark; Armon, Robert

    2012-01-01

    Highlights: ► Microalgae production costs were modeled as a function of specific expenses. ► The effects of uncontrollable expenses/factors were incorporated into the model. ► Modeled microalgae production costs were in the range $102–1503 t −1 ha −1 y −1 . - Abstract: Microalgae CO 2 sequestering facilities might become an industrial reality if microalgae biomass could be produced at cost below $500.00 t −1 . We develop a model for estimation of total production costs of microalgae as a function of known production-specific expenses, and incorporate into the model the effects of uncontrollable factors which affect known production-specific expenses. Random fluctuations were intentionally incorporated into the model, consequently into generated cost/technology scenarios, because each and every logically interconnected equipment/operation that is used in design/construction/operation/maintenance of a production process is inevitably subject to random cost/price fluctuations which can neither be eliminated nor a priori controlled. A total of 152 costs/technology scenarios were evaluated to find 44 scenarios in which predicted total production costs of microalgae (PTPCM) was in the range $200–500 t −1 ha −1 y −1 . An additional 24 scenarios were found with PTCPM in the range of $102–200 t −1 ha −1 y −1 . These findings suggest that microalgae CO 2 sequestering and the production of commercial compounds from microalgal biomass can be economically viable venture even today when microalgae production technology is still far from its optimum.

  10. Impact of agroforestry plantings for bioenergy production on soil organic carbon

    Science.gov (United States)

    Tree windbreaks are an attractive multiple-benefit land use through their ability to mitigate climate change by modifying the local microclimate to improve crop growth and by sequestering carbon in the soil and tree biomass. Recently, such agroforestry practices are also being considered for their b...

  11. Sponge-like reduced graphene oxide/silicon/carbon nanotube composites for lithium ion batteries

    Science.gov (United States)

    Fang, Menglu; Wang, Zhao; Chen, Xiaojun; Guan, Shiyou

    2018-04-01

    Three-dimensional sponge-like reduced graphene oxide/silicon/carbon nanotube composites were synthesized by one-step hydrothermal self-assembly using silicon nanoparticles, graphene oxide and amino modified carbon nanotubes to develop high-performance anode materials of lithium ion batteries. Scanning electron microscopy and transmission electron microscopy images show the structure of composites that Silicon nanoparticles are coated with reduced graphene oxide while amino modified carbon nanotubes wrap around the reduced graphene oxide in the composites. When applied to lithium ion battery, these composites exhibit high initial specific capacity of 2552 mA h/g at a current density of 0.05 A/g. In addition, reduced graphene oxide/silicon/carbon nanotube composites also have better cycle stability than bare Silicon nanoparticles electrode with the specific capacity of 1215 mA h/g after 100 cycles. The three-dimension sponge-like structure not only ensures the electrical conductivity but also buffers the huge volume change, which has broad potential application in the field of battery.

  12. Monitoring the chemical nature of the carbon pool of Louisiana wetland soils undergoing erosion: carbon speciation and redox processes

    Science.gov (United States)

    Haywood, B.; Cook, R. L.; Hayes, M. P.; White, J. R.

    2017-12-01

    Wetlands account for approximately one third of all the soil carbon on the planet; however, due to erosion caused by a range of factors, including sea level rising, they are also some of the most vulnerable carbon pools. Small changes within this sequestered carbon pool can have a large impact on atmospheric CO2 levels. Thus, it is essential to understand how this sequestered carbon reacts to wetland loss in order to gain deeper insight into the global carbon cycle. In the study to be presented, Barataria Bay, Louisiana, USA is used as a model system for wetland loss. A sampling site and sampling grid has been established, and consists of three transects on and from an individual island. Each transect has five different distances ranging from 2 m inland to 8 m outland (into the water). At each of these different distances, depth profiles from 0 to 100 cm for inland samples, and 0-70 cm for submerged samples, were collected in order to identify spatial trends not only from inland to submerged, but also through the depth of the soil profile. Three types of samples were collected, namely water, pore water, and soil samples, with the latter being obtained from the combined collection of water and core samples. Samples have undergone spectroscopic characterizing including UV/Vis, fluorescence (excitation emission matrices, EEMs, and parallel factor, PARAFAC, analysis of the EEMs), nuclear magnetic resonance (NMR, solid state 13C), and electron pair resonance (EPR) spectroscopy in concert with inductively coupled plasma atomic emission spectroscopy to monitor the initial state of carbon speciation as well as redox processes. The data are used to establish a starting point on which to monitor changes within the carbon pool as the sampling site experience erosion over the next few years. The discussion will focus on the lability of different carbon pools and the potential lability-inducing mechanisms as well as the initial carbon speciation and redox state of the sampling

  13. Carbon dynamics and ecosystem diversity of Amazonian peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Laehteenoja, O.

    2011-07-01

    The overall aim was to initiate peatland research in Amazonia, which has been referred to as 'one of the large white spots on the global peatland map'. Specifically, the study was to clarify how common peat accumulation is on Amazonian floodplains, and how extensive and thick peat deposits can be encountered. Secondly, the intention was to study how rapidly Amazonian peatlands sequester carbon, and how much carbon they store and thirdly, to gain some understanding of the diversity of peatland ecosystem types and of the processes forming these ecosystems

  14. Balancing carbon sequestration and GHG emissions in a constructed wetland

    NARCIS (Netherlands)

    Klein, de J.J.M.; Werf, van der A.K.

    2014-01-01

    In many countries wetlands are constructed or restored for removing nutrients from surface water. At the same time vegetated wetlands can act as carbon sinks when CO2 is sequestered in biomass. However, it is well known that wetlands also produce substantial amounts of greenhouse gasses CH4 and N2O.

  15. Abundant and stable char residues in soils: Implications for soil fertility and carbon sequestration

    Science.gov (United States)

    Large-scale soil application of biochar might enhance soil fertility and increase crop production, while also sequestering atmospheric carbon. Reaching these outcomes requires an undertanding of the chemical structure of biochar. Using advanced solid-state 13C nuclear magnetic resonance spectroscopy...

  16. Sequester of metals and mineralization of organic contaminants with microbial mats

    International Nuclear Information System (INIS)

    Bender, J.; Phillips, P.; Gould, J.P.

    1995-01-01

    Several recalcitrant organic contaminants are completely mineralized to simple products by microbial mats. Contaminants include chlordane, PCB, TNT, petroleum distillates, BM compounds and TCE in a mixed contaminant solution containing Zn. Degradation rates are relatively rapid under both dark and light conditions. In addition to complete degradation of organic materials, mats have been used to reduce selenate to elemental selenium, remove Pb, Cd, Cu, Zn, Co, Cr, Fe and Mn from water and sequester uranium (U 238 ) at a rate of 3.19 mg/m 2 /h. Results of three pilot projects, including field pond treatment of mine drainage and bioreactor treatment of BTEX compounds will be reported. Microbial mats are natural heterotrophic and autotrophic communities dominated by cyanobacteria (blue-green algae). They are self-organized laminated structures annealed fightly together by slimy secretions from various microbial components. The surface slime of the mats effectively immobilizes the ecosystem to a variety of substrates, thereby stabilizing the most efficient internal microbial structure. Cyanobacteria mats are generated for bioremediation applications by enriching a water surface with ensiled grass clippings together with mat inocula developed in the laboratory

  17. Carbon sequestration potential of the Habanero reservoir when carbon dioxide is used as the heat exchange fluid

    Directory of Open Access Journals (Sweden)

    Chaoshui Xu

    2016-02-01

    Full Text Available The use of sequestered carbon dioxide (CO2 as the heat exchange fluid in enhanced geothermal system (EGS has significant potential to increase their productivity, contribute further to reducing carbon emissions and increase the economic viability of geothermal power generation. Coupled CO2 sequestration and geothermal energy production from hot dry rock (HDR EGS were first proposed 15 years ago but have yet to be practically implemented. This paper reviews some of the issues in assessing these systems with particular focus on the power generation and CO2 sequestration capacity. The Habanero geothermal field in the Cooper Basin of South Australia is assessed for its potential CO2 storage capacity if supercritical CO2 is used as the working fluid for heat extraction. The analysis suggests that the major CO2 sequestration mechanisms are the storage in the fracture-stimulation damaged zone followed by diffusion into the pores within the rock matrix. The assessment indicates that 5% of working fluid loss commonly suggested as the storage capacity might be an over-estimate of the long-term CO2 sequestration capacity of EGS in which supercritical CO2 is used as the circulation fluid.

  18. Examining the Efforts of a Small, Open Economy to Reduce Carbon Emissions

    DEFF Research Database (Denmark)

    Levitt, Clinton J.; Saaby Pedersen, Morten; Sørensen, Anders

    2015-01-01

    emissions by relatively small, open economies. Although, these economies are small players in international markets, international trade has an important influence on their economies. Investigating the outcome of efforts to curb emissions by these small, open economies provides insights into the situation...... faced by a large set of the world's economies. This paper has three objectives: (1) investigate the outcome of Denmark's efforts to reduce its carbon emissions by characterizing the relationship between Denmark's macroeconomic activity and carbon emissions; (2) determine the carbon content of Danish...... trade and document the important effects that growing trade with China has had on Danish consumption emissions; and (3), investigate the robustness of measures of consumption emissions under varying information requirements. Our analysis of the outcomes of Danish efforts to reduce carbon emissions...

  19. Mitigating greenhouse gas emissions: Voluntary reporting

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-10-01

    The Voluntary Reporting Program, developed pursuant to Section 1605(b) of the Energy Policy Act of 1992, permits corporations, government agencies, households, and voluntary organizations to report on their emissions of greenhouse gases, and on actions taken that have reduced or avoided emissions or sequestered carbon, to the Energy Information Administration (EIA). This, the second annual report of the Voluntary Reporting Program, describes information provided by the participating organizations on their aggregate emissions and emissions reductions, as well as their emissions reduction or avoidance projects, through 1995. This information has been compiled into a database that includes reports from 142 organizations and descriptions of 967 projects that either reduced greenhouse gas emissions or sequestered carbon. Fifty-one reporters also provided estimates of emissions, and emissions reductions achieved, for their entire organizations. The projects described actions taken to reduce emissions of carbon dioxide from energy production and use; to reduce methane and nitrous oxide emissions from energy use, waste management, and agricultural processes; to reduce emissions of halocarbons, such as CFCs and their replacements; and to increase carbon sequestration.

  20. Reducing our Carbon Footprint - an initial action plan for Northern Ireland

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-11-14

    In the Energy White Paper, Our Energy Future - Creating a low carbon economy, the UK Government accepted the Royal Commission on Environmental Pollution's (RCEP) recommendations on how the UK should address the threat of climate change. These recommendations included the early development of a concerted, coordinated and integrated strategy across all Government Departments that would put the UK economy on an early path to reducing carbon dioxide (CO{sub 2}) emissions by at least 60% by 2050. Responding to this challenge, the Carbon Trust and Invest NI sponsored a project to develop an action plan that will set Northern Ireland on the path to realising the deep reductions in carbon emissions needed to reach this target. During the project, the prospects for reducing CO{sub 2} emissions (or carbon emissions) in five key sectors of the economy were examined. The main conclusion of this work was that it was possible to realise a 60% reduction in carbon emissions by 2050, provided early action is taken to set Northern Ireland on the path to a low carbon economy. The project also prepared an initial action plan to help initiate change. This consists of: Immediate actions, including encouraging the uptake of energy efficiency measures, revising building regulations and changing public procurement procedures. Developing options for the future, by supporting the exploitation of renewable resources, modifying the regulatory scheme to support combined heat and power (CHP) and encouraging additional investment in low carbon technologies. Cross-cutting actions, including developing planning procedures that take account of sustainability, marketing campaigns to capture hearts and minds, developing a skills base in low carbon technologies and exploring more radical ways of cutting carbon emissions. (UK)

  1. Novel endotoxin-sequestering compounds with terephthalaldehyde-bis-guanylhydrazone scaffolds.

    Science.gov (United States)

    Khownium, Kriangsak; Wood, Stewart J; Miller, Kelly A; Balakrishna, Rajalakshmi; Nguyen, Thuan B; Kimbrell, Matthew R; Georg, Gunda I; David, Sunil A

    2006-03-01

    We have shown that lipopolyamines bind to the lipid A moiety of lipopolysaccharide, a constituent of Gram-negative bacterial membranes, and neutralize its toxicity in animal models of endotoxic shock. In an effort to identify non-polyamine scaffolds with similar endotoxin-recognizing features, we had observed an unusually high frequency of hits containing guanylhydrazone scaffolds in high-throughput screens. We now describe the syntheses and preliminary structure-activity relationships in a homologous series of bis-guanylhydrazone compounds decorated with hydrophobic functionalities. These first-generation compounds bind and neutralize lipopolysaccharide with a potency comparable to that of polymyxin B, a peptide antibiotic known to sequester LPS.

  2. Greenhouse gas emissions and carbon sequestration by agroforestry systems in southeastern Brazil.

    Science.gov (United States)

    Torres, Carlos Moreira Miquelino Eleto; Jacovine, Laércio Antônio Gonçalves; Nolasco de Olivera Neto, Sílvio; Fraisse, Clyde William; Soares, Carlos Pedro Boechat; de Castro Neto, Fernando; Ferreira, Lino Roberto; Zanuncio, José Cola; Lemes, Pedro Guilherme

    2017-12-01

    Agrosilvopastoral and silvopastoral systems can increase carbon sequestration, offset greenhouse gas (GHG) emissions and reduce the carbon footprint generated by animal production. The objective of this study was to estimate GHG emissions, the tree and grass aboveground biomass production and carbon storage in different agrosilvopastoral and silvopastoral systems in southeastern Brazil. The number of trees required to offset these emissions were also estimated. The GHG emissions were calculated based on pre-farm (e.g. agrochemical production, storage, and transportation), and on-farm activities (e.g. fertilization and machinery operation). Aboveground tree grass biomass and carbon storage in all systems was estimated with allometric equations. GHG emissions from the agroforestry systems ranged from 2.81 to 7.98 t CO 2 e ha -1 . Carbon storage in the aboveground trees and grass biomass were 54.6, 11.4, 25.7 and 5.9 t C ha -1 , and 3.3, 3.6, 3.8 and 3.3 t C ha -1 for systems 1, 2, 3 and 4, respectively. The number of trees necessary to offset the emissions ranged from 17 to 44 trees ha -1 , which was lower than the total planted in the systems. Agroforestry systems sequester CO 2 from the atmosphere and can help the GHG emission-reduction policy of the Brazilian government.

  3. Xerogel-Sequestered Silanated Organochalcogenide Catalysts for Bromination with Hydrogen Peroxide and Sodium Bromide

    Directory of Open Access Journals (Sweden)

    Caitlyn M. Gatley

    2015-05-01

    Full Text Available While H2O2 is a powerful oxidant, decomposing into environmentally benign H2O and O2, a catalyst is often required for reactions with H2O2 to proceed at synthetically useful rates. Organotellurium and organoselenium compounds catalyze the oxidation of halide salts to hypohalous acids using H2O2. When sequestered into xerogel monoliths, the xerogel-chalcogenide combinations have demonstrated increased catalytic activity relative to the organochalcogen compound alone in solution for the oxidation of halide salts to hypohalous acids with H2O2. Diorganotellurides, diorganoselenides, and diorganodiselenides bearing triethoxysilane functionalities were sequestered into xerogel monoliths and their catalytic activity and longevity were investigated. The longevity of the catalyst-xerogel combinations was examined by isolating and recycling the catalyst-xerogel combination. It was found tellurium-containing catalyst 3 and selenium-containing catalyst 8 maintained their catalytic activity through three recycling trials and adding electron-donating substituents to catalyst 3 also increased the catalytic rate. The presence of organotellurium and organoselenium groups in the +4 oxidation state was determined by X-ray photoelectron spectroscopy.

  4. Digital earth for manipulating urban greens towards achieving a low carbon urban society

    International Nuclear Information System (INIS)

    Tripathi, N G; Bedi, P

    2014-01-01

    Urban greens are integral components of urban ecosystem, contributing towards quality of life and sustainable urban development. Urban greens can help in creating Low Carbon Society (LCS) by playing an integral role through sequestering carbon. India is undergoing significant change in the process and pace of its urbanization. As the growing population becomes more urban, the importance of the way urban areas are developed and managed will be a central point of intervention for addressing climate change and maintaining low carbon trajectories in Indian cities

  5. Intensive management modifies soil CO2 efflux in 6-year-old Pinus taeda L. stands

    Science.gov (United States)

    Lisa J. Samuelson; Kurt Johnsen; Tom Stokes; Weinlang Lu

    2004-01-01

    Intensive forestry may reduce net CO2 emission into atmosphere by storing carbon in living biomass, dead organic matter and soil, and durable wood products. Because quantification of belowground carbon dynamics is important for reliable estimation of the carbon sequestered by intensively managed plantations, we examined soil CO2...

  6. Carbon and nitrogen pools in oak-hickory forests of varying productivity

    Science.gov (United States)

    Donald J. Kaczmarek; Karyn S. Rodkey; Robert T. Reber; Phillip E. Pope; Felix, Jr. Ponder

    1995-01-01

    Carbon (C) and nitrogen (N) storage capacities are critical issues facing forest ecosystem management in the face of potential global climate change. The amount of C sequestered by forest ecosystems can be a significant sink for increasing atmospheric CO2 levels. N availability can interact with other environmental factors such as water...

  7. Long-term decomposition of grass roots as affected by elevated atmospheric carbon dioxide

    NARCIS (Netherlands)

    Ginkel, van J.H.; Gorissen, A.; Veen, van J.A.

    1996-01-01

    Carbon input into the soil and decomposition processes under elevated CO2 are highly relevant for C sequestering in the soil. Plant growth and decomposition of root material under ambient and elevated atmospheric CO2 concentrations were monitored in wind tunnels. Grass roots (Lolium perenne L.) were

  8. Reducing carbon emissions through improved household energy efficiency in the UK

    International Nuclear Information System (INIS)

    Ekins, P.; Hargreaves, C.

    2002-01-01

    A number of schemes to increase household energy efficiency have operated in the UK over the last 5-10 years. This paper evaluates their effectiveness in terms of reducing household energy use, carbon emissions and fuel poverty. It then draws on the quantitative results of these schemes, and published plans for their continuation, to model an extended and expanded Household Energy Efficiency Scenario to 2020, using an integrated economy-energy-environment model of the UK. The results suggest that while such schemes can play a significant role in reducing carbon emissions from households, much more ambitious schemes than those currently implemented will be necessary to offset the underlying growth in these emissions. Finally, the results are compared with the UK government's own estimates, in its Climate Change Programme, of carbon emission reductions from such schemes to 2010. The paper concludes that the government's estimates are somewhat optimistic, and that it will need substantial new policy measures beyond those already announced if its carbon reduction targets in this area are to be met. (author)

  9. Endotoxemia reduces cerebral perfusion but enhances dynamic cerebrovascular autoregulation at reduced arterial carbon dioxide tension*

    DEFF Research Database (Denmark)

    Brassard, Patrice; Kim, Yu-Sok; van Lieshout, Johannes

    2012-01-01

    OBJECTIVE:: The administration of endotoxin to healthy humans reduces cerebral blood flow but its influence on dynamic cerebral autoregulation remains unknown. We considered that a reduction in arterial carbon dioxide tension would attenuate cerebral perfusion and improve dynamic cerebral autoreg...

  10. Carbonation of metal silicates for long-term CO2 sequestration

    Science.gov (United States)

    Blencoe, James G; Palmer, Donald A; Anovitz, Lawrence M; Beard, James S

    2014-03-18

    In a preferred embodiment, the invention relates to a process of sequestering carbon dioxide. The process comprises the steps of: (a) reacting a metal silicate with a caustic alkali-metal hydroxide to produce a hydroxide of the metal formerly contained in the silicate; (b) reacting carbon dioxide with at least one of a caustic alkali-metal hydroxide and an alkali-metal silicate to produce at least one of an alkali-metal carbonate and an alkali-metal bicarbonate; and (c) reacting the metal hydroxide product of step (a) with at least one of the alkali-metal carbonate and the alkali-metal bicarbonate produced in step (b) to produce a carbonate of the metal formerly contained in the metal silicate of step (a).

  11. Family matters: effect of host plant variation in chemical and mechanical defenses on a sequestering specialist herbivore.

    Science.gov (United States)

    Dimarco, Romina D; Nice, Chris C; Fordyce, James A

    2012-11-01

    Insect herbivores contend with various plant traits that are presumed to function as feeding deterrents. Paradoxically, some specialist insect herbivores might benefit from some of these plant traits, for example by sequestering plant chemical defenses that herbivores then use as their own defense against natural enemies. Larvae of the butterfly species Battus philenor (L.) (Papilionidae) sequester toxic alkaloids (aristolochic acids) from their Aristolochia host plants, rendering larvae and adults unpalatable to a broad range of predators. We studied the importance of two putative defensive traits in Aristolochia erecta: leaf toughness and aristolochic acid content, and we examined the effect of intra- and interplant chemical variation on the chemical phenotype of B. philenor larvae. It has been proposed that genetic variation for sequestration ability is "invisible to natural selection" because intra- and interindividual variation in host-plant chemistry will largely eliminate a role for herbivore genetic variation in determining an herbivore's chemical phenotype. We found substantial intra- and interplant variation in leaf toughness and in the aristolochic acid chemistry in A. erecta. Based on field observations and laboratory experiments, we showed that first-instar larvae preferentially fed on less tough, younger leaves and avoided tougher, older leaves, and we found no evidence that aristolochic acid content influenced first-instar larval foraging. We found that the majority of variation in the amount of aristolochic acid sequestered by larvae was explained by larval family, not by host-plant aristolochic acid content. Heritable variation for sequestration is the predominant determinant of larval, and likely adult, chemical phenotype. This study shows that for these highly specialized herbivores that sequester chemical defenses, traits that offer mechanical resistance, such as leaf toughness, might be more important determinants of early-instar larval

  12. Mapping aboveground carbon stocks using LiDAR data in Eucalyptus spp. plantations in the state of Sao Paulo, Brazil

    Science.gov (United States)

    Carlos Alberto Silva; Carine Klauberg; Samuel de Padua Chaves e Carvalho; Andrew T. Hudak; e Luiz Carlos Estraviz. Rodriguez

    2014-01-01

    Fast growing plantation forests provide a low-cost means to sequester carbon for greenhouse gas abatement. The aim of this study was to evaluate airborne LiDAR (Light Detection And Ranging) to predict aboveground carbon (AGC) stocks in Eucalyptus spp. plantations. Biometric parameters (tree height (Ht) and diameter at breast height (DBH)) were collected from...

  13. Carbon sequestration in surface flow constructed wetland after 12 years of swine wastewater treatment

    Science.gov (United States)

    Constructed wetlands used for the treatment of swine wastewater may potentially sequester significant amounts of carbon. In past studies, we evaluated the treatment efficiency of wastewater in marsh-pond-marsh design wetland system. The functionality of this system was highly dependent on soil carbo...

  14. Hierarchical saturation of soil carbon pools near a natural CO2 spring

    NARCIS (Netherlands)

    Kool, D.M.; Chung, H.; Tate, K.R.; Ross, D.J.; Newton, P.C.D.; Six, J.

    2007-01-01

    Soil has been identified as a possible carbon (C) sink to mitigate increasing atmospheric CO2 concentration. However, several recent studies have suggested that the potential of soil to sequester C is limited and that soil may become saturated with C under increasing CO2 levels. To test this concept

  15. Organic carbon stocks and sequestration rates of forest soils in Germany.

    Science.gov (United States)

    Grüneberg, Erik; Ziche, Daniel; Wellbrock, Nicole

    2014-08-01

    The National Forest Soil Inventory (NFSI) provides the Greenhouse Gas Reporting in Germany with a quantitative assessment of organic carbon (C) stocks and changes in forest soils. Carbon stocks of the organic layer and the mineral topsoil (30 cm) were estimated on the basis of ca. 1.800 plots sampled from 1987 to 1992 and resampled from 2006 to 2008 on a nationwide grid of 8 × 8 km. Organic layer C stock estimates were attributed to surveyed forest stands and CORINE land cover data. Mineral soil C stock estimates were linked with the distribution of dominant soil types according to the Soil Map of Germany (1 : 1 000 000) and subsequently related to the forest area. It appears that the C pool of the organic layer was largely depending on tree species and parent material, whereas the C pool of the mineral soil varied among soil groups. We identified the organic layer C pool as stable although C was significantly sequestered under coniferous forest at lowland sites. The mineral soils, however, sequestered 0.41 Mg C ha(-1) yr(-1) . Carbon pool changes were supposed to depend on stand age and forest transformation as well as an enhanced biomass input. Carbon stock changes were clearly attributed to parent material and soil groups as sandy soils sequestered higher amounts of C, whereas clayey and calcareous soils showed small gains and in some cases even losses of soil C. We further showed that the largest part of the overall sample variance was not explained by fine-earth stock variances, rather by the C concentrations variance. The applied uncertainty analyses in this study link the variability of strata with measurement errors. In accordance to other studies for Central Europe, the results showed that the applied method enabled a reliable nationwide quantification of the soil C pool development for a certain period. © 2014 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

  16. Terrestrial nitrogen-carbon cycle interactions at the global scale.

    Science.gov (United States)

    Zaehle, S

    2013-07-05

    Interactions between the terrestrial nitrogen (N) and carbon (C) cycles shape the response of ecosystems to global change. However, the global distribution of nitrogen availability and its importance in global biogeochemistry and biogeochemical interactions with the climate system remain uncertain. Based on projections of a terrestrial biosphere model scaling ecological understanding of nitrogen-carbon cycle interactions to global scales, anthropogenic nitrogen additions since 1860 are estimated to have enriched the terrestrial biosphere by 1.3 Pg N, supporting the sequestration of 11.2 Pg C. Over the same time period, CO2 fertilization has increased terrestrial carbon storage by 134.0 Pg C, increasing the terrestrial nitrogen stock by 1.2 Pg N. In 2001-2010, terrestrial ecosystems sequestered an estimated total of 27 Tg N yr(-1) (1.9 Pg C yr(-1)), of which 10 Tg N yr(-1) (0.2 Pg C yr(-1)) are due to anthropogenic nitrogen deposition. Nitrogen availability already limits terrestrial carbon sequestration in the boreal and temperate zone, and will constrain future carbon sequestration in response to CO2 fertilization (regionally by up to 70% compared with an estimate without considering nitrogen-carbon interactions). This reduced terrestrial carbon uptake will probably dominate the role of the terrestrial nitrogen cycle in the climate system, as it accelerates the accumulation of anthropogenic CO2 in the atmosphere. However, increases of N2O emissions owing to anthropogenic nitrogen and climate change (at a rate of approx. 0.5 Tg N yr(-1) per 1°C degree climate warming) will add an important long-term climate forcing.

  17. Methods for sequestering carbon dioxide into alcohols via gasification fermentation

    Science.gov (United States)

    Gaddy, James L; Ko, Ching-Whan; Phillips, J. Randy; Slape, M. Sean

    2013-11-26

    The present invention is directed to improvements in gasification for use with synthesis gas fermentation. Further, the present invention is directed to improvements in gasification for the production of alcohols from a gaseous substrate containing at least one reducing gas containing at least one microorganism.

  18. Migration rates and formation injectivity to determine containment time scales of sequestered carbon dioxide

    Science.gov (United States)

    Burke, Lauri

    2012-01-01

    Supercritical carbon dioxide exhibits highly variable behavior over a range of reservoir pressure and temperature conditions. Because geologic sequestration of supercritical carbon dioxide is targeted for subsurface injection and containment at depths ranging from approximately 3,000 to 13,000 feet, the investigation into the physical properties of this fluid can be restricted to the pressure and temperature conditions likely encountered in the sedimentary strata within this depth interval. A petrophysical based approach was developed to study the widest range of formation properties potentially encountered in sedimentary strata. Fractional porosities were varied from 5 to 95 percent, in 5-percent increments, and permeability values were varied over thirteen orders of magnitude, from 10.0 darcys down to 1.0 picodarcy.

  19. Reforestation can sequester two petagrams of carbon in US topsoils in a century

    Science.gov (United States)

    Lucas E. Nave; Grant M. Domke; Kathryn L. Hofmeister; Umakant Mishra; Charles H. Perry; Brian F. Walters; Christopher W. Swanston

    2018-01-01

    Soils are Earth’s largest terrestrial carbon (C) pool, and their responsiveness to land use and management make them appealing targets for strategies to enhance C sequestration. Numerous studies have identified practices that increase soil C, but their inferences are often based on limited data extrapolated over large areas. Here, we combine 15,000 observations from...

  20. A Novel Strategy of Carbon Capture and Sequestration by rHLPD Processing

    Directory of Open Access Journals (Sweden)

    Richard Eric Riman

    2016-01-01

    Full Text Available Monoethanolamine (MEA scrubbing is an energy intensive process for Carbon Capture and Sequestration (CCS due to the regeneration of amine in stripping towers at high temperature (100-120 ºC and the subsequent pressurization of CO2 for geologic sequestration. In this paper, we introduce a novel method, reactive hydrothermal liquid phase densification (rHLPD, which is able to solidify (densify monolithic materials without using high temperature kilns. Then we integrate MEA-based CCS processing and mineral carbonation by using rHLPD technology. This integration is designated as rHLPD-Carbon Sequestration (rHLPD-CS process. Our results show that the CO2 captured in the MEA-CO2 solution was sequestered by the mineral (wollastonite CaSiO3 carbonation at a low operating temperature (60 ºC and simultaneously monolithic materials with a compressive strength of ~121 MPa were formed. This suggests that the use of rHLPD-CS technology eliminates the energy consumed for CO2-MEA stripping and CO2 compression and also sequesters CO2 to form value-added products, which have a potential to be utilized as construction and infrastructure materials. In contrast to the high energy requirements and excessive greenhouse gas emissions from conventional Portland cement manufacturing, our calculations show that the integration of rHLPD and CS technologies provides a low energy alternative to production of traditional cementitious binding materials.

  1. In vivo release of aflatoxin B1 bound to different sequestering agents in dairy cows

    Directory of Open Access Journals (Sweden)

    D. Diaz

    2010-04-01

    Full Text Available Nine lactating dairy cows, producing 31.08±5.00 kg of milk/cow/day and fed with a Total Mixed Ration (TMR with an intake of 22.3±0.8 Kg s.s./cow, were used to investigate the resistance of the AFs-SA complex in the rumen and in the gastro-intestinal tract. Two commercial sequestering agents Atox® and Mycosorb® were used. The AFB1 was also mixed to a rumen fluid (R-SA. AFB1 sequestered by Atox®, Mycosorb® and by R-SA were then fed to cows before the morning meal. Milk samples were collected for 6 consecutive milkings and analyzed for AFM1 content. The in vitro binding capacity of the two SA were 94.2% for Atox®, 84.3% for Mycosorb® and 71.86% for the R-SA. Both Atox® and Mycosorb® released some of the sequestered AFB1 determining an increase of the AFM1 in milk as soon as in the 1st milking from oral drenching (4.23±7.33; 23.60±8.23 and 46.06±39.84 ppt for Atox®, Mycosorb® and R-SA respectively. The AFM1 (ng/cow in milk at the 4th milking was lower (66.04, 661.77 and 1613.04; P<0.05 in Atox® and Mycosorb® than R-SA, respectively. The percentage release of bound AFB1 were 1.63% for Atox®, 20.27% for Mycosorb® and 50.48% for R-SA.

  2. Management options to reduce the carbon footprint of livestock products

    DEFF Research Database (Denmark)

    Hermansen, John Erik; Kristensen, Troels

    2011-01-01

    Livestock products carry a large carbon footprint compared with other foods, and thus there is a need to focus on how to reduce it. The major contributing factors are emissions related to feed use and manure handling as well as the nature of the land required to produce the feed in question. We can....... Basically, it is important to make sure that all beneficial interactions in the livestock system are optimized instead of focusing only on animal productivity. There is an urgent need to arrive at a sound framework for considering the interaction between land use and carbon footprints of foods....... conclude that the most important mitigation options include - better feed conversion at the system level, - use of feeds that increase soil carbon sequestration versus carbon emission, - ensure that the manure produced substitutes for synthetic fertilizer, and - use manure for bio-energy production...

  3. U.S. Geological Survey Methodology Development for Ecological Carbon Assessment and Monitoring

    Science.gov (United States)

    Zhu, Zhi-Liang; Stackpoole, S.M.

    2009-01-01

    Ecological carbon sequestration refers to transfer and storage of atmospheric carbon in vegetation, soils, and aquatic environments to help offset the net increase from carbon emissions. Understanding capacities, associated opportunities, and risks of vegetated ecosystems to sequester carbon provides science information to support formulation of policies governing climate change mitigation, adaptation, and land-management strategies. Section 712 of the Energy Independence and Security Act (EISA) of 2007 mandates the Department of the Interior to develop a methodology and assess the capacity of our nation's ecosystems for ecological carbon sequestration and greenhouse gas (GHG) flux mitigation. The U.S. Geological Survey (USGS) LandCarbon Project is responding to the Department of Interior's request to develop a methodology that meets specific EISA requirements.

  4. Autophagy induction under carbon starvation conditions is negatively regulated by carbon catabolite repression.

    Science.gov (United States)

    Adachi, Atsuhiro; Koizumi, Michiko; Ohsumi, Yoshinori

    2017-12-01

    Autophagy is a conserved process in which cytoplasmic components are sequestered for degradation in the vacuole/lysosomes in eukaryotic cells. Autophagy is induced under a variety of starvation conditions, such as the depletion of nitrogen, carbon, phosphorus, zinc, and others. However, apart from nitrogen starvation, it remains unclear how these stimuli induce autophagy. In yeast, for example, it remains contentious whether autophagy is induced under carbon starvation conditions, with reports variously suggesting both induction and lack of induction upon depletion of carbon. We therefore undertook an analysis to account for these inconsistencies, concluding that autophagy is induced in response to abrupt carbon starvation when cells are grown with glycerol but not glucose as the carbon source. We found that autophagy under these conditions is mediated by nonselective degradation that is highly dependent on the autophagosome-associated scaffold proteins Atg11 and Atg17. We also found that the extent of carbon starvation-induced autophagy is positively correlated with cells' oxygen consumption rate, drawing a link between autophagy induction and respiratory metabolism. Further biochemical analyses indicated that maintenance of intracellular ATP levels is also required for carbon starvation-induced autophagy and that autophagy plays an important role in cell viability during prolonged carbon starvation. Our findings suggest that carbon starvation-induced autophagy is negatively regulated by carbon catabolite repression. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  5. Carbonation of metal silicates for long-term CO.sub.2 sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Blencoe, James G.; Palmer, Donald A.; Anovitz, Lawrence M.; Beard, James S.

    2017-08-01

    In a preferred embodiment, the invention relates to a process of sequestering carbon dioxide. The process comprises the steps of: (a) reacting a metal silicate with a caustic alkali-metal hydroxide to produce a hydroxide of the metal formerly contained in the silicate; (b) reacting carbon dioxide with at least one of a caustic alkali-metal hydroxide and an alkali-metal silicate to produce at least one of an alkali-metal carbonate and an alkali-metal bicarbonate; and (c) reacting the metal hydroxide product of step (a) with at least one of the alkali-metal carbonate and the alkali-metal bicarbonate produced in step (b) to produce a carbonate of the metal formerly contained in the metal silicate of step (a).

  6. Carbonation of metal silicates for long-term CO.sub.2 sequestration

    Science.gov (United States)

    Blencoe, James G [Harriman, TN; Palmer, Donald A [Oliver Springs, TN; Anovitz, Lawrence M [Knoxville, TN; Beard, James S [Martinsville, VA

    2012-02-14

    In a preferred embodiment, the invention relates to a process of sequestering carbon dioxide. The process comprises the steps of: (a) reacting a metal silicate with a caustic alkali-metal hydroxide to produce a hydroxide of the metal formerly contained in the silicate; (b) reacting carbon dioxide with at least one of a caustic alkali-metal hydroxide and an alkali-metal silicate to produce at least one of an alkali-metal carbonate and an alkali-metal bicarbonate; and (c) reacting the metal hydroxide product of step (a) with at least one of the alkali-metal carbonate and the alkali-metal bicarbonate produced in step (b) to produce a carbonate of the metal formerly contained in the metal silicate of step (a).

  7. Carbon dioxide efficiency of terrestrial enhanced weathering.

    Science.gov (United States)

    Moosdorf, Nils; Renforth, Phil; Hartmann, Jens

    2014-05-06

    Terrestrial enhanced weathering, the spreading of ultramafic silicate rock flour to enhance natural weathering rates, has been suggested as part of a strategy to reduce global atmospheric CO2 levels. We budget potential CO2 sequestration against associated CO2 emissions to assess the net CO2 removal of terrestrial enhanced weathering. We combine global spatial data sets of potential source rocks, transport networks, and application areas with associated CO2 emissions in optimistic and pessimistic scenarios. The results show that the choice of source rocks and material comminution technique dominate the CO2 efficiency of enhanced weathering. CO2 emissions from transport amount to on average 0.5-3% of potentially sequestered CO2. The emissions of material mining and application are negligible. After accounting for all emissions, 0.5-1.0 t CO2 can be sequestered on average per tonne of rock, translating into a unit cost from 1.6 to 9.9 GJ per tonne CO2 sequestered by enhanced weathering. However, to control or reduce atmospheric CO2 concentrations substantially with enhanced weathering would require very large amounts of rock. Before enhanced weathering could be applied on large scales, more research is needed to assess weathering rates, potential side effects, social acceptability, and mechanisms of governance.

  8. Reduced graphene oxide supported gold nanoparticles for electrocatalytic reduction of carbon dioxide

    Science.gov (United States)

    Saquib, Mohammad; Halder, Aditi

    2018-02-01

    Electrochemical reduction of carbon dioxide is one of the methods which have the capability to recycle CO2 into valuable products for energy and industrial applications. This research article describes about a new electrocatalyst "reduced graphene oxide supported gold nanoparticles" for selective electrochemical conversion of carbon dioxide to carbon monoxide. The main aim for conversion of CO2 to CO lies in the fact that the latter is an important component of syn gas (a mixture of hydrogen and carbon monoxide), which is then converted into liquid fuel via well-known industrial process called Fischer-Tropsch process. In this work, we have synthesized different composites of the gold nanoparticles supported on defective reduced graphene oxide to evaluate the catalytic activity of reduced graphene oxide (RGO)-supported gold nanoparticles and the role of defective RGO support towards the electrochemical reduction of CO2. Electrochemical and impedance measurements demonstrate that higher concentration of gold nanoparticles on the graphene support led to remarkable decrease in the onset potential of 240 mV and increase in the current density for CO2 reduction. Lower impedance and Tafel slope values also clearly support our findings for the better performance of RGOAu than bare Au for CO2 reduction.

  9. Human APC sequesters beta-catenin even in the absence of GSK-3beta in a Drosophila model.

    Science.gov (United States)

    Rao, P R; Makhijani, K; Shashidhara, L S

    2008-04-10

    There have been conflicting reports on the requirement of GSK-3beta-mediated phosphorylation of the tumor suppressor adenomatous polyposis coli (APC) vis-à-vis its ability to bind and degrade beta-catenin. Using a unique combination of loss of function for Shaggy/GSK-3beta and a gain of function for human APC in Drosophila, we show that misexpressed human APC (hAPC) can still sequester Armadillo/beta-catenin. In addition, human APC could suppress gain of Wnt/Wingless phenotypes associated with loss of Shaggy/GSK-3beta activity, suggesting that sequestered Armadillo/beta-catenin is non-functional. Based on these studies, we propose that binding per se of beta-catenin by APC does not require phosphorylation by GSK-3beta.

  10. Tropical protected areas reduced deforestation carbon emissions by one third from 2000-2012.

    Science.gov (United States)

    Bebber, Daniel P; Butt, Nathalie

    2017-10-25

    Tropical deforestation is responsible for around one tenth of total anthropogenic carbon emissions, and tropical protected areas (PAs) that reduce deforestation can therefore play an important role in mitigating climate change and protecting biodiversity and ecosystem services. While the effectiveness of PAs in reducing deforestation has been estimated, the impact on global carbon emissions remains unquantified. Here we show that tropical PAs overall reduced deforestation carbon emissions by 4.88 Pg, or around 29%, between 2000 and 2012, when compared to expected rates of deforestation controlling for spatial variation in deforestation pressure. The largest contribution was from the tropical Americas (368.8 GgC y -1 ), followed by Asia (25.0 GgC y -1 ) and Africa (12.7 GgC y -1 ). Variation in PA effectiveness is largely driven by local factors affecting individual PAs, rather than designations assigned by governments.

  11. Precipitation of hydrated Mg carbonate with the aid of carbonic anhydrase for CO2 sequestration

    Science.gov (United States)

    Power, I. M.; Harrison, A. L.; Dipple, G. M.

    2011-12-01

    Strategies for sequestering CO2 directly from the atmosphere are likely required to achieve the desired reduction in CO2 concentration and avoid the most damaging effects of climate change [1]. Numerous studies have demonstrated the accelerated precipitation of calcium carbonate minerals with the aid of carbonic anhydrase (CA) as a means of sequestering CO2 in solid carbonate form; however, no study has examined precipitation of magnesium carbonate minerals using CA. Precipitation of magnesite (MgCO3) is kinetically inhibited [2]; therefore, Mg2+ must be precipitated as hydrated carbonate minerals. In laboratory experiments, the uptake of atmospheric CO2 into brine solutions (0.1 M Mg) was rate-limiting for the precipitation of dypingite [Mg5(CO3)4(OH)2-5H2O] with initial precipitation requiring 15 days [3]. It was also found that dypingite precipitation outpaced the uptake of CO2 gas into solution. CO2 uptake is limited by the hydration of CO2 to form carbonate ions [4]. Carbonic anhydrase (CA) enzymes are among the fastest known in nature and are able to catalyze the hydration of CO2, i.e., converting CO2(aq) to CO32- and HCO3- [5]. CA plays an important role in the carbon concentrating mechanism of photoautotrophic, chemoautotrophic, and heterotrophic prokaryotes and is involved in pH homeostasis, facilitated diffusion of CO2, ion transport, and the interconversion of CO2 and HCO3- [6]. Introducing CA into buffered Mg-rich solutions should allow for more rapid precipitation of hydrated magnesium carbonate minerals. Batch experiments were conducted using 125 mL flasks containing 100 mL of Millipore deionized water with 0.2 M of MgCl2-6H2O. To buffer pH, 1.0 g of pulverized brucite [Mg(OH)2] or 1.0 g of NaOH was added to the systems, which were amended with Bovine carbonic anhydrase (BCA) (Sigma-Aldrich). Solutions were stirred continuously and kept at room temperature (~22°C) with laboratory air introduced by bubbling. Temperature and pH were measured routinely

  12. A review of activated carbon technologies for reducing MSW incinerator emissions

    International Nuclear Information System (INIS)

    Clarke, M.J.

    1991-01-01

    Though activated carbon is, by no means, a newcomer to the pollution control field, having been used as a water purifier and more recently demonstrated as a flue gas cleaner on power plants, it is now attracting considerable attention in Europe as a means to reduce further the quantity of toxic organic and metal emissions from new and existing municipal waste combustors. Since activated carbon is a potentially important future emissions control technology for MWCs in the US, particularly for removal of mercury and dioxin, this paper discusses the impetus which has motivated the experimentation with various activated carbon technologies which is now taking place, will describe how some of the activated carbon systems (e.g., post-emissions control fixed carbon bed and injection of carbon with scrubber reagent) being tested now function and where they fit in existing pollution control trains, and will present available performance data and emissions reductions actually achieved for each system

  13. Turnover of soil carbon pools following addition of switchgrass-derived biochar to four soils

    Science.gov (United States)

    The amendment of soils with biochar may improve plant growth and sequester carbon, especially in marginal soils not suitable for the majority of commodity production. While biochar can persist in soils, it is not clear whether its persistence is affected by soil type. Moreover, we know little of how...

  14. The role of carbon sequestration and the tonne-year approach in fulfilling the objective of climate convention

    International Nuclear Information System (INIS)

    Korhonen, Riitta; Pingoud, Kim; Savolainen, Ilkka; Matthews, Robert

    2002-01-01

    Carbon can be sequestered from the atmosphere to forests in order to lower the atmospheric carbon dioxide concentration. Tonne-years of sequestered carbon have been suggested to be used as a measure of global warming impact for these projects of finite lifetimes. It is illustrated here by simplified example cases that the objective of the stabilisation of the atmospheric greenhouse gas concentrations expressed in the UN Climate convention and the tonne-year approach can be in contradiction. Tonne-years generated by the project can indicate that carbon sequestration helps in the mitigation of climate change even when the impact of the project on the CO 2 concentration is that concentration increases. Hence, the use of the tonne-years might waste resources of fulfilling the objective of the convention. The studied example cases are closely related to the IPCC estimates on global forestation potentials by 2050. It is also illustrated that the use of bioenergy from the reforested areas to replace fossil fuels can in the long term contribute more effectively to the control of carbon dioxide concentrations than permanent sequestration of carbon to forests. However, the estimated benefits depend on the time frame considered, whether we are interested in the decadal scale of controlling of the rate of climate change or in the centennial scale of controlling or halting the climate change

  15. The role of protected areas in land use/land cover change and the carbon cycle in the conterminous United States

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Xiaoliang [The Ecosystems Center, Marine Biological Laboratory, Woods Hole MA USA; Zhou, Yuyu [Departments of Geological and Atmospheric Sciences, Iowa State University, Ames IA USA; Liu, Yaling [Pacific Northwest National Laboratory, Joint Global Change Research Institute, College Park MD USA; Le Page, Yannick [Department Tapada da Ajuda, Centro de Estudos Florestais, Instituto Superior de Agronomia, Universidade de Lisboa, Lisbon Portugal

    2017-08-08

    Protected areas (PAs) cover about 22% of the conterminous United States. Understanding their role on historical land use and land cover change (LULCC) and on the carbon cycle is essential to provide guidance for environmental policies. In this study, we compiled historical LULCC and PAs data to explore these interactions within the terrestrial ecosystem model (TEM). We found that intensive LULCC occurred in the conterminous United States from 1700 to 2005. More than 3 million km2 of forest, grassland and shrublands were converted into agricultural lands, which caused 10,607 Tg C release from land ecosystems to atmosphere. PAs had experienced little LULCC as they were generally established in the 20th century after most of the agricultural expansion had occurred. PAs initially acted as a carbon source due to land use legacies, but their accumulated carbon budget switched to a carbon sink in the 1960s, sequestering an estimated 1,642 Tg C over 1700–2005, or 13.4% of carbon losses in non-PAs. We also find that PAs maintain larger carbon stocks and continue sequestering carbon in recent years (2001–2005), but at a lower rate due to increased heterotrophic respiration as well as lower productivity associated to aging ecosystems. It is essential to continue efforts to maintain resilient, biodiverse ecosystems and avoid large-scale disturbances that would release large amounts of carbon in PAs.

  16. One-carbon metabolism in acetogenic and sulfate-reducing bacteria

    NARCIS (Netherlands)

    Visser, M.

    2015-01-01

    ABSTRACT

    One-carbon metabolism in acetogenic and sulfate-reducing bacteria

    Life on earth is sustained by the constant cycling of six essential elements: oxygen, hydrogen, nitrogen,

  17. Implications of observed and simulated soil carbon sequestration for management options in corn-based rotations

    Science.gov (United States)

    Managing cropping systems to sequester soil organic carbon (SOC) improves soil health and a system’s resiliency to impacts of changing climate. Our objectives were to 1) monitor SOC from a bio-energy cropping study in central Pennsylvania that included a corn-soybean-alfalfa rotation, switchgrass, a...

  18. Implications of observed and simulated soil carbon sequestration for management options in corn-based rotations

    Science.gov (United States)

    Managing cropping systems to sequester soil organic carbon (SOC) improves soil health and a system’s resiliency to impacts of changing climate. Our objectives were to 1) monitor SOC from a bio-energy cropping study in central Pennsylvania that included a corn-soybean-alfalfa rotation, switchgrass, ...

  19. Reducing US carbon emissions: an econometric general equilibrium assessment

    International Nuclear Information System (INIS)

    Jorgenson, D.W.; Wilcoxen, P.J.

    1993-01-01

    This paper describes research conducted as part of Energy Modeling Forum 12, a recent study of the costs of limiting carbon dioxide emissions organized by the Energy Modeling Forum at Stanford University. It discusses how this approach differed from that of other participants in EMF-12 and presents several important findings. In particular, it is shown that in the United States the effects of a carbon tax will be very similar to the effects of a tax placed solely on coal. Outside the coal sector, the principal effect of carbon tax will be to raise the cost of electricity and to shift base load electric generating capacity toward fuels other than coal. At the aggregate level, higher energy prices will cause gross national product to fall unless the revenue from tax is used to reduce high marginal tax rates elsewhere in the economy. 22 refs., 6 figs., 5 tabs

  20. Evaluating Soil Carbon Sequestration in Central Iowa

    Science.gov (United States)

    Doraiswamy, P. C.; Hunt, E. R.; McCarty, G. W.; Daughtry, C. S.; Izaurralde, C.

    2005-12-01

    The potential for reducing atmospheric carbon dioxide (CO2) concentration through landuse and management of agricultural systems is of great interest worldwide. Agricultural soils can be a source of CO2 when not properly managed but can also be a sink for sequestering CO2 through proper soil and crop management. The EPIC-CENTURY biogeochemical model was used to simulate the baseline level of soil carbon from soil survey data and project changes in soil organic carbon (SOC) under different tillage and crop management practices for corn and soybean crops. The study was conducted in central Iowa (50 km x 100 km) to simulate changes in soil carbon over the next 50 years. The simulations were conducted in two phases; initially a 25-year period (1971-1995) was simulated using conventional tillage practices since there was a transition in new management after 1995. In the second 25-year period (1996-2020), four different modeling scenarios were applied namely; conventional tillage, mulch tillage, no-tillage and no-tillage with a rye cover crop over the winter. The model simulation results showed potential gains in soil carbon in the top layers of the soil for conservation tillage. The simulations were made at a spatial resolution of 1.6 km x 1.6 km and mapped for the study area. There was a mean reduction in soil organic carbon of 0.095 T/ha per year over the 25-year period starting with 1996 for the conventional tillage practice. However, for management practices of mulch tillage, no tillage and no tillage with cover crop there was an increase in soil organic carbon of 0.12, 0.202 and 0.263 T/ha respectively over the same 25-year period. These results are in general similar to studies conducted in this region.

  1. Toxicology Study of Single-walled Carbon Nanotubes and Reduced Graphene Oxide in Human Sperm.

    Science.gov (United States)

    Asghar, Waseem; Shafiee, Hadi; Velasco, Vanessa; Sah, Vasu R; Guo, Shirui; El Assal, Rami; Inci, Fatih; Rajagopalan, Adhithi; Jahangir, Muntasir; Anchan, Raymond M; Mutter, George L; Ozkan, Mihrimah; Ozkan, Cengiz S; Demirci, Utkan

    2016-08-19

    Carbon-based nanomaterials such as single-walled carbon nanotubes and reduced graphene oxide are currently being evaluated for biomedical applications including in vivo drug delivery and tumor imaging. Several reports have studied the toxicity of carbon nanomaterials, but their effects on human male reproduction have not been fully examined. Additionally, it is not clear whether the nanomaterial exposure has any effect on sperm sorting procedures used in clinical settings. Here, we show that the presence of functionalized single walled carbon nanotubes (SWCNT-COOH) and reduced graphene oxide at concentrations of 1-25 μg/mL do not affect sperm viability. However, SWCNT-COOH generate significant reactive superoxide species at a higher concentration (25 μg/mL), while reduced graphene oxide does not initiate reactive species in human sperm. Further, we demonstrate that exposure to these nanomaterials does not hinder the sperm sorting process, and microfluidic sorting systems can select the sperm that show low oxidative stress post-exposure.

  2. Toxicology Study of Single-walled Carbon Nanotubes and Reduced Graphene Oxide in Human Sperm

    Science.gov (United States)

    Asghar, Waseem; Shafiee, Hadi; Velasco, Vanessa; Sah, Vasu R.; Guo, Shirui; El Assal, Rami; Inci, Fatih; Rajagopalan, Adhithi; Jahangir, Muntasir; Anchan, Raymond M.; Mutter, George L.; Ozkan, Mihrimah; Ozkan, Cengiz S.; Demirci, Utkan

    2016-08-01

    Carbon-based nanomaterials such as single-walled carbon nanotubes and reduced graphene oxide are currently being evaluated for biomedical applications including in vivo drug delivery and tumor imaging. Several reports have studied the toxicity of carbon nanomaterials, but their effects on human male reproduction have not been fully examined. Additionally, it is not clear whether the nanomaterial exposure has any effect on sperm sorting procedures used in clinical settings. Here, we show that the presence of functionalized single walled carbon nanotubes (SWCNT-COOH) and reduced graphene oxide at concentrations of 1-25 μg/mL do not affect sperm viability. However, SWCNT-COOH generate significant reactive superoxide species at a higher concentration (25 μg/mL), while reduced graphene oxide does not initiate reactive species in human sperm. Further, we demonstrate that exposure to these nanomaterials does not hinder the sperm sorting process, and microfluidic sorting systems can select the sperm that show low oxidative stress post-exposure.

  3. Exceptionally strong sorption of infochemicals to activated carbon reduces their bioavailability to fish

    NARCIS (Netherlands)

    Jonker, Michiel T O; van Mourik, Louise

    2014-01-01

    The addition of activated carbon (AC) to sediments is a relatively new approach to remediate contaminated sites. Activated carbon strongly sorbs hydrophobic organic contaminants, thereby reducing their bioavailability and uptake in organisms. Because of its high sorption capacity, AC might, however,

  4. Soil carbon sequestration and the CDM. Opportunities and challenges for Africa

    Energy Technology Data Exchange (ETDEWEB)

    Ringius, Lasse

    1999-12-17

    The agriculture sector dominates the economies of most sub-Saharan countries, contributing about one-third of the region's GDP, accounting for forty percent of the export, and employing about two-thirds of the economically active population. Moreover, some soils in sub-Saharan Africa could, by providing sinks for carbon sequestration, play an important role in managing global climate change. Improvements in agricultural techniques and land use practices could lead to higher agricultural productivity and accumulate soil carbon. Hence, soil carbon sequestration could produce local economic income as well as social and other benefits in Africa. The Clean Development Mechanism (CDM) established in the 1997 Kyoto Protocol is designed to give developed countries with high domestic abatement cost access to low-cost greenhouse gas abatement projects in developing countries, and to benefit developing countries selling projects to investors in developed countries. It is presently unclear whether the CDM will provide credit for sink enhancement and permit broader sink activities. Unfortunately, few cost estimates of soil carbon sequestration strategies presently exist. While these costs are uncertain and all input costs have not been estimated, manure-based projects in small-holdings in Kenya could increase maize yield significantly and sequester one ton of soil carbon for a net cost of -US$806. Clearly, such projects would be very attractive economically. There is presently an urgent need to launch useful long-term (>10 years) field experiments and demonstration projects in Africa. Existing data are not readily comparable, it is uncertain how large amount of carbon could be sequestered, findings are site-specific, and it is unclear how well the sites represent wider areas. To develop CDM projects, it is important that experimental trials generate reliable and comparable data. Finally, it will be important to estimate local environmental effects and economic benefits

  5. Sequestration of carbon dioxide and production of biomolecules using cyanobacteria.

    Science.gov (United States)

    Upendar, Ganta; Singh, Sunita; Chakrabarty, Jitamanyu; Chandra Ghanta, Kartik; Dutta, Susmita; Dutta, Abhishek

    2018-07-15

    A cyanobacterial strain, Synechococcus sp. NIT18, has been applied to sequester CO 2 using sodium carbonate as inorganic carbon source due to its efficiency of CO 2 bioconversion and high biomass production. The biomass obtained is used for the extraction of biomolecules - protein, carbohydrate and lipid. The main objective of the study is to maximize the biomass and biomolecules production with CO 2 sequestration using cyanobacterial strain cultivated under different concentrations of CO 2 (5-20%), pH (7-11) and inoculum size (5-12.5%) within a statistical framework. Maximum sequestration of CO 2 and maximum productivities of protein, carbohydrate and lipid are 71.02%, 4.9 mg/L/day, 6.7 mg/L/day and 1.6 mg/L/day respectively, at initial CO 2 concentration: 10%, pH: 9 and inoculum size: 12.5%. Since flue gas contains 10-15% CO 2 and the present strain is able to sequester CO 2 in this range, the strain could be considered as a useful tool for CO 2 mitigation for greener world. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. Carbon dioxide sequestration by aqueous mineral carbonation of magnesium silicate minerals

    Energy Technology Data Exchange (ETDEWEB)

    Gerdemann, Stephen J.; Dahlin, David C.; O' Connor, William K.; Penner, Larry R.

    2003-01-01

    The dramatic increase in atmospheric carbon dioxide since the Industrial Revolution has caused concerns about global warming. Fossil-fuel-fired power plants contribute approximately one third of the total human-caused emissions of carbon dioxide. Increased efficiency of these power plants will have a large impact on carbon dioxide emissions, but additional measures will be needed to slow or stop the projected increase in the concentration of atmospheric carbon dioxide. By accelerating the naturally occurring carbonation of magnesium silicate minerals it is possible to sequester carbon dioxide in the geologically stable mineral magnesite (MgCO3). The carbonation of two classes of magnesium silicate minerals, olivine (Mg2SiO4) and serpentine (Mg3Si2O5(OH)4), was investigated in an aqueous process. The slow natural geologic process that converts both of these minerals to magnesite can be accelerated by increasing the surface area, increasing the activity of carbon dioxide in the solution, introducing imperfections into the crystal lattice by high-energy attrition grinding, and in the case of serpentine, by thermally activating the mineral by removing the chemically bound water. The effect of temperature is complex because it affects both the solubility of carbon dioxide and the rate of mineral dissolution in opposing fashions. Thus an optimum temperature for carbonation of olivine is approximately 185 degrees C and 155 degrees C for serpentine. This paper will elucidate the interaction of these variables and use kinetic studies to propose a process for the sequestration of the carbon dioxide.

  7. Nutrient amendment does not increase mineralisation of sequestered carbon during incubation of a nitrogen limited mangrove soil

    KAUST Repository

    Keuskamp, Joost A.; Schmitt, Heike; Laanbroek, Hendrikus J.; Verhoeven, Jos T.A.; Hefting, Mariet M.

    2013-01-01

    Mangrove forests are sites of intense carbon and nutrient cycling, which result in soil carbon sequestration on a global scale. Currently, mangrove forests receive increasing quantities of exogenous nutrients due to coastal development. The present

  8. Potential of windbreak trees to reduce carbon emissions by agricultural operations in the US

    Science.gov (United States)

    William Ballesteros-Possu; James R. Brandle; Michele Schoeneberger

    2017-01-01

    Along with sequestering C in forest, trees on farms are able to contribute to greenhouse mitigation through emission avoidance mechanisms. To evaluate the magnitude of these contributions, emission avoidance contributions for field and farmstead windbreak designs in regions across the United States were estimated, along with greenhouse gas (GHG) emission budgets for...

  9. Role of organic soils in the world carbon cycle: problem definition and research needs

    Energy Technology Data Exchange (ETDEWEB)

    Armentano, T.V. (ed.)

    1979-01-01

    Findings and recommendations of the workshop on organic soils are summarized. The major finding of the workshop is that organic soils are important in the overall carbon budget. Histosols and gleysols, the major organic soil deposits of the world, normally sequester organic carbon fixed by plants. They may now be releasing enough carbon to account for nearly 10% of the annual rise in atmospheric content of CO/sub 2/. Current annual release of carbon from organic soils is estimated to fall within the range of 0.03 to 0.37 x 10/sup 9/ t, a release equivalent to 1.3% to 16% of the annual increase of carbon in the atmosphere. If half of the released carbon remains airborne, organic soils contribute 0.6% to 8.0% of the annual rise in CO/sub 2/. Uncertainties in data suggest the actual release could lie outside the range. Present annual releases of carbon from the Everglades Agricultural Area in Florida and the Sacramento-San Joaquin Valley in California are estimated at 0.017 x 10/sup 9/ tons. When combined with additional carbon release from other known drainage programs and the possibility of major drainage activity in the tropics, this figure suggests that the lower limit of the world estimate of carbon release from organic soils is too low. Annual sequestering of carbon by undrained organic soils has been estimated at about 0.045 x 10/sup 9/ tons. This estimate is based on only a few studies, however, and precision is probably no better than an order of magnitude. Several strategies for peatland management are available, including creation, preservation, functional designation, and use of wetlands for agriculture and energy supply.

  10. Estimating carbon sequestration in the piedmont ecoregion of the United States from 1971 to 2010

    Science.gov (United States)

    Liu, Jinxun; Sleeter, Benjamin M.; Zhu, Zhiliang; Heath, Linda S.; Tan, Zhengxi; Wilson, Tamara; Sherba, Jason T.; Zhou, Decheng

    2016-01-01

    Background: Human activities have diverse and profound impacts on ecosystem carbon cycles. The Piedmont ecoregion in the eastern United States has undergone significant land use and land cover change in the past few decades. The purpose of this study was to use newly available land use and land cover change data to quantify carbon changes within the ecoregion. Land use and land cover change data (60-m spatial resolution) derived from sequential remotely sensed Landsat imagery were used to generate 960-m resolution land cover change maps for the Piedmont ecoregion. These maps were used in the Integrated Biosphere Simulator (IBIS) to simulate ecosystem carbon stock and flux changes from 1971 to 2010. Results: Results show that land use change, especially urbanization and forest harvest had significant impacts on carbon sources and sinks. From 1971 to 2010, forest ecosystems sequestered 0.25 Mg C ha−1 yr−1, while agricultural ecosystems sequestered 0.03 Mg C ha−1 yr−1. The total ecosystem C stock increased from 2271 Tg C in 1971 to 2402 Tg C in 2010, with an annual average increase of 3.3 Tg C yr−1. Conclusions: Terrestrial lands in the Piedmont ecoregion were estimated to be weak net carbon sink during the study period. The major factors contributing to the carbon sink were forest growth and afforestation; the major factors contributing to terrestrial emissions were human induced land cover change, especially urbanization and forest harvest. An additional amount of carbon continues to be stored in harvested wood products. If this pool were included the carbon sink would be stronger. Keywords: Land-use change, Carbon change, Piedmont ecoregion, IBIS model

  11. Community Based Forest Management as a Climate Strategy (with carbon as a non-timber forest product)

    NARCIS (Netherlands)

    Skutsch, Margaret

    2003-01-01

    Under the Kyoto Protocol, forestry is permitted as a sink measure under the Clean Development Mechanism (CDM), but only in the form of ‘afforestation’ and ‘reforestation’. These tend to involve large-scale plantation systems, which although cost effective in terms of carbon sequestered, in most

  12. Hydrogenation of carbon to methane in reduced sponge iron, chromium, and ferrochromium

    Energy Technology Data Exchange (ETDEWEB)

    Qayyum, M A; Reeve, D A

    1976-01-01

    Hydrogenation of excess carbon to methane in reduced sponge iron, chromium and ferrochromium under isothermal and temperature-programmed conditions indicates that it is possible to control the residual carbon content of the metallized products which may be an advantage if further processing of the products is contemplated. Hydrogenation starts above 800/sup 0/C and a shrinking-core kinetic model fits the experimental data. The mean apparent activation energy for the hydrogenation of residual carbon to methane in sponge iron, chromium and ferrochromium is 21 kcal/mole.

  13. Potential of Windbreak Trees to Reduce Carbon Emissions by Agricultural Operations in the US

    Directory of Open Access Journals (Sweden)

    William Ballesteros-Possu

    2017-04-01

    Full Text Available Along with sequestering C in forest, trees on farms are able to contribute to greenhouse mitigation through emission avoidance mechanisms. To evaluate the magnitude of these contributions, emission avoidance contributions for field and farmstead windbreak designs in regions across the United States were estimated, along with greenhouse gas (GHG emission budgets for corn, soybean, winter wheat, and potato operations. We looked at farming scenarios with large (600 ha, mid (300 ha, and small-size (60 ha farms containing farmsteads built before and after 2000, and growing different cropping systems. Windbreak scenarios were assumed to be up to 5% of the crop area for field windbreaks, while emission avoidance for farmstead windbreaks were assumed to provide a 10% and 25% reduction in energy usage for space conditioning and heating, respectively. Total reduction of C equivalent (CE emissions by windbreaks on farm systems ranged from a low of 0.9 Mg CE year−1 for a 60-ha farm with a home built before 2000 to 39.1 Mg CE year−1 for a 600-ha farm with a home built after 2000. By reducing fossil fuel usage from farm operations, windbreaks provide a promising strategy for reducing GHG emissions from agriculture in the USA.

  14. A carbon tax to reduce CO2 emissions in Europe

    International Nuclear Information System (INIS)

    Agostini, Paola; Botteon, Michele; Carraro, Carlo

    1992-01-01

    This paper examines the effects of introducing a tax on carbon dioxide emissions produced by combustion processes in OECD-European countries. A sectoral model of energy consumption is constructed to examine energy-saving and inter-fuel substitution effects induced by the introduction of various carbon taxes. The simulation period is 1989-94. Our results provide a mild support to the environmental role of a carbon tax. Energy-saving or inter-fuel substitution processes, that result from the introduction of environmental taxation, stabilize emissions at the 1988 level only in the electricity generation sector, and only if high tax rates are assumed ($100/ton.C). By contrast, total emissions (all sectors and all fuels) keep growing, and the implementation of a tax of $100/ton.C can only reduce the emission growth rate. (Author)

  15. Using Geothermal Electric Power to Reduce Carbon Footprint

    Science.gov (United States)

    Crombie, George W.

    Human activities, including the burning of fossil fuels, increase carbon dioxide levels, which contributes to global warming. The research problem of the current study examined if geothermal electric power could adequately replace fossil fuel by 2050, thus reducing the emissions of carbon dioxide while avoiding potential problems with expanding nuclear generation. The purpose of this experimental research was to explore under what funding and business conditions geothermal power could be exploited to replace fossil fuels, chiefly coal. Complex systems theory, along with network theory, provided the theoretical foundation for the study. Research hypotheses focused on parameters, such as funding level, exploration type, and interfaces with the existing power grid that will bring the United States closest to the goal of phasing out fossil based power by 2050. The research was conducted by means of computer simulations, using agent-based modeling, wherein data were generated and analyzed. The simulations incorporated key information about the location of geothermal resources, exploitation methods, transmission grid limits and enhancements, and demand centers and growth. The simulation suggested that rapid and aggressive deployment of geothermal power plants in high potential areas, combined with a phase out of coal and nuclear plants, would produce minimal disruptions in the supply of electrical power in the United States. The implications for social change include reduced risk of global warming for all humans on the planet, reduced pollution due to reduction or elimination of coal and nuclear power, increased stability in energy supply and prices in the United States, and increased employment of United States citizens in jobs related to domestic energy production.

  16. A shift of thermokarst lakes from carbon sources to sinks during the Holocene epoch

    Science.gov (United States)

    Walter Anthony, K. M.; Zimov, S. A.; Grosse, G.; Jones, Miriam C.; Anthony, P.; Chapin, F. S.; Finlay, J. C.; Mack, M. C.; Davydov, S.; Frenzel, P.F.; Frolking, S.

    2014-01-01

    Thermokarst lakes formed across vast regions of Siberia and Alaska during the last deglaciation and are thought to be a net source of atmospheric methane and carbon dioxide during the Holocene epoch1,2,3,4. However, the same thermokarst lakes can also sequester carbon5, and it remains uncertain whether carbon uptake by thermokarst lakes can offset their greenhouse gas emissions. Here we use field observations of Siberian permafrost exposures, radiocarbon dating and spatial analyses to quantify Holocene carbon stocks and fluxes in lake sediments overlying thawed Pleistocene-aged permafrost. We find that carbon accumulation in deep thermokarst-lake sediments since the last deglaciation is about 1.6 times larger than the mass of Pleistocene-aged permafrost carbon released as greenhouse gases when the lakes first formed. Although methane and carbon dioxide emissions following thaw lead to immediate radiative warming, carbon uptake in peat-rich sediments occurs over millennial timescales. We assess thermokarst-lake carbon feedbacks to climate with an atmospheric perturbation model and find that thermokarst basins switched from a net radiative warming to a net cooling climate effect about 5,000 years ago. High rates of Holocene carbon accumulation in 20 lake sediments (47±10 grams of carbon per square metre per year; mean±standard error) were driven by thermokarst erosion and deposition of terrestrial organic matter, by nutrient release from thawing permafrost that stimulated lake productivity and by slow decomposition in cold, anoxic lake bottoms. When lakes eventually drained, permafrost formation rapidly sequestered sediment carbon. Our estimate of about 160petagrams of Holocene organic carbon in deep lake basins of Siberia and Alaska increases the circumpolar peat carbon pool estimate for permafrost regions by over 50 per cent (ref. 6). The carbon in perennially frozen drained lake sediments may become vulnerable to mineralization as permafrost disappears7

  17. A Novel Strategy for Carbon Capture and Sequestration by rHLPD Processing

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qinghua; Gupta, Surojit; Tang, Ling; Quinn, Sean [Department of Material Science and Engineering, Rutgers, The State University of New Jersey, Piscataway, NJ (United States); Atakan, Vahit [Solidia Technologies, Inc., Piscataway, NJ (United States); Riman, Richard E., E-mail: riman@rci.rutgers.edu [Department of Material Science and Engineering, Rutgers, The State University of New Jersey, Piscataway, NJ (United States)

    2016-01-22

    Monoethanolamine (MEA) scrubbing is an energy-intensive process for carbon capture and sequestration (CCS) due to the regeneration of amine in stripping towers at high temperature (100–120°C) and the subsequent pressurization of CO{sub 2} for geological sequestration. In this paper, we introduce a novel method, reactive hydrothermal liquid phase densification (rHLPD), which is able to solidify (densify) monolithic materials without using high temperature kilns. Then, we integrate MEA-based CCS processing and mineral carbonation by using rHLPD technology. This integration is designated as rHLPD-carbon sequestration (rHLPD-CS) process. Our results show that the CO{sub 2} captured in the MEA-CO{sub 2} solution was sequestered by the mineral (wollastonite CaSiO{sub 3}) carbonation at a low operating temperature (60°C) and simultaneously monolithic materials with a compressive strength of ~121 MPa were formed. This suggests that the use of rHLPD-CS technology eliminates the energy consumed for CO{sub 2}-MEA stripping and CO{sub 2} compression and also sequesters CO{sub 2} to form value-added products, which have a potential to be utilized as construction and infrastructure materials. In contrast to the high energy requirements and excessive greenhouse gas emissions from conventional Portland cement manufacturing, our calculations show that the integration of rHLPD and CS technologies provides a low energy alternative to production of traditional cementitious-binding materials.

  18. Biochar production for carbon sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Thakkar, J.; Kumar, A. [Alberta Univ., Edmonton, AB (Canada). Dept. of Mechanical Engineering

    2010-07-01

    This study examined the use of agricultural biomass for biochar production and its storage in a landfill to sequester carbon. Capturing the energy from biomass that would otherwise decay, is among the many options available to mitigate the impact of the greenhouse gas (GHG) emissions associated with fossil fuel consumption. Biochar is a solid fuel which can be produced from agricultural biomass such as wheat and barley straw. This organic solid can be produced by slow pyrolysis of straw. A conceptual techno-economic model based on actual data was used to estimate the cost of producing biochar from straw in a centralized plant. The objectives of the study were to estimate the overall delivered cost of straw to the charcoal production plant; estimate the transportation costs of charcoal to the landfill site; estimate the cost of landfill; and estimate the overall cost of carbon sequestration through a charcoal landfill. According to preliminary results, the cost of carbon sequestration through this pathway is greater than $50 per tonne of carbon dioxide.

  19. Carbon Sequestration and Optimal Climate Policy

    International Nuclear Information System (INIS)

    Grimaud, Andre; Rouge, Luc

    2009-01-01

    We present an endogenous growth model in which the use of a non-renewable natural resource generates carbon-dioxide emissions that can be partly sequestered. This approach breaks with the systematic link between resource use and pollution emission. The accumulated stock of remaining emissions has a negative impact on household utility and corporate productivity. While sequestration quickens the optimal extraction rate, it can also generate higher emissions in the short run. It also has an adverse effect on economic growth. We study the impact of a carbon tax: the level of the tax has an effect in our model, its optimal level is positive, and it can be interpreted ex post as a decreasing ad valorem tax on the resource

  20. Plankton networks driving carbon export in the oligotrophic ocean

    Science.gov (United States)

    Larhlimi, Abdelhalim; Roux, Simon; Darzi, Youssef; Audic, Stephane; Berline, Léo; Brum, Jennifer; Coelho, Luis Pedro; Espinoza, Julio Cesar Ignacio; Malviya, Shruti; Sunagawa, Shinichi; Dimier, Céline; Kandels-Lewis, Stefanie; Picheral, Marc; Poulain, Julie; Searson, Sarah; Stemmann, Lars; Not, Fabrice; Hingamp, Pascal; Speich, Sabrina; Follows, Mick; Karp-Boss, Lee; Boss, Emmanuel; Ogata, Hiroyuki; Pesant, Stephane; Weissenbach, Jean; Wincker, Patrick; Acinas, Silvia G.; Bork, Peer; de Vargas, Colomban; Iudicone, Daniele; Sullivan, Matthew B.; Raes, Jeroen; Karsenti, Eric; Bowler, Chris; Gorsky, Gabriel

    2015-01-01

    The biological carbon pump is the process by which CO2 is transformed to organic carbon via photosynthesis, exported through sinking particles, and finally sequestered in the deep ocean. While the intensity of the pump correlates with plankton community composition, the underlying ecosystem structure driving the process remains largely uncharacterised. Here we use environmental and metagenomic data gathered during the Tara Oceans expedition to improve our understanding of carbon export in the oligotrophic ocean. We show that specific plankton communities, from the surface and deep chlorophyll maximum, correlate with carbon export at 150 m and highlight unexpected taxa such as Radiolaria, alveolate parasites, as well as Synechococcus and their phages, as lineages most strongly associated with carbon export in the subtropical, nutrient-depleted, oligotrophic ocean. Additionally, we show that the relative abundance of just a few bacterial and viral genes can predict most of the variability in carbon export in these regions. PMID:26863193

  1. Plankton networks driving carbon export in the oligotrophic ocean

    Science.gov (United States)

    2016-04-01

    The biological carbon pump is the process by which CO2 is transformed to organic carbon via photosynthesis, exported through sinking particles, and finally sequestered in the deep ocean. While the intensity of the pump correlates with plankton community composition, the underlying ecosystem structure driving the process remains largely uncharacterized. Here we use environmental and metagenomic data gathered during the Tara Oceans expedition to improve our understanding of carbon export in the oligotrophic ocean. We show that specific plankton communities, from the surface and deep chlorophyll maximum, correlate with carbon export at 150 m and highlight unexpected taxa such as Radiolaria and alveolate parasites, as well as Synechococcus and their phages, as lineages most strongly associated with carbon export in the subtropical, nutrient-depleted, oligotrophic ocean. Additionally, we show that the relative abundance of a few bacterial and viral genes can predict a significant fraction of the variability in carbon export in these regions.

  2. Combined gauge-mediated and anomaly-mediated supersymmetry breaking and conformal sequestering

    International Nuclear Information System (INIS)

    Sundrum, Raman

    2005-01-01

    Anomaly-mediated supersymmetry breaking in the context of 4D conformally sequestered models is combined with Poppitz-Trivedi D-type gauge-mediation. The implementation of the two mediation mechanisms naturally leads to visible soft masses at the same scale so that they can cooperatively solve the μ and flavor problems of weak scale supersymmetry, as well as the tachyonic-slepton problem of pure anomaly-mediation. The tools are developed in a modular fashion for more readily fitting into the general program of optimizing supersymmetric dynamics in hunting for the most attractive weak scale phenomenologies combined with Planck-scale plausibility

  3. Synergistic toughening of composite fibres by self-alignment of reduced graphene oxide and carbon nanotubes

    Science.gov (United States)

    Shin, Min Kyoon; Lee, Bommy; Kim, Shi Hyeong; Lee, Jae Ah; Spinks, Geoffrey M.; Gambhir, Sanjeev; Wallace, Gordon G.; Kozlov, Mikhail E.; Baughman, Ray H.; Kim, Seon Jeong

    2012-01-01

    The extraordinary properties of graphene and carbon nanotubes motivate the development of methods for their use in producing continuous, strong, tough fibres. Previous work has shown that the toughness of the carbon nanotube-reinforced polymer fibres exceeds that of previously known materials. Here we show that further increased toughness results from combining carbon nanotubes and reduced graphene oxide flakes in solution-spun polymer fibres. The gravimetric toughness approaches 1,000 J g-1, far exceeding spider dragline silk (165 J g-1) and Kevlar (78 J g-1). This toughness enhancement is consistent with the observed formation of an interconnected network of partially aligned reduced graphene oxide flakes and carbon nanotubes during solution spinning, which act to deflect cracks and allow energy-consuming polymer deformation. Toughness is sensitive to the volume ratio of the reduced graphene oxide flakes to the carbon nanotubes in the spinning solution and the degree of graphene oxidation. The hybrid fibres were sewable and weavable, and could be shaped into high-modulus helical springs.

  4. Synergistic toughening of composite fibres by self-alignment of reduced graphene oxide and carbon nanotubes.

    Science.gov (United States)

    Shin, Min Kyoon; Lee, Bommy; Kim, Shi Hyeong; Lee, Jae Ah; Spinks, Geoffrey M; Gambhir, Sanjeev; Wallace, Gordon G; Kozlov, Mikhail E; Baughman, Ray H; Kim, Seon Jeong

    2012-01-31

    The extraordinary properties of graphene and carbon nanotubes motivate the development of methods for their use in producing continuous, strong, tough fibres. Previous work has shown that the toughness of the carbon nanotube-reinforced polymer fibres exceeds that of previously known materials. Here we show that further increased toughness results from combining carbon nanotubes and reduced graphene oxide flakes in solution-spun polymer fibres. The gravimetric toughness approaches 1,000 J g(-1), far exceeding spider dragline silk (165 J g(-1)) and Kevlar (78 J g(-1)). This toughness enhancement is consistent with the observed formation of an interconnected network of partially aligned reduced graphene oxide flakes and carbon nanotubes during solution spinning, which act to deflect cracks and allow energy-consuming polymer deformation. Toughness is sensitive to the volume ratio of the reduced graphene oxide flakes to the carbon nanotubes in the spinning solution and the degree of graphene oxidation. The hybrid fibres were sewable and weavable, and could be shaped into high-modulus helical springs.

  5. Evaluating Carbon Sequestration and Solar Forcing Feedbacks Resulting from North American Afforestation

    Science.gov (United States)

    Mykleby, P.; Snyder, P. K.; Twine, T. E.

    2013-12-01

    The planting of trees and forests has long been accepted as a practical and efficient method to sequester carbon dioxide from the atmosphere. Assertive measures are now needed to ensure that atmospheric levels of carbon dioxide (CO2) do not continue to rise and cause additional planetary warming. However, recent studies have detected inadvertent biophysical feedbacks associated with land cover changes, especially in higher northern latitudes. The changes in surface reflectivity that occur when converting a lighter, more reflective surface, such as a grassland or bare soil, into a darker conifer forest, can result in surface warming due to the forest absorbing more shortwave radiation. This warming counteracts the cooling effect resulting from a reduction in atmospheric CO2 with increased vegetation productivity. This effect is further intensified in the higher northern latitudes where snow cover is prevalent during the long winter; the planting of trees can significantly decrease the reflectivity compared with white snow. The goal of this study is to determine whether the amount of carbon sequestered exceeds the carbon equivalent of the radiative forcing due to the change in surface reflectivity. This study uses the IBIS dynamic vegetation model with modified carbon dynamics for conifer forests validated with numerous Ameriflux and Fluxnet Canada field sites with varying stand ages and species compositions. We present results of model performance based on validation of net ecosystem exchange (NEE) and net radiation observations. Results from this study will be used to assess not only the net effect of conifer forest establishment on the long term carbon storage, but also the duration of time that a given location would remain a carbon sink during the lifetime of the forest. Only then, can policymakers begin to discuss the efficacy of afforestation as a sound climate mitigation strategy.

  6. Carbon Sequestration in loblolly pine plantations: Methods, limitations, and research needs for estimating storage pools

    Science.gov (United States)

    Kurt Johnsen; Bob Teskey; Lisa Samuelson; John Butnor; David Sampson; Felipe Sanchez; Chris Maier; Steve McKeand

    2004-01-01

    Globally, the species most widely used for plantation forestry is loblolly pine (Pinus taeda L.). Because loblolly pine plantations are so extensive and grow so rapidly, they provide a great potential for sequestering atmospheric carbon (C). Because loblolly pine plantations are relatively simple ecosystems and because such a great volume of...

  7. Soil erosion, sedimentation and the carbon cycle

    Science.gov (United States)

    Cammeraat, L. H.; Kirkels, F.; Kuhn, N. J.

    2012-04-01

    Historically soil erosion focused on the effects of on-site soil quality loss and consequently reduced crop yields, and off-site effects related to deposition of material and water quality issues such as increased sediment loads of rivers. In agricultural landscapes geomorphological processes reallocate considerable amounts of soil and soil organic carbon (SOC). The destiny of SOC is of importance because it constitutes the largest C pool of the fast carbon cycle, and which cannot only be understood by looking at the vertical transfer of C from soil to atmosphere. Therefore studies have been carried out to quantify this possible influence of soil erosion and soil deposition and which was summarized by Quinton et al. (2010) by "We need to consider soils as mobile systems to make accurate predictions about the consequences of global change for terrestrial biogeochemical cycles and climate feedbacks". Currently a debate exists on the actual fate of SOC in relation to the global carbon cycle, represented in a controversy between researchers claiming that erosion is a sink, and those who claim the opposite. This controversy is still continuing as it is not easy to quantify and model the dominating sink and source processes at the landscape scale. Getting insight into the balance of the carbon budget requires a comprehensive research of all relevant processes at broad spatio-temporal scales, from catchment to regional scales and covering the present to the late Holocene. Emphasising the economic and societal benefits, the merits for scientific knowledge of the carbon cycle and the potential to sequester carbon and consequently offset increasing atmospheric CO2 concentrations, make the fate of SOC in agricultural landscapes a high-priority research area. Quinton, J.N., Govers, G., Van Oost, K., Bardgett, R.D., 2010. The impact of agricultural soil erosion on biogeochemical cycling. Nature Geosci, 3, 311-314.

  8. Leveraging Carbon Cycling in Coastal Wetlands for Habitat Conservation: Blue Carbon Policy Opportunities (Invited)

    Science.gov (United States)

    Sutton-Grier, A.

    2013-12-01

    Recent scientific studies suggest that the carbon sequestered and stored in coastal wetlands (specifically mangroves, salt marshes, and seagrass meadows) is an important, previously not well-recognized service provided by these ecosystems. Coastal wetlands have unique characteristics that make them incredibly efficient, natural carbon sinks with most carbon stored belowground in soils. Based on this new scientific evidence, there is growing interest in leveraging the carbon services of these habitats (termed 'blue carbon') to develop new policy opportunities to protect and restore coastal wetlands around the globe. The overall goal is to take full advantage of the carbon services of these habitats in order to ensure and maintain the many benefits provided to society by these habitats - including natural climate, food security, and storm protection benefits - and to enhance the resiliency of coastal communities and economies around the world. This presentation will give an update on some of the policy opportunities including: (1) examining how the implementation of U.S. federal policies can be expanded to include carbon services of ecosystems in order to improve management and decision making; (2) developing an international blue carbon community of science and practice to provide best practice guidance for protection and restoration of blue carbon habitats; and (3) developing innovative financing mechanisms for coastal conservation including carbon market credits for wetlands. Finally, the presentation will conclude by highlighting some of the most pressing blue carbon scientific gaps that need to be filled in order to support these developing policies.

  9. Estimating carbon sequestration in the piedmont ecoregion of the United States from 1971 to 2010

    Directory of Open Access Journals (Sweden)

    Jinxun Liu

    2016-06-01

    Full Text Available Abstract Background Human activities have diverse and profound impacts on ecosystem carbon cycles. The Piedmont ecoregion in the eastern United States has undergone significant land use and land cover change in the past few decades. The purpose of this study was to use newly available land use and land cover change data to quantify carbon changes within the ecoregion. Land use and land cover change data (60-m spatial resolution derived from sequential remotely sensed Landsat imagery were used to generate 960-m resolution land cover change maps for the Piedmont ecoregion. These maps were used in the Integrated Biosphere Simulator (IBIS to simulate ecosystem carbon stock and flux changes from 1971 to 2010. Results Results show that land use change, especially urbanization and forest harvest had significant impacts on carbon sources and sinks. From 1971 to 2010, forest ecosystems sequestered 0.25 Mg C ha−1 yr−1, while agricultural ecosystems sequestered 0.03 Mg C ha−1 yr−1. The total ecosystem C stock increased from 2271 Tg C in 1971 to 2402 Tg C in 2010, with an annual average increase of 3.3 Tg C yr−1. Conclusions Terrestrial lands in the Piedmont ecoregion were estimated to be weak net carbon sink during the study period. The major factors contributing to the carbon sink were forest growth and afforestation; the major factors contributing to terrestrial emissions were human induced land cover change, especially urbanization and forest harvest. An additional amount of carbon continues to be stored in harvested wood products. If this pool were included the carbon sink would be stronger.

  10. Soil carbon and nitrogen sequestration over an age sequence of Pinus patula plantations in Zimbabwean Eastern Highlands

    NARCIS (Netherlands)

    Mujuru, L.; Gotora, T.; Velthorst, E.J.; Nyamangara, J.; Hoosbeek, M.R.

    2014-01-01

    Forests play a major role in regulating the rate of increase of global atmospheric carbon dioxide (CO2) concentrations creating a need to investigate the ability of exotic plantations to sequester atmospheric CO2. This study examined pine plantations located in the Eastern Highlands of Zimbabwe

  11. Nitrous oxide and methane fluxes vs. carbon, nitrogen and phosphorous burial in new intertidal and saltmarsh sediments

    Energy Technology Data Exchange (ETDEWEB)

    Adams, C.A., E-mail: christopher.adams@uea.ac.uk; Andrews, J.E.; Jickells, T.

    2012-09-15

    Carbon (C), nitrogen (N) and phosphorous (P) burial rates were determined within natural saltmarsh (NSM) and 'managed realignment' (MR) sediments of the Blackwater estuary, UK. Methane (CH{sub 4}) and nitrous oxide (N{sub 2}O) fluxes were measured along with their ability to offset a portion of the C burial to give net C sequestration. C and N densities (C{rho} and N{rho}) of NSM sediments (0.022 and 0.0019 g cm{sup -3}) are comparable to other UK NSM sediments. Less vegetationally developed MR sediments have lower C{rho} and N{rho} (0.012 and 0.0011 g cm{sup -3}) while the more vegetationally developed sites possess higher C{rho} and N{rho} (0.023 and 0.0030 g cm{sup -3}) than NSM. Both NSM and MR areas were small CH{sub 4} (0.10-0.40 g m{sup -2} yr{sup -1}) and N{sub 2}O (0.03-0.37 g m{sup -2} yr{sup -1}) sources. Due to their large Global Warming Potentials, even these relatively small greenhouse gas (GHG) fluxes reduced the net C sequestration within MR marshes by as much as 49%, but by only 2% from NSM. Potential MR areas within the Blackwater estuary (29.5 km{sup 2} saltmarsh and 23.7 km{sup 2} intertidal mudflat) could bury 5478 t C yr{sup -1} and 695.5 t N yr{sup -1}, with a further 476 t N yr{sup -1} denitrified. The saltmarsh MR would also sequester 139.4 t P yr{sup -1}. GHG fluxes would reduce the C burial benefit by 24% giving a C sequestration rate of 4174 t C yr{sup -1}. Similar areas within the Humber estuary (74.95 km{sup 2}) could bury 3597 t C yr{sup -1} and 180 t N yr{sup -1}, with a further 442 t N yr{sup -1} denitrified. GHG fluxes would reduce the C burial benefit by 31% giving a C sequestration rate of 2492 t C yr{sup -1}. Overall, MR sites provide sustainable coastal defence options with significant biogeochemical value and, despite being net sources of CH{sub 4} and N{sub 2}O, can sequester C and reduce estuarine nutrient loads. -- Highlights: Black-Right-Pointing-Pointer We investigated C, N, P, CH{sub 4} and N{sub 2}O fluxes

  12. Proteomic analysis of carbon concentrating chemolithotrophic bacteria Serratia sp. for sequestration of carbon dioxide.

    Science.gov (United States)

    Bharti, Randhir K; Srivastava, Shaili; Thakur, Indu Shekhar

    2014-01-01

    A chemolithotrophic bacterium enriched in the chemostat in presence of sodium bicarbonate as sole carbon source was identified as Serratia sp. by 16S rRNA sequencing. Carbon dioxide sequestering capacity of bacterium was detected by carbonic anhydrase enzyme and ribulose-1, 5- bisphosphate carboxylase/oxygenase (RuBisCO). The purified carbonic anhydrase showed molecular weight of 29 kDa. Molecular weight of RuBisCO was 550 kDa as determined by fast protein liquid chromatography (FPLC), however, sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) showed presence of two subunits whose molecular weights were 56 and 14 kDa. The Western blot analysis of the crude protein and purified sample cross reacted with RuBisCO large-subunit polypeptides antibodies showed strong band pattern at molecular weight around 56 kDa regions. Whole cell soluble proteins of Serratia sp. grown under autotrophic and heterotrophic conditions were resolved by two-dimensional gel electrophoresis and MALDI-TOF/MS for differential expression of proteins. In proteomic analysis of 63 protein spots, 48 spots were significantly up-regulated in the autotrophically grown cells; seven enzymes showed its utilization in autotrophic carbon fixation pathways and other metabolic activities of bacterium including lipid metabolisms indicated sequestration potency of carbon dioxide and production of biomaterials.

  13. Proteomic analysis of carbon concentrating chemolithotrophic bacteria Serratia sp. for sequestration of carbon dioxide.

    Directory of Open Access Journals (Sweden)

    Randhir K Bharti

    Full Text Available A chemolithotrophic bacterium enriched in the chemostat in presence of sodium bicarbonate as sole carbon source was identified as Serratia sp. by 16S rRNA sequencing. Carbon dioxide sequestering capacity of bacterium was detected by carbonic anhydrase enzyme and ribulose-1, 5- bisphosphate carboxylase/oxygenase (RuBisCO. The purified carbonic anhydrase showed molecular weight of 29 kDa. Molecular weight of RuBisCO was 550 kDa as determined by fast protein liquid chromatography (FPLC, however, sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE showed presence of two subunits whose molecular weights were 56 and 14 kDa. The Western blot analysis of the crude protein and purified sample cross reacted with RuBisCO large-subunit polypeptides antibodies showed strong band pattern at molecular weight around 56 kDa regions. Whole cell soluble proteins of Serratia sp. grown under autotrophic and heterotrophic conditions were resolved by two-dimensional gel electrophoresis and MALDI-TOF/MS for differential expression of proteins. In proteomic analysis of 63 protein spots, 48 spots were significantly up-regulated in the autotrophically grown cells; seven enzymes showed its utilization in autotrophic carbon fixation pathways and other metabolic activities of bacterium including lipid metabolisms indicated sequestration potency of carbon dioxide and production of biomaterials.

  14. Reduced carbon sequestration potential of biochar in acidic soil.

    Science.gov (United States)

    Sheng, Yaqi; Zhan, Yu; Zhu, Lizhong

    2016-12-01

    Biochar application in soil has been proposed as a promising method for carbon sequestration. While factors affecting its carbon sequestration potential have been widely investigated, the number of studies on the effect of soil pH is limited. To investigate the carbon sequestration potential of biochar across a series of soil pH levels, the total carbon emission, CO 2 release from inorganic carbon, and phospholipid fatty acids (PLFAs) of six soils with various pH levels were compared after the addition of straw biochar produced at different pyrolysis temperatures. The results show that the acidic soils released more CO 2 (1.5-3.5 times higher than the control) after the application of biochar compared with neutral and alkaline soils. The degradation of both native soil organic carbon (SOC) and biochar were accelerated. More inorganic CO 2 release in acidic soil contributed to the increased degradation of biochar. Higher proportion of gram-positive bacteria in acidic soil (25%-36%) was responsible for the enhanced biochar degradation and simultaneously co-metabolism of SOC. In addition, lower substrate limitation for bacteria, indicated by higher C-O stretching after the biochar application in the acidic soil, also caused more CO 2 release. In addition to the soil pH, other factors such as clay contents and experimental duration also affected the phsico-chemical and biotic processes of SOC dynamics. Gram-negative/gram-positive bacteria ratio was found to be negatively related to priming effects, and suggested to serve as an indicator for priming effect. In general, the carbon sequestration potential of rice-straw biochar in soil reduced along with the decrease of soil pH especially in a short-term. Given wide spread of acidic soils in China, carbon sequestration potential of biochar may be overestimated without taking into account the impact of soil pH. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Environment, Renewable Energy and Reduced Carbon Emissions

    Science.gov (United States)

    Sen, S.; Khazanov, G.; Kishimoto, Y.

    2011-01-01

    Increased energy security and reduced carbon emissions pose significant challenges for science and technology. However, they also create substantial opportunities for innovative research and development. In this review paper, we highlight some of the key opportunities and mention public policies that are needed to enable the efforts and to maximize the probability of their success. Climate is among the uttermost nonlinear behaviors found around us. As recent studies showed the possible effect of cosmic rays on the Earth's climate, we investigate how complex interactions between the planet and its environment can be responsible for climate anomalies.

  16. Effect of liming and organic and inorganic fertilization on soil carbon sequestered in macro-and microaggregates in a 17-year old Pinus radiata silvopastoral system.

    Science.gov (United States)

    Mosquera-Losada, M R; Rigueiro-Rodríguez, A; Ferreiro-Domínguez, N

    2015-03-01

    Agroforestry systems have been recognized as a potential greenhouse gas mitigation strategy under the Kyoto Protocol because of their ability to absorb carbon dioxide from the atmosphere and store carbon mainly in the soil. Soil particle size and land management practices are known to have a considerable influence on carbon storage in soils. This study evaluated changes in soil chemical and physical properties, and quantified and compared the amount of C stored in the bulk soil and in three different soil fractions (250-2000, 53-250 and silvopastoral system located on an acidic forest soil under Pinus radiata D. Don. Areas of this system were subjected ten years ago to one of nine fertilization treatments: three different doses of sewage sludge or no fertilization, all with or without the addition of lime, and mineral fertilizer with no liming. Seventeen years after reforestation and seven years after canopy closure, strong gradients with soil depth were found regarding soil bulk density, pH and carbon storage. Intense soil management (high doses of sewage sludge and liming) generally reduced soil carbon storage, mainly in coarse aggregates, but this could be compensated by the increase in tree and pasture development observed in soils subject to intermediate sewage sludge doses. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Ocean Fertilization for Sequestration of Carbon Dioxide from the Atmosphere

    Science.gov (United States)

    Boyd, Philip W.

    The ocean is a major sink for both preindustrial and anthropogenic carbon dioxide. Both physically and biogeochemically driven pumps, termed the solubility and biological pump, respectively Fig.5.1) are responsible for the majority of carbon sequestration in the ocean's interior [1]. The solubility pump relies on ocean circulation - specifically the impact of cooling of the upper ocean at high latitudes both enhances the solubility of carbon dioxide and the density of the waters which sink to great depth (the so-called deepwater formation) and thereby sequester carbon in the form of dissolved inorganic carbon (Fig.5.1). The biological pump is driven by the availability of preformed plant macronutrients such as nitrate or phosphate which are taken up by phytoplankton during photosynthetic carbon fixation. A small but significant proportion of this fixed carbon sinks into the ocean's interior in the form of settling particles, and in order to maintain equilibrium carbon dioxide from the atmosphere is transferred across the air-sea interface into the ocean (the so-called carbon drawdown) thereby decreasing atmospheric carbon dioxide (Fig.5.1).Fig.5.1

  18. Soil carbon sequestration and changes in fungal and bacterial biomass following incorporation of forest residues

    Science.gov (United States)

    Matt D. Busse; Felipe G. Sanchez; Alice W. Ratcliff; John R. Butnor; Emily A. Carter; Robert F. Powers

    2009-01-01

    Sequestering carbon (C) in forest soils can benefit site fertility and help offset greenhouse gas emissions. However, identifying soil conditions and forest management practices which best promote C accumulation remains a challenging task. We tested whether soil incorporation of masticated woody residues alters short-term C storage at forested sites in western and...

  19. BIOGENIC VS. ABIOGENIC ISOTOPE SIGNATURES OF REDUCED CARBON COMPOUNDS: A LESSON FROM HYDROTHERMAL SYNTHESIS EXPERIMENTS

    International Nuclear Information System (INIS)

    Horita, J.

    2001-01-01

    With growing interest in and demonstrated cases of inorganic hydrothermal synthesis of reduced or organic carbon compounds from CO and CO(sub 2), it becomes crucial to establish geochemical criteria to distinguish reduced/organic carbon compounds of abiogenic origin from those of biogenic origin with overwhelming abundances on the surface and in subsurface of the Earth. Chemical and isotopic compositions, particularly(sup 13)C/(sup 12)C ratios, of reduced/organic carbon compounds have been widely utilized for deducing the origins and formation pathways of these compounds. An example is isotopic and C(sub 1)/(C(sub 2)+C(sub 3)) ratios of natural gases, which have been used to distinguish bacterial, thermogenic, and possible abiogenic origins. Another example is that ancient graphitic carbon with(delta)(sup 13)C values c-25per thousand has been considered of biogenic origin. Although these criteria could be largely valid, growing data including those from our hydrothermal experiments suggest that a great caution must be exercised

  20. Forest management strategies for reducing carbon emissions, the French case

    Science.gov (United States)

    Valade, Aude; Luyssaert, Sebastiaan; Bellassen, Valentin; Vallet, Patrick; Martin, Manuel

    2015-04-01

    International agreements now recognize the role of forest in the mitigation of climate change through the levers of in-situ sequestration, storage in products and energy and product substitution. These three strategies of carbon management are often antagonistic and it is still not clear which strategy would have the most significant impact on atmospheric carbon concentrations. With a focus on France, this study compares several scenarios of forest management in terms of their effect on the overall carbon budget from trees to wood-products. We elaborated four scenarios of forest management that target different wood production objectives. One scenario is 'Business as usual' and reproduces the current forest management and wood production levels. Two scenarios target an increase in bioenergy wood production, with either long-term or short-term goals. One scenario aims at increasing the production of timber for construction. For this, an empirical regression model was developed building on the rich French inventory database. The model can project the current forest resource at a time horizon of 20 years for characteristic variables diameter, standing volume, above-ground biomass, stand age. A simplified life-cycle analysis provides a full carbon budget for each scenario from forest management to wood use and allows the identification of the scenario that most reduces carbon emissions.

  1. Carbon footprint of telemedicine solutions--unexplored opportunity for reducing carbon emissions in the health sector.

    Science.gov (United States)

    Holmner, Asa; Ebi, Kristie L; Lazuardi, Lutfan; Nilsson, Maria

    2014-01-01

    The healthcare sector is a significant contributor to global carbon emissions, in part due to extensive travelling by patients and health workers. To evaluate the potential of telemedicine services based on videoconferencing technology to reduce travelling and thus carbon emissions in the healthcare sector. A life cycle inventory was performed to evaluate the carbon reduction potential of telemedicine activities beyond a reduction in travel related emissions. The study included two rehabilitation units at Umeå University Hospital in Sweden. Carbon emissions generated during telemedicine appointments were compared with care-as-usual scenarios. Upper and lower bound emissions scenarios were created based on different teleconferencing solutions and thresholds for when telemedicine becomes favorable were estimated. Sensitivity analyses were performed to pinpoint the most important contributors to emissions for different set-ups and use cases. Replacing physical visits with telemedicine appointments resulted in a significant 40-70 times decrease in carbon emissions. Factors such as meeting duration, bandwidth and use rates influence emissions to various extents. According to the lower bound scenario, telemedicine becomes a greener choice at a distance of a few kilometers when the alternative is transport by car. Telemedicine is a potent carbon reduction strategy in the health sector. But to contribute significantly to climate change mitigation, a paradigm shift might be required where telemedicine is regarded as an essential component of ordinary health care activities and not only considered to be a service to the few who lack access to care due to geography, isolation or other constraints.

  2. Energy and economic considerations for ex-situ and aqueous mineral carbonation

    Energy Technology Data Exchange (ETDEWEB)

    O' Connor, William K.; Dahlin, David C.; Rush, G.E.; Gerdemann, Stephen J.; Penner, L.R.

    2004-01-01

    Due to the scale and breadth of carbon dioxide emissions, and speculation regarding their impact on global climate, sequestration of some portion of these emissions has been under increased study. A practical approach to carbon sequestration will likely include several options, which will be driven largely by the energy demand and economics of operation. Aqueous mineral carbonation of calcium and magnesium silicate minerals has been studied as one potential method to sequester carbon dioxide. Although these carbonation reactions are all thermodynamically favored, they occur at geologic rates of reaction. Laboratory studies have demonstrated that these rates of reaction are accelerated with increasing temperature, pressure, and particle surface area. Mineral-specific activation methods were identified, however, each of these techniques incurs energy as well as economic costs. An overview of the mineral availability, pretreatment options and energy demands, and process economics is provided.

  3. Bayesian Evaluation of Dynamical Soil Carbon Models Using Soil Carbon Flux Data

    Science.gov (United States)

    Xie, H. W.; Romero-Olivares, A.; Guindani, M.; Allison, S. D.

    2017-12-01

    2016 was Earth's hottest year in the modern temperature record and the third consecutive record-breaking year. As the planet continues to warm, temperature-induced changes in respiration rates of soil microbes could reduce the amount of carbon sequestered in the soil organic carbon (SOC) pool, one of the largest terrestrial stores of carbon. This would accelerate temperature increases. In order to predict the future size of the SOC pool, mathematical soil carbon models (SCMs) describing interactions between the biosphere and atmosphere are needed. SCMs must be validated before they can be chosen for predictive use. In this study, we check two SCMs called CON and AWB for consistency with observed data using Bayesian goodness of fit testing that can be used in the future to compare other models. We compare the fit of the models to longitudinal soil respiration data from a meta-analysis of soil heating experiments using a family of Bayesian goodness of fit metrics called information criteria (IC), including the Widely Applicable Information Criterion (WAIC), the Leave-One-Out Information Criterion (LOOIC), and the Log Pseudo Marginal Likelihood (LPML). These IC's take the entire posterior distribution into account, rather than just one outputted model fit line. A lower WAIC and LOOIC and larger LPML indicate a better fit. We compare AWB and CON with fixed steady state model pool sizes. At equivalent SOC, dissolved organic carbon, and microbial pool sizes, CON always outperforms AWB quantitatively by all three IC's used. AWB monotonically improves in fit as we reduce the SOC steady state pool size while fixing all other pool sizes, and the same is almost true for CON. The AWB model with the lowest SOC is the best performing AWB model, while the CON model with the second lowest SOC is the best performing model. We observe that AWB displays more changes in slope sign and qualitatively displays more adaptive dynamics, which prevents AWB from being fully ruled out for

  4. Land-use change to bioenergy production in Europe: implications for the greenhouse gas balance and soil carbon

    DEFF Research Database (Denmark)

    Don, Axel; Osborne, Bruce; Hastings, Astley

    2012-01-01

    for Miscanthus). However, there was no positive or even negative effects on the C balance if energy crops are established on former grassland. Increased bioenergy production may also result in direct and indirect land-use changes with potential high C losses when native vegetation is converted to annual crops......Bioenergy from crops is expected to make a considerable contribution to climate change mitigation. However, bioenergy is not necessarily carbon neutral because emissions of CO2, N2O and CH4 during crop production may reduce or completely counterbalance CO2 savings of the substituted fossil fuels...... of lower fertilizer requirements as well as a higher N-use efficiency, due to effective N-recycling. Perennial energy crops have the potential to sequester additional carbon in soil biomass if established on former cropland (0.44 Mg soil C ha 1 yr 1 for poplar and willow and 0.66 Mg soil C ha 1 yr 1...

  5. Baseload coal investment decisions under uncertain carbon legislation.

    Science.gov (United States)

    Bergerson, Joule A; Lave, Lester B

    2007-05-15

    More than 50% of electricity in the U.S. is generated by coal. The U.S. has large coal resources, the cheapest fuel in most areas. Coal fired power plants are likely to continue to provide much of U.S. electricity. However, the type of power plant that should be built is unclear. Technology can reduce pollutant discharges and capture and sequester the CO2 from coal-fired generation. The U.S. Energy Policy Act of 2005 provides incentives for large scale commercial deployment of Integrated Coal Gasification Combined Cycle (IGCC) systems (e.g., loan guarantees and project tax credits). This analysis examines whether a new coal plant should be Pulverized Coal (PC) or IGCC. Do stricter emissions standards (PM, SO2, NOx, Hg) justify the higher costs of IGCC over PC? How does potential future carbon legislation affect the decision to add carbon capture and storage (CCS) technology? Finally, can the impact of uncertain carbon legislation be minimized? We find that SO2, NOx, PM, and Hg emission standards would have to be far more stringent than twice current standards to justify the increased costs of the IGCC system. A C02 tax less than $29/ton would lead companies to continuing to choose PC, paying the tax for emitted CO2. The earlier a decision-maker believes the carbon tax will be imposed and the higher the tax, the more likely companies will choose IGCC w/CCS. Having government announce the date and level of a carbon tax would promote more sensible decisions, but government would have to use a tax or subsidy to induce companies to choose the technology that is best for society.

  6. Land-use change and carbon sinks: Econometric estimation of the carbon sequestration supply function

    Energy Technology Data Exchange (ETDEWEB)

    Lubowski, Ruben N.; Plantinga, Andrew J.; Stavins, Robert N.

    2001-01-01

    Increased attention by policy makers to the threat of global climate change has brought with it considerable interest in the possibility of encouraging the expansion of forest area as a means of sequestering carbon dioxide. The marginal costs of carbon sequestration or, equivalently, the carbon sequestration supply function will determine the ultimate effects and desirability of policies aimed at enhancing carbon uptake. In particular, marginal sequestration costs are the critical statistic for identifying a cost-effective policy mix to mitigate net carbon dioxide emissions. We develop a framework for conducting an econometric analysis of land use for the forty-eight contiguous United States and employing it to estimate the carbon sequestration supply function. By estimating the opportunity costs of land on the basis of econometric evidence of landowners' actual behavior, we aim to circumvent many of the shortcomings of previous sequestration cost assessments. By conducting the first nationwide econometric estimation of sequestration costs, endogenizing prices for land-based commodities, and estimating land-use transition probabilities in a framework that explicitly considers the range of land-use alternatives, we hope to provide better estimates eventually of the true costs of large-scale carbon sequestration efforts. In this way, we seek to add to understanding of the costs and potential of this strategy for addressing the threat of global climate change.

  7. Can a carbon permit system reduce Spanish unemployment?

    International Nuclear Information System (INIS)

    Faehn, Taran; Gomez-Plana, Antonio G.; Kverndokk, Snorre

    2009-01-01

    This paper analyses the impact of carbon policy on unemployment in Spain and whether recycling the public revenues earned from permit auctions can alleviate this problem. While Spain's deviation from the European Union's intermediate emission goals is more serious than most other member countries' unemployment in Spain is also well above average for the European Union. We use a computable general equilibrium model that includes unemployment in the markets for unskilled and skilled labour. We find that introducing carbon permits does not aggravate Spanish unemployment. In fact, if supplied with revenue recycling schemes, unemployment rates may actually fall. Contrary to other European studies, we find that the best option is to reduce payroll taxes on relatively skilled types of labour. This reform is successful in both increasing labour demand and dampening the supply response to rising wages. However, while all of the recycling schemes generate dividends in terms of aggregate welfare, none entirely offsets the abatement costs. (author)

  8. Sedimentology of polar carbonate systems

    Science.gov (United States)

    Frank, T. D.; James, N. P.

    2013-12-01

    terrigenous clastics are sequestered inboard and invigorated ocean circulation enhances upwelling. Radiocarbon data from Quaternary deposits in the Ross Sea indicate that short windows of accumulation during favorable conditions are followed by longer intervals of non-productivity, during which skeletal debris undergoes dissolution and infestation by endolithic borers, carbonate sediments are reworked by bottom currents, and glacigene siliciclastic facies are deposited. Similar patterns are evident in Permian deposits. We interpret the post-carbonate depositional periods as not only due to increased terrigenous input but also dramatically reduced trophic resources. The foregoing hypothesis is at odds with most current thinking about carbonate deposition and points to an evolving paradigm within which polar carbonate deposition is dramatically different than that in temperate and tropical settings.

  9. Research developments in methods to reduce the carbon footprint of the food system: a review.

    Science.gov (United States)

    Xu, Zhongyue; Sun, Da-Wen; Zeng, Xin-An; Liu, Dan; Pu, Hongbin

    2015-01-01

    Global warming is a worldwide issue with its evident impact across a wide range of systems and sectors. It is caused by a number of greenhouse gases (GHGs) emissions, in which food system has made up of a large part. Recently, reduction of GHG emissions has become an urgent issue to be resolved in the food system. Many governments and organizations are making great endeavors to alleviate the adverse effect of this phenomenon. In this review, methods to reduce the carbon footprint within the life cycle of a food system are presented from the technical, consumption behavior and environmental policies perspectives. The whole food system including raw material acquisition, processing, packaging, preservation, transportation, consumption, and disposal are covered. Improving management techniques, and adopting advanced technology and equipment are critical for every stage of a food system. Rational site selection is important to alleviate the influence of land use change. In addition, environmental choices of packaging stage, reduction in refrigeration dependence, and correct waste treatment are essential to reduce the total carbon footprint of the production. However, only technical methods cannot radically reverse the trend of climate change, as consumption behaviors present a great deal of influence over climate change. Appropriate purchase patterns and substitution within food product categories by low carbon products can reduce GHG emissions. Development of methods to calculate the carbon footprint of every kind of food and its processing technology enable people to make environmental choice. Policy can shape and cultivate the new code of consumption and influence the direction of emerging technology and science. From political perspectives, government intervention and carbon offset are common tools, especially for carbon tax and a real or implicit price of carbon. Finally, by mitigating the methodologies described above, the rate and magnitude of climate changes

  10. Does carbonation of steel slag particles reduce their toxicity? An in vitro approach.

    Science.gov (United States)

    Ibouraadaten, Saloua; van den Brule, Sybille; Lison, Dominique

    2015-06-01

    Mineral carbonation can stabilize industrial residues and, in the steel industry, may contribute to simultaneously valorize CO2 emissions and slag. We hypothesized that, by restricting the leaching of metals of toxicological concern such as Cr and V, carbonation can suppress the toxicity of these materials. The cytotoxic activity (WST1 assay) of slag dusts collected from a stainless and a Linz-Donawitz (LD) steel plant, before and after carbonation, was examined in J774 macrophages. The release of Cr, V, Fe, Mn and Ni was measured after incubation in artificial lung fluids mimicking the extracellular and phagolysosomal milieu to which particles are confronted after inhalation. LD slag had the higher Fe, Mn and V content, and was more cytotoxic than stainless steel slag. The cytotoxic activity of LD but not of stainless dusts was reduced after carbonation. The cytotoxic activity of the dusts toward J774 macrophages necessitated a direct contact with the cells and was reduced in the presence of inhibitors of phagocytosis (cytochalasin D) or phagolysosome acidification (bafilomycin), pointing to a key role of metallic constituents released in phagolysosomes. This in vitro study supports a limited reduction of the cytotoxic activity of LD, but not of stainless, steel dusts upon carbonation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Post-fire management regimes affect carbon sequestration and storage in a Sierra Nevada mixed conifer forest

    Science.gov (United States)

    Elizabeth M. Powers; John D. Marshall; Jianwei Zhang; Liang Wei

    2013-01-01

    Forests mitigate climate change by sequestering CO2 from the atmosphere and accumulating it in biomass storage pools. However, in dry conifer forests, fire occasionally returns large quantities of CO2 to the atmosphere. Both the total amount of carbon stored and its susceptibility to loss may be altered by post-fire land...

  12. Soil carbon and nitrogen content and stabilization in mid-rotation, intensively managed sweetgum and loblolly stands

    Science.gov (United States)

    Kurt H. Johnsen; Lisa J. Samuelson; Felipe G. Sanchez; Bob Eaton

    2013-01-01

    Intensive forestry has resulted in considerable increases in aboveground stand productivity including foliar and belowground biomass which are the primary sources of soil organic matter. Soil organic matter is important for the maintenance of soil physical, chemical and biological quality. Additionally, sequestering carbon (C) in soils may provide a means of mitigating...

  13. Carbon Sequestration and Sedimentation in Mangrove Swamps Influenced by Hydrogeomorphic Conditions and Urbanization in Southwest Florida

    Directory of Open Access Journals (Sweden)

    Daniel A. Marchio

    2016-05-01

    Full Text Available This study compares carbon sequestration rates along two independent tidal mangrove creeks near Naples Bay in Southwest Florida, USA. One tidal creek is hydrologically disturbed due to upstream land use changes; the other is an undisturbed reference creek. Soil cores were collected in basin, fringe, and riverine hydrogeomorphic settings along each of the two tidal creeks and analyzed for bulk density, total organic carbon profiles, and sediment accretion. Radionuclides 137Cs and 210Pb were used to estimate recent sediment accretion and carbon sequestration rates. Carbon sequestration rates (mean ± standard error for seven sites in the two tidal creeks on the Naples Bay (98 ± 12 g-C m−2·year−1 (n = 18 are lower than published global means for mangrove wetlands, but consistent with other estimates from the same region. Mean carbon sequestration rates in the reference riverine setting were highest (162 ± 5 g-C m−2·year−1, followed by rates in the reference fringe and disturbed riverine settings (127 ± 6 and 125 ± 5 g-C m−2·year−1, respectively. The disturbed fringe sequestered 73 ± 10 g-C m−2·year−1, while rates within the basin settings were 50 ± 4 g-C m−2·year−1 and 47 ± 4 g-C m−2·year−1 for the reference and disturbed creeks, respectively. These data support our hypothesis that mangroves along a hydrologically disturbed tidal creek sequestered less carbon than did mangroves along an adjacent undisturbed reference creek.

  14. Effect of thinning, fertilization with biosolids, and weather on interannual ring specific gravity and carbon accumulation of a 55-year-old Douglas-fir stand in western Washington

    Energy Technology Data Exchange (ETDEWEB)

    Kantavichai, R.; Briggs, D.G.; Turnblom, E.C. [Washington Univ., Seattle, WA (United States). School of Forest Resources

    2010-01-15

    Soil moisture deficits (SMD) cause trees to conserve water by closing stomata, which in turn limits the uptake of atmospheric carbon dioxide (CO{sub 2}) and curtails photosynthesis and wood formation. This study investigated the combined effect of temperature, precipitation, SMD, and various silviculture treatments on interannual ring specific gravity (SG). A model was developed to predict post-treatment interannual ring SG from the treatment and environmental variables. The study assumed that thinning the stand would increase SG, while fertilization with biosolids would decrease SG. The SGs associated with each treatment were then used to calculate the dry mass and carbon content associated with stem growth. Results were then compared with estimates taken from standard publications. The experiment was conducted on a 55-year old Douglas fir stand. Twelve rings were used to assess the effect of the treatments. The study showed that use of the published average to consider only carbon sequestered by tree growth distorts the comparison of management regimes. The thinning process produced logs from which long-term structures were built, and continue to sequester carbon. When product pools of stored carbon are combined with forest carbon pools, thinning and biosolids treatment regimes are preferable to other carbon storage regimes. 40 refs., 6 tabs., 2 figs.

  15. Abundant pre-industrial carbon detected in Canadian Arctic headwaters: implications for the permafrost carbon feedback

    Science.gov (United States)

    Dean, J. F.; van der Velde, Y.; Garnett, M. H.; Dinsmore, K. J.; Baxter, R.; Lessels, J. S.; Smith, P.; Street, L. E.; Subke, J.-A.; Tetzlaff, D.; Washbourne, I.; Wookey, P. A.; Billett, M. F.

    2018-03-01

    Mobilization of soil/sediment organic carbon into inland waters constitutes a substantial, but poorly-constrained, component of the global carbon cycle. Radiocarbon (14C) analysis has proven a valuable tool in tracing the sources and fate of mobilized carbon, but aquatic 14C studies in permafrost regions rarely detect ‘old’ carbon (assimilated from the atmosphere into plants and soil prior to AD1950). The emission of greenhouse gases derived from old carbon by aquatic systems may indicate that carbon sequestered prior to AD1950 is being destabilized, thus contributing to the ‘permafrost carbon feedback’ (PCF). Here, we measure directly the 14C content of aquatic CO2, alongside dissolved organic carbon, in headwater systems of the western Canadian Arctic—the first such concurrent measurements in the Arctic. Age distribution analysis indicates that the age of mobilized aquatic carbon increased significantly during the 2014 snow-free season as the active layer deepened. This increase in age was more pronounced in DOC, rising from 101-228 years before sampling date (a 120%-125% increase) compared to CO2, which rose from 92-151 years before sampling date (a 59%-63% increase). ‘Pre-industrial’ aged carbon (assimilated prior to ~AD1750) comprised 15%-40% of the total aquatic carbon fluxes, demonstrating the prevalence of old carbon to Arctic headwaters. Although the presence of this old carbon is not necessarily indicative of a net positive PCF, we provide an approach and baseline data which can be used for future assessment of the PCF.

  16. Carbon sequestration index as a determinant for climate change mitigation: Case study of Bintan Island

    Science.gov (United States)

    Wahyudi, A.'an J.; Afdal; Prayudha, Bayu; Dharmawan, I. W. E.; Irawan, Andri; Abimanyu, Haznan; Meirinawati, Hanny; Surinati, Dewi; Syukri, Agus F.; Yuliana, Chitra I.; Yuniati, Putri I.

    2018-02-01

    The increase of the anthropogenic carbon dioxide (CO2) affects the global carbon cycle altering the atmospheric system and initiates the climate changes. There are two ways to mitigate these changes, by maintaining the greenhouse gasses below the carbon budget and by conserving the marine and terrestrial vegetation for carbon sequestration. These two strategies become variable to the carbon sequestration index (CSI) that represents the potential of a region in carbon sequestration, according to its natural capacity. As a study case, we conducted carbon sequestration research in Bintan region (Bintan Island and its surrounding), Riau Archipelago province. This research was aimed to assess the CSI and its possibility for climate change mitigation. We observed carbon sequestration of seagrass meadows and mangrove, greenhouse gas (CO2) emission (correlated to population growth, the increase of vehicles), and CSI. Bintan region has 125,849.9 ha of vegetation area and 14,879.6 ha of terrestrial and marine vegetation area, respectively. Both vegetation areas are able to sequester 0.262 Tg C yr-1 in total and marine vegetation contributes about 77.1%. Total CO2 emission in Bintan region is up to 0.273 Tg C yr-1, produced by transportation, industry and land use sectors. Therefore, CSI of the Bintan region is 0.98, which is above the global average (i.e. 0.58). This value demonstrates that the degree of sequestration is comparable to the total carbon emission. This result suggests that Bintan’s vegetation has high potential for reducing greenhouse gas effects.

  17. Phylogenetic variation of phytolith carbon sequestration in bamboos.

    Science.gov (United States)

    Li, Beilei; Song, Zhaoliang; Li, Zimin; Wang, Hailong; Gui, Renyi; Song, Ruisheng

    2014-04-16

    Phytoliths, the amorphous silica deposited in plant tissues, can occlude organic carbon (phytolith-occluded carbon, PhytOC) during their formation and play a significant role in the global carbon balance. This study explored phylogenetic variation of phytolith carbon sequestration in bamboos. The phytolith content in bamboo varied substantially from 4.28% to 16.42%, with the highest content in Sasa and the lowest in Chimonobambusa, Indocalamus and Acidosasa. The mean PhytOC production flux and rate in China's bamboo forests were 62.83 kg CO2 ha(-1) y(-1) and 4.5 × 10(8)kg CO2 y(-1), respectively. This implies that 1.4 × 10(9) kg CO2 would be sequestered in world's bamboo phytoliths because the global bamboo distribution area is about three to four times higher than China's bamboo. Therefore, both increasing the bamboo area and selecting high phytolith-content bamboo species would increase the sequestration of atmospheric CO2 within bamboo phytoliths.

  18. The Potential of Road Pricing Schemes for Reducing Carbon Emissions

    Energy Technology Data Exchange (ETDEWEB)

    Nocera, S.; Giaretta, F.; Cavallaro, F.

    2016-07-01

    Road pricing is a transport measure mainly conceived to fund road management, to regulate the demand for traffic and to reduce the number of private vehicles circulating in urban areas. It can also grant benefits in terms of environmental externalities including the reduction of CO2 emissions, which has recently become one of the most important elements defining the sustainability of a transport system. However, the carbon potential granted by road charging is rarely assessed, thus confirming a sort of secondary role attributed to CO2 in urban premises. This paper provides an accurate analysis of the relationship between the different forms of road pricing (including distance-based, congestion-based and pay-as-you-drive) and their effective role in terms of carbon reduction, which in some contexts is higher than 10%. Furthermore, practical suggestions to policy makers in terms of implementation of the measure are discussed, highlighting the precautions necessary to include a fair carbon evaluation into an overall effective analysis. (Author)

  19. Reducing CO2 emissions on the electric grid through a carbon disincentive policy

    International Nuclear Information System (INIS)

    Li, Chiao-Ting; Peng, Huei; Sun, Jing

    2013-01-01

    This paper studies the operation of an electric grid with renewable wind generation and plug-in electric vehicles (PEVs). In particular, PEVs will be the controllable demand that can mitigate the intermittency in wind generation and improve the capacity factors of the non-renewable generation assets on the grid. Optimization problems are formulated to minimize the costs of electricity generation, and two approaches are proposed to address the grid CO 2 emission in the optimization. The first approach directly penalizes CO 2 in the objective function, and the second approach adopts a carbon disincentive policy to alter the dispatch order of power plants, so that expensive low-CO 2 plants can replace cheap high-CO 2 plants. These two approaches result in very different outcomes: the first approach affects only the PEV charging demand on the grid and does not result in significant CO 2 reduction, whereas the second approach controls both the generation and load, and CO 2 can be reduced substantially. In addition, the carbon disincentive policy, unlike a carbon tax, does not collect any revenue; therefore, the increase in electricity cost is minimal. The effect of the proposed algorithms on the grid electricity cost and carbon emission is analyzed in details and reported. - Highlights: • We study the tradeoff between CO 2 emissions and generation cost on an electric grid. • The tradeoff was shown by Pareto fronts obtained from optimizations. • Pareto fronts shows that a carbon disincentive is effective in reducing emissions. • Controlling both supply and demand on the grid is necessary to reduce CO 2 and costs

  20. Exercise-based transportation reduces oil dependence, carbon emissions and obesity

    Energy Technology Data Exchange (ETDEWEB)

    Higgins, P.A.T.

    2005-09-15

    Societal dependence on oil leads to increasingly negative social consequences throughout the world, including climate change, air pollution, political and economic instability, and habitat degradation. Reliance on the automobile for transportation also contributes to a sedentary lifestyle, an obesity epidemic and poor health. These problems are particularly pronounced in the USA, which currently consumes c. 27% of global oil production and produces c. 25% of global carbon emissions, and where c. 65% of adults are overweight or obese. Other countries throughout the world that replicate or hope to replicate the automobile-based lifestyle of the USA face similar problems now or in the near future. This paper develops and applies calculations relating the distances that could be travelled through recommended daily walking or cycling with weight loss, oil consumption and carbon emissions. These straightforward calculations demonstrate that widespread substitution of driving with distances travelled during recommended daily exercise could reduce the USA's oil consumption by up to 38%. This saving far exceeds the amount of oil recoverable from the Arctic National Wildlife Refuge, suggesting that exercise can reduce foreign oil dependence and provide an alternative to oil extraction from environmentally sensitive habitat. At the same time, an average individual who substitutes this amount of exercise for transportation would burn respectively c. 12.2 and 26.0 kg of fat per year for walking and cycling. This is sufficient to eliminate obese and overweight conditions in a few years without dangerous or draconian diet plans. Furthermore, a reduction in carbon dioxide emissions of c. 35% is possible if the revenue saved through decreased health care spending on obesity is redirected toward carbon abatement. As a result, exercise-based transportation may constitute a favourable alternative to the energy and diet plans that are currently being implemented in the USA and may

  1. Land-use change and carbon sinks: Econometric estimation of the carbon sequestration supply function; FINAL

    International Nuclear Information System (INIS)

    Lubowski, Ruben N.; Plantinga, Andrew J.; Stavins, Robert N.

    2001-01-01

    Increased attention by policy makers to the threat of global climate change has brought with it considerable interest in the possibility of encouraging the expansion of forest area as a means of sequestering carbon dioxide. The marginal costs of carbon sequestration or, equivalently, the carbon sequestration supply function will determine the ultimate effects and desirability of policies aimed at enhancing carbon uptake. In particular, marginal sequestration conts are the critical statistic for identifying a cost-effective policy mix to mitigate net carbon dioxide emissions. We develop a framework for conducting an econometric analysis of land use for the forty-eight contiguous United States and employing it to estimate the carbon sequestration supply function. By estimating the opportunity costs of land on the basis of econometric evidence of landowners' actual behavior, we aim to circumvent many of the shortcomings of previous sequestration cost assessments. By conducting the first nationwide econometric estimation of sequestration costs, endogenizing prices for land-based commodities, and estimating land-use transition probabilities in a framework that explicitly considers the range of land-use alternatives, we hope to provide better estimates eventually of the true costs of large-scale carbon sequestration efforts. In this way, we seek to add to understanding of the costs and potential of this strategy for addressing the threat of global climate change

  2. Micropore clogging by leachable pyrogenic organic carbon: A new perspective on sorption irreversibility and kinetics of hydrophobic organic contaminants to black carbon.

    Science.gov (United States)

    Wang, Bingyu; Zhang, Wei; Li, Hui; Fu, Heyun; Qu, Xiaolei; Zhu, Dongqiang

    2017-01-01

    Black carbon (BC) plays a crucial role in sequestering hydrophobic organic contaminants in the environment. This study investigated key factors and mechanisms controlling nonideal sorption (e.g., sorption irreversibility and slow kinetics) of model hydrophobic organic contaminants (nitrobenzene, naphthalene, and atrazine) by rice-straw-derived BC. After removing the fraction of leachable pyrogenic organic carbon (LPyOC) (referring to composites of dissoluble non-condensed organic carbon and associated mineral components) with deionized water or 0.5 M NaOH, sorption of these sorbates to BC was enhanced. The sorption enhancement was positively correlated with sorbate molecular size in the order of atrazine > naphthalene > nitrobenzene. The removal of LPyOC also accelerated sorption kinetics and reduced sorption irreversibility. These observations were attributed to increased accessibility of BC micropores initially clogged by the LPyOC. Comparison of BC pore size distributions before and after atrazine sorption further suggested that the sorbate molecules preferred to access the micropores that were more open, and the micropore accessibility was enhanced by the removal of LPyOC. Consistently, the sorption of nitrobenzene and atrazine to template-synthesized mesoporous carbon (CMK3), a model sorbent with homogeneous pore structures, showed decreased kinetics, but increased irreversibility by impregnating sorbent pores with surface-grafted alkylamino groups and by subsequent loading of humic acid. These findings indicated an important and previously unrecognized role of LPyOC (i.e., micropore clogging) in the nonideal sorption of organic contaminants to BC. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Climate Impacts on Soil Carbon Processes along an Elevation Gradient in the Tropical Luquillo Experimental Forest

    Directory of Open Access Journals (Sweden)

    Dingfang Chen

    2017-03-01

    Full Text Available Tropical forests play an important role in regulating the global climate and the carbon cycle. With the changing temperature and moisture along the elevation gradient, the Luquillo Experimental Forest in Northeastern Puerto Rico provides a natural approach to understand tropical forest ecosystems under climate change. In this study, we conducted a soil translocation experiment along an elevation gradient with decreasing temperature but increasing moisture to study the impacts of climate change on soil organic carbon (SOC and soil respiration. As the results showed, both soil carbon and the respiration rate were impacted by microclimate changes. The soils translocated from low elevation to high elevation showed an increased respiration rate with decreased SOC content at the end of the experiment, which indicated that the increased soil moisture and altered soil microbes might affect respiration rates. The soils translocated from high elevation to low elevation also showed an increased respiration rate with reduced SOC at the end of the experiment, indicating that increased temperature at low elevation enhanced decomposition rates. Temperature and initial soil source quality impacted soil respiration significantly. With the predicted warming climate in the Caribbean, these tropical soils at high elevations are at risk of releasing sequestered carbon into the atmosphere.

  4. The economic value of biochar in crop production and carbon sequestration

    International Nuclear Information System (INIS)

    Galinato, Suzette P.; Yoder, Jonathan K.; Granatstein, David

    2011-01-01

    This paper estimates the economic value of biochar application on agricultural cropland for carbon sequestration and its soil amendment properties. In particular, we consider the carbon emissions avoided when biochar is applied to agricultural soil, instead of agricultural lime, the amount of carbon sequestered, and the value of carbon offsets, assuming there is an established carbon trading mechanism for biochar soil application. We use winter wheat production in Eastern Whitman County, Washington as a case study, and consider different carbon offset price scenarios and different prices of biochar to estimate a farm profit. Our findings suggest that it may be profitable to apply biochar as a soil amendment under some conditions if the biochar market price is low enough and/or a carbon offset market exists. - Highlights: → We estimate the economic value of biochar application on agricultural cropland. → We consider biochar's carbon sequestration and soil amendment properties. → Biochar soil application may be profitable if a carbon offset market exists for it. → Farmers may use biochar if its market price is low enough to earn a profit.

  5. Fuel treatment impacts on estimated wildfire carbon loss from forests in Montana, Oregon, California, and Arizona

    Science.gov (United States)

    Stephens, Scott L.; Boerner, Ralph E.J.; Maghaddas, Jason J.; Maghaddas, Emily E.Y.; Collins, Brandon M.; Dow, Christopher B.; Edminster, Carl; Fiedler, Carl E.; Fry, Danny L.; Hartsough, Bruce R.; Keeley, Jon E.; Knapp, Eric E.; McIver, James D.; Skinner, Carl N.; Youngblood, Andrew P.

    2012-01-01

    Using forests to sequester carbon in response to anthropogenically induced climate change is being considered across the globe. A recent U.S. executive order mandated that all federal agencies account for sequestration and emissions of greenhouse gases, highlighting the importance of understanding how forest carbon stocks are influenced by wildfire. This paper reports the effects of the most common forest fuel reduction treatments on carbon pools composed of live and dead biomass as well as potential wildfire emissions from six different sites in four western U.S. states. Additionally, we predict the median forest product life spans and uses of materials removed during mechanical treatments. Carbon loss from modeled wildfire-induced tree mortality was lowest in the mechanical plus prescribed fire treatments, followed by the prescribed fire-only treatments. Wildfire emissions varied from 10–80 Mg/ha and were lowest in the prescribed fire and mechanical followed by prescribed fire treatments at most sites. Mean biomass removals per site ranged from approximately 30–60 dry Mg/ha; the median lives of products in first use varied considerably (from 50 years). Our research suggests most of the benefits of increased fire resistance can be achieved with relatively small reductions in current carbon stocks. Retaining or growing larger trees also reduced the vulnerability of carbon loss from wildfire. In addition, modeled vulnerabilities to carbon losses and median forest product life spans varied considerably across our study sites, which could be used to help prioritize treatment implementation.

  6. Modelling short-rotation coppice and tree planting for urban carbon management - a citywide analysis.

    Science.gov (United States)

    McHugh, Nicola; Edmondson, Jill L; Gaston, Kevin J; Leake, Jonathan R; O'Sullivan, Odhran S

    2015-10-01

    The capacity of urban areas to deliver provisioning ecosystem services is commonly overlooked and underutilized. Urban populations have globally increased fivefold since 1950, and they disproportionately consume ecosystem services and contribute to carbon emissions, highlighting the need to increase urban sustainability and reduce environmental impacts of urban dwellers. Here, we investigated the potential for increasing carbon sequestration, and biomass fuel production, by planting trees and short-rotation coppice (SRC), respectively, in a mid-sized UK city as a contribution to meeting national commitments to reduce CO 2 emissions.Iterative GIS models were developed using high-resolution spatial data. The models were applied to patches of public and privately owned urban greenspace suitable for planting trees and SRC, across the 73 km 2 area of the city of Leicester. We modelled tree planting with a species mix based on the existing tree populations, and SRC with willow and poplar to calculate biomass production in new trees, and carbon sequestration into harvested biomass over 25 years.An area of 11 km 2 comprising 15% of the city met criteria for tree planting and had the potential over 25 years to sequester 4200 tonnes of carbon above-ground. Of this area, 5·8 km 2 also met criteria for SRC planting and over the same period this could yield 71 800 tonnes of carbon in harvested biomass.The harvested biomass could supply energy to over 1566 domestic homes or 30 municipal buildings, resulting in avoided carbon emissions of 29 236 tonnes of carbon over 25 years when compared to heating by natural gas. Together with the net carbon sequestration into trees, a total reduction of 33 419 tonnes of carbon in the atmosphere could be achieved in 25 years by combined SRC and tree planting across the city. Synthesis and applications . We demonstrate that urban greenspaces in a typical UK city are underutilized for provisioning ecosystem services by trees and

  7. Integrated mangrove-shrimp cultivation: Potential for blue carbon sequestration.

    Science.gov (United States)

    Ahmed, Nesar; Thompson, Shirley; Glaser, Marion

    2018-05-01

    Globally, shrimp farming has had devastating effects on mangrove forests. However, mangroves are the most carbon-rich forests, with blue carbon (i.e., carbon in coastal and marine ecosystems) emissions seriously augmented due to devastating effects on mangrove forests. Nevertheless, integrated mangrove-shrimp cultivation has emerged as a part of the potential solution to blue carbon emissions. Integrated mangrove-shrimp farming is also known as organic aquaculture if deforested mangrove area does not exceed 50% of the total farm area. Mangrove destruction is not permitted in organic aquaculture and the former mangrove area in parts of the shrimp farm shall be reforested to at least 50% during a period of maximum 5 years according to Naturland organic aquaculture standards. This article reviews integrated mangrove-shrimp cultivation that can help to sequester blue carbon through mangrove restoration, which can be an option for climate change mitigation. However, the adoption of integrated mangrove-shrimp cultivation could face several challenges that need to be addressed in order to realize substantial benefits from blue carbon sequestration.

  8. Pore Structure Characterization in Concrete Prepared with Carbonated Fly Ash

    Science.gov (United States)

    Sahoo, Sanjukta

    2018-03-01

    Carbon dioxide capture and storage (CCS) is a technique to address the global concern of continuously rising CO2 level in the atmosphere. Fly ash is considered as a suitable medium for CCS due to presence of metal oxides. The fly ash which has already sequestered carbon dioxide is referred to as carbonated fly ash. Recent research reveals better durability of concretes using carbonated fly ash as part replacement of cement. In the present research pore structure characterization of the carbonated fly ash concrete has been carried out. Mercury Intrusion porosimetry test has been conducted on control concrete and concrete specimens using fly ash and carbonated fly ash at replacement levels of 25% and 40%. The specimens have been water cured for 28 days and 90 days. It is observed that porosity reduction rate is more pronounced in carbonated fly ash concrete compared to control concrete at higher water curing age. Correlation analysis is also carried out which indicates moderately linear relationship between porosity % and pore distribution with particle size and water curing.

  9. An improved machine learning protocol for the identification of correct Sequest search results

    Directory of Open Access Journals (Sweden)

    Lu Hui

    2010-12-01

    Full Text Available Abstract Background Mass spectrometry has become a standard method by which the proteomic profile of cell or tissue samples is characterized. To fully take advantage of tandem mass spectrometry (MS/MS techniques in large scale protein characterization studies robust and consistent data analysis procedures are crucial. In this work we present a machine learning based protocol for the identification of correct peptide-spectrum matches from Sequest database search results, improving on previously published protocols. Results The developed model improves on published machine learning classification procedures by 6% as measured by the area under the ROC curve. Further, we show how the developed model can be presented as an interpretable tree of additive rules, thereby effectively removing the 'black-box' notion often associated with machine learning classifiers, allowing for comparison with expert rule-of-thumb. Finally, a method for extending the developed peptide identification protocol to give probabilistic estimates of the presence of a given protein is proposed and tested. Conclusions We demonstrate the construction of a high accuracy classification model for Sequest search results from MS/MS spectra obtained by using the MALDI ionization. The developed model performs well in identifying correct peptide-spectrum matches and is easily extendable to the protein identification problem. The relative ease with which additional experimental parameters can be incorporated into the classification framework, to give additional discriminatory power, allows for future tailoring of the model to take advantage of information from specific instrument set-ups.

  10. The role of old forests and big trees in forest carbon sequestration in the Pacific Northwest

    Science.gov (United States)

    Andrew N. Gray

    2015-01-01

    Forest ecosystems are an important component of the global carbon (C) cycle. Recent research has indicated that large trees in general, and old-growth forests in particular, sequester substantial amounts of C annually. C sequestration rates are thought to peak and decline with stand age but the timing and controls are not well-understood. The objectives of this study...

  11. The Lifestyle Carbon Dividend: Assessment of the Carbon Sequestration Potential of Grasslands and Pasturelands Reverted to Native Forests

    Science.gov (United States)

    Rao, S.; Jain, A. K.; Shu, S.

    2015-12-01

    What is the potential of a global transition to a vegan lifestyle to sequester carbon and mitigate climate change? To answer this question, we use an Earth System Model (ESM), the Integrated Science Assessment Model (ISAM). ISAM is a fully coupled biogeochemistry (carbon and nitrogen cycles) and biogeophysics (hydrology and thermal energy) ESM, which calculates carbon sources and sinks due to land cover and land use change activities, such as reforestation and afforestation. We calculate the carbon sequestration potential of grasslands and pasturelands that can be reverted to native forests as 265 GtC on 1.96E+7 km2 of land area, just 41% of the total area of such lands on Earth. The grasslands and pasturelands are assumed to revert back to native forests which existed prior to any human intervention and these include tropical, temperate and boreal forests. The results are validated with above ground regrowth measurements. Since this carbon sequestration potential is greater than the 240 GtC of that has been added to the atmosphere since the industrial era began, it shows that such global lifestyle transitions have tremendous potential to mitigate and even reverse climate change.

  12. Preparation of activated carbon from banana peel waste for reducing air pollutant from motorcycle muffler

    Directory of Open Access Journals (Sweden)

    Chafidz Achmad

    2018-01-01

    Full Text Available The exhaust gas or emission from motor vehicle contains various pollutants and some of them are toxic and very harmful for human health. In the present work, we prepared an activated carbon to reduce the toxic pollutants (via adsorption process from the exhaust gas of the motor vehicle (particularly motorcycle in this work. The activated carbon was prepared from local banana peel which considered as an agricultural waste without economic value. To prepare the activated carbon, banana peel was carbonized using furnace at 500°C. Then the resulted carbon was activated using chemical activation with ZnCl2 and physical activation with either microwave (300 W or furnace (700°C. The prepared activated carbon was then characterized using Scanning Electron Microscope (SEM and Fourier Transform Infrared (FT-IR analysis. The SEM result showed that the pore of microwave induced ZnCl2 activated carbon (ACM was larger than the pore of virgin char/carbon and furnace induced ZnCl2 activataed carbon (ACF. The FT-IR spectrum of ACM showed some peaks at 3408.59 cm-1, 1589.25 cm-1, and 1093.63 cm-1. They are assigned to O-H stretching, C=O stretching, and C-OH stretching. Additionally, the adsorption performance of the prepared activation carbon to reduce the pollutants concentration (i.e. CO and CH from the exhaust gas of motor vehicle was investigated. The results showed that the activated carbon induced by microwave and ZnCl2 activation (ACM gave the best result. The adsorption or removal efficiency of gas CO reached approximately 97.64 %vol.

  13. Assessing the effects of vegetation types on carbon storage fifteen years after reforestation on a Chinese fir site

    Science.gov (United States)

    Qinkui Wang; Silong Wang; Jianwei Zhang

    2009-01-01

    Forest ecosystems play a significant role in sequestering carbon (C) in biomass and soils. Plantations established in subtropical China since the 1980s, mainly of Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) in monocultures, have proved to be major C sinks. However, information is lacking about whether mixing Chinese fir with broadleaved tree...

  14. UK company strategies in reducing carbon dioxide emissions

    Directory of Open Access Journals (Sweden)

    Yongmei Bentley

    2016-07-01

    Full Text Available This study investigated a number of large UK companies’ strategies in reducing emissions of carbon dioxide (CO2 in their supply chain operations. In-depth interviews were conducted with logistics/supply chain (SC managers across different sectors. The research identified the main CO2 reduction strategies, and examined these in the light of existing literature in the research domain. One of the key findings was that there was a strong tension between cost reduction (identified as the major driver for reducing CO2 and lack of resources (the main barrier. It was also found that most CO2 reduction strategies had started only fairly recently, and so far, were mainly operational and tactical in nature. This study makes an empirical contribution to a better understanding of how companies form their CO2 reduction strategies in response to environmental pressures. It has implications for policy makers in terms of how to motivate logistics/SC managers to implement strategies to reduce the environmental impact of CO2 emissions in their business operations. Therefore, it is recommended that logistics/SC managers develop and implement practical initiatives and strategies to reduce CO2 emissions, and to embed these into corporate strategy.

  15. A Pathway to Reduce Energy Consumption in the Thermal Stabilization Process of Carbon Fiber Production

    Directory of Open Access Journals (Sweden)

    Srinivas Nunna

    2018-05-01

    Full Text Available Process parameters, especially in the thermal stabilization of polyacrylonitrile (PAN fibers, play a critical role in controlling the cost and properties of the resultant carbon fibers. This study aimed to efficiently handle the energy expense areas during carbon fiber manufacturing without reducing the quality of carbon fibers. We introduced a new parameter (recirculation fan frequency in the stabilization stage and studied its influence on the evolution of the structure and properties of fibers. Initially, the progress of the cyclization reaction in the fiber cross-sections with respect to fan frequencies (35, 45, and 60 Hz during stabilization was analyzed using the Australian Synchrotron-high resolution infrared imaging technique. A parabolic trend in the evolution of cyclic structures was observed in the fiber cross-sections during the initial stages of stabilization; however, it was transformed to a uniform trend at the end of stabilization for all fan frequencies. Simultaneously, the microstructure and property variations at each stage of manufacturing were assessed. We identified nominal structural variations with respect to fan frequencies in the intermediate stages of thermal stabilization, which were reduced during the carbonization process. No statistically significant variations were observed between the tensile properties of fibers. These observations suggested that, when using a lower fan frequency (35 Hz, it was possible to manufacture carbon fibers with a similar performance to those produced using a higher fan frequency (60 Hz. As a result, this study provided an opportunity to reduce the energy consumption during carbon fiber manufacturing.

  16. Simulating the carbon balance in reclaimed forest ecosystems with the FORECAST model

    Energy Technology Data Exchange (ETDEWEB)

    Welham, C. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Forest Sciences, Forest Ecosystem Simulation Group; ForRx Consulting, Belcarra, BC (Canada); 3GreenTree Ecosystem Services Ltd., Belcarra, BC (Canada)

    2010-07-01

    Large emission sources are beginning to report their carbon footprint on an annual basis as a result of government mandates, shareholder demand for disclosure of a company's risk to climate change, and as part of corporate social responsibility initiatives. Oil sands mining is a carbon intensive activity from the perspective of carbon dioxide emissions. The intensity of carbon emissions can be mitigated through technological and process innovations. However, reclamation is the only mining-related activity that directly removes atmospheric carbon dioxide. This presentation described a modeling exercise that had 3 principal objectives, notably to simulate the carbon balance in a developing reclaimed upland forest ecosystem; to explore the relative change in carbon pools over time; and to compare the carbon balance of the reclaimed ecosystem to its natural analogue. The presentation provided a description of the model and methodology and discussed the simulation protocol. Imperial Oil's Kearl Lake operation, which was used as a test case, showed that approximately 83,000 tonnes of carbon dioxide per hectare can be sequestered per year as a result of reclamation. tabs., figs.

  17. RsmV a small non-coding regulatory RNA in Pseudomonas aeruginosa that sequesters RsmA and RsmF from target mRNAs.

    Science.gov (United States)

    Janssen, Kayley H; Diaz, Manisha R; Gode, Cindy J; Wolfgang, Matthew C; Yahr, Timothy L

    2018-06-04

    The Gram-negative opportunistic pathogen Pseudomonas aeruginosa has distinct genetic programs that favor either acute or chronic virulence gene expression. Acute virulence is associated with twitching and swimming motility, expression of a type III secretion system (T3SS), and the absence of alginate, Psl, or Pel polysaccharide production. Traits associated with chronic infection include growth as a biofilm, reduced motility, and expression of a type VI secretion system (T6SS). The Rsm post-transcriptional regulatory system plays important roles in the inverse control of phenotypes associated with acute and chronic virulence. RsmA and RsmF are RNA-binding proteins that interact with target mRNAs to control gene expression at the post-transcriptional level. Previous work found that RsmA activity is controlled by at least three small, non-coding regulatory RNAs (RsmW, RsmY, and RsmZ). In this study, we took an in-silico approach to identify additional sRNAs that might function in the sequestration of RsmA and/or RsmF and identified RsmV, a 192 nt transcript with four predicted RsmA/RsmF consensus binding sites. RsmV is capable of sequestering RsmA and RsmF in vivo to activate translation of tssA1 , a component of the T6SS, and to inhibit T3SS gene expression. Each of the predicted RsmA/RsmF consensus binding sites contribute to RsmV activity. Electrophoretic mobility shifts assays show that RsmF binds RsmV with >10-fold higher affinity than RsmY and RsmZ. Gene expression studies revealed that the temporal expression pattern of RsmV differs from RsmW, RsmY, and RsmZ. These findings suggest that each sRNA may play distinct roles in controlling RsmA and RsmF activity. IMPORTANCE The CsrA/RsmA family of RNA-binding proteins play important roles in post-transcriptional control of gene expression. The activity of CsrA/RsmA proteins is controlled by small non-coding RNAs that function as decoys to sequester CsrA/RsmA from target mRNAs. Pseudomonas aeruginosa has two Csr

  18. The interconnectedness between landowner knowledge, value, belief, attitude, and willingness to act: policy implications for carbon sequestration on private rangelands.

    Science.gov (United States)

    Cook, Seth L; Ma, Zhao

    2014-02-15

    Rangelands can be managed to increase soil carbon and help mitigate emissions of carbon dioxide. This study assessed Utah rangeland owner's environmental values, beliefs about climate change, and awareness of and attitudes towards carbon sequestration, as well as their perceptions of potential policy strategies for promoting carbon sequestration on private rangelands. Data were collected from semi-structured interviews and a statewide survey of Utah rangeland owners, and were analyzed using descriptive and bivariate statistics. Over two-thirds of respondents reported some level of awareness of carbon sequestration and a generally positive attitude towards it, contrasting to their lack of interest in participating in a relevant program in the future. Having a positive attitude was statistically significantly associated with having more "biocentric" environmental values, believing the climate had been changing over the past 30 years, and having a stronger belief of human activities influencing the climate. Respondents valued the potential ecological benefits of carbon sequestration more than the potential financial or climate change benefits. Additionally, respondents indicated a preference for educational approaches over financial incentives. They also preferred to work with a private agricultural entity over a non-profit or government entity on improving land management practices to sequester carbon. These results suggest potential challenges for developing technically sound and socially acceptable policies and programs for promoting carbon sequestration on private rangelands. Potential strategies for overcoming these challenges include emphasizing the ecological benefits associated with sequestering carbon to appeal to landowners with ecologically oriented management objectives, enhancing the cooperation between private agricultural organizations and government agencies, and funneling resources for promoting carbon sequestration into existing land management and

  19. Carbon sequestration by mangrove forest: One approach for managing carbon dioxide emission from coal-based power plant

    Science.gov (United States)

    Ray, Raghab; Jana, Tapan Kumar

    2017-12-01

    Mangroves are known as natural carbon sinks, taking CO2 out of the atmosphere and store it in their biomass for many years. This study aimed to investigate the capacity of world's largest mangrove, the Sundarbans (Indian part) to sequester anthropogenic CO2 emitted from the proximate coal-based thermal power plant in Kolaghat (∼100 km away from mangrove site). Study also includes Kolkata, one of the largest metropolises of India (∼150 km away from mangrove site) for comparing micrometeorological parameters, biosphere-atmosphere CO2 exchange fluxes and atmospheric pollutants between three distinct environments: mangrove-power plant-metropolis. Hourly sampling of atmospheric CO2 in all three sites (late December 2011 and early January 2012) revealed that CO2 concentrations and emission fluxes were maximum around the power plant (360-621 ppmv, 5.6-56.7 mg m-2s-1 respectively) followed by the metropolis (383-459 ppmv, 3.8-20.4 mg m-2s-1 respectively) and mangroves (277-408 ppmv, -8.9-11.4 mg m-2s-1, respectively). Monthly coal consumption rates (41-57, in 104 ton month-1) were converted to CO2 suggesting that 2.83 Tg C was added to the atmosphere in 2011 for the generation of 7469732 MW energy from the power plant. Indian Sundarbans (4264 km2) sequestered total of 2.79 Tg C which was 0.64% of the annual fossil fuel emission from India in the same time period. Based on these data from 2010 to 2011, it is calculated that about 4328 km2 mangrove forest coverage is needed to sequester all CO2 emitted from the Kolaghat power plant.

  20. Peatland geoengineering: an alternative approach to terrestrial carbon sequestration.

    Science.gov (United States)

    Freeman, Christopher; Fenner, Nathalie; Shirsat, Anil H

    2012-09-13

    Terrestrial and oceanic ecosystems contribute almost equally to the sequestration of ca 50 per cent of anthropogenic CO(2) emissions, and already play a role in minimizing our impact on Earth's climate. On land, the majority of the sequestered carbon enters soil carbon stores. Almost one-third of that soil carbon can be found in peatlands, an area covering just 2-3% of the Earth's landmass. Peatlands are thus well established as powerful agents of carbon capture and storage; the preservation of archaeological artefacts, such as ancient bog bodies, further attest to their exceptional preservative properties. Peatlands have higher carbon storage densities per unit ecosystem area than either the oceans or dry terrestrial systems. However, despite attempts over a number of years at enhancing carbon capture in the oceans or in land-based afforestation schemes, no attempt has yet been made to optimize peatland carbon storage capacity or even to harness peatlands to store externally captured carbon. Recent studies suggest that peatland carbon sequestration is due to the inhibitory effects of phenolic compounds that create an 'enzymic latch' on decomposition. Here, we propose to harness that mechanism in a series of peatland geoengineering strategies whereby molecular, biogeochemical, agronomical and afforestation approaches increase carbon capture and long-term sequestration in peat-forming terrestrial ecosystems.

  1. Valuation of temporary and future greenhouse gas reductions

    Energy Technology Data Exchange (ETDEWEB)

    Richards, K.R.

    1993-06-01

    The potential of augmented carbon sinks to decrease atmospheric levels of carbon dioxide has proved attractive to many government policy markers, politicians and industry representatives. Consequently, several proposals for new laws, both domestic and international, have recognized the CO{sub 2} emitters who are encouraged or required to reduce levels of emissions should also be allowed to offset their emissions by sequestering carbon in forest stands. This idea is described.

  2. Carboxysomal carbonic anhydrases: Structure and role in microbial CO2 fixation

    Energy Technology Data Exchange (ETDEWEB)

    Cannon, Gordon C.; Heinhorst, Sabine; Kerfeld, Cheryl A.

    2010-06-23

    Cyanobacteria and some chemoautotrophic bacteria are able to grow in environments with limiting CO2 concentrations by employing a CO2-concentrating mechanism (CCM) that allows them to accumulate inorganic carbon in their cytoplasm to concentrations several orders of magnitude higher than that on the outside. The final step of this process takes place in polyhedral protein microcompartments known as carboxysomes, which contain the majority of the CO2-fixing enzyme, RubisCO. The efficiency of CO2 fixation by the sequestered RubisCO is enhanced by co-localization with a specialized carbonic anhydrase that catalyzes dehydration of the cytoplasmic bicarbonate and ensures saturation of RubisCO with its substrate, CO2. There are two genetically distinct carboxysome types that differ in their protein composition and in the carbonic anhydrase(s) they employ. Here we review the existing information concerning the genomics, structure and enzymology of these uniquely adapted carbonic anhydrases, which are of fundamental importance in the global carbon cycle.

  3. Three-dimensional Nitrogen-Doped Reduced Graphene Oxide/Carbon Nanotube Composite Catalysts for Vanadium Flow Batteries

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Shaofang [School of Mechanical and Materials Engineering, Washington State University, WA, 99164 USA.; Zhu, Chengzhou [School of Mechanical and Materials Engineering, Washington State University, WA, 99164 USA.; Song, Junhua [School of Mechanical and Materials Engineering, Washington State University, WA, 99164 USA.; Engelhard, Mark H. [Environmental Molecular Science Laboratory, Pacific Northwest National Laboratory, Richland, WA 99354 USA.; Du, Dan [School of Mechanical and Materials Engineering, Washington State University, WA, 99164 USA.; Lin, Yuehe [School of Mechanical and Materials Engineering, Washington State University, WA, 99164 USA.; Environmental Molecular Science Laboratory, Pacific Northwest National Laboratory, Richland, WA 99354 USA.

    2017-02-22

    The development of vanadium redox flow battery is limited by the sluggish kinetics of the reaction, especially the cathodic VO2+/VO2+ redox couples. Therefore, it is vital to develop new electrocatalyst with enhanced activity to improve the battery performance. Herein, we first synthesized the hydrogel precursor by a facile hydrothermal method. After the following carbonization, nitrogen-doped reduced graphene oxide/carbon nanotube composite was obtained. By virtue of the large surface area and good conductivey, which are ensured by the unique hybrid structure, as well as the proper nitrogen doping, the as-prepared composite presents enhanced catalytic performance toward the VO2+/VO2+ redox reaction. We also demonstrated the composite with carbon nanotube loading of 2 mg/mL exhibits the highest activity and remarkable stability in aqueous solution due to the strong synergy between reduced graphene oxide and carbon nanotubes, indicating that this composite might show promising applications in vanadium redox flow battery.

  4. The impact of whaling on the ocean carbon cycle: why bigger was better.

    Directory of Open Access Journals (Sweden)

    Andrew J Pershing

    Full Text Available BACKGROUND: Humans have reduced the abundance of many large marine vertebrates, including whales, large fish, and sharks, to only a small percentage of their pre-exploitation levels. Industrial fishing and whaling also tended to preferentially harvest the largest species and largest individuals within a population. We consider the consequences of removing these animals on the ocean's ability to store carbon. METHODOLOGY/PRINCIPAL FINDINGS: Because body size is critical to our arguments, our analysis focuses on populations of baleen whales. Using reconstructions of pre-whaling and modern abundances, we consider the impact of whaling on the amount of carbon stored in living whales and on the amount of carbon exported to the deep sea by sinking whale carcasses. Populations of large baleen whales now store 9.1×10(6 tons less carbon than before whaling. Some of the lost storage has been offset by increases in smaller competitors; however, due to the relative metabolic efficiency of larger organisms, a shift toward smaller animals could decrease the total community biomass by 30% or more. Because of their large size and few predators, whales and other large marine vertebrates can efficiently export carbon from the surface waters to the deep sea. We estimate that rebuilding whale populations would remove 1.6×10(5 tons of carbon each year through sinking whale carcasses. CONCLUSIONS/SIGNIFICANCE: Even though fish and whales are only a small portion of the ocean's overall biomass, fishing and whaling have altered the ocean's ability to store and sequester carbon. Although these changes are small relative to the total ocean carbon sink, rebuilding populations of fish and whales would be comparable to other carbon management schemes, including ocean iron fertilization.

  5. Estimating global "blue carbon" emissions from conversion and degradation of vegetated coastal ecosystems.

    Directory of Open Access Journals (Sweden)

    Linwood Pendleton

    Full Text Available Recent attention has focused on the high rates of annual carbon sequestration in vegetated coastal ecosystems--marshes, mangroves, and seagrasses--that may be lost with habitat destruction ('conversion'. Relatively unappreciated, however, is that conversion of these coastal ecosystems also impacts very large pools of previously-sequestered carbon. Residing mostly in sediments, this 'blue carbon' can be released to the atmosphere when these ecosystems are converted or degraded. Here we provide the first global estimates of this impact and evaluate its economic implications. Combining the best available data on global area, land-use conversion rates, and near-surface carbon stocks in each of the three ecosystems, using an uncertainty-propagation approach, we estimate that 0.15-1.02 Pg (billion tons of carbon dioxide are being released annually, several times higher than previous estimates that account only for lost sequestration. These emissions are equivalent to 3-19% of those from deforestation globally, and result in economic damages of $US 6-42 billion annually. The largest sources of uncertainty in these estimates stems from limited certitude in global area and rates of land-use conversion, but research is also needed on the fates of ecosystem carbon upon conversion. Currently, carbon emissions from the conversion of vegetated coastal ecosystems are not included in emissions accounting or carbon market protocols, but this analysis suggests they may be disproportionally important to both. Although the relevant science supporting these initial estimates will need to be refined in coming years, it is clear that policies encouraging the sustainable management of coastal ecosystems could significantly reduce carbon emissions from the land-use sector, in addition to sustaining the well-recognized ecosystem services of coastal habitats.

  6. Photosynthesis, Nitrogen, Their Adjustment and its Effects on Ecosystem Carbon Gain at Elevated CO(sub 2)l. A Comparison of Loblolly and Ponderosa Pines; FINAL

    International Nuclear Information System (INIS)

    Ball, J. Timothy; Eichelmann, Hillar Y.; Tissue, David T.; Lewis, James D.; Picone, Johnn B.; Ross, Peter D.

    1996-01-01

    A functional understanding of terrestrial ecosystem carbon processes is essential for two reasons. First, carbon flow is a most fundamental aspects of ecosystem function as it mediates most of the energy flow in these systems. Second, carbon flow also mediates the majority of energy flow in the global economy and will do for the foreseeable future. The increased atmospheric carbon dioxide and its inevitable flow through global ecosystems will influence ecosystem processes. There is, of course, great interest in the potential of ecosystems to sequester some of the carbon being loaded into the atmosphere by economic activity

  7. Big Sky Carbon Sequestration Partnership

    Energy Technology Data Exchange (ETDEWEB)

    Susan Capalbo

    2005-12-31

    has significant potential to sequester large amounts of CO{sub 2}. Simulations conducted to evaluate mineral trapping potential of mafic volcanic rock formations located in the Idaho province suggest that supercritical CO{sub 2} is converted to solid carbonate mineral within a few hundred years and permanently entombs the carbon. Although MMV for this rock type may be challenging, a carefully chosen combination of geophysical and geochemical techniques should allow assessment of the fate of CO{sub 2} in deep basalt hosted aquifers. Terrestrial carbon sequestration relies on land management practices and technologies to remove atmospheric CO{sub 2} where it is stored in trees, plants, and soil. This indirect sequestration can be implemented today and is on the front line of voluntary, market-based approaches to reduce CO{sub 2} emissions. Initial estimates of terrestrial sinks indicate a vast potential for increasing and maintaining soil Carbon (C) on rangelands, and forested, agricultural, and reclaimed lands. Rangelands can store up to an additional 0.05 mt C/ha/yr, while the croplands are on average four times that amount. Estimates of technical potential for soil sequestration within the region in cropland are in the range of 2.0 M mt C/yr over 20 year time horizon. This is equivalent to approximately 7.0 M mt CO{sub 2}e/yr. The forestry sinks are well documented, and the potential in the Big Sky region ranges from 9-15 M mt CO{sub 2} equivalent per year. Value-added benefits include enhanced yields, reduced erosion, and increased wildlife habitat. Thus the terrestrial sinks provide a viable, environmentally beneficial, and relatively low cost sink that is available to sequester C in the current time frame. The Partnership recognizes the critical importance of measurement, monitoring, and verification technologies to support not only carbon trading but all policies and programs that DOE and other agencies may want to pursue in support of GHG mitigation. The efforts

  8. Carbon dioxide (CO2) capture and storage : Canadian market development

    International Nuclear Information System (INIS)

    Hendriks, A.

    2006-01-01

    Carbon dioxide (CO 2 ) enhanced oil recovery (EOR) is used to extend the life of light oil reservoirs in Canada. An additional 13 per cent of original oil in place is typically recovered using CO 2 flooding processes. However, a carbon capture and storage (CCS) market is needed in order to commercialize CO 2 flooding technologies. CO 2 can be obtained from naturally-occurring accumulations in underground reservoirs, electrical and coal-fired generation plants, petrochemical facilities, and upstream oil and gas processing facilities. CO 2 is sequestered in EOR processes, in sour gas disposal processes, solvent recovery processes, and in coalbed methane (CBM) extraction. It is also disposed in depleted fields and aquifers. While CCS technologies are mature, project economics remain marginal. However, CCS in EOR is commercially feasible at current high oil prices. No transportation infrastructure is in place to transport sources of CO 2 in the high volumes needed to establish a market. While governments have created a favourable public policy environment for CCS, governments will need to address issues related to infrastructure, public perception of CCS, and stakeholder engagement with CCS projects. It was concluded that CCS and CO 2 flooding techniques have the capacity to reduce greenhouse gas (GHG) emissions while helping to sustain light oil production. tabs., figs

  9. Induction of autophagy by Imatinib sequesters Bcr-Abl in autophagosomes and down-regulates Bcr-Abl protein.

    LENUS (Irish Health Repository)

    Elzinga, Baukje M

    2013-06-01

    Chronic Myeloid Leukemia (CML) is a disease of hematopoietic stem cells which harbor the chimeric gene Bcr-Abl. Expression levels of this constitutively active tyrosine kinase are critical for response to tyrosine kinase inhibitor treatment and also disease progression, yet the regulation of protein stability is poorly understood. We have previously demonstrated that imatinib can induce autophagy in Bcr-Abl expressing cells. Autophagy has been associated with the clearance of large macromolecular signaling complexes and abnormal proteins, however, the contribution of autophagy to the turnover of Bcr-Abl protein in imatinib treated cells is unknown. In this study, we show that following imatinib treatment, Bcr-Abl is sequestered into vesicular structures that co-localize with the autophagy marker LC3 or GABARAP. This association is inhibited by siRNA mediated knockdown of autophagy regulators (Beclin 1\\/ATG7). Pharmacological inhibition of autophagy also reduced Bcr-Abl\\/LC3 co-localization in both K562 and CML patient cells. Bcr-Abl protein expression was reduced with imatinib treatment. Inhibition of both autophagy and proteasome activity in imatinib treated cells was required to restore Bcr-Abl protein levels to those of untreated cells. This ability to down-regulate Bcr-Abl protein levels through the induction of autophagy may be an additional and important feature of the activity of imatinib.

  10. Commentary: Ex Situ Aqueous Mineral Carbonation

    Energy Technology Data Exchange (ETDEWEB)

    Gadikota, Greeshma, E-mail: gadikota@princeton.edu [Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ (United States)

    2016-05-26

    CO{sub 2} conversion to calcium and magnesium carbonates has garnered considerable attention since it is a thermodynamically downhill pathway to safely and permanently sequester large quantities of CO{sub 2}. This seminal work performed at The National Energy Technology Laboratory in Albany (NETL-Albany) reports the conversion of calcium- and magnesium-bearing silicate minerals, such as olivine [(Mg, Fe){sub 2}SiO{sub 4}], wollastonite (CaSiO{sub 3}), and serpentine [Mg{sub 3}Si{sub 2}O{sub 5}(OH){sub 4}], as they are reacted with CO{sub 2} in an aqueous environment to form magnesium or calcium carbonates. This paper discusses various pretreatment methods of the starting materials, such as grinding or heat treatment of hydroxylated Mg silicates, to enhance the reaction kinetics. The effects of various chemical additives (e.g., NaCl and NaHCO{sub 3}), and reaction parameters, such as temperature, pressure, and reaction time, on the conversion are investigated. Feasibility assessments and energy and economic analyses of the direct carbonation of calcium- and magnesium-bearing minerals are presented.

  11. Carbon dioxide emission from bamboo culms.

    Science.gov (United States)

    Zachariah, E J; Sabulal, B; Nair, D N K; Johnson, A J; Kumar, C S P

    2016-05-01

    Bamboos are one of the fastest growing plants on Earth, and are widely considered to have high ability to capture and sequester atmospheric carbon, and consequently to mitigate climate change. We tested this hypothesis by measuring carbon dioxide (CO2 ) emissions from bamboo culms and comparing them with their biomass sequestration potential. We analysed diurnal effluxes from Bambusa vulgaris culm surface and gas mixtures inside hollow sections of various bamboos using gas chromatography. Corresponding variations in gas pressure inside the bamboo section and culm surface temperature were measured. SEM micrographs of rhizome and bud portions of bamboo culms were also recorded. We found very high CO2 effluxes from culm surface, nodes and buds of bamboos. Positive gas pressure and very high concentrations of CO2 were observed inside hollow sections of bamboos. The CO2 effluxes observed from bamboos were very high compared to their carbon sequestration potential. Our measurements suggest that bamboos are net emitters of CO2 during their lifespan. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  12. Preparation and Evaluation of Some Surface Active Sequestering Agents for Some Heavy Metals

    International Nuclear Information System (INIS)

    Badawi, A.M.; Mohamed, M.Z.; Mohamed, A.S.; Khowdry, M.M.; Bastway, A.F.

    2004-01-01

    A novel series of chelating agents has been synthesized by the reaction of ethylenediaminetetraacetic acid, citric acid and polyethylene glycol with different molecular weights and different number of moles. The unique structural features of these surfactants have been confirmed by FTIR spectra, elemental analysis and H 1 NMR spectrum. These surfactants exhibit excellent properties in sequestering heavy metal such as copper, lead and mercury. They show good surfactant properties, including surface tension, effectiveness, efficiency and emulsifying power. Critical micelle concentration, maximum surface excess and minimum surface area have been studied. Free energy of micellization and adsorption have been calculated

  13. Treatment of acid rock drainage using a sulfate-reducing bioreactor with zero-valent iron

    Energy Technology Data Exchange (ETDEWEB)

    Ayala-Parra, Pedro; Sierra-Alvarez, Reyes; Field, James A., E-mail: jimfield@email.arizona.edu

    2016-05-05

    Highlights: • Electron donor from zero-valent iron (ZVI) drives sulfate reduction to sulfide. • Sulfide converts soluble heavy metals into sulfide minerals. • Excess sulfide is sequestered by iron preventing discharge. • Corrosion of ZVI consumes acidity in acid rock drainage. • ZVI as reactive material outlasted limestone in removing heavy metals. - Abstract: This study assessed the bioremediation of acid rock drainage (ARD) in flow-through columns testing zero-valent iron (ZVI) for the first time as the sole exogenous electron donor to drive sulfate-reducing bacteria in permeable reactive barriers. Columns containing ZVI, limestone or a mixture of both materials were inoculated with an anaerobic mixed culture and fed a synthetic ARD containing sulfuric acid and heavy metals (initially copper, and later also cadmium and lead). ZVI significantly enhanced sulfate reduction and the heavy metals were extensively removed (>99.7%). Solid-phase analyses showed that heavy metals were precipitated with biogenic sulfide in the columns packed with ZVI. Excess sulfide was sequestered by iron, preventing the discharge of dissolved sulfide. In the absence of ZVI, heavy metals were also significantly removed (>99.8%) due to precipitation with hydroxide and carbonate ions released from the limestone. Vertical-profiles of heavy metals in the columns packing, at the end of the experiment, demonstrated that the ZVI columns still had excess capacity to remove heavy metals, while the capacity of the limestone control column was approaching saturation. The ZVI provided conditions that enhanced sulfate reduction and generated alkalinity. Collectively, the results demonstrate an innovative passive ARD remediation process using ZVI as sole electron-donor.

  14. Treatment of acid rock drainage using a sulfate-reducing bioreactor with zero-valent iron

    International Nuclear Information System (INIS)

    Ayala-Parra, Pedro; Sierra-Alvarez, Reyes; Field, James A.

    2016-01-01

    Highlights: • Electron donor from zero-valent iron (ZVI) drives sulfate reduction to sulfide. • Sulfide converts soluble heavy metals into sulfide minerals. • Excess sulfide is sequestered by iron preventing discharge. • Corrosion of ZVI consumes acidity in acid rock drainage. • ZVI as reactive material outlasted limestone in removing heavy metals. - Abstract: This study assessed the bioremediation of acid rock drainage (ARD) in flow-through columns testing zero-valent iron (ZVI) for the first time as the sole exogenous electron donor to drive sulfate-reducing bacteria in permeable reactive barriers. Columns containing ZVI, limestone or a mixture of both materials were inoculated with an anaerobic mixed culture and fed a synthetic ARD containing sulfuric acid and heavy metals (initially copper, and later also cadmium and lead). ZVI significantly enhanced sulfate reduction and the heavy metals were extensively removed (>99.7%). Solid-phase analyses showed that heavy metals were precipitated with biogenic sulfide in the columns packed with ZVI. Excess sulfide was sequestered by iron, preventing the discharge of dissolved sulfide. In the absence of ZVI, heavy metals were also significantly removed (>99.8%) due to precipitation with hydroxide and carbonate ions released from the limestone. Vertical-profiles of heavy metals in the columns packing, at the end of the experiment, demonstrated that the ZVI columns still had excess capacity to remove heavy metals, while the capacity of the limestone control column was approaching saturation. The ZVI provided conditions that enhanced sulfate reduction and generated alkalinity. Collectively, the results demonstrate an innovative passive ARD remediation process using ZVI as sole electron-donor.

  15. Carbonation of subduction-zone serpentinite (high-pressure ophicarbonate; Ligurian Western Alps) and implications for the deep carbon cycling

    Science.gov (United States)

    Scambelluri, Marco; Bebout, Gray E.; Belmonte, Donato; Gilio, Mattia; Campomenosi, Nicola; Collins, Nathan; Crispini, Laura

    2016-05-01

    Much of the long-term carbon cycle in solid earth occurs in subduction zones, where processes of devolatilization, partial melting of carbonated rocks, and dissolution of carbonate minerals lead to the return of CO2 to the atmosphere via volcanic degassing. Release of COH fluids from hydrous and carbonate minerals influences C recycling and magmatism at subduction zones. Contradictory interpretations exist regarding the retention/storage of C in subducting plates and in the forearc to subarc mantle. Several lines of evidence indicate mobility of C, of uncertain magnitude, in forearcs. A poorly constrained fraction of the 40-115 Mt/yr of C initially subducted is released into fluids (by decarbonation and/or carbonate dissolution) and 18-43 Mt/yr is returned at arc volcanoes. Current estimates suggest the amount of C released into subduction fluids is greater than that degassed at arc volcanoes: the imbalance could reflect C subduction into the deeper mantle, beyond subarc regions, or storage of C in forearc/subarc reservoirs. We examine the fate of C in plate-interface ultramafic rocks, and by analogy serpentinized mantle wedge, via study of fluid-rock evolution of marble and variably carbonated serpentinite in the Ligurian Alps. Based on petrography, major and trace element concentrations, and carbonate C and O isotope compositions, we demonstrate that serpentinite dehydration at 2-2.5 GPa, 550 °C released aqueous fluids triggering breakdown of dolomite in nearby marbles, thus releasing C into fluids. Carbonate + olivine veins document flow of COH fluids and that the interaction of these COH fluids with serpentinite led to the formation of high-P carbonated ultramafic-rock domains (high-P ophicarbonates). We estimate that this could result in the retention of ∼0.5-2.0 Mt C/yr in such rocks along subduction interfaces. As another means of C storage, 1 to 3 km-thick layers of serpentinized forearc mantle wedge containing 50 modal % dolomite could sequester 1.62 to

  16. Electricity without carbon dioxide: Assessing the role of carbon capture and sequestration in United States electric markets

    Science.gov (United States)

    Johnson, Timothy Lawrence

    2002-09-01

    Stabilization of atmospheric greenhouse gas concentrations will likely require significant cuts in electric sector carbon dioxide (CO2) emissions. The ability to capture and sequester CO2 in a manner compatible with today's fossil-fuel based power generating infrastructure offers a potentially low-cost contribution to a larger climate change mitigation strategy. This thesis fills a niche between economy-wide studies of CO 2 abatement and plant-level control technology assessments by examining the contribution that carbon capture and sequestration (CCS) might make toward reducing US electric sector CO2 emissions. The assessment's thirty year perspective ensures that costs sunk in current infrastructure remain relevant and allows time for technological diffusion, but remains free of assumptions about the emergence of unidentified radical innovations. The extent to which CCS might lower CO2 mitigation costs will vary directly with the dispatch of carbon capture plants in actual power-generating systems, and will depend on both the retirement of vintage capacity and competition from abatement alternatives such as coal-to-gas fuel switching and renewable energy sources. This thesis therefore adopts a capacity planning and dispatch model to examine how the current distribution of generating units, natural gas prices, and other industry trends affect the cost of CO2 control via CCS in an actual US electric market. The analysis finds that plants with CO2 capture consistently provide significant reductions in base-load emissions at carbon prices near 100 $/tC, but do not offer an economical means of meeting peak demand unless CO2 reductions in excess of 80 percent are required. Various scenarios estimate the amount by which turn-over of the existing generating infrastructure and the severity of criteria pollutant constraints reduce mitigation costs. A look at CO2 sequestration in the seabed beneath the US Outer Continental Shelf (OCS) complements this model

  17. Regenerating degraded soils and increasing water use efficiency on vegetable farms in Uruguay through ecological intensification

    NARCIS (Netherlands)

    Alliaume, F.

    2016-01-01

    This thesis investigated alternative soil management strategies for vegetable crop systems and their hypothesized effects on increasing systems resilience by sequestering soil carbon, increasing the efficiency of water use, and reducing erosion. The goal was to contribute knowledge on and tools

  18. Valuing blue carbon: carbon sequestration benefits provided by the marine protected areas in Colombia.

    Directory of Open Access Journals (Sweden)

    Tatiana G Zarate-Barrera

    Full Text Available Marine protected areas are aimed to protect and conserve key ecosystems for the provision of a number of ecosystem services that are the basis for numerous economic activities. Among the several services that these areas provide, the capacity of sequestering (capturing and storing organic carbon is a regulating service, provided mainly by mangroves and seagrasses, that gains importance as alternatives for mitigating global warming become a priority in the international agenda. The objective of this study is to value the services associated with the capture and storage of oceanic carbon, known as Blue Carbon, provided by a new network of marine protected areas in Colombia. We approach the monetary value associated to these services through the simulation of a hypothetical market for oceanic carbon. To do that, we construct a benefit function that considers the capacity of mangroves and seagrasses for capturing and storing blue carbon, and simulate scenarios for the variation of key variables such as the market carbon price, the discount rate, the natural rate of loss of the ecosystems, and the expectations about the post-Kyoto negotiations. The results indicate that the expected benefits associated to carbon capture and storage provided by these ecosystems are substantial but highly dependent on the expectations in terms of the negotiations surrounding the extension of the Kyoto Protocol and the dynamics of the carbon credit's demand and supply. We also find that the natural loss rate of these ecosystems does not seem to have a significant effect on the annual value of the benefits. This approach constitutes one of the first attempts to value blue carbon as one of the services provided by conservation.

  19. Carbon sequestration rate and aboveground biomass carbon potential of three young species in lower Gangetic plain.

    Science.gov (United States)

    Jana, Bipal K; Biswas, Soumyajit; Majumder, Mrinmoy; Roy, Pankaj K; Mazumdar, Asis

    2011-07-01

    Carbon is sequestered by the plant photosynthesis and stored as biomass in different parts of the tree. Carbon sequestration rate has been measured for young species (6 years age) of Shorea robusta at Chadra forest in Paschim Medinipur district, Albizzia lebbek in Indian Botanic Garden in Howrah district and Artocarpus integrifolia at Banobitan within Kolkata in the lower Gangetic plain of West Bengal in India by Automated Vaisala Made Instrument GMP343 and aboveground biomass carbon has been analyzed by CHN analyzer. The specific objective of this paper is to measure carbon sequestration rate and aboveground biomass carbon potential of three young species of Shorea robusta, Albizzia lebbek and Artocarpus integrifolia. The carbon sequestration rate (mean) from the ambient air during winter season as obtained by Shorea robusta, Albizzia lebbek and Artocarpus integrifolia were 11.13 g/h, 14.86 g/h and 4.22g/h, respectively. The annual carbon sequestration rate from ambient air were estimated at 8.97 t C ha(-1) by Shorea robusta, 11.97 t C ha(-1) by Albizzia lebbek and 3.33 t C ha(-1) by Artocarpus integrifolia. The percentage of carbon content (except root) in the aboveground biomass of Shorea robusta, Albizzia lebbek and Artocarpus integrifolia were 47.45, 47.12 and 43.33, respectively. The total aboveground biomass carbon stock per hectare as estimated for Shorea robusta, Albizzia lebbek and Artocarpus integrifolia were 5.22 t C ha(-1) , 6.26 t C ha(-1) and 7.28 t C ha(-1), respectively in these forest stands.

  20. Strategizing Carbon-Neutral Mines: A Case for Pilot Projects

    Directory of Open Access Journals (Sweden)

    Ian M. Power

    2014-05-01

    Full Text Available Ultramafic and mafic mine tailings are a valuable feedstock for carbon mineralization that should be used to offset carbon emissions generated by the mining industry. Although passive carbonation is occurring at the abandoned Clinton Creek asbestos mine, and the active Diavik diamond and Mount Keith nickel mines, there remains untapped potential for sequestering CO2 within these mine wastes. There is the potential to accelerate carbonation to create economically viable, large-scale CO2 fixation technologies that can operate at near-surface temperature and atmospheric pressure. We review several relevant acceleration strategies including: bioleaching of magnesium silicates; increasing the supply of CO2 via heterotrophic oxidation of waste organics; and biologically induced carbonate precipitation, as well as enhancing passive carbonation through tailings management practices and use of CO2 point sources. Scenarios for pilot scale projects are proposed with the aim of moving towards carbon-neutral mines. A financial incentive is necessary to encourage the development of these strategies. We recommend the use of a dynamic real options pricing approach, instead of traditional discounted cash-flow approaches, because it reflects the inherent value in managerial flexibility to adapt and capitalize on favorable future opportunities in the highly volatile carbon market.

  1. Ecosystem Carbon Stocks of Intertidal Wetlands in Singapore

    Science.gov (United States)

    Phang, V. X. H.; Friess, D.; Chou, L. M.

    2014-12-01

    Mangrove forests and seagrass meadows provide numerous ecosystem services, with huge recent interest in their carbon sequestration and storage value. Mangrove forests and seagrass meadows as well as mudflats and sandbars form a continuum of intertidal wetlands, but studies that consider these spatially-linked habitats as a whole are limited. This paper presents the results of a field-based and remote sensing carbon stock assessment, including the first study of the ecosystem carbon stocks of these adjacent habitats in the tropics. Aboveground, belowground and soil organic carbon pools were quantified at Chek Jawa, an intertidal wetland in Singapore. Total ecosystem carbon stocks averaged 499 Mg C ha-1 in the mangrove forest and 140 Mg C ha-1 in the seagrass meadow. Soil organic carbon dominated the total storage in both habitats. In the adjacent mudflats and sandbars, soil organic carbon averaged 143 and 124 Mg C ha-1 respectively. High amount of carbon stored in soil demonstrate the role of intertidal wetlands in sequestering large amount of carbon in sediments accumulated over millennia. High-resolution remote sensing imagery was used to create spatial models that upscaled field-based carbon measurements to the national scale. Field-based data and spatial modeling of ecosystem carbon stocks to the entire island through remote sensing provides a large-scale and holistic carbon stock value, important for the understanding and management of these threatened intertidal ecosystems.

  2. Fungal interactions reduce carbon use efficiency

    NARCIS (Netherlands)

    Maynard, Daniel S.; Crowther, Thomas W.; Bradford, Mark A.

    2017-01-01

    The efficiency by which fungi decompose organic matter contributes to the amount of carbon that is retained in biomass vs. lost to the atmosphere as respiration. This carbon use efficiency (CUE) is affected by various abiotic conditions, including temperature and nutrient availability.

  3. Equity and efficiency in policies to reduce carbon emissions in the domestic sector

    International Nuclear Information System (INIS)

    Barker, T.; Johnstone, N.

    1993-01-01

    It is frequently asserted that the distribution effects of a carbon/energy tax - such as that proposed by the Commission of the European Communities - will be largely regressive: that the burden of the tax will fall disproportionately on lower income households. Such an assertion, although valid within the confines of the respective analyses, is based upon an unduly limited treatment of the fiscal implications of such a tax as well as a simplification of the demand for energy services in the domestic sector. It will be argued that such analyses, by implicitly assuming that efficiency objectives (reducing carbon emissions at lowest cost) and equity objectives (ensuring that lower-income households do not suffer welfare losses) are to be separately achieved, overstate the cost of reducing emissions in terms of both objectives. (Author)

  4. Reducing the carbon footprint of fuels and petrochemicals. Preprints

    International Nuclear Information System (INIS)

    Ernst, S.; Balfanz, U.; Buchholz, S.; Lichtscheidl, J.; Marchionna, M.; Nees, F.; Santacesaria, E.

    2012-01-01

    Within the DGMK conference between 08th and 10th October, 2012, in Berlin (Federal Republic of Germany) the following lectures were held: (1) Energy demand and mix for global welfare and stable ecosystems (A. Jess); (2) The EU's roadmap for moving to a low-carbon economy - Aspirations and reality for refiners (J. Lichtscheidl); (3) Applications of CCS technology to the oil and gas industries (M. Marchionna); (4) A new chemical system solution for acid gas removal (M. Seiler); (5) Hydrogenation of carbon dioxide towards synthetic natural gas - A route to effective future energy storage (M. Schoder); (6) Bio-MTBE - How to reduce CO 2 footprint in fuels with a well known premium gasoline component (O. Busch); (7) Use of waste materials for Biodiesel production (R. Vitiello); (8) From algae to diesel and kerosene - Tailored fuels via selective catalysis (C. Zhao); (9) Chemo-catalytic valorization of cellulose (R. Palkovits); (10) Cellulosic ethanol: Potential, technology and development status (M. Rarbach); (11) Methanation of carbon oxides - History, status quo and future perspectives (W. Kaltner); (12) Chemical storage of renewable electricity in hydrocarbon fuels via H 2 (H. Eilers); (13) Materials for the 21st century: Can the carbon come from CO 2 (S. Kissling); (14) Effect of CO 2 admixture on the catalytic performance of Ni-Nb-M-O catalysts in oxidative dehydrogenation of ethane to ethylene (A. Qiao); (15) Oxidative dehydrogenation of light alkanes (A. Meiswinkel); (16) Low carbon fuel and chemical production from waste gases (S. Simpson); (17) Methanol to propylene: From development to commercialization (S. Haag); (18) On the impact of olefins and aromatics in the methanol-to-hydrocarbon conversion over H-ZSM-5 catalysts (X. Sun); (19) Mn-Na 2 WO 4 /SiO 2 - An industrial catalyst for methane coupling (M. Yildiz); (20) Biorefineries - Prerequisites for the realization of a future bioeconomy (K. Wagemann); (21) A new process for the valorisation of a bio

  5. Barriers to reducing carbon emissions in Eastern Europe and the Soviet Union

    International Nuclear Information System (INIS)

    Chandler, W.W.

    1991-01-01

    The Soviet Union and Eastern Europe accounted for 27% of global carbon emissions in 1986. Although the recent opening of the former planned economies offers numerous opportunities to improve energy use efficiency in these regions and reduce their energy-related carbon emissions, various barriers hinder changes in Eastern European energy use. These barriers include the following: lack of incentives; insufficient infrastructure; scarce human resources; and heavy reliance on low quality fuels. Energy intensity in these countries far surpasses the estimated energy intensity in the United States and Western Europe. However, substantial potential exists for improving the efficiency of energy use in these regions

  6. Autophagy sequesters damaged lysosomes to control lysosomal biogenesis and kidney injury.

    Science.gov (United States)

    Maejima, Ikuko; Takahashi, Atsushi; Omori, Hiroko; Kimura, Tomonori; Takabatake, Yoshitsugu; Saitoh, Tatsuya; Yamamoto, Akitsugu; Hamasaki, Maho; Noda, Takeshi; Isaka, Yoshitaka; Yoshimori, Tamotsu

    2013-08-28

    Diverse causes, including pathogenic invasion or the uptake of mineral crystals such as silica and monosodium urate (MSU), threaten cells with lysosomal rupture, which can lead to oxidative stress, inflammation, and apoptosis or necrosis. Here, we demonstrate that lysosomes are selectively sequestered by autophagy, when damaged by MSU, silica, or the lysosomotropic reagent L-Leucyl-L-leucine methyl ester (LLOMe). Autophagic machinery is recruited only on damaged lysosomes, which are then engulfed by autophagosomes. In an autophagy-dependent manner, low pH and degradation capacity of damaged lysosomes are recovered. Under conditions of lysosomal damage, loss of autophagy causes inhibition of lysosomal biogenesis in vitro and deterioration of acute kidney injury in vivo. Thus, we propose that sequestration of damaged lysosomes by autophagy is indispensable for cellular and tissue homeostasis.

  7. G-actin sequestering protein thymosin-β4 regulates the activity of myocardin-related transcription factor.

    Science.gov (United States)

    Morita, Tsuyoshi; Hayashi, Ken'ichiro

    2013-08-02

    Myocardin-related transcription factors (MRTFs) are robust coactivators of serum response factor (SRF). MRTFs contain three copies of the RPEL motif at their N-terminus, and they bind to monomeric globular actin (G-actin). Previous studies illustrate that G-actin binding inhibits MRTF activity by preventing the MRTFs nuclear accumulation. In the living cells, the majority of G-actin is sequestered by G-actin binding proteins that prevent spontaneous actin polymerization. Here, we demonstrate that the most abundant G-actin sequestering protein thymosin-β4 (Tβ4) was involved in the regulation of subcellular localization and activity of MRTF-A. Tβ4 competed with MRTF-A for G-actin binding; thus, interfering with G-actin-MRTF-A complex formation. Tβ4 overexpression induced the MRTF-A nuclear accumulation and activation of MRTF-SRF signaling. The activation rate of MRTF-A by the Tβ4 mutant L17A, whose affinity for G-actin is very low, was lower than that by wild-type Tβ4. In contrast, the β-actin mutant 3DA, which has a lower affinity for Tβ4, more effectively suppressed MRTF-A activity than wild-type β-actin. Furthermore, ectopic Tβ4 increased the endogenous expression of SRF-dependent actin cytoskeletal genes. Thus, Tβ4 is an important MRTF regulator that controls the G-actin-MRTFs interaction. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Carbon isotope fractionation by sulfate-reducing bacteria using different pathways for the oxidation of acetate.

    Science.gov (United States)

    Goevert, Dennis; Conrad, Ralf

    2008-11-01

    Acetate is a key intermediate in the anaerobic degradation of organic matter. In anoxic environments, available acetate is a competitive substrate for sulfate-reducing bacteria (SRB) and methane-producing archaea. Little is known about the fractionation of carbon isotopes by sulfate reducers. Therefore, we determined carbon isotope compositions in cultures of three acetate-utilizing SRB, Desulfobacter postgatei, Desulfobacter hydrogenophilus, and Desulfobacca acetoxidans. We found that these species showed strong differences in their isotope enrichment factors (epsilon) of acetate. During the consumption of acetate and sulfate, acetate was enriched in 13C by 19.3% per hundred in Desulfobacca acetoxidans. By contrast, both D. postgatei and D. hydrogenophilus showed a slight depletion of 13C resulting in epsilon(ac)-values of 1.8 and 1.5% per hundred, respectively. We suggest that the different isotope fractionation is due to the different metabolic pathways for acetate oxidation. The strongly fractionating Desulfobacca acetoxidans uses the acetyl-CoA/carbon monoxide dehydrogenase pathway, which is also used by acetoclastic methanogens that show a similar fractionation of acetate (epsilon(ac) = -21 to -27% per hundred). In contrast, Desulfobacter spp. oxidize acetate to CO2 via the tricarboxylic acid (TCA) cycle and apparently did not discriminate against 13C. Our results suggestthat carbon isotope fractionation in environments with sulfate reduction will strongly depend on the composition of the sulfate-reducing bacterial community oxidizing acetate.

  9. Climate warming feedback from mountain birch forest expansion: reduced albedo dominates carbon uptake.

    Science.gov (United States)

    de Wit, Heleen A; Bryn, Anders; Hofgaard, Annika; Karstensen, Jonas; Kvalevåg, Maria M; Peters, Glen P

    2014-07-01

    Expanding high-elevation and high-latitude forest has contrasting climate feedbacks through carbon sequestration (cooling) and reduced surface reflectance (warming), which are yet poorly quantified. Here, we present an empirically based projection of mountain birch forest expansion in south-central Norway under climate change and absence of land use. Climate effects of carbon sequestration and albedo change are compared using four emission metrics. Forest expansion was modeled for a projected 2.6 °C increase in summer temperature in 2100, with associated reduced snow cover. We find that the current (year 2000) forest line of the region is circa 100 m lower than its climatic potential due to land-use history. In the future scenarios, forest cover increased from 12% to 27% between 2000 and 2100, resulting in a 59% increase in biomass carbon storage and an albedo change from 0.46 to 0.30. Forest expansion in 2100 was behind its climatic potential, forest migration rates being the primary limiting factor. In 2100, the warming caused by lower albedo from expanding forest was 10 to 17 times stronger than the cooling effect from carbon sequestration for all emission metrics considered. Reduced snow cover further exacerbated the net warming feedback. The warming effect is considerably stronger than previously reported for boreal forest cover, because of the typically low biomass density in mountain forests and the large changes in albedo of snow-covered tundra areas. The positive climate feedback of high-latitude and high-elevation expanding forests with seasonal snow cover exceeds those of afforestation at lower elevation, and calls for further attention of both modelers and empiricists. The inclusion and upscaling of these climate feedbacks from mountain forests into global models is warranted to assess the potential global impacts. © 2013 John Wiley & Sons Ltd.

  10. Interactions between carbon sequestration and shade tree diversity in a smallholder coffee cooperative in El Salvador.

    Science.gov (United States)

    Richards, Meryl Breton; Méndez, V Ernesto

    2014-04-01

    Agroforestry systems have substantial potential to conserve native biodiversity and provide ecosystem services. In particular, agroforestry systems have the potential to conserve native tree diversity and sequester carbon for climate change mitigation. However, little research has been conducted on the temporal stability of species diversity and aboveground carbon stocks in these systems or the relation between species diversity and aboveground carbon sequestration. We measured changes in shade-tree diversity and shade-tree carbon stocks in 14 plots of a 35-ha coffee cooperative over 9 years and analyzed relations between species diversity and carbon sequestration. Carbon sequestration was positively correlated with initial species richness of shade trees. Species diversity of shade trees did not change significantly over the study period, but carbon stocks increased due to tree growth. Our results show a potential for carbon sequestration and long-term biodiversity conservation in smallholder coffee agroforestry systems and illustrate the opportunity for synergies between biodiversity conservation and climate change mitigation. © 2013 Society for Conservation Biology.

  11. Driving forces of organic carbon spatial distribution in the tropical seascape

    Science.gov (United States)

    Gillis, L. G.; Belshe, F. E.; Ziegler, A. D.; Bouma, T. J.

    2017-02-01

    An important ecosystem service of tropical coastal vegetation including seagrass beds and mangrove forests is their ability to accumulate carbon. Here we attempt to establish the driving forces for the accumulation of surface organic carbon in southern Thailand coastal systems. Across 12 sites we found that in line with expectations, seagrass beds (0.6 ± 0.09%) and mangrove forests (0.9 ± 0.3%) had higher organic carbon in the surface (top 5 cm) sediment than un-vegetated mudflats (0.4 ± 0.04%). Unexpectedly, however, mangrove forests in this region retained organic carbon, rather than outwell it, under normal tidal conditions. No relationship was found between organic carbon and substrate grain size. The most interesting finding of our study was that climax and pioneer seagrass species retained more carbon than mixed-species meadows, suggesting that plant morphology and meadow characteristics can be important factors in organic carbon accumulation. Insights such as these are important in developing carbon management strategies involving coastal ecosystems such as offsetting of carbon emissions. The ability of tropical coastal vegetation to sequester carbon is an important aspect for valuing the ecosystems. Our results provide some initial insight into the factors affecting carbon sequestration in these ecosystems, but also highlight the need for further research on a global scale.

  12. A pulmonary sequestered segment with an aberrant pulmonary arterial supply: A case of unique anomaly

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min Chul; Woo, Jeong Joo; An, Jin Kyung; Jung, Yoon Young; Choi, Yun Sun [Dept. of Radiology, Eulji Hospital, Eulji University, Seoul (Korea, Republic of)

    2016-04-15

    We presented a rare case of a 64-year-old man with a combined anomaly of the bronchus and pulmonary artery that was detected incidentally. Computed tomography showed a hyperlucent, aerated sequestered segment of the right lower lung with an independent ectopic bronchus, which had no connection to the other airway. The affected segment was supplied by its own aberrant pulmonary artery branch from the right pulmonary trunk. This anomaly cannot be classified with any of the previously reported anomalies.

  13. Effects of contemporary land-use and land-cover change on the carbon balance of terrestrial ecosystems in the United States

    Science.gov (United States)

    Sleeter, Benjamin M.; Liu, Jinxun; Daniel, Colin; Rayfield, Bronwyn; Sherba, Jason; Hawbaker, Todd J.; Zhu, Zhiliang; Selmants, Paul; Loveland, Thomas R.

    2018-01-01

    Changes in land use and land cover (LULC) can have profound effects on terrestrial carbon dynamics, yet their effects on the global carbon budget remain uncertain. While land change impacts on ecosystem carbon dynamics have been the focus of numerous studies, few efforts have been based on observational data incorporating multiple ecosystem types spanning large geographic areas over long time horizons. In this study we use a variety of synoptic-scale remote sensing data to estimate the effect of LULC changes associated with urbanization, agricultural expansion and contraction, forest harvest, and wildfire on the carbon balance of terrestrial ecosystems (forest, grasslands, shrublands, and agriculture) in the conterminous United States (i.e. excluding Alaska and Hawaii) between 1973 and 2010. We estimate large net declines in the area of agriculture and forest, along with relatively small increases in grasslands and shrublands. The largest net change in any class was an estimated gain of 114 865 km2 of developed lands, an average rate of 3282 km2 yr−1. On average, US ecosystems sequestered carbon at an annual rate of 254 Tg C yr−1. In forest lands, the net sink declined by 35% over the study period, largely a result of land-use legacy, increasing disturbances, and reductions in forest area due to land use conversion. Uncertainty in LULC change data contributed to a ~16% margin of error in the annual carbon sink estimate prior to 1985 (approximately ±40 Tg C yr−1). Improvements in LULC and disturbance mapping starting in the mid-1980s reduced this uncertainty by ~50% after 1985. We conclude that changes in LULC are a critical component to understanding ecosystem carbon dynamics, and continued improvements in detection, quantification, and attribution of change have the potential to significantly reduce current uncertainties.

  14. Effects of contemporary land-use and land-cover change on the carbon balance of terrestrial ecosystems in the United States

    Science.gov (United States)

    Sleeter, Benjamin M.; Liu, Jinxun; Daniel, Colin; Rayfield, Bronwyn; Sherba, Jason; Hawbaker, Todd J.; Zhu, Zhiliang; Selmants, Paul C.; Loveland, Thomas R.

    2018-04-01

    Changes in land use and land cover (LULC) can have profound effects on terrestrial carbon dynamics, yet their effects on the global carbon budget remain uncertain. While land change impacts on ecosystem carbon dynamics have been the focus of numerous studies, few efforts have been based on observational data incorporating multiple ecosystem types spanning large geographic areas over long time horizons. In this study we use a variety of synoptic-scale remote sensing data to estimate the effect of LULC changes associated with urbanization, agricultural expansion and contraction, forest harvest, and wildfire on the carbon balance of terrestrial ecosystems (forest, grasslands, shrublands, and agriculture) in the conterminous United States (i.e. excluding Alaska and Hawaii) between 1973 and 2010. We estimate large net declines in the area of agriculture and forest, along with relatively small increases in grasslands and shrublands. The largest net change in any class was an estimated gain of 114 865 km2 of developed lands, an average rate of 3282 km2 yr‑1. On average, US ecosystems sequestered carbon at an annual rate of 254 Tg C yr‑1. In forest lands, the net sink declined by 35% over the study period, largely a result of land-use legacy, increasing disturbances, and reductions in forest area due to land use conversion. Uncertainty in LULC change data contributed to a ~16% margin of error in the annual carbon sink estimate prior to 1985 (approximately ±40 Tg C yr‑1). Improvements in LULC and disturbance mapping starting in the mid-1980s reduced this uncertainty by ~50% after 1985. We conclude that changes in LULC are a critical component to understanding ecosystem carbon dynamics, and continued improvements in detection, quantification, and attribution of change have the potential to significantly reduce current uncertainties.

  15. Salinomycin kills cancer stem cells by sequestering iron in lysosomes

    Science.gov (United States)

    Mai, Trang Thi; Hamaï, Ahmed; Hienzsch, Antje; Cañeque, Tatiana; Müller, Sebastian; Wicinski, Julien; Cabaud, Olivier; Leroy, Christine; David, Amandine; Acevedo, Verónica; Ryo, Akihide; Ginestier, Christophe; Birnbaum, Daniel; Charafe-Jauffret, Emmanuelle; Codogno, Patrice; Mehrpour, Maryam; Rodriguez, Raphaël

    2017-10-01

    Cancer stem cells (CSCs) represent a subset of cells within tumours that exhibit self-renewal properties and the capacity to seed tumours. CSCs are typically refractory to conventional treatments and have been associated to metastasis and relapse. Salinomycin operates as a selective agent against CSCs through mechanisms that remain elusive. Here, we provide evidence that a synthetic derivative of salinomycin, which we named ironomycin (AM5), exhibits a more potent and selective activity against breast CSCs in vitro and in vivo, by accumulating and sequestering iron in lysosomes. In response to the ensuing cytoplasmic depletion of iron, cells triggered the degradation of ferritin in lysosomes, leading to further iron loading in this organelle. Iron-mediated production of reactive oxygen species promoted lysosomal membrane permeabilization, activating a cell death pathway consistent with ferroptosis. These findings reveal the prevalence of iron homeostasis in breast CSCs, pointing towards iron and iron-mediated processes as potential targets against these cells.

  16. Organic carbon sequestration under selected land use in Padang city, West Sumatra, Indonesia

    Science.gov (United States)

    Yulnafatmawita; Yasin, S.

    2018-03-01

    Organic carbon is a potential element to build biomass as well as emitting CO2 to the atmosphere and promotes global warming. This research was aimed to calculate the sequestered Carbon (C) within a 1-m soil depth under selected land use from 6 different sites in Padang city, Indonesia. Disturbed and undisturbed soil samples were taken from several horizons until 100 cm depth at each location. Soil parameters observed were organic carbon (OC), bulk density (BD), and soil texture. The result showed that soil OC content tended to decrease by the depth at all land use types, except under rice field in Kurao-Nanggalo which extremely increased at >65 cm soil depth with the highest carbon stock. The soil organic carbon sequestration from the highest to the lowest according to land use and the location is in the following order mix garden- Kayu Aro > mix garden- Aie Pacah > Rangeland- Parak Laweh >seasonal farming- Teluk Sirih > rice field- Kampuang Jua.

  17. GeoEthics from the Ground Up: A Carbon-Neutral Education

    Science.gov (United States)

    Moore, A.; Derry, L. A.

    2014-12-01

    Discussion with students about the science of global warming and the consequences of greenhouse gas emissions - while emitting greenhouse gasses in the process - is a focal point for geoethics in the Cornell University Earth and Environmental Systems (EES) Field Program. If we seek to educate students in the fundamentals of environmental stewardship we must also put stewardship into practice as part of that education. The EES program is a semester length earth systems field program held on Hawai`i Island. In Hawai`i students gain first-hand experience with the interconnected solid earth, living earth, ocean and atmosphere. They also gain first-hand experience with the consequences of unsustainable resource use: marine resource depletion, deforestation and species loss, development v. conservation, fossil fuel v. alternative energy options. Yet as a travel-based field program the pursuit of these goals carries a clear environmental cost. Thus a core element of EES education is to run a carbon-neutral program. To achieve this, students quantify every aspect of the program's carbon footprint. They decide which actions they must include as part of that footprint and learn how to monitor and calculate the resulting CO2 emissions. Students learn how to reduce emissions where possible, and offset emissions that cannot be eliminated. Working in partnership with island-based conservation organizations students engage in reforestation of degraded native forest landscapes. They model the carbon sequestration capacity of restored forest biomass and soil reservoirs. The outcome of this process has triple-bottom-line benefits: (1) native forest and endangered species habitat is restored, (2) carbon dioxide is removed from the atmosphere and sequestered, and (3) students gain hands-on, minds-on experience with carbon-cycle science, ecosystem science, and with the ethical imperative of putting one's knowledge into action.

  18. Accounting for urban biogenic fluxes in regional carbon budgets.

    Science.gov (United States)

    Hardiman, Brady S; Wang, Jonathan A; Hutyra, Lucy R; Gately, Conor K; Getson, Jackie M; Friedl, Mark A

    2017-08-15

    Many ecosystem models incorrectly treat urban areas as devoid of vegetation and biogenic carbon (C) fluxes. We sought to improve estimates of urban biomass and biogenic C fluxes using existing, nationally available data products. We characterized biogenic influence on urban C cycling throughout Massachusetts, USA using an ecosystem model that integrates improved representation of urban vegetation, growing conditions associated with urban heat island (UHI), and altered urban phenology. Boston's biomass density is 1/4 that of rural forests, however 87% of Massachusetts' urban landscape is vegetated. Model results suggest that, kilogram-for-kilogram, urban vegetation cycles C twice as fast as rural forests. Urban vegetation releases (R E ) and absorbs (GEE) the equivalent of 11 and 14%, respectively, of anthropogenic emissions in the most urban portions of the state. While urban vegetation in Massachusetts fully sequesters anthropogenic emissions from smaller cities in the region, Boston's UHI reduces annual C storage by >20% such that vegetation offsets only 2% of anthropogenic emissions. Asynchrony between temporal patterns of biogenic and anthropogenic C fluxes further constrains the emissions mitigation potential of urban vegetation. However, neglecting to account for biogenic C fluxes in cities can impair efforts to accurately monitor, report, verify, and reduce anthropogenic emissions. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Ocean Heat and Carbon Uptake in Transient Climate Change: Identifying Model Uncertainty

    Science.gov (United States)

    Romanou, Anastasia; Marshall, John

    2015-01-01

    Global warming on decadal and centennial timescales is mediated and ameliorated by the oceansequestering heat and carbon into its interior. Transient climate change is a function of the efficiency by whichanthropogenic heat and carbon are transported away from the surface into the ocean interior (Hansen et al. 1985).Gregory and Mitchell (1997) and Raper et al. (2002) were the first to identify the importance of the ocean heat uptakeefficiency in transient climate change. Observational estimates (Schwartz 2012) and inferences from coupledatmosphere-ocean general circulation models (AOGCMs; Gregory and Forster 2008; Marotzke et al. 2015), suggest thatocean heat uptake efficiency on decadal timescales lies in the range 0.5-1.5 W/sq m/K and is thus comparable to theclimate feedback parameter (Murphy et al. 2009). Moreover, the ocean not only plays a key role in setting the timing ofwarming but also its regional patterns (Marshall et al. 2014), which is crucial to our understanding of regional climate,carbon and heat uptake, and sea-level change. This short communication is based on a presentation given by A.Romanou at a recent workshop, Oceans Carbon and Heat Uptake: Uncertainties and Metrics, co-hosted by US CLIVARand OCB. As briefly reviewed below, we have incomplete but growing knowledge of how ocean models used in climatechange projections sequester heat and carbon into the interior. To understand and thence reduce errors and biases inthe ocean component of coupled models, as well as elucidate the key mechanisms at work, in the final section we outlinea proposed model intercomparison project named FAFMIP. In FAFMIP, coupled integrations would be carried out withprescribed overrides of wind stress and freshwater and heat fluxes acting at the sea surface.

  20. A new approach to quantify and map carbon stored, sequestered and emissions avoided by urban forests

    Science.gov (United States)

    E. Gregory McPherson; Qingfu Xiao; Elena Aguaron

    2013-01-01

    This paper describes the use of field surveys, biometric information for urban tree species and remote sensing to quantify and map carbon (C) storage, sequestration and avoided emissions from energy savings. Its primary contribution is methodological; the derivation and application of urban tree canopy (UTC) based transfer functions (t C ha-1 UTC). Findings for Los...

  1. High-temperature reactors for underground liquid-fuels production with direct carbon sequestration

    International Nuclear Information System (INIS)

    Forsberg, C. W.

    2008-01-01

    The world faces two major challenges: (1) reducing dependence on oil from unstable parts of the world and (2) minimizing greenhouse gas emissions. Oil provides 39% of the energy needs of the United States, and oil refineries consume over 7% of the total energy. The world is running out of light crude oil and is increasingly using heavier fossil feedstocks such as heavy oils, tar sands, oil shale, and coal for the production of liquid fuels (gasoline, diesel, and jet fuel). With heavier feedstocks, more energy is needed to convert the feedstocks into liquid fuels. In the extreme case of coal liquefaction, the energy consumed in the liquefaction process is almost twice the energy value of the liquid fuel. This trend implies large increases in carbon dioxide releases per liter of liquid transport fuel that is produced. It is proposed that high-temperature nuclear heat be used to refine hydrocarbon feedstocks (heavy oil, tar sands, oil shale, and coal) 'in situ ', i.e., underground. Using these resources for liquid fuel production would potentially enable the United States to become an exporter of oil while sequestering carbon from the refining process underground as carbon. This option has become potentially viable because of three technical developments: precision drilling, underground isolation of geological formations with freeze walls, and the understanding that the slow heating of heavy hydrocarbons (versus fast heating) increases the yield of light oils while producing a high-carbon solid residue. Required peak reactor temperatures are near 700 deg. C-temperatures within the current capabilities of high-temperature reactors. (authors)

  2. Fundamental Studies on the Electrochemical Behaviour of Carbon Steel Exposed in Sulphide and Sulphate-Reducing Environments

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel

    The aim of the report is to give a fundamental understanding of the response of different electrochemical techniques on carbon steel in a sulphide environment as well as in a biologically active sulphate-reducing environment (SRB). This will form the basis for further studies and for recommendati......The aim of the report is to give a fundamental understanding of the response of different electrochemical techniques on carbon steel in a sulphide environment as well as in a biologically active sulphate-reducing environment (SRB). This will form the basis for further studies...

  3. Aldehyde-sequestering drugs: tools for studying protein damage by lipid peroxidation products.

    Science.gov (United States)

    Burcham, Philip C; Kaminskas, Lisa M; Fontaine, Frank R; Petersen, Dennis R; Pyke, Simon M

    2002-12-27

    Elevated levels of reactive alpha,beta-unsaturated aldehydes (e.g. malondialdehyde, 4-hydroxynonenal and acrolein) in the affected tissues of various degenerative conditions suggest these substances are active propagators of the disease process. One experimental approach to attenuating damage by these intermediates employs 'aldehyde-sequestering drugs' as sacrificial nucleophiles, thereby sparing cell macromolecules and perhaps slowing disease progression. Drugs with demonstrated trapping activity toward lipid-derived aldehydes include various amine compounds such as aminoguanidine, carnosine and pyridoxamine. We have focused on identifying scavengers of acrolein, perhaps the most toxic aldehyde formed during lipid peroxidation cascades. Various phthalazine compounds (hydralazine and dihydralazine) were found to trap acrolein readily, forming hydrazone derivatives in a rapid Schiff-type reaction. These compounds strongly protect against acrolein-mediated toxicity in isolated hepatocytes.

  4. Quasifixed points from scalar sequestering and the little hierarchy problem in supersymmetry

    Science.gov (United States)

    Martin, Stephen P.

    2018-02-01

    In supersymmetric models with scalar sequestering, superconformal strong dynamics in the hidden sector suppresses the low-energy couplings of mass dimension 2, compared to the squares of the dimension-1 parameters. Taking into account restrictions on the anomalous dimensions in superconformal theories, I point out that the interplay between the hidden and visible sector renormalizations gives rise to quasifixed point running for the supersymmetric Standard Model squared mass parameters, rather than driving them to 0. The extent to which this dynamics can ameliorate the little hierarchy problem in supersymmetry is studied. Models of this type in which the gaugino masses do not unify are arguably more natural, and are certainly more likely to be accessible, eventually, to the Large Hadron Collider.

  5. Effect of forest drainage on the carbon balance and greenhouse impact of Finnish peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Laine, J; Minkkinen, K; Laiho, R [Helsinki Univ. (Finland). Dept. of Forest Ecology

    1997-12-31

    The aim of this project is to produce an estimate of the change in the biomass and peat carbon stores arising from the drainage of peatlands for forestry, and of the change of greenhouse impact of these ecosystems. The study shows that the subsidence of mire surfaces due to drainage has been relatively small, on average about 20 cm. The observed increase in bulk density after drainage is caused by the physical compression of peat and the post-drainage input of organic material in the form of litter production from the above and below ground parts of the tree layer. Oxidative decay of organic matter may have further increased the compaction of peat, especially in fertile sites. When the changes in peat and vegetation carbon stores are summed up, it seems that, within the site types studied, the total impact of drainage to the ecosystem carbon store is close to zero on the nutrient rich sites and clearly positive on the poorer types. Water level drawdown in peatlands after drainage for forestry appears to decrease the greenhouse impact at least for a few hundred years. The estimated changes in all three emission components (CH{sub 4} emissions, CO{sub 2} sink from peatland and CO{sub 2} sequestered in trees) reduce the radiative forcing by approximately similar amounts

  6. Effect of forest drainage on the carbon balance and greenhouse impact of Finnish peatlands

    Energy Technology Data Exchange (ETDEWEB)

    Laine, J.; Minkkinen, K.; Laiho, R. [Helsinki Univ. (Finland). Dept. of Forest Ecology

    1996-12-31

    The aim of this project is to produce an estimate of the change in the biomass and peat carbon stores arising from the drainage of peatlands for forestry, and of the change of greenhouse impact of these ecosystems. The study shows that the subsidence of mire surfaces due to drainage has been relatively small, on average about 20 cm. The observed increase in bulk density after drainage is caused by the physical compression of peat and the post-drainage input of organic material in the form of litter production from the above and below ground parts of the tree layer. Oxidative decay of organic matter may have further increased the compaction of peat, especially in fertile sites. When the changes in peat and vegetation carbon stores are summed up, it seems that, within the site types studied, the total impact of drainage to the ecosystem carbon store is close to zero on the nutrient rich sites and clearly positive on the poorer types. Water level drawdown in peatlands after drainage for forestry appears to decrease the greenhouse impact at least for a few hundred years. The estimated changes in all three emission components (CH{sub 4} emissions, CO{sub 2} sink from peatland and CO{sub 2} sequestered in trees) reduce the radiative forcing by approximately similar amounts

  7. Estimating Soil Organic Carbon Sequestration in Rice Paddies as Influenced by Climate Change under Scenario A2 and B2 of an i-EPIC model of Thailand

    Directory of Open Access Journals (Sweden)

    Noppol Arunrat

    2014-01-01

    Full Text Available Carbon sequestration in soils constitutes an important option that can be used to reduce CO2 emissions to the atmosphere and reduce environmental impacts. Soil organic carbon (SOC is both a source of carbon release and a sink for carbon sequestration. Our objectives in this study were to validate the interactive Environmental Policy Impact Calculator (i-EPIC model version 0509, as well as to estimate SOC sequestration under climate change scenarios A2 and B2 SRES emission scenarios in Thailand. The SOC estimated by i-EPIC was compared with data from the Office of Soil Resources Survey and Research, Land Development Department. The results indicated that performance testing of i-EPIC is able to estimate SOC. Validation of SOC proved to be satisfactory with a resulting root mean square error (RMSE % value of 34.60. The SOC content showed a decreasing trend under B2 and A2 climate scenarios (average 0.87% and 0.85%, respectively compared to the reference from 2007 (average 0.92%. Stepwise regression analysis also revealed that carbon from residue decomposition, biomass pool carbon, and the total change of the carbon pool were directly correlated with the SOC (R2= 0.99, p< 0.01. Furthermore, the change from rain supplied water to irrigation also resulted in an increase of carbon inputs but a decrease in the SOC sequestered during the 2007-2017 period. Regression analyses indicated that soil carbon sequestration responds linearly to carbon input. Significant changes in carbon input as well as decreases in SOC levels were observed as temperature and precipitation increased. Based on the testing and analysis, we concluded that i-EPIC is capable of reliably simulating effects of climate change on SOC sequestration. Based on the results, this knowledge and information can increase effectiveness in the promotion of integrated rice management for rice production in Thailand.

  8. Reducing the carbon footprint of fuels and petrochemicals. Preprints

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, S.; Balfanz, U.; Buchholz, S.; Lichtscheidl, J.; Marchionna, M.; Nees, F.; Santacesaria, E. (eds.)

    2012-07-01

    Within the DGMK conference between 08th and 10th October, 2012, in Berlin (Federal Republic of Germany) the following lectures were held: (1) Energy demand and mix for global welfare and stable ecosystems (A. Jess); (2) The EU's roadmap for moving to a low-carbon economy - Aspirations and reality for refiners (J. Lichtscheidl); (3) Applications of CCS technology to the oil and gas industries (M. Marchionna); (4) A new chemical system solution for acid gas removal (M. Seiler); (5) Hydrogenation of carbon dioxide towards synthetic natural gas - A route to effective future energy storage (M. Schoder); (6) Bio-MTBE - How to reduce CO{sub 2} footprint in fuels with a well known premium gasoline component (O. Busch); (7) Use of waste materials for Biodiesel production (R. Vitiello); (8) From algae to diesel and kerosene - Tailored fuels via selective catalysis (C. Zhao); (9) Chemo-catalytic valorization of cellulose (R. Palkovits); (10) Cellulosic ethanol: Potential, technology and development status (M. Rarbach); (11) Methanation of carbon oxides - History, status quo and future perspectives (W. Kaltner); (12) Chemical storage of renewable electricity in hydrocarbon fuels via H{sub 2} (H. Eilers); (13) Materials for the 21st century: Can the carbon come from CO{sub 2} (S. Kissling); (14) Effect of CO{sub 2} admixture on the catalytic performance of Ni-Nb-M-O catalysts in oxidative dehydrogenation of ethane to ethylene (A. Qiao); (15) Oxidative dehydrogenation of light alkanes (A. Meiswinkel); (16) Low carbon fuel and chemical production from waste gases (S. Simpson); (17) Methanol to propylene: From development to commercialization (S. Haag); (18) On the impact of olefins and aromatics in the methanol-to-hydrocarbon conversion over H-ZSM-5 catalysts (X. Sun); (19) Mn-Na{sub 2}WO{sub 4}/SiO{sub 2} - An industrial catalyst for methane coupling (M. Yildiz); (20) Biorefineries - Prerequisites for the realization of a future bioeconomy (K. Wagemann); (21) A new process

  9. Indirect human impacts reverse centuries of carbon sequestration and salt marsh accretion.

    Science.gov (United States)

    Coverdale, Tyler C; Brisson, Caitlin P; Young, Eric W; Yin, Stephanie F; Donnelly, Jeffrey P; Bertness, Mark D

    2014-01-01

    Direct and indirect human impacts on coastal ecosystems have increased over the last several centuries, leading to unprecedented degradation of coastal habitats and loss of ecological services. Here we document a two-century temporal disparity between salt marsh accretion and subsequent loss to indirect human impacts. Field surveys, manipulative experiments and GIS analyses reveal that crab burrowing weakens the marsh peat base and facilitates further burrowing, leading to bank calving, disruption of marsh accretion, and a loss of over two centuries of sequestered carbon from the marsh edge in only three decades. Analogous temporal disparities exist in other systems and are a largely unrecognized obstacle in attaining sustainable ecosystem services in an increasingly human impacted world. In light of the growing threat of indirect impacts worldwide and despite uncertainties in the fate of lost carbon, we suggest that estimates of carbon emissions based only on direct human impacts may significantly underestimate total anthropogenic carbon emissions.

  10. How can we reduce carbon in ash in firing pulverized coal

    Energy Technology Data Exchange (ETDEWEB)

    O' Keefe, W. (and others)

    1992-12-01

    The article discusses solutions to the problem of reducing carbon in ash in firing pulverized coal. Suggested solutions to the problem include: reviewing air flow through the mills; examining the pulverizers for coal fineness variations; investigating air distribution in the burners; review dual-firing equations; examining the burners for slag build up; checking coal fineness is appropriate to the boiler; increasing air flow; and checking instrumentation. 2 figs., 1 photo.

  11. Soil-Carbon Measurement System Based on Inelastic Neutron Scattering

    International Nuclear Information System (INIS)

    Orion, I.; Wielopolski, L.

    2002-01-01

    Increase in the atmospheric CO 2 is associated with concurrent increase in the amount of carbon sequestered in the soil. For better understanding of the carbon cycle it is imperative to establish a better and extensive database of the carbon concentrations in various soil types, in order to develop improved models for changes in the global climate. Non-invasive soil carbon measurement is based on Inelastic Neutron Scattering (INS). This method has been used successfully to measure total body carbon in human beings. The system consists of a pulsed neutron generator that is based on D-T reaction, which produces 14 MeV neutrons, a neutron flux monitoring detector and a couple of large NaI(Tl), 6'' diameter by 6'' high, spectrometers [4]. The threshold energy for INS reaction in carbon is 4.8 MeV. Following INS of 14 MeV neutrons in carbon 4.44 MeV photons are emitted and counted during a gate pulse period of 10 μsec. The repetition rate of the neutron generator is 104 pulses per sec. The gamma spectra are acquired only during the neutron generator gate pulses. The INS method for soil carbon content measurements provides a non-destructive, non-invasive tool, which can be optimized in order to develop a system for in field measurements

  12. Redox-controlled carbon and phosphorus burial: A mechanism for enhanced organic carbon sequestration during the PETM

    Science.gov (United States)

    Komar, Nemanja; Zeebe, Richard E.

    2017-12-01

    Geological records reveal a major perturbation in carbon cycling during the Paleocene-Eocene Thermal Maximum (PETM, ∼56 Ma), marked by global warming of more than 5 °C and a prominent negative carbon isotope excursion of at least 2.5‰ within the marine realm. The entire event lasted about 200,000 yr and was associated with a massive release of light carbon into the ocean-atmosphere system over several thousands of years. Here we focus on the terminal stage of the PETM, during which the ocean-atmosphere system rapidly recovered from the carbon cycle perturbation. We employ a carbon-cycle box model to examine the feedbacks between surface ocean biological production, carbon, oxygen, phosphorus, and carbonate chemistry during massive CO2 release events, such as the PETM. The model results indicate that the redox-controlled carbon-phosphorus feedback is capable of producing enhanced organic carbon sequestration during large carbon emission events. The locale of carbon oxidation (ocean vs. atmosphere) does not affect the amount of carbon sequestered. However, even though the model produces trends consistent with oxygen, excess accumulation rates of organic carbon (∼1700 Pg C during the recovery stage), export production and δ13 C data, it fails to reproduce the magnitude of change of sediment carbonate content and the CCD over-deepening during the recovery stage. The CCD and sediment carbonate content overshoot during the recovery stage is muted by a predicted increase in CaCO3 rain. Nonetheless, there are indications that the CaCO3 export remained relatively constant during the PETM. If this was indeed true, then an initial pulse of 3,000 Pg C followed by an additional, slow leak of 2,500 Pg C could have triggered an accelerated nutrient supply to the surface ocean instigating enhanced organic carbon export, consequently increasing organic carbon sequestration, resulting in an accelerated restoration of ocean-atmosphere biogeochemistry during the termination

  13. The role of glomalin, a protein produced by arbuscular mycorrhizal fungi, in sequestering potentially toxic elements

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Chavez, M.C.; Carrillo-Gonzalez, R.; Wright, S.F.; Nichols, K.A

    2004-08-01

    Naturally occurring soil organic compounds stabilize potentially toxic elements (PTEs) such as Cu, Cd, Pb, and Mn. The hypothesis of this work was that an insoluble glycoprotein, glomalin, produced in copious amounts on hyphae of arbuscular mycorrhizal fungi (AMF) sequesters PTEs. Glomalin can be extracted from laboratory cultures of AMF and from soils. Three different experiments were conducted. Experiment 1 showed that glomalin extracted from two polluted soils contained 1.6-4.3 mg Cu, 0.02-0.08 mg Cd, and 0.62-1.12 mg Pb/g glomalin. Experiment 2 showed that glomalin from hyphae of an isolate of Gigaspora rosea sequestered up to 28 mg Cu/g in vitro. Experiment 3 tested in vivo differences in Cu sequestration by Cu-tolerant and non-tolerant isolates of Glomus mosseae colonizing sorghum. Plants were fed with nutrient solution containing 0.5, 10 or 20 {mu}M of Cu. Although no differences between isolates were detected, mean values for the 20 {mu}M Cu level were 1.6, 0.4, and 0.3 mg Cu/g for glomalin extracted from hyphae, from sand after removal of hyphae and from hyphae attached to roots, respectively. Glomalin should be considered for biostabilization leading to remediation of polluted soils. - Glomalin may be useful in remediation of toxic elements in soils.

  14. The role of glomalin, a protein produced by arbuscular mycorrhizal fungi, in sequestering potentially toxic elements

    International Nuclear Information System (INIS)

    Gonzalez-Chavez, M.C.; Carrillo-Gonzalez, R.; Wright, S.F.; Nichols, K.A.

    2004-01-01

    Naturally occurring soil organic compounds stabilize potentially toxic elements (PTEs) such as Cu, Cd, Pb, and Mn. The hypothesis of this work was that an insoluble glycoprotein, glomalin, produced in copious amounts on hyphae of arbuscular mycorrhizal fungi (AMF) sequesters PTEs. Glomalin can be extracted from laboratory cultures of AMF and from soils. Three different experiments were conducted. Experiment 1 showed that glomalin extracted from two polluted soils contained 1.6-4.3 mg Cu, 0.02-0.08 mg Cd, and 0.62-1.12 mg Pb/g glomalin. Experiment 2 showed that glomalin from hyphae of an isolate of Gigaspora rosea sequestered up to 28 mg Cu/g in vitro. Experiment 3 tested in vivo differences in Cu sequestration by Cu-tolerant and non-tolerant isolates of Glomus mosseae colonizing sorghum. Plants were fed with nutrient solution containing 0.5, 10 or 20 μM of Cu. Although no differences between isolates were detected, mean values for the 20 μM Cu level were 1.6, 0.4, and 0.3 mg Cu/g for glomalin extracted from hyphae, from sand after removal of hyphae and from hyphae attached to roots, respectively. Glomalin should be considered for biostabilization leading to remediation of polluted soils. - Glomalin may be useful in remediation of toxic elements in soils

  15. Process based modelling of soil organic carbon redistribution on landscape scale

    Science.gov (United States)

    Schindewolf, Marcus; Seher, Wiebke; Amorim, Amorim S. S.; Maeso, Daniel L.; Jürgen, Schmidt

    2014-05-01

    Recent studies have pointed out the great importance of erosion processes in global carbon cycling. Continuous erosion leads to a massive loss of top soils including the loss of organic carbon accumulated over long time in the soil humus fraction. Lal (2003) estimates that 20% of the organic carbon eroded with top soils is emitted into atmosphere, due to aggregate breakdown and carbon mineralization during transport by surface runoff. Furthermore soil erosion causes a progressive decrease of natural soil fertility, since cation exchange capacity is associated with organic colloids. As a consequence the ability of soils to accumulate organic carbon is reduced proportionately to the drop in soil productivity. The colluvial organic carbon might be protected from further degradation depending on the depth of the colluvial cover and local decomposing conditions. Some colluvial sites can act as long-term sinks for organic carbon. The erosional transport of organic carbon may have an effect on the global carbon budget, however, it is uncertain, whether erosion is a sink or a source for carbon in the atmosphere. Another part of eroded soils and organic carbon will enter surface water bodies and might be transported over long distances. These sediments might be deposited in the riparian zones of river networks. Erosional losses of organic carbon will not pass over into atmosphere for the most part. But soil erosion limits substantially the potential of soils to sequester atmospheric CO2 by generating humus. The present study refers to lateral carbon flux modelling on landscape scale using the process based EROSION 3D soil loss simulation model, using existing parameter values. The selective nature of soil erosion results in a preferentially transport of fine particles while less carbonic larger particles remain on site. Consequently organic carbon is enriched in the eroded sediment compared to the origin soil. For this reason it is essential that EROSION 3D provides the

  16. Thick-shelled, grazer-protected diatoms decouple ocean carbon and silicon cycles in the iron-limited Antarctic Circumpolar Current

    Science.gov (United States)

    Assmy, Philipp; Smetacek, Victor; Montresor, Marina; Klaas, Christine; Henjes, Joachim; Strass, Volker H.; Arrieta, Jesús M.; Bathmann, Ulrich; Berg, Gry M.; Breitbarth, Eike; Cisewski, Boris; Friedrichs, Lars; Fuchs, Nike; Herndl, Gerhard J.; Jansen, Sandra; Krägefsky, Sören; Latasa, Mikel; Peeken, Ilka; Röttgers, Rüdiger; Scharek, Renate; Schüller, Susanne E.; Steigenberger, Sebastian; Webb, Adrian; Wolf-Gladrow, Dieter

    2013-01-01

    Diatoms of the iron-replete continental margins and North Atlantic are key exporters of organic carbon. In contrast, diatoms of the iron-limited Antarctic Circumpolar Current sequester silicon, but comparatively little carbon, in the underlying deep ocean and sediments. Because the Southern Ocean is the major hub of oceanic nutrient distribution, selective silicon sequestration there limits diatom blooms elsewhere and consequently the biotic carbon sequestration potential of the entire ocean. We investigated this paradox in an in situ iron fertilization experiment by comparing accumulation and sinking of diatom populations inside and outside the iron-fertilized patch over 5 wk. A bloom comprising various thin- and thick-shelled diatom species developed inside the patch despite the presence of large grazer populations. After the third week, most of the thinner-shelled diatom species underwent mass mortality, formed large, mucous aggregates, and sank out en masse (carbon sinkers). In contrast, thicker-shelled species, in particular Fragilariopsis kerguelensis, persisted in the surface layers, sank mainly empty shells continuously, and reduced silicate concentrations to similar levels both inside and outside the patch (silica sinkers). These patterns imply that thick-shelled, hence grazer-protected, diatom species evolved in response to heavy copepod grazing pressure in the presence of an abundant silicate supply. The ecology of these silica-sinking species decouples silicon and carbon cycles in the iron-limited Southern Ocean, whereas carbon-sinking species, when stimulated by iron fertilization, export more carbon per silicon. Our results suggest that large-scale iron fertilization of the silicate-rich Southern Ocean will not change silicon sequestration but will add carbon to the sinking silica flux. PMID:24248337

  17. How to reduce household carbon emissions: A review of experience and policy design considerations

    International Nuclear Information System (INIS)

    Zhang, Xiaoling; Wang, Yue

    2017-01-01

    Global warming and environment problems caused by the excessive emission of greenhouse gases (GHGs), along with rapid economic development has attracted the attention of many countries and regions of the world. Reducing GHG emissions is essential to mitigate the threat of global warming. Household carbon (dioxide) emissions have been recognized as one of the most important contributors to climate change, with a significant impact on both the local and global environment, and various policy instruments have been implemented by governments to bring about the reduction. This paper reviews these carbon abatement policy measures from demand-side and supply-side perspectives based on 144 countries across the world. The advantages and disadvantages of the policies are analyzed and it is found that income level largely affects the choice of policy, with high-income countries being mostly associated with demand-side policy instruments. Low-income countries adopt less demand-side policy measures and mainly depend on supply-side polices such as targets and regulations. Geographic location is also an important factor influencing the choice of policy instruments due to the different climates between different regions, although targets, regulations and carbon taxes are dominant GHG reduction policy measures worldwide. In America, tendering and net metering are popular, while in Europe feed-in-tariff (FIT) policies are implemented for more than 70% of the time. In Asia, policy measures, whether supply-side or demand-side, are comparatively weakly implemented and influenced by location, urbanization and economic growth. This paper suggests that, although the economic level is different, low-income countries and particularly developing countries can promote carbon abatement as well as the financial market by gradually changing from supply-side policy instruments to demand-side policies. This critical review provides a systematic understanding of various carbon emission policies in

  18. Carbon storage and recycling in short-rotation energy crops

    International Nuclear Information System (INIS)

    Ranney, J.W.; Wright, L.L.; Mitchell, C.P.

    1991-01-01

    Short-rotation energy crops can play a significant role in storing carbon compared to the agricultural land uses they would displace. However, the benefits from these plantations in avoiding further use of fossil fuel and in taking pressure off of native forests for energy uses provides longer term carbon benetfits than the plantation carbon sequestration itself. The fast growth and harvest frequency of plantations tends to limit the amount of above and below-ground carbon storage in them. The primary components of plantation carbon sequestering compared to sustained agricultural practices involve above-ground wood, possible increased soil carbon, litter layer formation, and increased root biomass. On the average, short-rotation plantations in total may increase carbon inventories by about 30 to 40 tonnes per hectare over about a 20- to 56-year period when displacing cropland. This is about doubling in storage over cropland and about one-half the storage in human-impacted forests. The sequestration benefit of wood energy crops over cropland would be negated in about 75 to 100 years by the use of fossil fuels to tend the plantations and handle biomass. Plantation interactions with other land uses and total landscape carbon inventory is important in assessing the relative role plantations play in terrestrial and atmospheric carbon dynamics. It is speculated that plantations, when viewed in this context. could trencrate a global leveling of net carbon emissions for approximately 10 to 20 years

  19. Estimation of carbon sequestration by tree species in three farms in Villa Clara province

    Directory of Open Access Journals (Sweden)

    José Carlos García Hernández

    2016-03-01

    Full Text Available The research took place in two farms of the Cifuentes municipality and in a farm of the Santa Clara municipality, province of Villa Clara. It was carried out from November 2008 to May 2009, with the objective of estimating the capture of Carbon by common arboreal species in these farms. The plant biomass analyses were made according to the methodology of Mercadet and Álvarez (2005. Several parameters were analyzed. Age, height and perimeter of the plants were the most influential parameters on the amount of carbon sequestered. In this regard, we performed a multivariate curve fitting, showing the age of the plants the highest percent of dependence (54.89%. Palma Real with values between 0.81 and 0.84 t / plant and the Mango between 0.60 and 0.81 t /plant of retained Carbon, were the most outstanding in the capture of Carbon.

  20. Improving city forests through assessment, modelling and monitoring

    Science.gov (United States)

    D.J. Nowak

    2018-01-01

    Urban and peri-urban forests produce numerous benefits for society. These include moderating the climate; reducing energy use in buildings; sequestering atmospheric carbon dioxide; improving air and water quality; mitigating rainfall run-off and flooding; providing an aesthetic environment and recreational opportunities; enhancing human health and social well-being;...

  1. Biotic interactions reduce microbial carbon use efficiency

    Science.gov (United States)

    Bradford, M.; Maynard, D. S.

    2017-12-01

    The efficiency by which microbes decompose organic matter governs the amount of carbon that is retained in microbial biomass versus lost to the atmosphere as respiration. This carbon use efficiency (CUE) is affected by various abiotic conditions, such as temperature and nutrient availability. In biogeochemical model simulations, CUE is a key variable regulating how much soil carbon is stored or lost from ecosystems under simulated global changes, such as climate warming. Theoretically, the physiological costs of biotic interactions such as competition should likewise alter CUE, yet the direction and magnitude of these costs are untested. Here we conduct a microcosm experiment to quantify how competitive interactions among saprotrophic fungi alter growth, respiration, and CUE. Free-living decomposer fungi representing a broad range of traits and phylogenies were grown alone, in pairwise competition, and in multi-species (up to 15) communities. By combing culturing and stable carbon isotope approaches, we could resolve the amount of carbon substrate allocated to fungal biomass versus respiration, and so estimate CUE. By then comparing individual performance to community-level outcomes, we show that species interactions induce consistent declines in CUE, regardless of abiotic conditions. Pairwise competition lowers CUE by as much as 25%, with the magnitude of these costs equal to or greater than the observed variation across abiotic conditions. However, depending on the competitive network structure, increasing species richness led to consistent gains or declines in CUE. Our results suggest that the extent to which microbial-mediated carbon fluxes respond to environmental change may be influenced strongly by competitive interactions. As such, knowledge of abiotic conditions and community composition is necessary to confidently project CUE and hence ecosystem carbon dynamics.

  2. Microbiologically influenced corrosion of carbon steel in the presence of sulphate reducing bacteria

    International Nuclear Information System (INIS)

    Tunaru, M.; Velciu, L.; Mihalache, M.; Laurentiu, P.

    2016-01-01

    Sulphate-reducing bacteria (SRB) are the most important organisms in microbiologically induced corrosion. In this context, the paper presents an assessment (by experimental tests) of the behaviour of carbon steel samples (SA106gr.B) in SRB media. Some of samples were immersed in microbial environment in order microbiological analysis of their surface and another part was used to perform accelerated electrochemical tests to determine electrochemical parameters for the system carbon steel / microbial medium (corrosion rate, the polarization resistance of the surface, susceptibility to pitting corrosion). The surfaces of the tested samples were analyzed using the optical and electronic microscope, and emphasized the role of bacteria in the development of biofilms under which appeared characteristics of corrosion attack. The correlation of all results confirmed that SRB accelerated the localized corrosion of the surfaces of SA 106gr.B carbon steel. (authors)

  3. Nitrogen and phosphorous limitation reduces the effects of land use change on land carbon uptake or emission

    International Nuclear Information System (INIS)

    Wang, Ying-Ping; Zhang, Qian; Dai, Yongjiu; Pitman, Andrew J

    2015-01-01

    We used an Earth System Model that includes both nitrogen (N) and phosphorus (P) cycling to simulate the impacts of land-use and land-cover change (LULCC) for two representative concentration pathways (RCPs): a reforestation scenario (RCP4.5) and a deforestation scenario (RCP8.5). For each RCP, we performed simulations with and without LULCC using the carbon (C only) mode or including the full C, N and P cycles (CNP). We show, for the first time, that inclusion of N and P cycling reduces both the carbon uptake from reforestation in RCP4.5 and the carbon emission from deforestation in RCP8.5. Specifically, carbon-nutrient interaction reduces carbon uptake in RCP4.5 from 55 Pg C (C only) to 21 Pg C (CNP), or the emissions in RCP8.5 from 72 Pg C (C only) to 56 Pg C (CNP). Most of those reductions result from much weaker responses of net primary production to CO 2 fertilization and climate change when carbon-nutrient interaction is taken into account, as compared to C only simulations. Our results highlight the importance of including nutrient-carbon interaction in estimating the carbon benefit from reforestation and carbon loss from deforestation in a future world with higher CO 2 and a warmer climate. Because of the stronger nutrient limitation, carbon gain from reforestation in the temperate and boreal regions is much less than the carbon loss from deforestation in the subtropical and tropical regions from 2006 to 2100 for the two RCPs. Therefore protecting the existing subtropical and tropical forests is about twice as effective as planting new forests in the temperate and boreal regions for climate mitigation. (letter)

  4. Stacked multilayers of alternating reduced graphene oxide and carbon nanotubes for planar supercapacitors

    Science.gov (United States)

    Moon, Geon Dae; Joo, Ji Bong; Yin, Yadong

    2013-11-01

    A simple layer-by-layer approach has been developed for constructing 2D planar supercapacitors of multi-stacked reduced graphene oxide and carbon nanotubes. This sandwiched 2D architecture enables the full utilization of the maximum active surface area of rGO nanosheets by using a CNT layer as a porous physical spacer to enhance the permeation of a gel electrolyte inside the structure and reduce the agglomeration of rGO nanosheets along the vertical direction. As a result, the stacked multilayers of rGO and CNTs are capable of offering higher output voltage and current production.A simple layer-by-layer approach has been developed for constructing 2D planar supercapacitors of multi-stacked reduced graphene oxide and carbon nanotubes. This sandwiched 2D architecture enables the full utilization of the maximum active surface area of rGO nanosheets by using a CNT layer as a porous physical spacer to enhance the permeation of a gel electrolyte inside the structure and reduce the agglomeration of rGO nanosheets along the vertical direction. As a result, the stacked multilayers of rGO and CNTs are capable of offering higher output voltage and current production. Electronic supplementary information (ESI) available: Experimental details, SEM and TEM images and additional electrochemical data. See DOI: 10.1039/c3nr04339h

  5. A Comparative Study on Biochar from Slow Pyrolysis of Corn Cob and Cassava Wastes

    OpenAIRE

    Adilah Shariff; Nurhidayah Mohamed Noor; Alexander Lau; Muhammad Azwan Mohd Ali

    2016-01-01

    Biomass such as corn and cassava wastes if left to decay will release significant quantities of greenhouse gases (GHG) including carbon dioxide and methane. The biomass wastes can be converted into biochar via thermochemical process such as slow pyrolysis. This approach can reduce the biomass wastes as well as preserve its carbon content. Biochar has the potential to be used as a carbon sequester and soil amendment. The aim of this study is to investigate the characteristics of the corn cob, ...

  6. Independent Recruitment of a Flavin-Dependent Monooxygenase for Safe Accumulation of Sequestered Pyrrolizidine Alkaloids in Grasshoppers and Moths

    OpenAIRE

    Wang, Linzhu; Beuerle, Till; Timbilla, James; Ober, Dietrich

    2012-01-01

    Several insect lineages have developed diverse strategies to sequester toxic pyrrolizidine alkaloids from food-plants for their own defense. Here, we show that in two highly divergent insect taxa, the hemimetabolous grasshoppers and the holometabolous butterflies, an almost identical strategy evolved independently for safe accumulation of pyrrolizidine alkaloids. This strategy involves a pyrrolizidine alkaloid N-oxygenase that transfers the pyrrolizidine alkaloids to their respective N-oxide,...

  7. Low sintering temperature glass waste forms for sequestering radioactive iodine

    Science.gov (United States)

    Nenoff, Tina M.; Krumhansl, James L.; Garino, Terry J.; Ockwig, Nathan W.

    2012-09-11

    Materials and methods of making low-sintering-temperature glass waste forms that sequester radioactive iodine in a strong and durable structure. First, the iodine is captured by an adsorbant, which forms an iodine-loaded material, e.g., AgI, AgI-zeolite, AgI-mordenite, Ag-silica aerogel, ZnI.sub.2, CuI, or Bi.sub.5O.sub.7I. Next, particles of the iodine-loaded material are mixed with powdered frits of low-sintering-temperature glasses (comprising various oxides of Si, B, Bi, Pb, and Zn), and then sintered at a relatively low temperature, ranging from 425.degree. C. to 550.degree. C. The sintering converts the mixed powders into a solid block of a glassy waste form, having low iodine leaching rates. The vitrified glassy waste form can contain as much as 60 wt % AgI. A preferred glass, having a sintering temperature of 500.degree. C. (below the silver iodide sublimation temperature of 500.degree. C.) was identified that contains oxides of boron, bismuth, and zinc, while containing essentially no lead or silicon.

  8. Preparation of sulfur/multiple pore size porous carbon composite via gas-phase loading method for lithium-sulfur batteries

    International Nuclear Information System (INIS)

    Li, Long-Yan; Chen, Yan-Xiao; Guo, Xiao-Dong; Zhong, Ben-He; Zhong, Yan-Jun

    2014-01-01

    A porous carbon with multiple pore size distribution was synthesized, and regarded as a carrier to obtain the sulfur/carbon (S/C) composite via a gas-phase loading method. We proposed this novel gas-phase loading method by using a specially designed fluid-bed reactor to encapsulate and sequester gas-phase sulfur molecules into the porous carbon in current study. The nitrogen Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) characterizations were investigated on both the porous carbon and the sulfur/carbon composite. The results show that the gas-phase loading method contributes to the combination of sulfur molecules and matrix porous carbon. Furthermore, the sulfur/multiple pore size distribution carbon composite based on the gas-phase loading method demonstrate an excellent electrochemical property. The initial specific discharge capacity is 795.0 mAh g −1 at 800 mA g −1 , with a capacity retention of 86.3% after 100 cycles

  9. The role of iron-sulfides on cycling of organic carbon in the St Lawrence River system: Evidence of sulfur-promoted carbon sequestration?

    Science.gov (United States)

    Balind, K.; Barber, A.; Gélinas, Y.

    2017-12-01

    The biogeochemical cycle of sulfur is intimately linked with that of carbon, as well as with that of iron through the formation of iron-sulfur complexes. Iron-sulfide minerals such as mackinawite (FeS) and greigite (Fe3S4) form below the oxic/anoxic redox boundary in marine and lacustrine sediments and soils. Reactive iron species, abundant in surface sediments, can undergo reductive dissolution leading to the formation of soluble Fe(II) which can then precipitate in the form of iron sulfur species. While sedimentary iron-oxides have been thoroughly explored in terms of their ability to sorb and sequester organic carbon (OC) (Lalonde et al.; 2012), the role of FeS in the long-term preservation of OC remains undefined. In this study, we present depth profiles for carbon, iron, and sulfur in the aqueous-phase, along with data from sequential extractions of sulfur speciation in the solid-phase collected from sediment cores from the St Lawrence River and estuarine system, demonstrating the transition from fresh to saltwater sediments. Additionally, we present synthetic iron sulfur sorption experiments using both model and natural organic molecules in order to assess the importance of FeS in sedimentary carbon storage.

  10. Soil carbon pools in different pasture systems

    Directory of Open Access Journals (Sweden)

    Francisco M. Cardozo, Jr.

    2016-03-01

    Full Text Available The aim of this study was to assess the carbon pools of a tropical soil where the native forest was replaced with different pasture systems. We studied five pasture production systems, including four monoculture systems with forage grasses such as Andropogon, Brachiaria, Panicum, and Cynodon, and an agroforestry system as well as a native vegetation plot. Greater availability of fulvic acid was detected in the agroforestry system as compared with that in the other systems. Higher lability of C was detected in the Andropogon system during the dry and rainy seasons and during the dry season in Cynodon. During the dry season, all pastures systems showed deficits in the net removal of atmospheric CO2. The structure and practices of the agroforestry system enables more carbon to be sequestered in the soil as compared with the monoculture pasture, suggesting that it is an important practice to mitigate climatic change and to improve soil quality.

  11. Carbon trading and carbon taxation: how to consider biotic sources and sinks

    International Nuclear Information System (INIS)

    Madlener, Reinhard; Schlamadinger, Bernhard

    1999-01-01

    The Kyoto Protocol (KP) to the UNFCCC includes land-use change and forestry in the carbon accounting process, limited to afforestation, reforestation and deforestation since 1990, and explicitly provides for the option of using a variety of flexibility mechanisms to meet the greenhouse gas (GHG) reduction targets stipulated in a more cost-efficient manner. Domestically, different countries might adopt different approaches to achieve their emission reduction objectives, such as carbon trading or carbon taxation, and it is not clear to date what the implications for bioenergy use, forestry, and land-use change can be expected to be. With respect to national GHG emissions trading, the main issues studied in this paper are: Should trading of fossil fuel emissions allowances be coupled with trading of biotic credits and debits? Should credits for carbon sequestration in forests be auctioned or grandfathered? Should there be a distinction between a carbon permit issued for an additional biotic sink and those issued for fossil fuel carbon emissions? Is there a difference for biotic carbon sinks and sources between one-time permits and permits that allow a continued release of GHG over some pre-specified time? Should permits be issued only for the carbon-stock changes that count under the KP? With respect to national carbon taxation schemes, two questions are investigated: Should a tax credit be given for afforestation/reforestation (and a tax debit for deforestation)? Should tax credits also be given for projects that sequester carbon but do not count under the KP (such as forest protection rather than forest management)? For both schemes a crucial point is that by the formulation chosen in the KP two different classes of forest are created (i.e. those counted and those not counted under the KP), so that the implications for land prices might be significant. From a conceptual point of view this paper addresses the above-mentioned questions and contrasts some of the major

  12. Mechanisms of Soil Carbon Sequestration

    Science.gov (United States)

    Lal, Rattan

    2015-04-01

    Carbon (C) sequestration in soil is one of the several strategies of reducing the net emission of CO2 into the atmosphere. Of the two components, soil organic C (SOC) and soil inorganic C (SIC), SOC is an important control of edaphic properties and processes. In addition to off-setting part of the anthropogenic emissions, enhancing SOC concentration to above the threshold level (~1.5-2.0%) in the root zone has numerous ancillary benefits including food and nutritional security, biodiversity, water quality, among others. Because of its critical importance in human wellbeing and nature conservancy, scientific processes must be sufficiently understood with regards to: i) the potential attainable, and actual sink capacity of SOC and SIC, ii) permanence of the C sequestered its turnover and mean residence time, iii) the amount of biomass C needed (Mg/ha/yr) to maintain and enhance SOC pool, and to create a positive C budget, iv) factors governing the depth distribution of SOC, v) physical, chemical and biological mechanisms affecting the rate of decomposition by biotic and abiotic processes, vi) role of soil aggregation in sequestration and protection of SOC and SIC pool, vii) the importance of root system and its exudates in transfer of biomass-C into the SOC pools, viii) significance of biogenic processes in formation of secondary carbonates, ix) the role of dissolved organic C (DOC) in sequestration of SOC and SIC, and x) importance of weathering of alumino-silicates (e.g., powered olivine) in SIC sequestration. Lack of understanding of these and other basic processes leads to misunderstanding, inconsistencies in interpretation of empirical data, and futile debates. Identification of site-specific management practices is also facilitated by understanding of the basic processes of sequestration of SOC and SIC. Sustainable intensification of agroecosystems -- producing more from less by enhancing the use efficiency and reducing losses of inputs, necessitates thorough

  13. Carbon sequestration in agricultural soils: a potential carbon trading opportunity?

    International Nuclear Information System (INIS)

    Cowie, Annette L.; Murphy, Brian; Rawson, Andrew; Wilson, Brian; Singh, Bhupinderpal; Young, Rick; Grange, Ian

    2007-01-01

    Full text: Emissions trading schemes emerging in Australia and internationally create a market mechanism by which release of greenhouse gases incurs a cost, and implementation of abatement measures generates a financial return. There is growing interest amongst Australian landholders in emissions trading based on sequestration of carbon in soil through modified land management practices. Intensively cropped soils have low carbon content, due to disturbance, erosion and regular periods of minimal organic matter input. Because cropping soils in Australia have lost a substantial amount of carbon there is significant potential to increase carbon stocks through improved land management practices. Evidence from long term trials and modelling indicates that modified cropping practices (direct drilling, stubble retention, controlled traffic) have limited impact on soil carbon (0 to +2 tC02e ha-' year1) whereas conversion from cropping to pasture gives greater increases. Small-increases in soil carbon over large areas can contribute significantly to mitigation of Australia's greenhouse gas emissions. Furthermore, increase in soil organic matter will improve soil health, fertility and resilience. However, the inclusion of soil carbon offsets in an emissions trading scheme cannot occur until several barriers are overcome. The first relates to credibility. Quantification of the extent to which specific land management practices can sequester carbon in different environments will provide the basis for promotion of the concept. Current research across Australia is addressing this need. Secondly, cost-effective and accepted methods of estimating soil carbon change must be available. Monitoring soil carbon to document change on a project scale is not viable due to the enormous variability in carbon stocks on micro and macro scales. Instead estimation of soil carbon change could be undertaken through a combination of baseline measurement to assess the vulnerability of soil carbon

  14. Potential and economics of forestry options for carbon sequestration in India

    International Nuclear Information System (INIS)

    Ravindranath, N.H.; Somashekhar, B.S.

    1995-01-01

    There is a need to understand the carbon (C) sequestration potential of the forestry option and its financial implications for each country. In India the C emissions from deforestation are estimated to be nearly offset by C sequestration in forests under succession and tree plantations. India has nearly succeeded in stabilizing the area under forests and has adequate forest conservation strategies. Biomass demands for softwood, hardwood and firewood are estimated to double or treble by the year 2020. A set of forestry options were developed to meet the projected biomass needs, and keeping in mind the features of land categories available, three scenarios were developed: potential; demand-driven; and programme-driven scenarios. Adoption of the demand-driven scenario, targeted at meeting the projected biomass needs, is estimated to sequester 78 Mt of C annually after accounting for all emissions resulting from clearfelling and end use of biomass. The demand-driven scenario is estimated to offset 50% of national C emission at 1990 level. The cost per t of C sequestered for forestry options is lower than the energy options considered. The annual investment required for implementing the demand-driven scenario is estimated to be US$ 2.1 billion for six years and is shown to be feasible. Among forestry options, the ranking based on investment cost per t of C sequestered from least cost to highest cost is; natural regeneration -agro-forestry-enhanced natural regeneration ( < US$ 2.5/t C) -timber-community-forestry (US$ 3.3 to 7.3 per t of C). (Author)

  15. Effectiveness of forest management strategies to mitigate effects of global change in south-central Siberia

    Science.gov (United States)

    Eric J. Gustafson; Anatoly Z. Shvidenko; Robert M. Scheller

    2011-01-01

    We investigated questions about the ability of broad silvicultural strategies to achieve multiple objectives (reduce disturbance losses, maintain the abundance of preferred species, mitigate fragmentation and loss of age-class diversity, and sequester aboveground carbon) under future climate conditions in Siberia. We conducted a factorial experiment using the LANDIS-II...

  16. G-actin sequestering protein thymosin-β4 regulates the activity of myocardin-related transcription factor

    International Nuclear Information System (INIS)

    Morita, Tsuyoshi; Hayashi, Ken’ichiro

    2013-01-01

    Highlights: •Tβ4 competed with MRTF-A for G-actin binding. •Tβ4 activated the MRTF–SRF signaling pathway. •Tβ4 increased the endogenous expression of SRF-dependent genes. -- Abstract: Myocardin-related transcription factors (MRTFs) are robust coactivators of serum response factor (SRF). MRTFs contain three copies of the RPEL motif at their N-terminus, and they bind to monomeric globular actin (G-actin). Previous studies illustrate that G-actin binding inhibits MRTF activity by preventing the MRTFs nuclear accumulation. In the living cells, the majority of G-actin is sequestered by G-actin binding proteins that prevent spontaneous actin polymerization. Here, we demonstrate that the most abundant G-actin sequestering protein thymosin-β4 (Tβ4) was involved in the regulation of subcellular localization and activity of MRTF-A. Tβ4 competed with MRTF-A for G-actin binding; thus, interfering with G-actin–MRTF-A complex formation. Tβ4 overexpression induced the MRTF-A nuclear accumulation and activation of MRTF–SRF signaling. The activation rate of MRTF-A by the Tβ4 mutant L17A, whose affinity for G-actin is very low, was lower than that by wild-type Tβ4. In contrast, the β-actin mutant 3DA, which has a lower affinity for Tβ4, more effectively suppressed MRTF-A activity than wild-type β-actin. Furthermore, ectopic Tβ4 increased the endogenous expression of SRF-dependent actin cytoskeletal genes. Thus, Tβ4 is an important MRTF regulator that controls the G-actin–MRTFs interaction

  17. G-actin sequestering protein thymosin-β4 regulates the activity of myocardin-related transcription factor

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Tsuyoshi, E-mail: tsuyo@nbiochem.med.osaka-u.ac.jp; Hayashi, Ken’ichiro

    2013-08-02

    Highlights: •Tβ4 competed with MRTF-A for G-actin binding. •Tβ4 activated the MRTF–SRF signaling pathway. •Tβ4 increased the endogenous expression of SRF-dependent genes. -- Abstract: Myocardin-related transcription factors (MRTFs) are robust coactivators of serum response factor (SRF). MRTFs contain three copies of the RPEL motif at their N-terminus, and they bind to monomeric globular actin (G-actin). Previous studies illustrate that G-actin binding inhibits MRTF activity by preventing the MRTFs nuclear accumulation. In the living cells, the majority of G-actin is sequestered by G-actin binding proteins that prevent spontaneous actin polymerization. Here, we demonstrate that the most abundant G-actin sequestering protein thymosin-β4 (Tβ4) was involved in the regulation of subcellular localization and activity of MRTF-A. Tβ4 competed with MRTF-A for G-actin binding; thus, interfering with G-actin–MRTF-A complex formation. Tβ4 overexpression induced the MRTF-A nuclear accumulation and activation of MRTF–SRF signaling. The activation rate of MRTF-A by the Tβ4 mutant L17A, whose affinity for G-actin is very low, was lower than that by wild-type Tβ4. In contrast, the β-actin mutant 3DA, which has a lower affinity for Tβ4, more effectively suppressed MRTF-A activity than wild-type β-actin. Furthermore, ectopic Tβ4 increased the endogenous expression of SRF-dependent actin cytoskeletal genes. Thus, Tβ4 is an important MRTF regulator that controls the G-actin–MRTFs interaction.

  18. Toxoplasma gondii sequesters lysosomes from mammalian hosts in the vacuolar space.

    Science.gov (United States)

    Coppens, Isabelle; Dunn, Joe Dan; Romano, Julia D; Pypaert, Marc; Zhang, Hui; Boothroyd, John C; Joiner, Keith A

    2006-04-21

    The intracellular compartment harboring Toxoplasma gondii satisfies the parasite's nutritional needs for rapid growth in mammalian cells. We demonstrate that the parasitophorous vacuole (PV) of T. gondii accumulates material coming from the host mammalian cell via the exploitation of the host endo-lysosomal system. The parasite actively recruits host microtubules, resulting in selective attraction of endo-lysosomes to the PV. Microtubule-based invaginations of the PV membrane serve as conduits for the delivery of host endo-lysosomes within the PV. These tubular conduits are decorated by a parasite coat, including the tubulogenic protein GRA7, which acts like a garrote that sequesters host endocytic organelles in the vacuolar space. These data define an unanticipated process allowing the parasite intimate and concentrated access to a diverse range of low molecular weight components produced by the endo-lysosomal system. More generally, they identify a unique mechanism for unidirectional transport and sequestration of host organelles.

  19. Assessing ecosystem carbon stocks of Indonesia's threatened wetland forests

    Science.gov (United States)

    Warren, M.; Kauffman, B.; Murdiyarso, D.; Kurnianto, S.

    2011-12-01

    Over millennia, atmospheric carbon dioxide has been sequestered and stored in Indonesia's tropical wetland forests. Waterlogged conditions impede decomposition, allowing the formation of deep organic soils. These globally significant C pools are highly vulnerable to deforestation, degradation and climate change which can potentially switch their function as C sinks to long term sources of greenhouse gas (GHG) emissions. Also at risk are critical ecosystem services which sustain millions of people and the conservation of unique biological communities. The multiple benefits derived from wetland forest conservation makes them attractive for international C offset programs such as the proposed Reduced Emissions from Deforestation and Degradation (REDD+) mechanism. Yet, ecosystem C pools and fluxes in wetland forests remain poorly quantified. Significant knowledge gaps exist regarding how land use changes impact C dynamics in tropical wetlands, and very few studies have simultaneously assessed above- and belowground ecosystem C pools in Indonesia's freshwater peat swamps and mangroves. In addition, most of what is known about Indonesia's tropical wetland forests is derived from few geographic locations where long-standing research has focused, despite their broad spatial distribution. Here we present results from an extensive survey of ecosystem C stocks across several Indonesian wetland forests. Ecosystem C stocks were measured in freshwater peat swamp forests in West Papua, Central Kalimantan, West Kalimantan, and Sumatra. Carbon storage was also measured for mangrove forests in W. Papua, W. Kalimantan, and Sumatra. One overarching goal of this research is to support the development of REDD+ for tropical wetlands by informing technical issues related to carbon measuring, monitoring, and verification (MRV) and providing baseline data about the variation of ecosystem C storage across and within several Indonesian wetland forests.

  20. Policy Needs for Carbon Capture & Storage

    Science.gov (United States)

    Peridas, G.

    2007-12-01

    Climate change is one of the most pressing environmental problems of our time. The widespread consensus that exists on climate science requires deep cuts in greenhouse gas emissions, on the order of 50-80% globally from current levels. Reducing energy demand, increasing energy efficiency and sourcing our energy from renewable sources will, and should, play a key role in achieving these cuts. Fossil fuels however are abundant, relatively inexpensive, and still make up the backbone of our energy system. Phasing out fossil fuel use will be a gradual process, and is likely to take far longer than the timeframe dictated by climate science for reducing emissions. A reliable way of decarbonizing the use of fossil fuels is needed. Carbon capture and storage (CCS) has already proven to be a technology that can safely and effectively accomplish this task. The technological know-how and the underground capacity exist to store billions of tons of carbon dioxide in mature oil and gas fields, and deep saline formations. Three large international commercial projects and several other applications have proved this, but substantial barriers remain to be overcome before CCS becomes the technology of choice in all major emitting sectors. Government has a significant role to play in surmounting these barriers. Without mandatory limits on greenhouse gas emissions and a price on carbon, CCS is likely to linger in the background. The expected initial carbon price levels and their potential volatility under such a scheme dictates that further policies be used in the early years in order for CCS to be implemented. Such policies could include a new source performance standard for power plants, and a low carbon generation obligation that would relieve first movers by spreading the additional cost of the technology over entire sectors. A tax credit for capturing and permanently sequestering anthropogenic CO2 would aid project economics. Assistance in the form of loan guarantees for components

  1. A rapid method for landscape assessment of carbon storage and ecosystem function in moss and lichen ground layers

    Science.gov (United States)

    Sarah Jovan; Robert J. Smith; Juan C. Benavides; Michael Amacher; Bruce McCune

    2015-01-01

    Mat-forming ‘‘ground layers’’ of mosses and lichens often have functional impacts disproportionate to their biomass, and are responsible for sequestering one-third of the world’s terrestrial carbon as they regulate water tables, cool soils and inhibit microbial decomposition. Without reliable assessment tools, the potential effects of climate and land use changes on...

  2. Microbial potential for carbon and nutrient cycling in a geogenic supercritical carbon dioxide reservoir.

    Science.gov (United States)

    Freedman, Adam J E; Tan, BoonFei; Thompson, Janelle R

    2017-06-01

    Microorganisms catalyze carbon cycling and biogeochemical reactions in the deep subsurface and thus may be expected to influence the fate of injected supercritical (sc) CO 2 following geological carbon sequestration (GCS). We hypothesized that natural subsurface scCO 2 reservoirs, which serve as analogs for the long-term fate of sequestered scCO 2 , harbor a 'deep carbonated biosphere' with carbon cycling potential. We sampled subsurface fluids from scCO 2 -water separators at a natural scCO 2 reservoir at McElmo Dome, Colorado for analysis of 16S rRNA gene diversity and metagenome content. Sequence annotations indicated dominance of Sulfurospirillum, Rhizobium, Desulfovibrio and four members of the Clostridiales family. Genomes extracted from metagenomes using homology and compositional approaches revealed diverse mechanisms for growth and nutrient cycling, including pathways for CO 2 and N 2 fixation, anaerobic respiration, sulfur oxidation, fermentation and potential for metabolic syntrophy. Differences in biogeochemical potential between two production well communities were consistent with differences in fluid chemical profiles, suggesting a potential link between microbial activity and geochemistry. The existence of a microbial ecosystem associated with the McElmo Dome scCO 2 reservoir indicates that potential impacts of the deep biosphere on CO 2 fate and transport should be taken into consideration as a component of GCS planning and modelling. © 2017 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

  3. Biofuels from pyrolysis in perspective: trade-offs between energy yields and soil-carbon additions.

    Science.gov (United States)

    Woolf, Dominic; Lehmann, Johannes; Fisher, Elizabeth M; Angenent, Largus T

    2014-06-03

    Coproduction of biofuels with biochar (the carbon-rich solid formed during biomass pyrolysis) can provide carbon-negative bioenergy if the biochar is sequestered in soil, where it can improve fertility and thus simultaneously address issues of food security, soil degradation, energy production, and climate change. However, increasing biochar production entails a reduction in bioenergy obtainable per unit biomass feedstock. Quantification of this trade-off for specific biochar-biofuel pathways has been hampered by lack of an accurate-yet-simple model for predicting yields, product compositions, and energy balances from biomass slow pyrolysis. An empirical model of biomass slow pyrolysis was developed and applied to several pathways for biochar coproduction with gaseous and liquid biofuels. Here, we show that biochar production reduces liquid biofuel yield by at least 21 GJ Mg(-1) C (biofuel energy sacrificed per unit mass of biochar C), with methanol synthesis giving this lowest energy penalty. For gaseous-biofuel production, the minimum energy penalty for biochar production is 33 GJ Mg(-1) C. These substitution rates correspond to a wide range of Pareto-optimal system configurations, implying considerable latitude to choose pyrolysis conditions to optimize for desired biochar properties or to modulate energy versus biochar yields in response to fluctuating price differentials for the two commodities.

  4. Urban tree effects on soil organic carbon.

    Directory of Open Access Journals (Sweden)

    Jill L Edmondson

    Full Text Available Urban trees sequester carbon into biomass and provide many ecosystem service benefits aboveground leading to worldwide tree planting schemes. Since soils hold ∼75% of ecosystem organic carbon, understanding the effect of urban trees on soil organic carbon (SOC and soil properties that underpin belowground ecosystem services is vital. We use an observational study to investigate effects of three important tree genera and mixed-species woodlands on soil properties (to 1 m depth compared to adjacent urban grasslands. Aboveground biomass and belowground ecosystem service provision by urban trees are found not to be directly coupled. Indeed, SOC enhancement relative to urban grasslands is genus-specific being highest under Fraxinus excelsior and Acer spp., but similar to grasslands under Quercus robur and mixed woodland. Tree cover type does not influence soil bulk density or C∶N ratio, properties which indicate the ability of soils to provide regulating ecosystem services such as nutrient cycling and flood mitigation. The trends observed in this study suggest that genus selection is important to maximise long-term SOC storage under urban trees, but emerging threats from genus-specific pathogens must also be considered.

  5. Incorporation of catalytic dehydrogenation into fischer-tropsch synthesis to significantly reduce carbon dioxide emissions

    Science.gov (United States)

    Huffman, Gerald P.

    2012-11-13

    A new method of producing liquid transportation fuels from coal and other hydrocarbons that significantly reduces carbon dioxide emissions by combining Fischer-Tropsch synthesis with catalytic dehydrogenation is claimed. Catalytic dehydrogenation (CDH) of the gaseous products (C1-C4) of Fischer-Tropsch synthesis (FTS) can produce large quantities of hydrogen while converting the carbon to multi-walled carbon nanotubes (MWCNT). Incorporation of CDH into a FTS-CDH plant converting coal to liquid fuels can eliminate all or most of the CO.sub.2 emissions from the water-gas shift (WGS) reaction that is currently used to elevate the H.sub.2 level of coal-derived syngas for FTS. Additionally, the FTS-CDH process saves large amounts of water used by the WGS reaction and produces a valuable by-product, MWCNT.

  6. Nitrous oxide emissions could reduce the blue carbon value of marshes on eutrophic estuaries

    Science.gov (United States)

    Roughan, Brittney L.; Kellman, Lisa; Smith, Erin; Chmura, Gail L.

    2018-04-01

    The supply of nitrogen to ecosystems has surpassed the Earth’s Planetary Boundary and its input to the marine environment has caused estuarine waters to become eutrophic. Excessive supply of nitrogen to salt marshes has been associated with shifts in species’ distribution and production, as well as marsh degradation and loss. Our study of salt marshes in agriculturally intensive watersheds shows that coastal eutrophication can have an additional impact. We measured gas fluxes from marsh soils and verified emissions of nitrous oxide (N2O) in nitrogen-loaded marshes while the reference marsh was a sink for this gas. Salt marsh soils are extremely efficient carbon sinks, but emissions of N2O, a greenhouse gas 298 times more potent than CO2, reduces the value of the carbon sink, and in some marshes, may counterbalance any value of stored carbon towards mitigation of climate change. Although more research is merited on the nitrogen transformations and carbon storage in eutrophic marshes, the possibility of significant N2O emissions should be considered when evaluating the market value of carbon in salt marshes subject to high levels of nitrogen loading.

  7. Preliminary work of mangrove ecosystem carbon stock mapping in small island using remote sensing: above and below ground carbon stock mapping on medium resolution satellite image

    Science.gov (United States)

    Wicaksono, Pramaditya; Danoedoro, Projo; Hartono, Hartono; Nehren, Udo; Ribbe, Lars

    2011-11-01

    Mangrove forest is an important ecosystem located in coastal area that provides various important ecological and economical services. One of the services provided by mangrove forest is the ability to act as carbon sink by sequestering CO2 from atmosphere through photosynthesis and carbon burial on the sediment. The carbon buried on mangrove sediment may persist for millennia before return to the atmosphere, and thus act as an effective long-term carbon sink. Therefore, it is important to understand the distribution of carbon stored within mangrove forest in a spatial and temporal context. In this paper, an effort to map carbon stocks in mangrove forest is presented using remote sensing technology to overcome the handicap encountered by field survey. In mangrove carbon stock mapping, the use of medium spatial resolution Landsat 7 ETM+ is emphasized. Landsat 7 ETM+ images are relatively cheap, widely available and have large area coverage, and thus provide a cost and time effective way of mapping mangrove carbon stocks. Using field data, two image processing techniques namely Vegetation Index and Linear Spectral Unmixing (LSU) were evaluated to find the best method to explain the variation in mangrove carbon stocks using remote sensing data. In addition, we also tried to estimate mangrove carbon sequestration rate via multitemporal analysis. Finally, the technique which produces significantly better result was used to produce a map of mangrove forest carbon stocks, which is spatially extensive and temporally repetitive.

  8. Individual-motivational factors in the acceptability of demand-side and supply-side measures to reduce carbon emissions

    International Nuclear Information System (INIS)

    Poortinga, Wouter; Spence, Alexa; Demski, Christina; Pidgeon, Nick F.

    2012-01-01

    As more than a third of all carbon dioxide emissions in the UK are generated by the domestic sector, individuals need to make drastic changes to their current lifestyle in order to play their part in climate change mitigation. Not only do they need to change their personal behaviour, they also have to accept new low-carbon technologies in order to decarbonise the energy they are using. This study uses an adapted version of the Value–Belief-Norm (VBN) model () to examine individual-motivational factors in the acceptability of demand-side and supply-side strategies to reduce carbon emissions. The study found that environmental identity, climate change concern, and personal norms are all significantly associated with the acceptability of both demand-side measures and supply-side technologies. While personal values were also important, their associations were mediated by more specific factors. Overall, the adapted VBN model was better able to explain the acceptability of low-carbon behaviours than of low-carbon energy-supply technologies. Concern about energy security appeared to be of limited importance. It was negatively associated with the willingness to engage in low-carbon behaviours, suggesting that a shift in focus towards energy security issues may not necessarily help a transition to a low-carbon society. - Highlights: ► An adapted VBN model is proposed to study environmentally significant behaviour.► Environmental identity is important for both demand-side and supply-side measures.► Energy security concern is of limited importance to support for supply-side measures.► Energy security concern reduces the willingness to engage in low-carbon behaviours.

  9. How ecological restoration alters ecosystem services: an analysis of carbon sequestration in China's Loess Plateau.

    Science.gov (United States)

    Feng, Xiaoming; Fu, Bojie; Lu, Nan; Zeng, Yuan; Wu, Bingfang

    2013-10-03

    Restoring disturbed and over-exploited ecosystems is important to mitigate human pressures on natural ecosystems. China has launched an ambitious national ecosystem restoration program called Grain to Green Program (GTGP) over the last decade. By using remote sensing techniques and ecosystem modelling, we quantitatively evaluated the changes in ecosystem carbon sequestration since China's GTGP program during period of 2000-2008. It was found the NPP and NEP in this region had steadily increased after the initiative of the GTGP program, and a total of 96.1 Tg of additional carbon had been sequestered during that period. Changes in soil carbon storage were lagged behind and thus insignificant over the period, but was expected to follow in the coming decades. As a result, the Loess Plateau ecosystem had shifted from a net carbon source in 2000 to a net carbon sink in 2008. The carbon sequestration efficiency was constrained by precipitation, and appropriate choices of restoration types (trees, shrubs, and grasses) in accordance to local climate are critical for achieving the best benefit/cost efficiency.

  10. Eelgrass Blue Carbon-Quantification of Carbon Stocks and Sequestration Rates in Zostera Marina Beds in the Salish Sea

    Science.gov (United States)

    Lutz, M. D.; Rybczyk, J.; Poppe, K.; Johnson, C.; Kaminsky, M.; Lanphear, M.

    2017-12-01

    Seagrass meadows provide more than habitat, biodiversity support, wave abatement, and water quality improvement; they help mitigate climate change by taking up and storing (sequestering) carbon (C), reportedly at rates only surpassed worldwide by salt marsh and mangrove ecosystems. Now that their climate mitigation capacity has earned seagrass ecosystems a place in the Verified Carbon Standard voluntary greenhouse gas program, accurate ecosystem carbon accounting is essential. Though seagrasses vary in carbon storage and accumulation greatly across species and geography, the bulk of data included in calculating global averages involves tropical and subtropical seagrasses. We know little regarding carbon stocks nor sequestration rates for eelgrass (Zostera marina) meadows in the Pacific Northwest. The intent of our study was to quantify carbon stocks and sequestration rates in the central Salish Sea of Washington State. We gathered sediment cores over three bays, as close to 1 m in depth as possible, both on foot and while scuba diving. We measured bulk density, carbon concentration, carbon stock, grain size, and carbon accumulation rate with depth. Results from our study show lower estimated Corg concentration (mean = 0.39% C, SE=0.01, range=0.11-1.75, SE=0.01), Corg stock (mean=24.46 Mg ha-1, SE=0.00, range=16.31-49.99.70), and C sequestration rates (mean=33.96 g m-2yr-1, range=11.4-49.5) than those reported in published studies from most other locations. Zostera marina is highly productive, yet does not seem to have the capacity to store C in its sediments like seagrasses in warmer climes. These data have implications in carbon market trading, when determining appropriate seagrass restoration site dimensions to offset emissions from transportation, industry, and seagrass habitat disturbance. Awareness of lower rates could prevent underestimating the area appropriate for mitigation or restoration.

  11. Ultra-Low Carbon Emissions from Coal-Fired Power Plants through Bio-Oil Co-Firing and Biochar Sequestration.

    Science.gov (United States)

    Dang, Qi; Mba Wright, Mark; Brown, Robert C

    2015-12-15

    This study investigates a novel strategy of reducing carbon emissions from coal-fired power plants through co-firing bio-oil and sequestering biochar in agricultural lands. The heavy end fraction of bio-oil recovered from corn stover fast pyrolysis is blended and co-fired with bituminous coal to form a bio-oil co-firing fuel (BCF). Life-cycle greenhouse gas (GHG) emissions per kWh electricity produced vary from 1.02 to 0.26 kg CO2-eq among different cases, with BCF heavy end fractions ranging from 10% to 60%, which corresponds to a GHG emissions reduction of 2.9% to 74.9% compared with that from traditional bituminous coal power plants. We found a heavy end fraction between 34.8% and 37.3% is required to meet the Clean Power Plan's emission regulation for new coal-fired power plants. The minimum electricity selling prices are predicted to increase from 8.8 to 14.9 cents/kWh, with heavy end fractions ranging from 30% to 60%. A minimum carbon price of $67.4 ± 13 per metric ton of CO2-eq was estimated to make BCF power commercially viable for the base case. These results suggest that BCF co-firing is an attractive pathway for clean power generation in existing power plants with a potential for significant reductions in carbon emissions.

  12. Preparation of carbon nanotubes by DC arc discharge process under reduced pressure in an air atmosphere

    International Nuclear Information System (INIS)

    Kim, Hyeon Hwan; Kim, Hyeong Joon

    2006-01-01

    Carbon nanotubes (CNTs) were grown using a DC arc discharge process in an air atmosphere and relevant process parameters were investigated. Without using an inert gas, multi walled carbon nanotubes could be synthesized in the deposit area of the cathode even in an air atmosphere, but single walled carbon nanotubes were not detected in the soot area despite using the same process conditions as in the inert gas. The air pressure for the highest yield of multi walled CNTs was 300 Torr. In addition, the quantity of amorphous carbon and other nanoparticles in the process chamber was remarkably reduced by this technique, showing that an efficient, feasible method of large scale CNT fabrication could be achieved by the arc discharge process

  13. Tools for valuing tree and park services

    Science.gov (United States)

    E.G. McPherson

    2010-01-01

    Arborists and urban foresters plan, design, construct, and manage trees and parks in cities throughout the world. These civic improvements create walkable, cool environments, save energy, reduce stormwater runoff, sequester carbon dioxide, and absorb air pollutants. The presence of trees and green spaces in cities is associated with increases in property values,...

  14. Energy supply measures to reduce regional carbon intensity: opportunities and constraints

    Energy Technology Data Exchange (ETDEWEB)

    McEvoy, D.; Gibbs, D.C.; Longhurst, J.W.S. [University of Hull, Hull (United Kingdom). Dept. of Geography

    1998-07-01

    The perceived threat of `enhanced` global warming has become a widespread public concern since the late 1980s, with the balance of informed opinion urging world-wide collaboration on combating the causes of global warming. The increasingly globalised status of the majority of late twentieth century economies ensures that remedial action will ultimately require a degree of international cooperation. Although the formulation of environmentally friendly energy policies, including carbon reduction strategies, can be framed at international and national levels, recent trends are for CO{sub 2} reduction measures to be instigated by regional, or local, authorities. This paper focuses on the city-region of Greater Manchester, UK, and reviews both existing and potential energy supply options for reducing regional CO{sub 2} emissions, highlighting the benefits and obstacles facing carbon reduction measures implemented at a `local` scale. Mitigation action at this level is considered desirable as remedial measures have most chance of success when accompanied by the supportive involvement of local people. 73 refs.

  15. Anthropogenic perturbation of the carbon fluxes from land to ocean

    KAUST Repository

    Regnier, Pierre

    2013-06-09

    A substantial amount of the atmospheric carbon taken up on land through photosynthesis and chemical weathering is transported laterally along the aquatic continuum from upland terrestrial ecosystems to the ocean. So far, global carbon budget estimates have implicitly assumed that the transformation and lateral transport of carbon along this aquatic continuum has remained unchanged since pre-industrial times. A synthesis of published work reveals the magnitude of present-day lateral carbon fluxes from land to ocean, and the extent to which human activities have altered these fluxes. We show that anthropogenic perturbation may have increased the flux of carbon to inland waters by as much as 1.0 Pg C yr -1 since pre-industrial times, mainly owing to enhanced carbon export from soils. Most of this additional carbon input to upstream rivers is either emitted back to the atmosphere as carbon dioxide (∼0.4 Pg C yr -1) or sequestered in sediments (∼0.5 Pg C yr -1) along the continuum of freshwater bodies, estuaries and coastal waters, leaving only a perturbation carbon input of ∼0.1 Pg C yr -1 to the open ocean. According to our analysis, terrestrial ecosystems store ∼0.9 Pg C yr -1 at present, which is in agreement with results from forest inventories but significantly differs from the figure of 1.5 Pg C yr -1 previously estimated when ignoring changes in lateral carbon fluxes. We suggest that carbon fluxes along the land-ocean aquatic continuum need to be included in global carbon dioxide budgets.

  16. Taking Stock of Carbon Rights in REDD+ Candidate Countries: Concept Meets Reality

    Directory of Open Access Journals (Sweden)

    Lasse Loft

    2015-04-01

    Full Text Available In the discourses on who should benefit from national REDD+ implementation, rights-based approaches are prominent across various countries. Options on how to create viable property rights arrangements are currently being debated by scholars, policy makers and practitioners alike. Many REDD+ advocates argue that assigning carbon rights represents a solution to insecure individual and community property rights. But carbon rights, i.e., the bundle of legal rights to carbon sequestered in biomass, present their own set of theoretical and practical challenges. We assess the status and approaches chosen in emerging carbon-rights legislations in five REDD+ countries based on a literature review and country expert knowledge: Peru, Brazil, Cameroon, Vietnam and Indonesia. We find that most countries assessed have not yet made final decisions as to the type of benefit sharing mechanisms they intend to implement and that there is a lack of clarity about who owns rights to carbon as a property and who is entitled to receive benefits. However, there is a trend of linking carbon rights to land rights. As such, the technical and also political challenges that land tenure clarification has faced over the past decades will still need to be addressed in the context of carbon rights.

  17. Above Ground Carbon Stock Estimates of Mangrove Forest Using Worldview-2 Imagery in Teluk Benoa, Bali

    Science.gov (United States)

    Candra, E. D.; Hartono; Wicaksono, P.

    2016-11-01

    Mangrove forests have a role as an absorbent and a carbon sink to a reduction CO2 in the atmosphere. Based on the previous studies found that mangrove forests have the ability to sequestering carbon through photosynthesis and carbon burial of sediment effectively. The value and distribution of carbon stock are important to understand through remote sensing technology. In this study, will estimate the carbon stock using WorldView-2 imagery with and without distinction mangrove species. Worldview-2 is a high resolution image with 2 meters spatial resolution and eight spectral bands. Worldview-2 potential to estimate carbon stock in detail. Vegetation indices such as DVI (Difference Vegetation Index), EVI (Enhanced Vegetation Index), and MRE-SR (Modified Red Edge-Simple Ratio) and field data were modeled to determine the best vegetation indices to estimate carbon stocks. Carbon stock estimated by allometric equation approach specific to each species of mangrove. Worldview-2 imagery to map mangrove species with an accuracy of 80.95%. Total carbon stock estimation results in the study area of 35.349,87 tons of dominant species Rhizophora apiculata, Rhizophora mucronata and Sonneratia alba.

  18. Role of a productive lake in carbon sequestration within a calcareous catchment.

    Science.gov (United States)

    Nõges, Peeter; Cremona, Fabien; Laas, Alo; Martma, Tõnu; Rõõm, Eva-Ingrid; Toming, Kaire; Viik, Malle; Vilbaste, Sirje; Nõges, Tiina

    2016-04-15

    For a long time, lakes were considered unimportant in the global carbon (C) cycle because of their small total area compared to the ocean. Over the last two decades, a number of studies have highlighted the important role of lakes in both sequestering atmospheric C and modifying the C flux from the catchment by degassing CO2 and methane and burying calcite and organic matter in the sediment. Based on a full C mass balance, high frequency measurements of lake metabolism and stable isotope analysis of a large shallow eutrophic lake in Estonia, we assess the role alkaline lakes play in augmenting the strength of terrestrial carbonate weathering as a temporary CO2 sink. We show that a large part of organic C buried in the sediments in this type of lakes originates from the catchment although a direct uptake from the atmosphere during periods of intensive phytoplankton growth in eutrophic conditions contributes to the carbon sink. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. The Evolution of Deep Ocean Chemistry and Respired Carbon in the Eastern Equatorial Pacific Over the Last Deglaciation

    Science.gov (United States)

    de la Fuente, Maria; Calvo, Eva; Skinner, Luke; Pelejero, Carles; Evans, David; Müller, Wolfgang; Povea, Patricia; Cacho, Isabel

    2017-12-01

    It has been shown that the deep Eastern Equatorial Pacific (EEP) region was poorly ventilated during the Last Glacial Maximum (LGM) relative to Holocene values. This finding suggests a more efficient biological pump, which indirectly supports the idea of increased carbon storage in the deep ocean contributing to lower atmospheric CO2 during the last glacial. However, proxies related to respired carbon are needed in order to directly test this proposition. Here we present Cibicides wuellerstorfi B/Ca ratios from Ocean Drilling Program Site 1240 measured by laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) as a proxy for deep water carbonate saturation state (Δ[CO32-], and therefore [CO32-]), along with δ13C measurements. In addition, the U/Ca ratio in foraminiferal coatings has been analyzed as an indicator of oxygenation changes. Our results show lower [CO32-], δ13C, and [O2] values during the LGM, which would be consistent with higher respired carbon levels in the deep EEP driven, at least in part, by reduced deep water ventilation. However, the difference between LGM and Holocene [CO32-] observed at our site is relatively small, in accordance with other records from across the Pacific, suggesting that a "counteracting" mechanism, such as seafloor carbonate dissolution, also played a role. If so, this mechanism would have increased average ocean alkalinity, allowing even more atmospheric CO2 to be "sequestered" by the ocean. Therefore, the deep Pacific Ocean very likely stored a significant amount of atmospheric CO2 during the LGM, specifically due to a more efficient biological carbon pump and also an increase in average ocean alkalinity.

  20. Betaine reduces hepatic lipidosis induced by carbon tetrachloride in Sprague-Dawley rats.

    Science.gov (United States)

    Junnila, M; Barak, A J; Beckenhauer, H C; Rahko, T

    1998-10-01

    Carbon tetrachloride-injected rats were given liquid diets with and without betaine for 7 d. Hepatic lipidosis was induced by 4 daily injections of carbon tetrachloride (CCl4). Animals were killed and their livers and blood taken for analysis of betaine, S-adenosylmethionine (SAM), betaine homocysteine methyltransferase (BHMT), triglyceride, alanine aminotransferase and aspartate aminotransferase. Liver samples were also processed and stained for histological examination. Supplemental betaine reduced triglyceride in the liver and centrilobular hepatic lipidosis induced by the CCl4 injections. In both the control and experimental groups receiving betaine, liver betaine, BHMT and SAM were significantly higher than in their respective groups not receiving betaine. This study provides evidence that betaine protects the liver against CCl4-induced lipidosis and may be a useful therapeutic and prophylactic agent in ameliorating the harmful effects of CCl4.

  1. Self-supporting activated carbon/carbon nanotube/reduced graphene oxide flexible electrode for high performance supercapacitor

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xing; Tang, Yao; Song, Junhua; Yang, Wei; Wang, Mingshan; Zhu, Chengzhou; Zhao, Wengao; Zheng, Jianming; Lin, Yuehe

    2018-04-30

    A self-supporting and flexible activated carbon/carbon nanotube/reduced graphene oxide (AC/CNT/RGO) film has been rationally designed for constructing high- performance supercapacitor. The AC/CNT/RGO film is prepared by anchoring the AC particles with a 3D and porous framework built by hierarchically weaving the 1 D CNT and 2D RGO using their intrinsic van der Waals force. The CNT network is beneficial for improving the electronic conductivity of the electrode, while the AC particles could effectively suppress the aggregation of RGO and CNT due to their blocking effect. The synergistic effects among the AC, CNT and RGO validate the AC/CNT/RGO as a promising electrode for supercapacitor, exhibiting greatly enhanced electrochemical performances in comparison with the pure RGO film, pure CNT film and AC electrode. The AC/CNT/RGO electrode delivers a high specific capacitance of 101 F g-1 at the current density of 0.2 A g-1, offering a maximum energy density of 30.0 W h kg-1 in organic electrolyte at the cut-off voltage range of 0.001~3.0 V. The findings of this work open a new avenue for the design of self-supporting electrodes for the development of flexible and light weight energy storage supercapacitor.

  2. The potential for control of carbon dioxide emissions from integrated gasification/combined-cycle systems

    Energy Technology Data Exchange (ETDEWEB)

    Livengood, C.D.; Doctor, R.D.; Molburg, J.C.; Thimmapuram, P.; Berry, G.F.

    1994-06-01

    Initiatives to limit carbon dioxide (CO{sub 2}) emissions have drawn considerable interest to integrated gasification/combined-cycle (IGCC) power generation, a process that reduces CO{sub 2} production through efficient fuel used is amenable to CO{sub 2} capture. This paper presents a comparison of energy systems that encompass fuel supply, an IGCC system, CO{sub 2} recovery using commercial technologies, CO{sub 2} transport by pipeline, and land-based sequestering in geological reservoirs. The intent is to evaluate the energy-efficiency impacts of controlling CO{sub 2} in such systems and to provide the CO{sub 2} budget, or an to equivalent CO{sub 2}`` budget, associated with each of the individual energy-cycle steps. The value used for the ``equivalent CO{sub 2}`` budget is 1 kg/kWh CO{sub 2}. The base case for the comparison is a 457-MW IGCC system that uses an air-blown Kellogg-Rust-Westinghouse (KRW) agglomerating fluidized-bed gasifier, Illinois No. 6 bituminous coal, and in-bed sulfur removal. Mining, preparation, and transportation of the coal and limestone result in a net system electric power production of 454 MW with a 0.835 kg/kwh CO{sub 2} release rate. For comparison, the gasifier output is taken through a water-gas shift to convert CO to CO{sub 2} and then processed in a glycol-based absorber unit to recover CO{sub 2} Prior to the combustion turbine. A 500-km pipeline then transports the CO{sub 2} for geological sequestering. The net electric power production for the system with CO{sub 2} recovery is 381 MW with a 0.156 kg/kwh CO{sub 2} release rate.

  3. Limited carbon storage in soil and litter of experimental forest plots under increased atmospheric CO2

    International Nuclear Information System (INIS)

    Schlesinger, W.H.; Lichter, J.

    2001-01-01

    The current rise in atmospheric CO 2 concentration is thought to be mitigated in part by carbon sequestration within forest ecosystems, where carbon can be stored in vegetation or soils. The storage of carbon in soils is determined by the fraction that is sequestered in persistent organic materials, such as humus. In experimental forest plots of loblolly pine (Pinus taeda) exposed to high CO 2 concentrations, nearly half of the carbon uptake is allocated to short-lived tissues, largely foliage. These tissues fall to the ground and decompose, normally contributing only a small portion of their carbon content to refractory soil humic materials. Such findings call into question the role of soils as long-term carbon sinks, and show the need for a better understanding of carbon cycling in forest soils. Here we report a significant accumulation of carbon in the litter layer of experimental forest plots after three years of growth at increased CO 2 concentrations (565 μ l 1 ). But fast turnover times of organic carbon in the litter layer (of about three years) appear to constrain the potential size of this carbon sink. Given the observation that carbon accumulation in the deeper mineral soil layers was absent, we suggest that significant, long-term net carbon sequestration in forest soils is unlikely. (author)

  4. Soil organic carbon of an intensively reclaimed region in China: Current status and carbon sequestration potential.

    Science.gov (United States)

    Deng, Xunfei; Zhan, Yu; Wang, Fei; Ma, Wanzhu; Ren, Zhouqiao; Chen, Xiaojia; Qin, Fangjin; Long, Wenli; Zhu, Zhenling; Lv, Xiaonan

    2016-09-15

    Land reclamation has been highly intensive in China, resulting in a large amount of soil organic carbon (SOC) loss to the atmosphere. Evaluating the factors which drive SOC dynamics and carbon sequestration potential in reclaimed land is critical for improving soil fertility and mitigating global warming. This study aims to determine the current status and factors important to the SOC density in a typical reclaimed land located in Eastern China, where land reclamation has been undergoing for centuries. A total of 4746 topsoil samples were collected from 2007 to 2010. The SOC density of the reclaimed land (3.18±0.05kgCm(-2); mean±standard error) is significantly lower than that of the adjacent non-reclaimed land (5.71±0.04kgCm(-2)) (pcarbon sequestration potential of the reclaimed lands may achieve a maximum of 5.80±1.81kgCO2m(-2) (mean±SD) when dryland is converted to flooded land with vegetable-rice cropping system and soil pH of ~5.9. Note that in some scenarios the methane emission substantially offsets the carbon sequestration potential, especially for continuous rice cropping system. With the optimal setting for carbon sequestration, it is estimated that the dryland reclaimed in the last 50years in China is able to sequester 0.12milliontons CO2 equivalent per year. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Inter-trading permanent emissions credits and rented temporary carbon emissions offsets. Some issues and alternatives

    International Nuclear Information System (INIS)

    Sedjo, Roger A.; Marland, Gregg

    2003-01-01

    Permit trading among polluting parties is now firmly established as a policy tool in a range of environmental policy areas. The Kyoto Protocol accepts the principle that sequestration of carbon in the terrestrial biosphere can be used to offset emissions of carbon from fossil fuel combustion and outlines mechanisms. Although the lack of guaranteed permanence of biological offsets is often viewed as a defect, this paper argues that the absence of guaranteed permanence need not be a fundamental problem. We view carbon emissions as a liability issue. One purpose of an emissions credit system is to provide the emitter with a means to satisfy the carbon liability associated with her firm's (or country's) release of carbon into the atmosphere. We have developed and here expand on a rental approach, in which sequestered carbon is explicitly treated as temporary: the emitter temporarily satisfies his liability by temporarily 'parking' his liability, for a fee, in a terrestrial carbon reservoir, or 'sink,' such as a forest or agricultural soil. Finally, the paper relates the value of permanent and temporary sequestration and argues that both instruments are tradable and have a high degree of substitutability that allows them to interact in markets

  6. Effect of vegetation in reducing carbon monoxide

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, J C

    1977-01-01

    Carbon monoxide is a product of incomplete combustion. Because almost all of this gas is produced by motor vehicles, it is considered to have a line rather than a stationary point source. Greatest concentrations of this lethal gas correspond to periods of peak traffic volume and congestion; therefore, there are two daily periods of maxima and minima. Carbon monoxide cannot be detected by sight or smell. For this reason, this gas is especially deadly. During the summer of 1975, a study involving carbon monoxide concentrations at selected sites in Sendai was undertaken in conjunction with an ongoing investigation of urban pollution under the directorship of Professor Toshio Noh of Tohoku University. This study was made possible by a grant from the Japan Society for the Promotion of Science. 5 references, 5 figures, 1 table.

  7. To Reduce of HC and SO2 Emission from Engine’s Exhaust with Local of TiO2 to Inserted in Active Carbon

    International Nuclear Information System (INIS)

    Kris Tri Basuki

    2007-01-01

    The Active carbon can be use to adsorb of emission HC and SO 2 gas from Engine’s exhaust. The result of this research, to make active carbon with 5 cm, 10 cm and 15 cm length in Engine’s exhaust can be reduce of HC are 78.480 %, 81.500 % and 86.320 %. The inserted of 5, 10, 15 % TiO 2 in active carbon with 15 cm length can be reduce of HC are 88.290 %, 91.550 % and 94.920 %. With 5 cm, 10 cm and 15 cm length of variation in Engine’s exhaust can be reduce of SO 2 are 48.630 %, 60.517 % and 60.517 %. The inserted of 5, 10, 15 % TiO 2 in active carbon to make 15 cm length can be reduce of SO 2 are 80.223 %, 82.594 % and 87.696 %. The result of this research to known that the make of 15 % of TiO 2 inserted in active carbon is more effective with 5 % and 10 % of TiO 2 . (author)

  8. The shedding activity of ADAM17 is sequestered in lipid rafts

    International Nuclear Information System (INIS)

    Tellier, Edwige; Canault, Matthias; Rebsomen, Laure; Bonardo, Bernadette; Juhan-Vague, Irene; Nalbone, Gilles; Peiretti, Franck

    2006-01-01

    The tumor necrosis factor-alpha (TNF) converting enzyme (ADAM17) is a metalloprotease-disintegrin responsible for the cleavage of several biologically active transmembrane proteins. However, the substrate specificity of ADAM17 and the regulation of its shedding activity are still poorly understood. Here, we report that during its transport through the Golgi apparatus, ADAM17 is included in cholesterol-rich membrane microdomains (lipid rafts) where its prodomain is cleaved by furin. Consequently, ADAM17 shedding activity is sequestered in lipid rafts, which is confirmed by the fact that metalloproteinase inhibition increases the proportion of ADAM17 substrates (TNF and its receptors TNFR1 and TNFR2) in lipid rafts. Membrane cholesterol depletion increases the ADAM17-dependent shedding of these substrates demonstrating the importance of lipid rafts in the control of this process. Furthermore, ADAM17 substrates are present in different proportions in lipid rafts, suggesting that the entry of each of these substrates in these particular membrane microdomains is specifically regulated. Our data support the idea that one of the mechanisms regulating ADAM17 substrate cleavage involves protein partitioning in lipid rafts

  9. Influence of calcareous deposit on corrosion behavior of Q235 carbon steel with sulfate-reducing bacteria

    Science.gov (United States)

    Zhang, Jie; Li, Xiaolong; Wang, Jiangwei; Xu, Weichen; Duan, Jizhou; Chen, Shougang; Hou, Baorong

    2017-12-01

    Cathodic protection is a very effective method to protect metals, which can form calcareous deposits on metal surface. Research on the interrelationship between fouling organism and calcareous deposits is very important but very limited, especially sulfate-reducing bacteria (SRB). SRB is a kind of very important fouling organism that causes microbial corrosion of metals. A study of the influence of calcareous deposit on corrosion behavior of Q235 carbon steel in SRB-containing culture medium was carried out using electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and surface spectroscopy (EDS). The calcareous deposit was formed with good crystallinity and smooth surface under the gradient current density of -30 μA cm-2 in natural seawater for 72 h. Our results can help elucidate the formation of calcareous deposits and reveal the interrelationship between SRB and calcareous deposits under cathodic protection. The results indicate that the corrosion tendency of carbon steel was obviously affected by Sulfate-reducing Bacteria (SRB) metabolic activity and the calcareous deposit formed on the surface of carbon steel under cathodic protection was favourable to reduce the corrosion rate. Calcareous deposits can promote bacterial adhesion before biofilm formation. The results revealed the interaction between biofouling and calcareous deposits, and the anti-corrosion ability was enhanced by a kind of inorganic and organic composite membranes formed by biofilm and calcareous deposits.

  10. Carbon stocks in tree biomass and soils of German forests

    Directory of Open Access Journals (Sweden)

    Wellbrock Nicole

    2017-06-01

    Full Text Available Close to one third of Germany is forested. Forests are able to store significant quantities of carbon (C in the biomass and in the soil. Coordinated by the Thünen Institute, the German National Forest Inventory (NFI and the National Forest Soil Inventory (NFSI have generated data to estimate the carbon storage capacity of forests. The second NFI started in 2002 and had been repeated in 2012. The reporting time for the NFSI was 1990 to 2006. Living forest biomass, deadwood, litter and soils up to a depth of 90 cm have stored 2500 t of carbon within the reporting time. Over all 224 t C ha-1 in aboveground and belowground biomass, deadwood and soil are stored in forests. Specifically, 46% stored in above-ground and below-ground biomass, 1% in dead wood and 53% in the organic layer together with soil up to 90 cm. Carbon stocks in mineral soils up to 30 cm mineral soil increase about 0.4 t C ha-1 yr-1 stocks between the inventories while the carbon pool in the organic layers declined slightly. In the living biomass carbon stocks increased about 1.0 t C ha-1 yr-1. In Germany, approximately 58 mill. tonnes of CO2 were sequestered in 2012 (NIR 2017.

  11. Carbon Storage and Allocation Pattern in Plant Biomass among Different Forest Plantation Stands in Guangdong, China

    Directory of Open Access Journals (Sweden)

    Yuanqi Chen

    2015-03-01

    Full Text Available In order to understand how carbon storage and allocation patterns vary among plantation types, we estimated carbon allocation between above- and below-ground compartments in four subtropical plantations and a naturally recovered shrubland (as a control. Results indicated that the carbon storage and allocation pattern varied greatly among forest types and was highly dependent on specific traits of trees and understory vegetation. The fast-growing species, such as Eucalyptus urophylla, accumulated more carbon in plant biomass. The biomass carbon was about 1.9- and 2.2-times greater than the 10-species mixed plantation and Castanopsis hystrix plantations, respectively. Meanwhile, the plantations sequestered 1.5- to 3-times more carbon in biomass than naturally recovered shrubland. The carbon allocation pattern between above- and below-ground compartments also varied with plantation type and stand age. The ratio of tree root carbon to tree aboveground carbon decreased with stand age for Eucalyptus urophylla and the 10-species mixed plantation. In contrast, the ratio increased for Acacia crassicarpa. Our data suggested that planting the fast-growing species in the degraded land of subtropical China was an effective choice in terms of carbon sequestration. The information about carbon allocation patterns was also valuable for decision making in sustainable forest management and climate change mitigation.

  12. Carbon sequestration capacity of sediments, algae, and zooplankton from fresh water aquaculture ponds.

    Science.gov (United States)

    Anikuttan, K K; Adhikari, S; Kavitha, M; Jayasankar, P

    2016-07-01

    The contribution of aquaculture and allied activities to the emission of green house gases and consequently to global warming is an emerging concern among environmentalists in the recent past. However, there exists ample scope for aquaculture activities to sequester carbon and thus compensate for the carbon emissions linked to aquaculture. This article attempts to elucidate the carbon sequestration capacity of sediments, algae, and zooplankton from fresh water aquaculture ponds. The percent organic carbon in the pond sediments ranged from 0.39 to 1.31 with an average value of 0.912 ± 0.321 whereas the carbon sequestration capacity ranged from 0.442 to 1.882 MgC/ha (1 Mg = 10(6) g) with an average value of 1.018 ± 0.447 MgC/ha. In the case of zooplankton and algae from pond, the percent organic carbon was 7.688 ± 0.196 and 2.354 ± 0.047, respectively, whereas the total estimated carbon burial rate was 0.009 ± 0.005 and 0.150 ± 0.003 MgC/ha, respectively. These findings are discussed with the previous reports available at present and are found to be in comparable ranges.

  13. Translating National Level Forest Service Goals to Local Level Land Management: Carbon Sequestration

    Science.gov (United States)

    McNulty, S.; Treasure, E.

    2017-12-01

    The USDA Forest Service has many national level policies related to multiple use management. However, translating national policy to stand level forest management can be difficult. As an example of how a national policy can be put into action, we examined three case studies in which a desired future condition is evaluated at the national, region and local scale. We chose to use carbon sequestration as the desired future condition because climate change has become a major area of concern during the last decade. Several studies have determined that the 193 million acres of US national forest land currently sequester 11% to 15% of the total carbon emitted as a nation. This paper provides a framework by which national scale strategies for maintaining or enhancing forest carbon sequestration is translated through regional considerations and local constraints in adaptive management practices. Although this framework used the carbon sequestration as a case study, this framework could be used with other national level priorities such as the National Environmental Protection Act (NEPA) or the Endangered Species Act (ESA).

  14. Using the Lashof Accounting Methodology to Assess Carbon Mitigation Projects Using LCA: Ethanol Biofuel as a Case Study

    DEFF Research Database (Denmark)

    Courchesne, Alexandre; Becaert, Valerie; Rosenbaum, Ralph K.

    2010-01-01

    and comparison of different carbon mitigation projects (e.g. biofuel use, sequestering plant, afforestation project, etc.). The Lashof accounting methodology is chosen amid other methods of greenhouse gas (GHG) emission characterization for its relative simplicity and capability of characterizing all types...... of carbon mitigation projects. It calculates the cumulative radiative forcing caused by GHG emission within a predetermined time frame. Basically, the developed framework uses the Mg-year as a functional unit and isolates impacts related to the climate mitigation function with system expansion. The proposed...... framework is demonstrated with a case study of tree ethanol pathways (maize, sugarcane and willow). Study shows that carbon mitigation assessment through LCA is possible and that it could be a useful tool for decision makers as it can compare different projects regardless of their original context. Case...

  15. Carbon sequestration, biological diversity, and sustainable development: Integrated forest management

    Energy Technology Data Exchange (ETDEWEB)

    Cairns, M.A. (Environmental Research Lab., Corvallis, OR (United States)); Meganck, R.A. (United Nations Environment Programme for the Wider Caribbean, Kingston (Jamaica))

    Tropical deforestation provides a significant contribution to anthropogenic increases in atmospheric CO[sub 2] concentration that may lead to global warming. Forestation and other forest management options to sequester CO[sub 2] in the tropical latitudes may fail unless they address local economic, social, environmental, and political needs of people in the developing world. Forest management is discussed in terms of three objectives: Carbon sequestration, sustainable development, and biodiversity conservation. An integrated forest management strategy of land-use planning is proposed to achieve these objectives and is centered around: Preservation of primary forest, intensified use of nontimber resources, agroforestry, and selective use of plantation forestry. 89 refs., 1 fig., 1 tab.

  16. Atlanta households’ willingness to increase urban forests to mitigate cimate change

    Science.gov (United States)

    Y. Tran; J. P.  Siry; J. M.  Bowker; N. C.  Poudyal

    2017-01-01

    Investments in urban forests have been increasing in many US cities. Urban forests have been shownto provide countless ecosystem benefits with many addressing climate change issues, such as seques-tering carbon, reducing air pollution, and decreasing the heat island effect. Individual groups within theAmerican public may not respond to the issue of climate change in...

  17. Short Communication: Soil carbon pools in different pasture systems

    Energy Technology Data Exchange (ETDEWEB)

    Cardozo, F.M. Jr.; Carneiro, R.F.V.; Leite, L.F.C.; Araujo, A.S.F.

    2016-11-01

    The aim of this study was to assess the carbon pools of a tropical soil where the native forest was replaced with different pasture systems. We studied five pasture production systems, including four monoculture systems with forage grasses such as Andropogon, Brachiaria, Panicum, and Cynodon, and an agroforestry system as well as a native vegetation plot. Greater availability of fulvic acid was detected in the agroforestry system as compared with that in the other systems. Higher lability of C was detected in the Andropogon system during the dry and rainy seasons and during the dry season in Cynodon. During the dry season, all pastures systems showed deficits in the net removal of atmospheric CO2. The structure and practices of the agroforestry system enables more carbon to be sequestered in the soil as compared with the monoculture pasture, suggesting that it is an important practice to mitigate climatic change and to improve soil quality. (Author)

  18. Salinity reduces carbon assimilation and the harvest index of cassava plants (Manihot esculenta Crantz

    Directory of Open Access Journals (Sweden)

    Jailson Lopes Cruz

    2017-08-01

    Full Text Available This study was developed to evaluate the effects of salinity on the growth and gas exchange of cassava plants, cultivar Verdinha. The four concentrations of NaCl (mM were as follows: 0, 20, 40, and 60. Under salinity, the lowest concentration of Na+ ions was observed in the tuberous roots; however, the dry matter of tuberous roots was reduced with an application of just 20 mM NaCl. The harvest index was reduced 50% with the highest salt concentration. Salinity reduced carbon assimilation (A, stomatal conductance (gs, transpiration, and the instantaneous water use efficiency. The correlation between gs and A was high and positive, showing that stomatal movement was one of the responsible for the lower A. Under salt stress, there was an increase in intercellular CO2 concentration, indicating the impairment of carbon metabolism. Based on the reduction of dry matter of the tuberous roots (reduction of 81% under 60 mM NaCl, it was concluded that cassava is sensitive to salinity. The growth of shoots and the absorbing roots were minimally affected by salinity, even in the situation where A was reduced; therefore, the sensitivity of cassava was related to the high sensitivity of the tuberous roots to the ionic and/or osmotic effects of salinity. Thus, tuberous roots can be the target organ in studies that aim to improve the tolerance of cassava to salinity.

  19. Carbon sequestration through urban ecosystem services: A case study from Finland.

    Science.gov (United States)

    Kuittinen, Matti; Moinel, Caroline; Adalgeirsdottir, Kristjana

    2016-09-01

    Plants and soil are natural regulators of atmospheric CO2. Whereas plants sequester atmospheric carbon, soils deposit it for decades. As cities become increasingly more densely built, the available land area for such ecosystem services may decrease. We studied seven different housing areas in the Finnish city of Espoo to ascertain the extent to which site efficiency affects to the ecosystem services if the full life-cycle GHG emissions of these areas are taken into account. The results show that the impact of CO2 uptake through carbon sinks in growing plants and the uptake of soil organic carbon vary greatly. Its share of all emissions varied from a marginal value of 1.2% to a more considerable value of 11.9%. The highest potential was calculated for a detached house located on a large site, while the weakest was calculated for compact apartment blocks. The study revealed that in order to quantify this potential more accurately, several knowledge gaps must first be addressed. These include impartial growth algorithms for Nordic wood species, missing accumulation factors for soil organic carbon in cold climates and statistical maintenance scenarios for gardens. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Carbon fiber/SiC composite for reduced activation

    International Nuclear Information System (INIS)

    Noda, T.; Araki, H.; Abe, F.; Okada, M.

    1991-01-01

    A carbon fiber/SiC composite fabricated by a chemical vapor infiltration process at 1173-1623 K was studied to develop a low-activation material. A high-purity composite was obtained with the total amount of impurities less than 0.02 wt%. The microstructure and the mechanical properties using a bend test were examined. A composite with woven carbon yarn showed both high strength and toughness. Further, the induced activity of the material was evaluated by calculations simulating fusion neutron irradiation. The carbon fiber/SiC composite shows an excellent low-activation behavior. (orig.)

  1. How did climate drying reduce ecosystem carbon storage in the forest-steppe ecotone? A case study in Inner Mongolia, China.

    Science.gov (United States)

    Zhang, Yuke; Liu, Hongyan

    2010-07-01

    The projected recession of forests in the forest-steppe ecotone under projected climate drying would restrict the carbon sink function of terrestrial ecosystems. Previous studies have shown that the forest-steppe ecotone in the southeastern Inner Mongolia Plateau originally resulted from climate drying and vegetation shifts during the mid- to late-Holocene, but the interrelated processes of changing soil carbon storage and vegetation and soil shifts remain unclear. A total of 44 forest soil profiles and 40 steppe soil profiles were excavated to determine soil carbon storage in deciduous broadleaf forests (DBF), coniferous forests (CF) and steppe (ST) in this area. Carbon density was estimated to be 106.51 t/hm(2) (DBF), 73.20 t/hm(2) (CF), and 28.14 t/hm(2) (ST) for these ecosystems. Soil organic carbon (SOC) content was negatively correlated with sand content (R = -0.879, P ecotone. Changes in carbon storage caused by climate drying can be divided into two stages: (1) carbon storage of the ecosystem was reduced to 68.7%, mostly by soil coarsening when DBF were replaced by CF at approximately 5,900 (14)C years before present (BP); and (2) carbon storage was reduced to 26.4%, mostly by vegetation shifts when CF were replaced by ST at approximately 2,900 (14)C years BP.

  2. Carbon Sequestration in Tidal Salt Marshes of the Northeast United States.

    Science.gov (United States)

    Drake, Katherine; Halifax, Holly; Adamowicz, Susan C; Craft, Christopher

    2015-10-01

    Tidal salt marshes provide important ecological services, habitat, disturbance regulation, water quality improvement, and biodiversity, as well as accumulation and sequestration of carbon dioxide (CO2) in vegetation and soil organic matter. Different management practices may alter their capacity to provide these ecosystem services. We examined soil properties (bulk density, percent organic C, percent N), C and N pools, C sequestration and N accumulation at four marshes managed with open marsh water management (OMWM) and four marshes that were not at U.S. Fish and Wildlife National Wildlife Refuges (NWRs) on the East Coast of the United States. Soil properties (bulk density, percent organic C, percent N) exhibited no consistent differences among managed and non-OMWM marshes. Soil organic carbon pools (0-60-cm depth) also did not differ. Managed marshes contained 15.9 kg C/m(2) compared to 16.2 kg C/m(2) in non-OMWM marshes. Proportionately, more C (per unit volume) was stored in surface than in subsurface soils. The rate of C sequestration, based on (137)Cs and (210)Pb dating of soil cores, ranged from 41 to 152 g/m(2)/year. Because of the low emissions of CH4 from salt marshes relative to freshwater wetlands and the ability to sequester C in soil, protection and restoration of salt marshes can be a vital tool for delivering key ecosystem services, while at the same time, reducing the C footprint associated with managing these wetlands.

  3. Carbon annuities and their potential to preserve tropical forests and slow global warming: an application for small-scale farmers

    Energy Technology Data Exchange (ETDEWEB)

    Caviglia-Harris, J.L. [Salisbury University, Salisbury, MD (United States). Dept. of Economics and Finance; Kahn, J.R. [Washington and Lee University, Lexington, VA (United States). Dept. of Economics

    2003-07-01

    Carbon annuities have been suggested as a means for rewarding landowners for preserving forests and sequestering carbon. Although this is an intuitively appealing approach, the benefits of the sequestration activities have not been compared with the opportunity cost of preserving the forest. This paper represents an initial attempt at analysing how large carbon annuities must be to induce a landowner in the Amazonian rainforest to accept the annuity and leave the forest intact. The benefits of carbon sequestration are computed based on estimates in the literature on the carbon contained in a hectare of rainforest and the damages associated with a ton of carbon emissions. This is compared with information on household income from Rondonia, Brazil. Our results show that, for the majority of our conservative assumptions about the damages of carbon emissions, the magnitude of an annuity is greater than the income from agriculture. For less conservative assumptions about the damages from global warming, a fraction of the annuity would be a sufficient incentive for small- scale farmers to switch to sustainable techniques that leave the forest intact. (author)

  4. Partitioning of carbon sources among functional pools to investigate short-term priming effects of biochar in soil: A 13C study

    International Nuclear Information System (INIS)

    Kerré, Bart; Hernandez-Soriano, Maria C.; Smolders, Erik

    2016-01-01

    Biochar sequesters carbon (C) in soils because of its prolonged residence time, ranging from several years to millennia. In addition, biochar can promote indirect C-sequestration by increasing crop yield while, potentially, reducing C-mineralization. This laboratory study was set up to evaluate effects of biochar on C-mineralization with due attention to source appointment by using 13 C isotope signatures. An arable soil (S) (7.9 g organic C, OC kg −1 ) was amended (single dose of 10 g kg −1 soil) with dried, grinded maize stover (leaves and stalks), either natural (R) or 13 C enriched (R*), and/or biochar (B/B*) prepared from the maize stover residues (450 °C). Accordingly, seven different combinations were set up (S, SR, SB, SR*, SB*, SRB*, SR*B) to trace the source of C in CO 2 (180 days), dissolved organic-C (115 days) and OC in soil aggregate fractions (90 days). The application of biochar to soil reduced the mineralization of native soil organic C but the effect on maize stover-C mineralization was not consistent. Biochar application decreased the mineralization of the non-enriched maize stover after 90 days, this being consistent with a significant reduction of dissolved organic C concentration from 45 to 18 mg L −1 . However, no significant effect was observed for the enriched maize stover, presumably due to differences between the natural and enriched materials. The combined addition of biochar and enriched maize stover significantly increased (twofold) the presence of native soil organic C or maize derived C in the free microaggregate fraction relative to soil added only with stover. Although consistent effects among C sources and biochar materials remains elusive, our outcomes indicate that some biochar products can reduce mineralization and solubilization of other sources of C while promoting their physical protection in soil particles. - Highlights: • Biochar can reduce native soil organic carbon mineralization. • Biochar can promote storage

  5. Interactive effects of agricultural management and topography on soil carbon sequestration

    Science.gov (United States)

    Ladoni, M.; Kravchenko, S.; Munoz, J.; Erickson, M.

    2012-12-01

    Proper agricultural management scenarios such as no-tillage, cover cropping, agroforestry, have demonstrated potential to increase the amount of carbon sequestered in soil and to mitigate atmospheric carbon levels. The knowledge about positive effects of cover cropping comes mostly from small uniform experimental plots, but whether these positive effects will exists in large scale fields with diverse topography and what would be the magnitude of these effects on a field scale remains to be seen. Our objective is to compare performance of different agricultural managements including those with cover crops in their influences on SOC across diverse topographical landscape in large agricultural fields. The three studied agricultural practices are Conventionally tilled and fertilized management without cover crops (T1), Low-input management with reduced chemical inputs (T3) and Organic (T4) management, the latter two have rye and red clover cover crops as part of their rotations. Within each field 1- 4 transects with three topographical positions of "depression", "slope" and "summit" were identified. The first soil sampling was done in spring 2010 and the second set of soil samples were collected from topographical positions during growing season of 2011. Samples were analyzed for total SOC and also particulate organic carbon (POC) content to show the changes in active pools of SOC. The results showed that topography has a significant influence in performance of cover crops. Agricultural managements with cover crops increased the POC in soil and the magnitude of this increase was different across space. Cover crops built the highest POC in depressions followed by summit and then slope. The conventional agricultural management increased POC in depression but decreased it on slopes. Low-input agricultural management when coupled with cover cropping has a potential to produce the highest increase in active pools of SOC across topographically diverse fields. The ratio of

  6. Accumulation of carbon in northern mire ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Tolonen, K; Turunen, J; Alm, J [Joensuu Univ. (Finland). Dept. of Biology; Korhola, A [Helsinki Univ. (Finland). Lab. of Physical Geography; Jungner, H [Helsinki Univ. (Finland). Dating Lab.; Vasander, H [Helsinki Univ. (Finland). Dept. of Forest Ecology

    1997-12-31

    The basic feature in the functional ecology of any mire ecosystem is retardation of the effective decay of organic material resulting in a conspicuous accumulation of plant debris as peat overtime. The carbon accumulation process is slow, and climatic change may have an impact on the carbon cycle of peatlands, therefore, it has been of interest to study the rate of carbon accumulation by geological methods from dated peat strata. The approach is hampered by several facts. First, the mires vary enormously as to their vegetation and hydrology and hence their production and decay properties. It follows that a great number of study sites are needed. Second, the peat in mires expands both vertically and laterally, and this requires a spatial reconstruction of carbon accumulation within a mire basin. Third, simple geological methods cannot account for the actual rate of carbon accumulation in peat, and finally, an additional carbon sink in the mire ecosystems can be the mineral subsoil beneath peat. The proposed warming will perhaps shift northwards the existing climatic mire regimes and, thus, the northern aapa fens will change to Sphagnum bogs that are more effective in sequestering carbon, but distinctly less effective in their CH{sub 4} and N{sub 2}O emanation. The role of mire fires in more remote northern areas may then become another important factor. The answer to the important question of future total sequestration of carbon to peatlands depends on the precipitation and its seasonal distribution pattern. Most climatic scenarios predict a decrease in the evaporation surplus during the summer at northern regions. Presumably, the consequent lowering of the water table would improve growth of forest on mires and simultaneously decrease the methane fluxes from peat. The combined net effect could be a clear restraining of the radiative forcing

  7. Accumulation of carbon in northern mire ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Tolonen, K.; Turunen, J.; Alm, J. [Joensuu Univ. (Finland). Dept. of Biology; Korhola, A. [Helsinki Univ. (Finland). Lab. of Physical Geography; Jungner, H. [Helsinki Univ. (Finland). Dating Lab.; Vasander, H. [Helsinki Univ. (Finland). Dept. of Forest Ecology

    1996-12-31

    The basic feature in the functional ecology of any mire ecosystem is retardation of the effective decay of organic material resulting in a conspicuous accumulation of plant debris as peat overtime. The carbon accumulation process is slow, and climatic change may have an impact on the carbon cycle of peatlands, therefore, it has been of interest to study the rate of carbon accumulation by geological methods from dated peat strata. The approach is hampered by several facts. First, the mires vary enormously as to their vegetation and hydrology and hence their production and decay properties. It follows that a great number of study sites are needed. Second, the peat in mires expands both vertically and laterally, and this requires a spatial reconstruction of carbon accumulation within a mire basin. Third, simple geological methods cannot account for the actual rate of carbon accumulation in peat, and finally, an additional carbon sink in the mire ecosystems can be the mineral subsoil beneath peat. The proposed warming will perhaps shift northwards the existing climatic mire regimes and, thus, the northern aapa fens will change to Sphagnum bogs that are more effective in sequestering carbon, but distinctly less effective in their CH{sub 4} and N{sub 2}O emanation. The role of mire fires in more remote northern areas may then become another important factor. The answer to the important question of future total sequestration of carbon to peatlands depends on the precipitation and its seasonal distribution pattern. Most climatic scenarios predict a decrease in the evaporation surplus during the summer at northern regions. Presumably, the consequent lowering of the water table would improve growth of forest on mires and simultaneously decrease the methane fluxes from peat. The combined net effect could be a clear restraining of the radiative forcing

  8. Dousing our inflammatory environment(s): is personal carbon trading an option for reducing obesity--and climate change?

    Science.gov (United States)

    Egger, G

    2008-09-01

    Obesity and climate change are two problems currently challenging humanity. Although apparently unrelated, an epidemiological approach to both shows a similar environmental aetiology, based in modern human lifestyles and their driving economic forces. One way of analysing this is through inflammation (defined as '. . . a disturbance of function following insult or injury') of both the internal (biological) and external (ecological) environments. Chronic, low-grade, systemic inflammation has recently been shown to accompany obesity, as well as a range of biological pathologies associated with obesity (diabetes, heart disease, some cancers, etc.). This is influenced by the body's inability to soak up excess glucose as a result of insulin resistance. In a broader sense, inflammation is a metaphor for ecological 'pathologies', manifest particularly in unnatural disturbances like climate change, ocean acidity, rising temperatures and species extinction, associated with the inability of the world's environmental 'sinks' to soak up carbon dioxide ('carbon resistance'?). The use of such a metaphorical analysis opens the possibilities for dealing with two interdisciplinary problems simultaneously. Strategies for managing climate change, including personal carbon trading, could provide a 'stealth intervention' for reducing population levels of obesity by increasing personal energy expenditure and decreasing energy-dense food intake, as well as reducing the carbon emissions causing climate change.

  9. Satellite Based Cropland Carbon Monitoring System

    Science.gov (United States)

    Bandaru, V.; Jones, C. D.; Sedano, F.; Sahajpal, R.; Jin, H.; Skakun, S.; Pnvr, K.; Kommareddy, A.; Reddy, A.; Hurtt, G. C.; Izaurralde, R. C.

    2017-12-01

    Agricultural croplands act as both sources and sinks of atmospheric carbon dioxide (CO2); absorbing CO2 through photosynthesis, releasing CO2 through autotrophic and heterotrophic respiration, and sequestering CO2 in vegetation and soils. Part of the carbon captured in vegetation can be transported and utilized elsewhere through the activities of food, fiber, and energy production. As well, a portion of carbon in soils can be exported somewhere else by wind, water, and tillage erosion. Thus, it is important to quantify how land use and land management practices affect the net carbon balance of croplands. To monitor the impacts of various agricultural activities on carbon balance and to develop management strategies to make croplands to behave as net carbon sinks, it is of paramount importance to develop consistent and high resolution cropland carbon flux estimates. Croplands are typically characterized by fine scale heterogeneity; therefore, for accurate carbon flux estimates, it is necessary to account for the contribution of each crop type and their spatial distribution. As part of NASA CMS funded project, a satellite based Cropland Carbon Monitoring System (CCMS) was developed to estimate spatially resolved crop specific carbon fluxes over large regions. This modeling framework uses remote sensing version of Environmental Policy Integrated Climate Model and satellite derived crop parameters (e.g. leaf area index (LAI)) to determine vertical and lateral carbon fluxes. The crop type LAI product was developed based on the inversion of PRO-SAIL radiative transfer model and downscaled MODIS reflectance. The crop emergence and harvesting dates were estimated based on MODIS NDVI and crop growing degree days. To evaluate the performance of CCMS framework, it was implemented over croplands of Nebraska, and estimated carbon fluxes for major crops (i.e. corn, soybean, winter wheat, grain sorghum, alfalfa) grown in 2015. Key findings of the CCMS framework will be presented

  10. Anthropogenic nitrogen deposition in boreal forests has a minor impact on the global carbon cycle.

    Science.gov (United States)

    Gundale, Michael J; From, Fredrik; Bach, Lisbet H; Nordin, Annika

    2014-01-01

    It is proposed that increases in anthropogenic reactive nitrogen (Nr ) deposition may cause temperate and boreal forests to sequester a globally significant quantity of carbon (C); however, long-term data from boreal forests describing how C sequestration responds to realistic levels of chronic Nr deposition are scarce. Using a long-term (14-year) stand-scale (0.1 ha) N addition experiment (three levels: 0, 12.5, and 50 kg N ha(-1)  yr(-1) ) in the boreal zone of northern Sweden, we evaluated how chronic N additions altered N uptake and biomass of understory communities, and whether changes in understory communities explained N uptake and C sequestration by trees. We hypothesized that understory communities (i.e. mosses and shrubs) serve as important sinks for low-level N additions, with the strength of these sinks weakening as chronic N addition rates increase, due to shifts in species composition. We further hypothesized that trees would exhibit nonlinear increases in N acquisition, and subsequent C sequestration as N addition rates increased, due to a weakening understory N sink. Our data showed that understory biomass was reduced by 50% in response to the high N addition treatment, mainly due to reduced moss biomass. A (15) N labeling experiment showed that feather mosses acquired the largest fraction of applied label, with this fraction decreasing as the chronic N addition level increased. Contrary to our hypothesis, the proportion of label taken up by trees was equal (ca. 8%) across all three N addition treatments. The relationship between N addition and C sequestration in all vegetation pools combined was linear, and had a slope of 16 kg C kg(-1)  N. While canopy retention of Nr deposition may cause C sequestration rates to be slightly different than this estimate, our data suggest that a minor quantity of annual anthropogenic CO2 emissions are sequestered into boreal forests as a result of Nr deposition. © 2013 John Wiley & Sons Ltd.

  11. Large-scale sequestration of atmospheric carbon via plant roots in natural and agricultural ecosystems: why and how.

    Science.gov (United States)

    Kell, Douglas B

    2012-06-05

    The soil holds twice as much carbon as does the atmosphere, and most soil carbon is derived from recent photosynthesis that takes carbon into root structures and further into below-ground storage via exudates therefrom. Nonetheless, many natural and most agricultural crops have roots that extend only to about 1 m below ground. What determines the lifetime of below-ground C in various forms is not well understood, and understanding these processes is therefore key to optimising them for enhanced C sequestration. Most soils (and especially subsoils) are very far from being saturated with organic carbon, and calculations show that the amounts of C that might further be sequestered (http://dbkgroup.org/carbonsequestration/rootsystem.html) are actually very great. Breeding crops with desirable below-ground C sequestration traits, and exploiting attendant agronomic practices optimised for individual species in their relevant environments, are therefore important goals. These bring additional benefits related to improvements in soil structure and in the usage of other nutrients and water.

  12. Large-scale sequestration of atmospheric carbon via plant roots in natural and agricultural ecosystems: why and how

    Science.gov (United States)

    Kell, Douglas B.

    2012-01-01

    The soil holds twice as much carbon as does the atmosphere, and most soil carbon is derived from recent photosynthesis that takes carbon into root structures and further into below-ground storage via exudates therefrom. Nonetheless, many natural and most agricultural crops have roots that extend only to about 1 m below ground. What determines the lifetime of below-ground C in various forms is not well understood, and understanding these processes is therefore key to optimising them for enhanced C sequestration. Most soils (and especially subsoils) are very far from being saturated with organic carbon, and calculations show that the amounts of C that might further be sequestered (http://dbkgroup.org/carbonsequestration/rootsystem.html) are actually very great. Breeding crops with desirable below-ground C sequestration traits, and exploiting attendant agronomic practices optimised for individual species in their relevant environments, are therefore important goals. These bring additional benefits related to improvements in soil structure and in the usage of other nutrients and water. PMID:22527402

  13. The importance of rapid, disturbance-induced losses in carbon management and sequestration

    Science.gov (United States)

    Breshears, D.D.; Allen, Craig D.

    2002-01-01

    Management of terrestrial carbon fluxes is being proposed as a means of increasing the amount of carbon sequestered in the terrestrial biosphere. This approach is generally viewed only as an interim strategy for the coming decades while other longer-term strategies are developed and implemented — the most important being the direct reduction of carbon emissions. We are concerned that the potential for rapid, disturbance-induced losses may be much greater than is currently appreciated, especially by the decision-making community. Here we wish to: (1) highlight the complex and threshold-like nature of disturbances — such as fire and drought, as well as the erosion associated with each — that could lead to carbon losses; (2) note the global extent of ecosystems that are at risk of such disturbance-induced carbon losses; and (3) call for increased consideration of and research on the mechanisms by which large, rapid disturbance-induced losses of terrestrial carbon could occur. Our lack of ability as a scientific community to predict such ecosystem dynamics is precluding the effective consideration of these processes into strategies and policies related to carbon management and sequestration. Consequently, scientists need to do more to improve quantification of these potential losses and to integrate them into sound, sustainable policy options.

  14. Forest carbon trading : legal, policy, ecological and aboriginal issues

    International Nuclear Information System (INIS)

    Elgie, S.

    2005-01-01

    was presented, including costs for sequestering carbon range and counting forest product sinks. Conservation and management costs as well as tree planting costs were also presented. The overall projected carbon price was estimated at $4.00 to $12.00 per tonne by 2008. tabs., figs

  15. Understanding Carbon Sequestration Options in the United States: Capabilities of a Carbon Management Geographic Information System

    Energy Technology Data Exchange (ETDEWEB)

    Dahowski, Robert T.; Dooley, James J.; Brown, Daryl R.; Mizoguchi, Akiyoshi; Shiozaki, Mai

    2001-04-03

    While one can discuss various sequestration options at a national or global level, the actual carbon management approach is highly site specific. In response to the need for a better understanding of carbon management options, Battelle in collaboration with Mitsubishi Corporation, has developed a state-of-the-art Geographic Information System (GIS) focused on carbon capture and sequestration opportunities in the United States. The GIS system contains information (e.g., fuel type, location, vintage, ownership, rated capacity) on all fossil-fired generation capacity in the Untied States with a rated capacity of at least 100 MW. There are also data on other CO2 sources (i.e., natural domes, gas processing plants, etc.) and associated pipelines currently serving enhanced oil recovery (EOR) projects. Data on current and prospective CO2 EOR projects include location, operator, reservoir and oil characteristics, production, and CO2 source. The system also contains information on priority deep saline aquifers and coal bed methane basins with potential for sequestering CO2. The GIS application not only enables data storage, flexible map making, and visualization capabilities, but also facilitates the spatial analyses required to solve complex linking of CO2 sources with appropriate and cost-effective sinks. A variety of screening criteria (spatial, geophysical, and economic) can be employed to identify sources and sinks most likely amenable to deployment of carbon capture and sequestration systems. The system is easily updateable, allowing it to stay on the leading edge of capture and sequestration technology as well as the ever-changing business landscape. Our paper and presentation will describe the development of this GIS and demonstrate its uses for carbon management analysis.

  16. Monitoring changes in soil carbon resulting from intensive production, a non-traditional agricultural methodology.

    Energy Technology Data Exchange (ETDEWEB)

    Dwyer, Brian P.

    2013-03-01

    New Mexico State University and a group of New Mexico farmers are evaluating an innovative agricultural technique they call Intensive Production (IP). In contrast to conventional agricultural practice, IP uses intercropping, green fallowing, application of soil amendments and soil microbial inocula to sequester carbon as plant biomass, resulting in improved soil quality. Sandia National Laboratories role was to identify a non-invasive, cost effective technology to monitor soil carbon changes. A technological review indicated that Laser Induced Breakdown Spectroscopy (LIBS) best met the farmers objectives. Sandia partnered with Los Alamos National Laboratory (LANL) to analyze farmers test plots using a portable LIBS developed at LANL. Real-time LIBS field sample analysis was conducted and grab samples were collected for laboratory comparison. The field and laboratory results correlated well implying the strong potential for LIBS as an economical field scale analytical tool for analysis of elements such as carbon, nitrogen, and phosphate.

  17. Carbon recycling by cyanobacteria: improving CO2 fixation through chemical production.

    Science.gov (United States)

    Zhang, Angela; Carroll, Austin L; Atsumi, Shota

    2017-09-01

    Atmospheric CO2 levels have reached an alarming level due to industrialization and the burning of fossil fuels. In order to lower the level of atmospheric carbon, strategies to sequester excess carbon need to be implemented. The CO2-fixing mechanism in photosynthetic organisms enables integration of atmospheric CO2 into biomass. Additionally, through exogenous metabolic pathways in these photosynthetic organisms, fixed CO2 can be routed to produce various commodity chemicals that are currently produced from petroleum. This review will highlight studies and modifications to different components of cyanobacterial CO2-fixing systems, as well as the application of these systems toward CO2-derived chemical production. 2,3-Butanediol is given particular focus as one of the most thoroughly studied systems for conversion of CO2 to a bioproduct. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Reducing uncertainty for estimating forest carbon stocks and dynamics using integrated remote sensing, forest inventory and process-based modeling

    Science.gov (United States)

    Poulter, B.; Ciais, P.; Joetzjer, E.; Maignan, F.; Luyssaert, S.; Barichivich, J.

    2015-12-01

    Accurately estimating forest biomass and forest carbon dynamics requires new integrated remote sensing, forest inventory, and carbon cycle modeling approaches. Presently, there is an increasing and urgent need to reduce forest biomass uncertainty in order to meet the requirements of carbon mitigation treaties, such as Reducing Emissions from Deforestation and forest Degradation (REDD+). Here we describe a new parameterization and assimilation methodology used to estimate tropical forest biomass using the ORCHIDEE-CAN dynamic global vegetation model. ORCHIDEE-CAN simulates carbon uptake and allocation to individual trees using a mechanistic representation of photosynthesis, respiration and other first-order processes. The model is first parameterized using forest inventory data to constrain background mortality rates, i.e., self-thinning, and productivity. Satellite remote sensing data for forest structure, i.e., canopy height, is used to constrain simulated forest stand conditions using a look-up table approach to match canopy height distributions. The resulting forest biomass estimates are provided for spatial grids that match REDD+ project boundaries and aim to provide carbon estimates for the criteria described in the IPCC Good Practice Guidelines Tier 3 category. With the increasing availability of forest structure variables derived from high-resolution LIDAR, RADAR, and optical imagery, new methodologies and applications with process-based carbon cycle models are becoming more readily available to inform land management.

  19. Partitioning of carbon sources among functional pools to investigate short-term priming effects of biochar in soil: A {sup 13}C study

    Energy Technology Data Exchange (ETDEWEB)

    Kerré, Bart [Department of Earth and Environmental Science, KU Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee (Belgium); Hernandez-Soriano, Maria C., E-mail: m.hernandezsoriano@uq.edu.au [Department of Earth and Environmental Science, KU Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee (Belgium); The University of Queensland, School of Agriculture and Food Sciences, St. Lucia, Queensland 4072 (Australia); Smolders, Erik [Department of Earth and Environmental Science, KU Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee (Belgium)

    2016-03-15

    Biochar sequesters carbon (C) in soils because of its prolonged residence time, ranging from several years to millennia. In addition, biochar can promote indirect C-sequestration by increasing crop yield while, potentially, reducing C-mineralization. This laboratory study was set up to evaluate effects of biochar on C-mineralization with due attention to source appointment by using {sup 13}C isotope signatures. An arable soil (S) (7.9 g organic C, OC kg{sup −1}) was amended (single dose of 10 g kg{sup −1} soil) with dried, grinded maize stover (leaves and stalks), either natural (R) or {sup 13}C enriched (R*), and/or biochar (B/B*) prepared from the maize stover residues (450 °C). Accordingly, seven different combinations were set up (S, SR, SB, SR*, SB*, SRB*, SR*B) to trace the source of C in CO{sub 2} (180 days), dissolved organic-C (115 days) and OC in soil aggregate fractions (90 days). The application of biochar to soil reduced the mineralization of native soil organic C but the effect on maize stover-C mineralization was not consistent. Biochar application decreased the mineralization of the non-enriched maize stover after 90 days, this being consistent with a significant reduction of dissolved organic C concentration from 45 to 18 mg L{sup −1}. However, no significant effect was observed for the enriched maize stover, presumably due to differences between the natural and enriched materials. The combined addition of biochar and enriched maize stover significantly increased (twofold) the presence of native soil organic C or maize derived C in the free microaggregate fraction relative to soil added only with stover. Although consistent effects among C sources and biochar materials remains elusive, our outcomes indicate that some biochar products can reduce mineralization and solubilization of other sources of C while promoting their physical protection in soil particles. - Highlights: • Biochar can reduce native soil organic carbon mineralization.

  20. The Midwest Regional Carbon Sequestration Partnership (MRCSP)

    Energy Technology Data Exchange (ETDEWEB)

    James J. Dooley; Robert Dahowski; Casie Davidson

    2005-12-01

    This final report summarizes the Phase I research conducted by the Midwest regional Carbon Sequestration Partnership (MRCSP). The Phase I effort began in October 2003 and the project period ended on September 31, 2005. The MRCSP is a public/private partnership led by Battelle with the mission of identifying the technical, economic, and social issues associated with implementation of carbon sequestration technologies in its seven state geographic region (Indiana, Kentucky, Maryland, Michigan, Ohio, Pennsylvania, and West Virginia) and identifying viable pathways for their deployment. It is one of seven partnerships that together span most of the U.S. and parts of Canada that comprise the U.S. Department of Energy's (DOE's) Regional Carbon Sequestration Program led by DOE's national Energy Technology Laboratory (NETL). The MRCSP Phase I research was carried out under DOE Cooperative Agreement No. DE-FC26-03NT41981. The total value of Phase I was $3,513,513 of which the DOE share was $2,410,967 or 68.62%. The remainder of the cost share was provided in varying amounts by the rest of the 38 members of MRCSP's Phase I project. The next largest cost sharing participant to DOE in Phase I was the Ohio Coal Development Office within the Ohio Air Quality Development Authority (OCDO). OCDO's contribution was $100,000 and was contributed under Grant Agreement No. CDO/D-02-17. In this report, the MRCSP's research shows that the seven state MRCSP region is a major contributor to the U. S. economy and also to total emissions of CO2, the most significant of the greenhouse gases thought to contribute to global climate change. But, the research has also shown that the region has substantial resources for sequestering carbon, both in deep geological reservoirs (geological sequestration) and through improved agricultural and land management practices (terrestrial sequestration). Geological reservoirs, especially deep saline reservoirs, offer the potential

  1. Does a carbon tax make sense in countries with still a high potential for energy efficiency? Comparison between the reducing-emissions effects of carbon tax and energy efficiency measures in the Chilean case

    International Nuclear Information System (INIS)

    Vera, Sonia; Sauma, Enzo

    2015-01-01

    Many countries have not yet successfully decoupled their growth and their energy consumption. Moreover, power production frequently entails a number of negative externalities, like greenhouse gas emissions from thermo electrical units. This situation has highlighted the need for countries to move towards sustainable economic growth. Accordingly, many countries have proposed and established measures to decrease their carbon emissions. In this line, the Chilean government has just passed a carbon tax of $5/Ton CO 2 e. In this work, we compare the effects on reducing CO 2 emissions of this carbon tax and of some energy efficiency measures in the power sector. The results obtained indicate that the imposed carbon tax will produce an expected annual reduction in CO 2 emissions of 1% with respect to the estimated baseline during the 2014–2024 period. However, this reduction will be accompanied by an expected 3.4% increase in the marginal cost of power production on the main Chilean power system. In contrast, the introduction of some energy efficiency measures, aimed to reduce 2% of the power demand of the residential sector, could achieve larger reductions in CO 2 emissions, while simultaneously decreasing energy price. - Highlights: • We estimate CO 2 emission reductions due to a carbon tax and EE measures in Chile. • We simulate the main Chilean power system with diverse levels of carbon tax and EE. • Energy efficiency measures could achieve better results than carbon tax in Chile. • The carbon tax imposed in Chile reduces CO 2 emissions in 1% in the 2014–2024 period. • The carbon tax imposed in Chile increases system marginal cost in 3.4% in 2014–2024

  2. Accelerating Net Terrestrial Carbon Uptake During the Warming Hiatus Due to Reduced Respiration

    Science.gov (United States)

    Ballantyne, Ashley; Smith, William; Anderegg, William; Kauppi, Pekka; Sarmiento, Jorge; Tans, Pieter; Shevliakova, Elena; Pan, Yude; Poulter, Benjamin; Anav, Alessandro; hide

    2017-01-01

    The recent warming hiatus presents an excellent opportunity to investigate climate sensitivity of carbon cycle processes. Here we combine satellite and atmospheric observations to show that the rate of net biome productivity (NBP) has significantly accelerated from - 0.007 +/- 0.065 PgC yr(exp -2) over the warming period (1982 to 1998) to 0.119 +/- 0.071 PgC yr(exp -2) over the warming hiatus (19982012). This acceleration in NBP is not due to increased primary productivity, but rather reduced respiration that is correlated (r = 0.58; P = 0.0007) and sensitive ( y = 4.05 to 9.40 PgC yr(exp -1) per C) to land temperatures. Global land models do not fully capture this apparent reduced respiration over the warming hiatus; however, an empirical model including soil temperature and moisture observations better captures the reduced respiration.

  3. Abatement and mitigation of carbon dioxide emissions from power generation

    International Nuclear Information System (INIS)

    Freund, P.; Audus, H.

    1998-01-01

    Current understanding of the world's climate indicates that human-induced changes are occurring and may be sufficient in magnitude to require preventative action, such as limiting atmospheric concentrations of greenhouse gases. The main anthropogenic greenhouse gas is carbon dioxide and its largest source is combustion of fossil fuels for power generation. Many different technologies can be used for reducing emissions, as well as increasing the removal of CO 2 from the atmosphere through enhancement of natural sinks, such as by forestry. Some of these options are available today and could be implemented at relatively little overall cost. For example, improving energy efficiency and switching from high carbon fuels to low carbon fuels, if suitable supplies are available. These can achieve significant reductions in CO 2 emissions. Introduction of renewable sources of energy or nuclear power to displace fossil fuels would achieve deep reductions in emissions if applied widely. However, to avoid disruptive changes, it will also be necessary to find ways of continuing to use fossil fuels but with much less emissions. Capture and storage of CO 2 is a technology which could deliver deep reductions in emissions from fossil fuels. In this paper, methods of removing CO 2 from the flue gas streams of coal and gas-fired power plants are examined, considering both plant as built today as well as possible future variants. Methods of CO 2 storage are also discussed. The results on capture and storage of CO 2 are put into perspective by comparison with studies of the large-scale application of forestry for sequestering atmospheric CO 2 , and also large-scale use of renewable energy sources, in this case growth and harvesting of woody biomass for power generation. Each of these options has different characteristics, providing a range of choices of ways of tackling climate change

  4. Overview of mitigation policies and measures in the forestry sector

    Energy Technology Data Exchange (ETDEWEB)

    Sathaye, J. [Lawrence Berkeley National Lab., CA (United States)

    1996-12-31

    In this paper the author addresses questions on how the forestry sector can make a contribution to the general problem of greenhouse gases in the environment. Primarily this is in the form of carbon conservation and sequestering. There is a potential land area for conservation and sequestration estimated to be 700 Mha. The total carbon that could be sequestered and conserved globally by 2050 on this land is 60 - 87 GtC. Slowing deforestation, assisting regeneration, forestation and agroforestry are the primary mitigation measures for carbon conservation and sequestration. For long term success, enforcement to halt deforestation has to be accompained by economic and/or other benefits to the deforesters that equal or exceed their current remuneration. Making plantations a significant fuel for utility electricity generation will require higher biomass yields and thermal efficiency matching that of conventional plants. Significant reduction of global carbon emissions requires national governments to institute measures that provide local, national, economic and other benefits while conserving and sequestering carbon.

  5. Carbon/Carbon Pistons for Internal Combustion Engines

    Science.gov (United States)

    Taylor, A. H.

    1986-01-01

    Carbon/carbon piston performs same function as aluminum pistons in reciprocating internal combustion engines while reducing weight and increasing mechanical and thermal efficiencies of engine. Carbon/carbon piston concept features low piston-to-cylinder wall clearance - so low piston rings and skirts unnecessary. Advantages possible by negligible coefficient of thermal expansion of carbon/carbon.

  6. Laboratory-scale model of carbon dioxide deposition for soil stabilisation

    Directory of Open Access Journals (Sweden)

    Mohammad Hamed Fasihnikoutalab

    2016-04-01

    Full Text Available Olivine sand is a natural mineral, which, when added to soil, can improve the soil's mechanical properties while also sequester carbon dioxide (CO2 from the surrounding environment. The originality of this paper stems from the novel two-stage approach. In the first stage, natural carbonation of olivine and carbonation of olivine treated soil under different CO2 pressures and times were investigated. In this stage, the unconfined compression test was used as a tool to evaluate the strength performance. In the second stage, details of the installation and performance of carbonated olivine columns using a laboratory-scale model were investigated. In this respect, olivine was mixed with the natural soil using the auger and the columns were then carbonated with gaseous CO2. The unconfined compressive strengths of soil in the first stage increased by up to 120% compared to those of the natural untreated soil. The strength development was found to be proportional to the CO2 pressure and carbonation period. Microstructural analyses indicated the presence of magnesite on the surface of carbonated olivine-treated soil, demonstrating that modified physical properties provided a stronger and stiffer matrix. The performance of the carbonated olivine-soil columns, in terms of ultimate bearing capacity, showed that the carbonation procedure occurred rapidly and yielded a bearing capacity value of 120 kPa. Results of this study are of significance to the construction industry as the feasibility of carbonated olivine for strengthening and stabilizing soil is validated. Its applicability lies in a range of different geotechnical applications whilst also mitigates the global warming through the sequestration of CO2.

  7. Economic implications of reducing carbon emissions from energy use and industrial processes in Brazil.

    Science.gov (United States)

    Chen, Y-H Henry; Timilsina, Govinda R; Landis, Florian

    2013-11-30

    This study assesses the economy-wide impacts of cutting CO2 emissions on the Brazilian economy. It finds that in 2040, the business-as-usual CO2 emissions from energy use and industrial processes would be almost three times as high as those in 2010 and would account for more than half of total national CO2 emissions. The current policy aims to reduce deforestation by 70 percent by 2017 and lower emissions intensity of the overall economy by 36-39 percent by 2020. If the policy were implemented as planned and continued to 2040, there would be no need to cut CO2 emissions from energy use and industrial processes until 2035, as emissions reduction through controlling deforestation would be enough to meet the voluntary carbon mitigation target of Brazil. The study also finds that using the carbon tax revenue to subsidize wind power can effectively increase the country's wind power output if that is the policy priority. Further, it finds evidence supporting the double dividend hypothesis, i.e., using revenue from a hypothetical carbon tax to finance a cut in labor income tax can significantly lower the GDP impacts of the carbon tax. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Assessing the potential to sequester carbon within state highway rights-of-way in New Mexico phase 2: development of a right-of-way carbon sequestration program.

    Science.gov (United States)

    2016-06-13

    The New Mexico Department of Transportation (NMDOT) was selected by the Federal Highway : Administration (FHWA) to determine the feasibility of maximizing carbon sequestration within state : highway rightsofway (ROW). Golder Associates Inc. was...

  9. Carbon sequestration in wood products: a method for attribution to multiple parties

    International Nuclear Information System (INIS)

    Tonn, Bruce; Marland, Gregg

    2007-01-01

    When forest is harvested some of the forest carbon ends up in wood products. If the forest is managed so that the standing stock of the forest remains constant over time, and the stock of wood products is increasing, then carbon dioxide is being removed from the atmosphere in net and this should be reflected in accounting for greenhouse gas emissions. We suggest that carbon sequestration in wood products requires cooperation of multiple parties; from the forest owner to the product manufacturer to the product user, and perhaps others. Credit for sequestering carbon away from the atmosphere could acknowledge the contributions of these multiple parties. Accounting under a cap-and-trade or tax system is not necessarily an inventory system, it is a system designed to motivate and/or reward an environmental objective. We describe a system of attribution whereby credits for carbon sequestration would be shared among multiple, contributing parties. It is hoped that the methodology outlined herein proves attractive enough to parties concerned to spur them to address the details of such a system. The system of incentives one would choose for limiting or controlling greenhouse gas emissions could be quite different, depending on how the attribution for emissions and sequestration is chosen

  10. New Hampshire Carbon Challenge: Reducing Residential Energy Use and Greenhouse Gas Emissions

    Science.gov (United States)

    Schloss, A. L.; Bartlett, D.; Blaha, D.; Skoglund, C.; Dundorf, J.; Froburg, E.; Pasinella, B.

    2007-12-01

    The New Hampshire Carbon Challenge is an initiative of the Institute for the Study of Earth, Oceans and Space at the University of New Hampshire. Our goal is to educate New Hampshire residents about climate change and also encourage them to reduce their household greenhouse gas emissions by 10,000 pounds. The Northeast region is undergoing climate changes consistent with those expected due to increasing levels of CO2 in the atmosphere, while also contributing to climate change as the world's seventh largest source of CO2 emissions. In the USA, approximately 40 percent of CO2 emissions from fossil fuel combustion come from residential energy consumption for space heating, electricity usage, and transportation. Homeowners typically are not aware that modest energy reductions can result in significant carbon savings. Most campaigns that raise awareness of climate change and residential energy usage disseminate information to consumers through newspaper articles, brochures, websites, or other traditional means of communication. These information-only campaigns have not been very effective in changing residential energy consumption. Bombarded with information in their daily lives, the public has become quite adept at tuning most of it out. When much of the information they receive about climate change is confusing and contradictory, residents have even less incentive to change their behavior. The Challenge is unique in that it couples accurate information about climate change with concrete actions homeowners can take to reduce their carbon emissions. Our strategy is to utilize the tools of Community Based Social Marketing, which has been shown to be effective in changing behavior, and also to leverage existing networks including the NH Department of Environmental Services, UNH Cooperative Extension, faith-based communities, municipal energy committees and Climate Project volunteers, to effectively reach residents throughout the state. The response to our program has

  11. Historical carbon emissions and uptake from the agricultural frontier of the Brazilian Amazon.

    Science.gov (United States)

    Galford, Gillian L; Melillo, Jerry M; Kicklighter, David W; Mustard, John F; Cronin, Timothy W; Cerri, Carlos E P; Cerri, Carlos C

    2011-04-01

    Tropical ecosystems play a large and complex role in the global carbon cycle. Clearing of natural ecosystems for agriculture leads to large pulses of CO2 to the atmosphere from terrestrial biomass. Concurrently, the remaining intact ecosystems, especially tropical forests, may be sequestering a large amount of carbon from the atmosphere in response to global environmental changes including climate changes and an increase in atmospheric CO2. Here we use an approach that integrates census-based historical land use reconstructions, remote-sensing-based contemporary land use change analyses, and simulation modeling of terrestrial biogeochemistry to estimate the net carbon balance over the period 1901-2006 for the state of Mato Grosso, Brazil, which is one of the most rapidly changing agricultural frontiers in the world. By the end of this period, we estimate that of the state's 925 225 km2, 221 092 km2 have been converted to pastures and 89 533 km2 have been converted to croplands, with forest-to-pasture conversions being the dominant land use trajectory but with recent transitions to croplands increasing rapidly in the last decade. These conversions have led to a cumulative release of 4.8 Pg C to the atmosphere, with 80% from forest clearing and 20% from the clearing of cerrado. Over the same period, we estimate that the residual undisturbed ecosystems accumulated 0.3 Pg C in response to CO2 fertilization. Therefore, the net emissions of carbon from Mato Grosso over this period were 4.5 Pg C. Net carbon emissions from Mato Grosso since 2000 averaged 146 Tg C/yr, on the order of Brazil's fossil fuel emissions during this period. These emissions were associated with the expansion of croplands to grow soybeans. While alternative management regimes in croplands, including tillage, fertilization, and cropping patterns promote carbon storage in ecosystems, they remain a small portion of the net carbon balance for the region. This detailed accounting of a region's carbon

  12. Carbon and nitrogen distribution in oak-hickory forests distributed along a productivity gradient

    Energy Technology Data Exchange (ETDEWEB)

    Reber, R.T.; Kaczmarek, D.J.; Pope, P.E.; Rodkey, K.S. [Purdue Univ., West Lafayette, IN (United States)

    1993-12-31

    Biomass, carbon and nitrogen pools were determined for oak-hickory forests of varying productivity. Little information of this type is available for the central hardwood region. Six oak-hickory dominated forests were chosen to represent a range in potential site productivity as influenced by soil type, amount of recyclable nutrients and available water. Biomass, carbon and nitrogen storage were determined for the following components: above ground standing biomass, fine root biomass, forest floor organic layers and litterfall. As site sequestered at each site was dependent more on the amount of living biomass at each site Litterfall, to some extent, increased with increasing site productivity. As potential site productivity decreased, total fine root biomass increased. The data suggest that as site quality decreased fine root production and turnover may become as important in nutrient cycling as annual litterfall.

  13. Forests in a water limited world under climate change

    Science.gov (United States)

    C. Mátyás; G. Sun

    2014-01-01

    The debate on ecological and climatic benefits of planted forests at the sensitive dry edge of the closed forest belt (i.e. at the ‘xeric limits’) is still unresolved. Forests sequester atmospheric carbon dioxide, accumulate biomass, control water erosion and dust storms, reduce river sedimentation, and mitigate small floods. However, planting trees in areas previously...

  14. On leakage and seepage from geological carbon sequestration sites

    Energy Technology Data Exchange (ETDEWEB)

    Oldenburg, C.M.; Unger, A.J.A.; Hepple, R.P.; Jordan, P.D.

    2002-07-18

    Geologic carbon sequestration is one strategy for reducing the rate of increase of global atmospheric carbon dioxide (CO{sub 2} ) concentrations (IEA, 1997; Reichle, 2000). As used here, the term geologic carbon sequestration refers to the direct injection of supercritical CO{sub 2} deep into subsurface target formations. These target formations will typically be either depleted oil and gas reservoirs, or brine-filled permeable formations referred to here as brine formations. Injected CO{sub 2} will tend to be trapped by one or more of the following mechanisms: (1) permeability trapping, for example when buoyant supercritical CO{sub 2} rises until trapped by a confining caprock; (2) solubility trapping, for example when CO{sub 2} dissolves into the aqueous phase in water-saturated formations, or (3) mineralogic trapping, such as occurs when CO{sub 2} reacts to produce stable carbonate minerals. When CO{sub 2} is trapped in the subsurface by any of these mechanisms, it is effectively sequestered away from the atmosphere where it would otherwise act as a greenhouse gas. The purpose of this report is to summarize our work aimed at quantifying potential CO{sub 2} seepage due to leakage from geologic carbon sequestration sites. The approach we take is to present first the relevant properties of CO{sub 2} over the range of conditions from the deep subsurface to the vadose zone (Section 2), and then discuss conceptual models for how leakage might occur (Section 3). The discussion includes consideration of gas reservoir and natural gas storage analogs, along with some simple estimates of seepage based on assumed leakage rates. The conceptual model discussion provides the background for the modeling approach wherein we focus on simulating transport in the vadose zone, the last potential barrier to CO{sub 2} seepage (Section 4). Because of the potentially wide range of possible properties of actual future geologic sequestration sites, we carry out sensitivity analyses by

  15. Organic carbon and reducing conditions lead to cadmium immobilization by secondary Fe mineral formation in a pH-neutral soil.

    Science.gov (United States)

    Muehe, E Marie; Adaktylou, Irini J; Obst, Martin; Zeitvogel, Fabian; Behrens, Sebastian; Planer-Friedrich, Britta; Kraemer, Ute; Kappler, Andreas

    2013-01-01

    Cadmium (Cd) is of environmental relevance as it enters soils via Cd-containing phosphate fertilizers and endangers human health when taken up by crops. Cd is known to associate with Fe(III) (oxyhydr)oxides in pH-neutral to slightly acidic soils, though it is not well understood how the interrelation of Fe and Cd changes under Fe(III)-reducing conditions. Therefore, we investigated how the mobility of Cd changes when a Cd-bearing soil is faced with organic carbon input and reducing conditions. Using fatty acid profiles and quantitative PCR, we found that both fermenting and Fe(III)-reducing bacteria were stimulated by organic carbon-rich conditions, leading to significant Fe(III) reduction. The reduction of Fe(III) minerals was accompanied by increasing soil pH, increasing dissolved inorganic carbon, and decreasing Cd mobility. SEM-EDX mapping of soil particles showed that a minor fraction of Cd was transferred to Ca- and S-bearing minerals, probably carbonates and sulfides. Most of the Cd, however, correlated with a secondary iron mineral phase that was formed during microbial Fe(III) mineral reduction and contained mostly Fe, suggesting an iron oxide mineral such as magnetite (Fe3O4). Our data thus provide evidence that secondary Fe(II) and Fe(II)/Fe(III) mixed minerals could be a sink for Cd in soils under reducing conditions, thus decreasing the mobility of Cd in the soil.

  16. Soil salinity decreases global soil organic carbon stocks.

    Science.gov (United States)

    Setia, Raj; Gottschalk, Pia; Smith, Pete; Marschner, Petra; Baldock, Jeff; Setia, Deepika; Smith, Jo

    2013-11-01

    Saline soils cover 3.1% (397 million hectare) of the total land area of the world. The stock of soil organic carbon (SOC) reflects the balance between carbon (C) inputs from plants, and losses through decomposition, leaching and erosion. Soil salinity decreases plant productivity and hence C inputs to the soil, but also microbial activity and therefore SOC decomposition rates. Using a modified Rothamsted Carbon model (RothC) with a newly introduced salinity decomposition rate modifier and a plant input modifier we estimate that, historically, world soils that are currently saline have lost an average of 3.47 tSOC ha(-1) since they became saline. With the extent of saline soils predicted to increase in the future, our modelling suggests that world soils may lose 6.8 Pg SOC due to salinity by the year 2100. Our findings suggest that current models overestimate future global SOC stocks and underestimate net CO2 emissions from the soil-plant system by not taking salinity effects into account. From the perspective of enhancing soil C stocks, however, given the lower SOC decomposition rate in saline soils, salt tolerant plants could be used to sequester C in salt-affected areas. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Estimating carbon and showing impacts of drought using satellite data in regression-tree models

    Science.gov (United States)

    Boyte, Stephen; Wylie, Bruce K.; Howard, Danny; Dahal, Devendra; Gilmanov, Tagir G.

    2018-01-01

    Integrating spatially explicit biogeophysical and remotely sensed data into regression-tree models enables the spatial extrapolation of training data over large geographic spaces, allowing a better understanding of broad-scale ecosystem processes. The current study presents annual gross primary production (GPP) and annual ecosystem respiration (RE) for 2000–2013 in several short-statured vegetation types using carbon flux data from towers that are located strategically across the conterminous United States (CONUS). We calculate carbon fluxes (annual net ecosystem production [NEP]) for each year in our study period, which includes 2012 when drought and higher-than-normal temperatures influence vegetation productivity in large parts of the study area. We present and analyse carbon flux dynamics in the CONUS to better understand how drought affects GPP, RE, and NEP. Model accuracy metrics show strong correlation coefficients (r) (r ≥ 94%) between training and estimated data for both GPP and RE. Overall, average annual GPP, RE, and NEP are relatively constant throughout the study period except during 2012 when almost 60% less carbon is sequestered than normal. These results allow us to conclude that this modelling method effectively estimates carbon dynamics through time and allows the exploration of impacts of meteorological anomalies and vegetation types on carbon dynamics.

  18. Variability in the carbon storage of seagrass habitats and its implications for global estimates of blue carbon ecosystem service.

    Directory of Open Access Journals (Sweden)

    Paul S Lavery

    Full Text Available The recent focus on carbon trading has intensified interest in 'Blue Carbon'-carbon sequestered by coastal vegetated ecosystems, particularly seagrasses. Most information on seagrass carbon storage is derived from studies of a single species, Posidonia oceanica, from the Mediterranean Sea. We surveyed 17 Australian seagrass habitats to assess the variability in their sedimentary organic carbon (C org stocks. The habitats encompassed 10 species, in mono-specific or mixed meadows, depositional to exposed habitats and temperate to tropical habitats. There was an 18-fold difference in the Corg stock (1.09-20.14 mg C org cm(-3 for a temperate Posidonia sinuosa and a temperate, estuarine P. australis meadow, respectively. Integrated over the top 25 cm of sediment, this equated to an areal stock of 262-4833 g C org m(-2. For some species, there was an effect of water depth on the C org stocks, with greater stocks in deeper sites; no differences were found among sub-tidal and inter-tidal habitats. The estimated carbon storage in Australian seagrass ecosystems, taking into account inter-habitat variability, was 155 Mt. At a 2014-15 fixed carbon price of A$25.40 t(-1 and an estimated market price of $35 t(-1 in 2020, the C org stock in the top 25 cm of seagrass habitats has a potential value of $AUD 3.9-5.4 bill. The estimates of annual C org accumulation by Australian seagrasses ranged from 0.093 to 6.15 Mt, with a most probable estimate of 0.93 Mt y(-1 (10.1 t. km(-2 y(-1. These estimates, while large, were one-third of those that would be calculated if inter-habitat variability in carbon stocks were not taken into account. We conclude that there is an urgent need for more information on the variability in seagrass carbon stock and accumulation rates, and the factors driving this variability, in order to improve global estimates of seagrass Blue Carbon storage.

  19. The Natural Terrestrial Carbon Sequestration Potential of Rocky Mountain Soils Derived From Volcanic Bedrock

    Science.gov (United States)

    Yager, D. B.; Burchell, A.; Johnson, R. H.

    2008-12-01

    .01 to 0.78 Wt. %), C:N (2.4 to 6.5), and arylsulfatase (0 to 41). However, reclaimed and undisturbed mined-lands soils derived from propylitized andesite have high C (13.5 - 25.6 Wt. %), C:N (27), arylsulfatase (338). In our previous studies, propylitic bedrock were also found to have a high acid neutralizing capacity (ANC) characterized by epidote-chlorite-calcite. Radiocarbon dates on charcoal collected from paleo-burn horizons (found in high C, N soils) indicate an old carbon pool (840-5,440 ]pm40 yrs B.P). High-flow dissolved organic carbon (DOC) concentrations are low (ave. 1.9 ppm) in both surface water and ground-water samples collected in subalpine catchments underlain by intermediate to mafic igneous bedrocks. The low DOC concentrations are consistent with these soils sequestering carbon. This is likely related to high specific surface area and high adsorption-enhancing Ca-Mg-Fe clays. Observations at naturally-reclaimed mine sites indicate the use of ANC rock plus other soil amendments (biochar, soil nutrients, bioactive teas, native vegetation seeding) can aid more traditional reclamation measures that use limestone and compost hauled from long distances by reducing both the cost and carbon footprint of reclamation projects.

  20. Sequestration of Soil Carbon as Secondary Carbonates (Invited)

    Science.gov (United States)

    Lal, R.

    2013-12-01

    Rattan Lal Carbon Management and Sequestration Center The Ohio State University Columbus, OH 43210 USA Abstract World soils, the major carbon (C) reservoir among the terrestrial pools, contain soil organic C (SOC) and soil inorganic C (SIC). The SIC pool is predominant in soils of arid and semi-arid regions. These regions cover a land area of about 4.9x109 ha. The SIC pool in soils containing calcic and petrocalcic horizons is estimated at about 695-748 Pg (Pg = 1015 g = 1 gigaton) to 1-m depth. There are two types of carbonates. Lithogenic or primary carbonates are formed from weathering of carbonaceous rocks. Pedogenic or secondary carbonates are formed by dissolution of CO2 in the soil air to form carbonic acid and precipitation as carbonates of Ca+2 or Mg+2. It is the availability of Ca+2 or Mg+2 from outside the ecosystem that is essential to sequester atmospheric CO2. Common among outside sources of Ca+2 or Mg+2 are irrigation water, aerial deposition, sea breeze, fertilizers, manure and other amendments. The decomposition of SOC and root respiration may increase the partial pressure of CO2 in the soil air and lead to the formation of HCO_3^- upon dissolution in H20. Precipitation of secondary carbonates may result from decreased partial pressure of CO2 in the sub-soil, increased concentration of Ca+2, Mg+2 and HCO_3^- in soil solution, and decreased soil moisture content by evapotranspiration. Transport of bicarbonates in irrigated soils and subsequent precipitation above the ground water (calcrete), activity of termites and other soil fauna, and management of urban soils lead to formation of secondary carbonates. On a geologic time scale, weathering of silicate minerals and transport of the by-products into the ocean is a geological process of sequestration of atmospheric CO2. Factors affecting formation of secondary carbonates include land use, and soil and crop management including application of biosolids, irrigation and the quality of irrigation water