Increasing Mississippi river discharge throughout the twenty-first century influenced by changes in climate, land use and atmospheric CO2

Science.gov (United States)

Tao, B.; Tian, H.; Ren, W.; Yang, J.; Yang, Q.; He, R.; Cai, W. J.; Lohrenz, S. E.

2014-12-01

Previous studies have demonstrated that changes in temperature and precipitation (hereafter climate change) would influence river discharge, but the relative importance of climate change, land use, and elevated atmospheric CO2 have not yet been fully investigated. Here we examined how river discharge in the Mississippi River basin in the 21st century might be influenced by these factors using the Dynamic Land Ecosystem Model driven by atmospheric CO2, downscaled GCMs climate and land use scenarios. Our results suggest that river discharge would be substantially enhanced (10.7-59.8%) by the 2090s compared to the recent decade (2000s), though large discrepancies exist among different climate, atmospheric CO2, and land use change scenarios. Our factorial analyses further indicate that the combined effects of land use change and human-induced atmospheric CO2 elevation on river discharge would outweigh climate change effect under the high emission scenario (A2) of Intergovernmental Panel for Climate Change. Our study offers the first attempt to project potential changes in river discharge in response to multiple future environmental changes. It demonstrates the importance of land use change and atmospheric CO2 concentrations in projecting future changes in hydrologic processes. The projected increase river discharge implies that riverine fluxes of carbon, nutrients and pesticide from the MRB to the coastal regions would increase in the future, and thus may influence the states of ocean acidification and hypoxia and deteriorate ocean water quality. Further efforts will also be needed to account for additional environmental factors (such as nitrogen deposition, tropospheric ozone pollution, dam construction, etc.) in projecting changes in the hydrological cycle.

Climate change impacts on crop yield and quality with CO2 fertilization in China

Science.gov (United States)

Erda, Lin; Wei, Xiong; Hui, Ju; Yinlong, Xu; Yue, Li; Liping, Bai; Liyong, Xie

2005-01-01

A regional climate change model (PRECIS) for China, developed by the UK's Hadley Centre, was used to simulate China's climate and to develop climate change scenarios for the country. Results from this project suggest that, depending on the level of future emissions, the average annual temperature increase in China by the end of the twenty-first century may be between 3 and 4 °C. Regional crop models were driven by PRECIS output to predict changes in yields of key Chinese food crops: rice, maize and wheat. Modelling suggests that climate change without carbon dioxide (CO2) fertilization could reduce the rice, maize and wheat yields by up to 37% in the next 20–80 years. Interactions of CO2 with limiting factors, especially water and nitrogen, are increasingly well understood and capable of strongly modulating observed growth responses in crops. More complete reporting of free-air carbon enrichment experiments than was possible in the Intergovernmental Panel on Climate Change's Third Assessment Report confirms that CO2 enrichment under field conditions consistently increases biomass and yields in the range of 5–15%, with CO2 concentration elevated to 550 ppm Levels of CO2 that are elevated to more than 450 ppm will probably cause some deleterious effects in grain quality. It seems likely that the extent of the CO2 fertilization effect will depend upon other factors such as optimum breeding, irrigation and nutrient applications. PMID:16433100

Modeling the response of plants and ecosystems to elevated CO sub 2 and climate change

Energy Technology Data Exchange (ETDEWEB)

Reynolds, J.F.; Hilbert, D.W.; Chen, Jia-lin; Harley, P.C.; Kemp, P.R.; Leadley, P.W.

1992-03-01

While the exact effects of elevated CO{sub 2} on global climate are unknown, there is a growing consensus among climate modelers that global temperature and precipitation will increase, but that these changes will be non-uniform over the Earth's surface. In addition to these potential climatic changes, CO{sub 2} also directly affects plants via photosynthesis, respiration, and stomatal closure. Global climate change, in concert with these direct effects of CO{sub 2} on plants, could have a significant impact on both natural and agricultural ecosystems. Society's ability to prepare for, and respond to, such changes depends largely on the ability of climate and ecosystem researchers to provide predictions of regional level ecosystem responses with sufficient confidence and adequate lead time.

Modeling the response of plants and ecosystems to elevated CO{sub 2} and climate change

Energy Technology Data Exchange (ETDEWEB)

Reynolds, J.F.; Hilbert, D.W.; Chen, Jia-lin; Harley, P.C.; Kemp, P.R.; Leadley, P.W.

1992-03-01

While the exact effects of elevated CO{sub 2} on global climate are unknown, there is a growing consensus among climate modelers that global temperature and precipitation will increase, but that these changes will be non-uniform over the Earth`s surface. In addition to these potential climatic changes, CO{sub 2} also directly affects plants via photosynthesis, respiration, and stomatal closure. Global climate change, in concert with these direct effects of CO{sub 2} on plants, could have a significant impact on both natural and agricultural ecosystems. Society`s ability to prepare for, and respond to, such changes depends largely on the ability of climate and ecosystem researchers to provide predictions of regional level ecosystem responses with sufficient confidence and adequate lead time.

Uncertainty in the response of transpiration to CO2 and implications for climate change

International Nuclear Information System (INIS)

Mengis, N; Keller, D P; Oschlies, A; Eby, M

2015-01-01

While terrestrial precipitation is a societally highly relevant climate variable, there is little consensus among climate models about its projected 21st century changes. An important source of precipitable water over land is plant transpiration. Plants control transpiration by opening and closing their stomata. The sensitivity of this process to increasing CO 2 concentrations is uncertain. To assess the impact of this uncertainty on future climate, we perform experiments with an intermediate complexity Earth System Climate Model (UVic ESCM) for a range of model-imposed transpiration-sensitivities to CO 2 . Changing the sensitivity of transpiration to CO 2 causes simulated terrestrial precipitation to change by −10% to +27% by 2100 under a high emission scenario. This study emphasises the importance of an improved assessment of the dynamics of environmental impact on vegetation to better predict future changes of the terrestrial hydrological and carbon cycles. (letter)

CO/sub 2/, carbon cycle and climate interactions. Pt. 2

Energy Technology Data Exchange (ETDEWEB)

Grassl, H; Maier-Reimer, E; Degens, E T; Kempe, S; Spitzy, A

1984-05-01

To assess the reaction of the climate system on increased CO/sub 2/ in the air either numerical atmospheric models have been used, or one has tried to filter a CO/sub 2/-induced climate trend (such as increasing temperature) from existing meteorological records. Even though a serious effect of increased CO/sub 2/ on climate has become highly probable, it has neither been empirically proven so far (diagnosis of observations) nor is the effect theoretically undisputed (prognosis by climate models).

Effects of climate change, CO2 and O3 on wheat productivity in Eastern China, singly and in combination

Science.gov (United States)

Tao, Fulu; Feng, Zhaozhong; Tang, Haoye; Chen, Yi; Kobayashi, Kazuhiko

2017-03-01

Air pollution and climate change are increasing threats to agricultural production and food security. Extensive studies have focused on the effect of climate change, but the interactive effects of multiple global change factors are poorly understood. Here, we incorporate the interactions between climate change, carbon dioxide (CO2) and ozone (O3) into an eco-physiological mechanistic model based on three years of O3 Free-Air Concentration Elevation (O3-FACE) experiments. We then investigate the effects of climate change, elevated CO2 concentration ([CO2]) and rising O3 concentration ([O3]) on wheat growth and productivity in eastern China in 1996-2005 (2000s) and 2016-2025 (2020s) under two climate change scenarios, singly and in combination. We find the interactive effects of climate change, CO2 and O3 on wheat productivity have spatially explicit patterns; the effect of climate change dominates the general pattern, which is however subject to the large uncertainties of climate change scenarios. Wheat productivity is estimated to increase by 2.8-9.0% due to elevated [CO2] however decline by 2.8-11.7% due to rising [O3] in the 2020s, relative to the 2000s. The combined effects of CO2 and O3 are less than that of O3 only, on average by 4.6-5.2%, however with O3 damage outweighing CO2 benefit in most of the region. This study demonstrates a more biologically meaningful and appropriate approach for assessing the interactive effects of climate change, CO2 and O3 on crop growth and productivity. Our findings promote the understanding on the interactive effects of multiple global change factors across contrasting climate conditions, cast doubt on the potential of CO2 fertilization effect in offsetting possible negative effect of climate change on crop productivity as suggested by many previous studies.

Climate Change and employment. Impact on employment in the European Union-25 of climate change and CO2 emission reduction measures by 2030

Energy Technology Data Exchange (ETDEWEB)

Dupressoir, S.; Belen Sanchez, A.; Bobe, P.; Hoefele, V. (and others)

2007-05-15

This study was intended provide an analysis of the potential costs and benefits for employment of the policies and measures against climate change as well as of the manifestations of the consequences of climate change in Europe. This report comprises two divisions. The first, entitled 'Impact of climate change', attempts to determine the potential impact on employment in Europe of the consequences of climate change (Part 1). The second, entitled 'Impact of CO2 emission reduction measures', analyses the potential implications for employment of climate-change prevention policies in the EU with time-horizons of 2012 and 2030 (Parts 2 to 4). The conclusions and recommendations of the study appear in four parts : Part 1 analyses the potential consequences for employment of climatic warming in Europe; Part 2 presents the objectives, the hypotheses and the methodology of the 'impact of CO2 emission reduction measures' division; Part 3 analyses the foreseeable effects of CO2 emission reduction measures on employment in Europe; Part 4 offers general (or sector-wide) recommendations for measures and policies to promote positive effects and prevent negative effects. The concluding part discusses the uncertainties and identifies the questions deserving further investigation.

Climatic change on a water planet. Critical review of the CO2 problem

International Nuclear Information System (INIS)

Roersch, A.; Thoenes, D.; De Wit, F.

2005-01-01

The purpose of this book is to bring the discussion about climatic change back to a scientific level. One of the conclusions is that the increased concentration of CO2 is more the result of increased solar activity than of human activities. This conclusion is based on two hypotheses: the A-theory that fossil fuel combustion leads to accumulation of CO2 in the atmosphere and thus a rise of temperature and climatic change, and the Z-theory that a rise of temperature is caused by exceptional activity of the sun and thus an increase of the CO2 concentration in the atmosphere [nl

Isolating and Quantifying the Effects of Climate and CO2 Changes (1980–2014 on the Net Primary Productivity in Arid and Semiarid China

Directory of Open Access Journals (Sweden)

Xia Fang

2017-02-01

Full Text Available Although the net primary productivity (NPP of arid/semiarid ecosystem is generally thought to be controlled by precipitation, other factors like CO2 fertilization effect and temperature change may also have important impacts, especially in the cold temperate areas of the northern China, where significant warming was reported in the recent decades. However, the impacts of climate and atmospheric CO2 changes to the NPP dynamics in the arid and semiarid areas of China (ASA-China is still unclear, hindering the development of climate adaptation strategy. Based on numeric experiments and factorial analysis, this study isolated and quantified the effects of climate and CO2 changes between 1980–2014 on ASA-China’s NPP, using the Arid Ecosystem Model (AEM that performed well in predicting ecosystems’ responses to climate/CO2 change according to our evaluation based on 21 field experiments. Our results showed that the annual variation in NPP was dominated by changes in precipitation, which reduced the regional NPP by 10.9 g·C/(m2·year. The precipitation-induced loss, however, has been compensated by the CO2 fertilization effect that increased the regional NPP by 14.9 g·C/(m2·year. The CO2 fertilization effect particularly benefited the extensive croplands in the Northern China Plain, but was weakened in the dry grassland of the central Tibetan Plateau due to suppressed plant activity as induced by a drier climate. Our study showed that the climate change in ASA-China and the ecosystem’s responses were highly heterogeneous in space and time. There were complex interactive effects among the climate factors, and different plant functional types (e.g., phreatophyte vs. non-phreatophyte could have distinct responses to similar climate change. Therefore, effective climate-adaptive strategies should be based on careful analysis of local climate pattern and understanding of the characteristic responses of the dominant species. Particularly, China�

Response of a tundra ecosytem to elevated atmospheric carbon dioxide and CO2-induced climate change. Final report

International Nuclear Information System (INIS)

Oechel, W.C.

1996-11-01

The overall objective of this research was to document current patterns of CO 2 flux in selected locations of the circumpolar arctic, and to develop the information necessary to predict how these fluxes may be affected by climate change. In fulfillment of these objectives, net CO 2 flux was measured at several sites on the North Slope of Alaska during the 1990-94 growing season (June-August) to determine the local and regional patterns, of seasonal CO 2 exchange. In addition, net CO 2 flux was measured in the Russian and Icelandic Arctic to determine if the patterns of CO 2 exchange observed in Arctic Alaska were representative of the circumpolar arctic, while cold-season CO 2 flux measurements were carried out during the 1993-94 winter season to determine the magnitude of CO 2 efflux not accounted for by the growing season measurements. Manipulations of soil water table depth and surface temperature, which were identified from the extensive measurements as being the most important variables in determining the magnitude and direction of net CO 2 exchange, were carried out during the 1993-94 growing seasons in tussock and wet sedge tundra ecosystems. Finally, measurements of CH 4 flux were also measured at several of the North Slope study sites during the 1990-91 growing seasons. Measurements were made on small (e.g. 0.5 m 2 ) plots using a portable gas-exchange system and cuvette. The sample design allowed frequent measurements of net CO 2 exchange and respiration over diurnal and seasonal cycles, and a large spatial extent that incorporated both locally and regionally diverse tundra surface types. Measurements both within and between ecosystem types typically extended over soil water table depth and temperature gradients, allowing for the indirect analysis of the effects of anticipated climate change scenarios on net CO 2 exchange. In situ experiments provided a direct means for testing hypotheses

Modelling land surface fluxes of CO2 in response to climate change and nitrogen deposition

DEFF Research Database (Denmark)

Hansen, Kristina; Ambelas Skjøth, Carsten; Geels, Camilla

Climate change, land use variations, and impacts of atmospheric nitrogen (N) deposition represent uncertainties for the prediction of future greenhouse gas exchange between land surfaces and the atmosphere as the mechanisms describing nutritional effects are not well developed in climate...... climate feedback mechanisms of CO2 between changes in management, land use practise, and climate change....

Response of a tundra ecosystem to elevated atmospheric carbon dioxide and CO{sub 2}-induced climate change. Annual technical report

Energy Technology Data Exchange (ETDEWEB)

Oechel, W.C.

1992-04-01

Northern ecosystems contain up to 455 Gt of C in the soil active layer and upper permafrost. The soil carbon in these layers is equivalent to approximately 60% of the carbon currently in the atmosphere as CO{sub 2}. Much of this carbon is stored in the soil as dead organic matter. Its fate is subject to the net effects of global change on the plant and soil systems of northern ecosystems. The arctic alone contains about 60 Gt C, 90% of which is present in the soil active layer and upper permafrost. The arctic is assumed to have been a sink for CO{sub 2} during the historic and recent geologic past. The arctic has the potential to be a very large, long-term source or sink of CO{sub 2} with respect to the atmosphere. In situ experimental manipulations of atmospheric CO{sub 2}, indicated that there is little effect of elevated atmospheric CO{sub 2} on leaf level photosynthesis or whole-ecosystem CO{sub 2} flux over the course of weeks to years, respectively. However, there may be longer- term ecosystem responses to elevated CO{sub 2} that could ultimately affect ecosystem CO{sub 2} balance. In addition to atmospheric CO{sub 2}, climate may affect net ecosystem carbon balance. Recent results indicate that the arctic has become a source of CO{sub 2} to the atmosphere. This change coincides with recent climatic variation in the arctic, and suggests a positive feedback of arctic ecosystems on atmospheric CO{sub 2} and global change. The research proposed in this application has four principal aspects: (A) Long-term response of arctic plants and ecosystems to elevated atmospheric CO{sub 2}; (B) Circumpolar patterns of net ecosystem CO{sub 2} flux; (C) In situ controls by temperature and moisture on net ecosystem CO{sub 2} flux; (D) Scaling of CO{sub 2} flux from plot, to landscape, to regional scales (In conjunction with research proposed for NSF support).

The impact of climate and CO{sub 2} changes on ecosystem dynamics of the continental United States

Energy Technology Data Exchange (ETDEWEB)

Ojima, D.S. [Colorado State Univ., Ft. Collins, CO (United States)

1995-06-01

The VEMAP study used three biogeochemical (BGC) models to investigate the impact of changes in climate and CO{sub 2} concentrations over the continental US. These models were Biome-BGC, CENTURY, and TEM. Differences among the BGC models and the climate scenarios (three different GCM-derived 2xCO{sub 2} climates were used) contributed equally to the variation in estimates of C dynamics under changing climate and CO,. The response of the individual biogeochemical models to increases in temperature and tp water stress are largely responsible for their behavior under climate change. All three models generally predict increases in C uptake when increases in temperature are not vastly greater than increases in precipitation, such as seen in the GFDL scenario. Differences in the biotic response to elevated CO{sub 2} determined the overall response of NPP and total system C storage due to differences on the manner in which plant C/N, transpiration, and photosynthesis are modified by the three different BGC models.

Future CO2 Emissions and Climate Change from Existing Energy Infrastructure

Science.gov (United States)

Davis, S. J.; Caldeira, K.; Matthews, D.

2010-12-01

If current greenhouse gas (GHG) concentrations remain constant, the world would be committed to several centuries of increasing global mean temperatures and sea level rise. By contrast, near elimination of anthropogenic CO2 emissions would be required to produce diminishing GHG concentrations consistent with stabilization of mean temperatures. Yet long-lived energy and transportation infrastructure now operating can be expected to contribute substantial CO2 emissions over the next 50 years. Barring widespread retrofitting of existing power plants with carbon capture and storage (CCS) technologies or the early decommissioning of serviceable infrastructure, these “committed emissions” represent infrastructural inertia which may be the primary contributor to total future warming commitment. With respect to GHG emissions, infrastructural inertia may be thought of as having two important and overlapping components: (i) infrastructure that directly releases GHGs to the atmosphere, and (ii) infrastructure that contributes to the continued production of devices that emit GHGs to the atmosphere. For example, the interstate highway and refueling infrastructure in the United States facilitates continued production of gasoline-powered automobiles. Here, we focus only on the warming commitment from infrastructure that directly releases CO2 to the atmosphere. Essentially, we answer the question: What if no additional CO2-emitting devices (e.g., power plants, motor vehicles) were built, but all the existing CO2-emitting devices were allowed to live out their normal lifetimes? What CO2 levels and global mean temperatures would we attain? Of course, the actual lifetime of devices may be strongly influenced by economic and policy constraints. For instance, a ban on new CO2-emitting devices would create tremendous incentive to prolong the lifetime of existing devices. Thus, our scenarios are not realistic, but offer a means of gauging the threat of climate change from existing

Response of a tundra ecosytem to elevated atmospheric carbon dioxide and CO{sub 2}-induced climate change. Final report

Energy Technology Data Exchange (ETDEWEB)

Oechel, W.C.

1996-11-01

The overall objective of this research was to document current patterns of CO{sub 2} flux in selected locations of the circumpolar arctic, and to develop the information necessary to predict how these fluxes may be affected by climate change. In fulfillment of these objectives, net CO{sub 2} flux was measured at several sites on the North Slope of Alaska during the 1990-94 growing season (June-August) to determine the local and regional patterns, of seasonal CO{sub 2} exchange. In addition, net CO{sub 2} flux was measured in the Russian and Icelandic Arctic to determine if the patterns of CO{sub 2} exchange observed in Arctic Alaska were representative of the circumpolar arctic, while cold-season CO{sub 2} flux measurements were carried out during the 1993-94 winter season to determine the magnitude of CO{sub 2} efflux not accounted for by the growing season measurements. Manipulations of soil water table depth and surface temperature, which were identified from the extensive measurements as being the most important variables in determining the magnitude and direction of net CO{sub 2} exchange, were carried out during the 1993-94 growing seasons in tussock and wet sedge tundra ecosystems. Finally, measurements of CH{sub 4} flux were also measured at several of the North Slope study sites during the 1990-91 growing seasons. Measurements were made on small (e.g. 0.5 m{sup 2}) plots using a portable gas-exchange system and cuvette. The sample design allowed frequent measurements of net CO{sub 2} exchange and respiration over diurnal and seasonal cycles, and a large spatial extent that incorporated both locally and regionally diverse tundra surface types. Measurements both within and between ecosystem types typically extended over soil water table depth and temperature gradients, allowing for the indirect analysis of the effects of anticipated climate change scenarios on net CO{sub 2} exchange. In situ experiments provided a direct means for testing hypotheses.

Potential forcing of CO2, technology and climate changes in maize (Zea mays) and bean (Phaseolus vulgaris) yield in southeast Brazil

International Nuclear Information System (INIS)

Costa, L C; Justino, F; Oliveira, L J C; Sediyama, G C; Lemos, C F; Ferreira, W P M

2009-01-01

Based upon sensitivity experiments, this study aims to investigate the impact of increased atmospheric CO 2 concentration, climate changes, and ongoing technological advancements on bean (Phaseolus vulgaris) and maize (Zea mays) yield. This investigation assumes that the atmospheric CO 2 concentration evolves according to the A2 scenario. For these analyses we have used climate data as projected by climate simulations conducted with the HadCM3 climate model for both present day and greenhouse warming conditions. The results demonstrated that warming conditions associated with increased greenhouse gases as delivered by the HadCM3 model lead to reductions in the potential productivity of maize and beans for the years 2050 and 2080 by up to 30%. This thermal response is, however, damped by the highly efficient CO 2 fertilization effect which is expected to increase bean productivity as compared to present day conditions. A similar investigation for maize yield revealed a different picture. It has been found that the CO 2 fertilization feedback is much weaker and cannot cancel out the thermal effect. We have found, therefore, that climate changes as simulated to occur in the future are not favorable for increasing the maize yield in southeast Brazil. By the inclusion of the third forcing evaluated, representing technological advancements, it is demonstrated that improvements in the crop system reduce the negative effect associated with warmer climate conditions for both crops. We conclude that appropriate soil and technological management as well as genetic improvements may very likely induce an increase in bean and maize yield despite the unfavorable future climate conditions.

From Oil Crisis to Climate Change. Understanding CO2 Emission Trends in IEA Countries

International Nuclear Information System (INIS)

Unander, F.

2003-11-01

OECD CO2 emissions from fuel combustion increased 13% between 1990 and 2001. This signals an important shift since, over the 1973 to 1990 period, emissions only increased by 3.4%. As a result, CO2 emissions from energy use (fuel combustion) contributed 81.1% of total OECD greenhouse gas emissions in 2001 compared to 77.7% in 1990. As these figures make clear, reducing CO2 emissions from fuel combustion constitutes a key challenge to combat climate change. Developing and successfully implementing the most efficient policies for reducing CO2 emissions requires a good understanding of how factors such as income, prices, demography, economic structure, lifestyle, climate, energy efficiency and fuel mix affect energy use and resulting CO2 emissions. This paper presents selected results from the analysis of CO2 developments included in the IEA publication 'From Oil Crisis to Climate Challenge: 30 Years of Energy Use in IEA Countries'. The paper gives a brief overview of aggregate CO2 emission trends and of how recent developments in selected IEA countries compare to emissions levels implied by the Kyoto targets. A deeper understanding of the aggregate trends is provided by showing results from a decomposition analysis and by discussing developments in key end-use sectors. The full publication presents a more detailed analysis of how various factors have shaped energy use patterns and CO2 emissions since 1973. The analysis draws on a newly developed database with detailed information on energy use in the manufacturing, household, service and transport sectors. The database represents the most disaggregated information available on a consistent basis across countries and sectors. The study uses quantitative measures to illustrate the forces that drive or restrain energy use. These measures - or indicators - include: activities such as manufacturing output or heated-floor-area of homes; structural developments such as changes in manufacturing output mix or changes in the

Detection of Greenhouse-Gas-Induced Climatic Change

Energy Technology Data Exchange (ETDEWEB)

Jones, P.D.; Wigley, T.M.L.

1998-05-26

The objective of this report is to assemble and analyze instrumental climate data and to develop and apply climate models as a basis for (1) detecting greenhouse-gas-induced climatic change, and (2) validation of General Circulation Models.

Sensitivity of global and regional terrestrial carbon storage to the direct CO2 effect and climate change based on the CMIP5 model intercomparison.

Science.gov (United States)

Peng, Jing; Dan, Li; Huang, Mei

2014-01-01

Global and regional land carbon storage has been significantly affected by increasing atmospheric CO2 concentration and climate change. Based on fully coupled climate-carbon-cycle simulations from the Coupled Model Intercomparison Project Phase 5 (CMIP5), we investigate sensitivities of land carbon storage to rising atmospheric CO2 concentration and climate change over the world and 21 regions during the 130 years. Overall, the simulations suggest that consistently spatial positive effects of the increasing CO2 concentrations on land carbon storage are expressed with a multi-model averaged value of 1.04 PgC per ppm. The stronger positive values are mainly located in the broad areas of temperate and tropical forest, especially in Amazon basin and western Africa. However, large heterogeneity distributed for sensitivities of land carbon storage to climate change. Climate change causes decrease in land carbon storage in most tropics and the Southern Hemisphere. In these regions, decrease in soil moisture (MRSO) and enhanced drought somewhat contribute to such a decrease accompanied with rising temperature. Conversely, an increase in land carbon storage has been observed in high latitude and altitude regions (e.g., northern Asia and Tibet). The model simulations also suggest that global negative impacts of climate change on land carbon storage are predominantly attributed to decrease in land carbon storage in tropics. Although current warming can lead to an increase in land storage of high latitudes of Northern Hemisphere due to elevated vegetation growth, a risk of exacerbated future climate change may be induced due to release of carbon from tropics.

Sensitivity of global and regional terrestrial carbon storage to the direct CO2 effect and climate change based on the CMIP5 model intercomparison.

Directory of Open Access Journals (Sweden)

Jing Peng

Full Text Available Global and regional land carbon storage has been significantly affected by increasing atmospheric CO2 concentration and climate change. Based on fully coupled climate-carbon-cycle simulations from the Coupled Model Intercomparison Project Phase 5 (CMIP5, we investigate sensitivities of land carbon storage to rising atmospheric CO2 concentration and climate change over the world and 21 regions during the 130 years. Overall, the simulations suggest that consistently spatial positive effects of the increasing CO2 concentrations on land carbon storage are expressed with a multi-model averaged value of 1.04 PgC per ppm. The stronger positive values are mainly located in the broad areas of temperate and tropical forest, especially in Amazon basin and western Africa. However, large heterogeneity distributed for sensitivities of land carbon storage to climate change. Climate change causes decrease in land carbon storage in most tropics and the Southern Hemisphere. In these regions, decrease in soil moisture (MRSO and enhanced drought somewhat contribute to such a decrease accompanied with rising temperature. Conversely, an increase in land carbon storage has been observed in high latitude and altitude regions (e.g., northern Asia and Tibet. The model simulations also suggest that global negative impacts of climate change on land carbon storage are predominantly attributed to decrease in land carbon storage in tropics. Although current warming can lead to an increase in land storage of high latitudes of Northern Hemisphere due to elevated vegetation growth, a risk of exacerbated future climate change may be induced due to release of carbon from tropics.

Potential forcing of CO{sub 2}, technology and climate changes in maize (Zea mays) and bean (Phaseolus vulgaris) yield in southeast Brazil

Energy Technology Data Exchange (ETDEWEB)

Costa, L C; Justino, F; Oliveira, L J C; Sediyama, G C; Lemos, C F [Department of Agricultural Engineering, Federal University of Vicosa, PH Rolfs S/N, Vicosa, MG, 36570 000 (Brazil); Ferreira, W P M [Embrapa Milho e Sorgo, Rodovia MG 424, km 45, Caixa Postal 285, CEP 35701-970 Sete Lagoas, MG (Brazil)], E-mail: fjustino@ufv.br

2009-01-15

Based upon sensitivity experiments, this study aims to investigate the impact of increased atmospheric CO{sub 2} concentration, climate changes, and ongoing technological advancements on bean (Phaseolus vulgaris) and maize (Zea mays) yield. This investigation assumes that the atmospheric CO{sub 2} concentration evolves according to the A2 scenario. For these analyses we have used climate data as projected by climate simulations conducted with the HadCM3 climate model for both present day and greenhouse warming conditions. The results demonstrated that warming conditions associated with increased greenhouse gases as delivered by the HadCM3 model lead to reductions in the potential productivity of maize and beans for the years 2050 and 2080 by up to 30%. This thermal response is, however, damped by the highly efficient CO{sub 2} fertilization effect which is expected to increase bean productivity as compared to present day conditions. A similar investigation for maize yield revealed a different picture. It has been found that the CO{sub 2} fertilization feedback is much weaker and cannot cancel out the thermal effect. We have found, therefore, that climate changes as simulated to occur in the future are not favorable for increasing the maize yield in southeast Brazil. By the inclusion of the third forcing evaluated, representing technological advancements, it is demonstrated that improvements in the crop system reduce the negative effect associated with warmer climate conditions for both crops. We conclude that appropriate soil and technological management as well as genetic improvements may very likely induce an increase in bean and maize yield despite the unfavorable future climate conditions.

Sensitivity of ocean acidification and oxygen to the uncertainty in climate change

International Nuclear Information System (INIS)

Cao, Long; Wang, Shuangjing; Zheng, Meidi; Zhang, Han

2014-01-01

Due to increasing atmospheric CO 2 concentrations and associated climate change, the global ocean is undergoing substantial physical and biogeochemical changes. Among these, changes in ocean oxygen and carbonate chemistry have great implication for marine biota. There is considerable uncertainty in the projections of future climate change, and it is unclear how the uncertainty in climate change would also affect the projection of oxygen and carbonate chemistry. To investigate this issue, we use an Earth system model of intermediate complexity to perform a set of simulations, including that which involves no radiative effect of atmospheric CO 2 and those which involve CO 2 -induced climate change with climate sensitivity varying from 0.5 °C to 4.5 °C. Atmospheric CO 2 concentration is prescribed to follow RCP 8.5 pathway and its extensions. Climate change affects carbonate chemistry and oxygen mainly through its impact on ocean temperature, ocean ventilation, and concentration of dissolved inorganic carbon and alkalinity. It is found that climate change mitigates the decrease of carbonate ions at the ocean surface but has negligible effect on surface ocean pH. Averaged over the whole ocean, climate change acts to decrease oxygen concentration but mitigates the CO 2 -induced reduction of carbonate ion and pH. In our simulations, by year 2500, every degree increase of climate sensitivity warms the ocean by 0.8 °C and reduces ocean-mean dissolved oxygen concentration by 5.0%. Meanwhile, every degree increase of climate sensitivity buffers CO 2 -induced reduction in ocean-mean carbonate ion concentration and pH by 3.4% and 0.02 units, respectively. Our study demonstrates different sensitivities of ocean temperature, carbonate chemistry, and oxygen, in terms of both the sign and magnitude to the amount of climate change, which have great implications for understanding the response of ocean biota to climate change. (letters)

Response of a tundra ecosystem to elevated atmospheric carbon dioxide and CO{sub 2}-induced climate change. Annual technical report

Energy Technology Data Exchange (ETDEWEB)

Oechel, W.C.

1993-02-01

Northern ecosystems contain up to 455 Gt of C in the soil active layer and upper permafrost, which is equivalent to approximately 60% of the carbon currently in the atmosphere as CO{sub 2}. Much of this carbon is stored in the soil as dead organic matter. Its fate is subject to the net effects of global change on the plant and soil systems of northern ecosystems. The arctic alone contains about 60 Gt C, 90% of which is present in the soil active layer and upper permafrost, and is assumed to have been a sink for CO{sub 2} during the historic and recent geologic past. Depending on the nature, rate, and magnitude of global environmental change, the arctic may have a positive or negative feedback on global change. Results from the DOE- funded research efforts of 1990 and 1991 indicate that the arctic has become a source of CO{sub 2} to the atmosphere. Measurements made in the Barrow, Alaska region during 1992 support these results. This change coincides with recent climatic variation in the arctic, and suggests a positive feedback of arctic ecosystems on atmospheric CO{sub 2} and global change. There are obvious potential errors in scaling plot level measurements to landscape, mesoscale, and global spatial scales. In light of the results from the recent DOE-funded research, and the remaining uncertainties regarding the change in arctic ecosystem function due to high latitude warming, a revised set of research goals is proposed for the 1993--94 year. The research proposed in this application has four principal aspects: (A) Long- term response of arctic plants and ecosystems to elevated atmospheric CO{sub 2}. (B) Circumpolar patterns of net ecosystem CO{sub 2} flux. (C) In situ controls by temperature and moisture on net ecosystem CO{sub 2} flux. (D) Scaling of CO{sub 2} flux from plot, to landscape, to regional scales.

Response of a tundra ecosystem to elevated atmospheric carbon dioxide and CO{sub 2}-induced climate change. Final report

Energy Technology Data Exchange (ETDEWEB)

Oechel, W.C.

1996-11-01

The overall objective of this research was to document current patterns of CO{sub 2} flux in selected locations of the circumpolar arctic, and to develop the information necessary to predict how these fluxes may be affected by climate change. In fulfillment of these objectives, net CO{sub 2} flux was measured at several sites on the North Slope of Alaska during the 1990--94 growing season (June--August) to determine the local and regional patterns of seasonal CO{sub 2} exchange. In addition, net CO{sub 2} flux was measured in the Russian and Icelandic Arctic to determine if the patterns of CO{sub 2} exchange observed in Arctic Alaska were representative of the circumpolar Arctic, while cold-season CO{sub 2} flux measurements were carried out during the 1993--94 winter season to determine the magnitude of CO{sub 2} efflux not accounted for by the growing season measurements. Manipulations of soil water table depth and surface temperature, which were identified from the extensive measurements as being the most important variables in determining the magnitude and direction of net CO{sub 2} exchange, were carried out during the 1993--94 growing seasons in tussock and wet sedge tundra ecosystems. Finally, measurements of CH{sub 4} flux were also measured at several of the North Slope study sites during the 1990--91 growing seasons.

Responses of pink salmon to CO2-induced aquatic acidification

Science.gov (United States)

Ou, Michelle; Hamilton, Trevor J.; Eom, Junho; Lyall, Emily M.; Gallup, Joshua; Jiang, Amy; Lee, Jason; Close, David A.; Yun, Sang-Seon; Brauner, Colin J.

2015-10-01

Ocean acidification negatively affects many marine species and is predicted to cause widespread changes to marine ecosystems. Similarly, freshwater ecosystems may potentially be affected by climate-change-related acidification; however, this has received far less attention. Freshwater fish represent 40% of all fishes, and salmon, which rear and spawn in freshwater, are of immense ecosystem, economical and cultural importance. In this study, we investigate the impacts of CO2-induced acidification during the development of pink salmon, in freshwater and following early seawater entry. At this critical and sensitive life stage, we show dose-dependent reductions in growth, yolk-to-tissue conversion and maximal O2 uptake capacity; as well as significant alterations in olfactory responses, anti-predator behaviour and anxiety under projected future increases in CO2 levels. These data indicate that future populations of pink salmon may be at risk without mitigation and highlight the need for further studies on the impact of CO2-induced acidification on freshwater systems.

Climate Change and the Impact of Greenhouse Gasses: CO2 and NO, Friends and Foes of Plant Oxidative Stress

Science.gov (United States)

Cassia, Raúl; Nocioni, Macarena; Correa-Aragunde, Natalia; Lamattina, Lorenzo

2018-01-01

Here, we review information on how plants face redox imbalance caused by climate change, and focus on the role of nitric oxide (NO) in this response. Life on Earth is possible thanks to greenhouse effect. Without it, temperature on Earth’s surface would be around -19°C, instead of the current average of 14°C. Greenhouse effect is produced by greenhouse gasses (GHG) like water vapor, carbon dioxide (CO2), methane (CH4), nitrous oxides (NxO) and ozone (O3). GHG have natural and anthropogenic origin. However, increasing GHG provokes extreme climate changes such as floods, droughts and heat, which induce reactive oxygen species (ROS) and oxidative stress in plants. The main sources of ROS in stress conditions are: augmented photorespiration, NADPH oxidase (NOX) activity, β-oxidation of fatty acids and disorders in the electron transport chains of mitochondria and chloroplasts. Plants have developed an antioxidant machinery that includes the activity of ROS detoxifying enzymes [e.g., superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), glutathione peroxidase (GPX), and peroxiredoxin (PRX)], as well as antioxidant molecules such as ascorbic acid (ASC) and glutathione (GSH) that are present in almost all subcellular compartments. CO2 and NO help to maintain the redox equilibrium. Higher CO2 concentrations increase the photosynthesis through the CO2-unsaturated Rubisco activity. But Rubisco photorespiration and NOX activities could also augment ROS production. NO regulate the ROS concentration preserving balance among ROS, GSH, GSNO, and ASC. When ROS are in huge concentration, NO induces transcription and activity of SOD, APX, and CAT. However, when ROS are necessary (e.g., for pathogen resistance), NO may inhibit APX, CAT, and NOX activity by the S-nitrosylation of cysteine residues, favoring cell death. NO also regulates GSH concentration in several ways. NO may react with GSH to form GSNO, the NO cell reservoir and main source of S

Climate Change and the Impact of Greenhouse Gasses: CO2 and NO, Friends and Foes of Plant Oxidative Stress.

Science.gov (United States)

Cassia, Raúl; Nocioni, Macarena; Correa-Aragunde, Natalia; Lamattina, Lorenzo

2018-01-01

Here, we review information on how plants face redox imbalance caused by climate change, and focus on the role of nitric oxide (NO) in this response. Life on Earth is possible thanks to greenhouse effect. Without it, temperature on Earth's surface would be around -19°C, instead of the current average of 14°C. Greenhouse effect is produced by greenhouse gasses (GHG) like water vapor, carbon dioxide (CO 2 ), methane (CH 4 ), nitrous oxides (N x O) and ozone (O 3 ). GHG have natural and anthropogenic origin. However, increasing GHG provokes extreme climate changes such as floods, droughts and heat, which induce reactive oxygen species (ROS) and oxidative stress in plants. The main sources of ROS in stress conditions are: augmented photorespiration, NADPH oxidase (NOX) activity, β-oxidation of fatty acids and disorders in the electron transport chains of mitochondria and chloroplasts. Plants have developed an antioxidant machinery that includes the activity of ROS detoxifying enzymes [e.g., superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), glutathione peroxidase (GPX), and peroxiredoxin (PRX)], as well as antioxidant molecules such as ascorbic acid (ASC) and glutathione (GSH) that are present in almost all subcellular compartments. CO 2 and NO help to maintain the redox equilibrium. Higher CO 2 concentrations increase the photosynthesis through the CO 2 -unsaturated Rubisco activity. But Rubisco photorespiration and NOX activities could also augment ROS production. NO regulate the ROS concentration preserving balance among ROS, GSH, GSNO, and ASC. When ROS are in huge concentration, NO induces transcription and activity of SOD, APX, and CAT. However, when ROS are necessary (e.g., for pathogen resistance), NO may inhibit APX, CAT, and NOX activity by the S-nitrosylation of cysteine residues, favoring cell death. NO also regulates GSH concentration in several ways. NO may react with GSH to form GSNO, the NO cell reservoir and main source of S

Forecasting carbon budget under climate change and CO2 fertilization for subtropical region in China using integrated biosphere simulator (IBIS) model

Science.gov (United States)

Zhu, Q.; Jiang, H.; Liu, J.; Peng, C.; Fang, X.; Yu, S.; Zhou, G.; Wei, X.; Ju, W.

2011-01-01

The regional carbon budget of the climatic transition zone may be very sensitive to climate change and increasing atmospheric CO2 concentrations. This study simulated the carbon cycles under these changes using process-based ecosystem models. The Integrated Biosphere Simulator (IBIS), a Dynamic Global Vegetation Model (DGVM), was used to evaluate the impacts of climate change and CO2 fertilization on net primary production (NPP), net ecosystem production (NEP), and the vegetation structure of terrestrial ecosystems in Zhejiang province (area 101,800 km2, mainly covered by subtropical evergreen forest and warm-temperate evergreen broadleaf forest) which is located in the subtropical climate area of China. Two general circulation models (HADCM3 and CGCM3) representing four IPCC climate change scenarios (HC3AA, HC3GG, CGCM-sresa2, and CGCM-sresb1) were used as climate inputs for IBIS. Results show that simulated historical biomass and NPP are consistent with field and other modelled data, which makes the analysis of future carbon budget reliable. The results indicate that NPP over the entire Zhejiang province was about 55 Mt C yr-1 during the last half of the 21st century. An NPP increase of about 24 Mt C by the end of the 21st century was estimated with the combined effects of increasing CO2 and climate change. A slight NPP increase of about 5 Mt C was estimated under the climate change alone scenario. Forests in Zhejiang are currently acting as a carbon sink with an average NEP of about 2.5 Mt C yr-1. NEP will increase to about 5 Mt C yr-1 by the end of the 21st century with the increasing atmospheric CO2 concentration and climate change. However, climate change alone will reduce the forest carbon sequestration of Zhejiang's forests. Future climate warming will substantially change the vegetation cover types; warm-temperate evergreen broadleaf forest will be gradually substituted by subtropical evergreen forest. An increasing CO2 concentration will have little

Climate change feedbacks on future oceanic acidification

International Nuclear Information System (INIS)

McNeil, Ben I.; Matear, Richard J.

2007-01-01

Oceanic anthropogenic CO 2 uptake will decrease both the pH and the aragonite saturation state (Oarag) of seawater leading to an oceanic acidification. However, the factors controlling future changes in pH and Oarag are independent and will respond differently to oceanic climate change feedbacks such as ocean warming, circulation and biological changes. We examine the sensitivity of these two CO 2 -related parameters to climate change feedbacks within a coupled atmosphere-ocean model. The ocean warming feedback was found to dominate the climate change responses in the surface ocean. Although surface pH is projected to decrease relatively uniformly by about 0.3 by the year 2100, we find pH to be insensitive to climate change feedbacks, whereas Oarag is buffered by ∼15%. Ocean carbonate chemistry creates a situation whereby the direct pH changes due to ocean warming are almost cancelled by the pH changes associated with dissolved inorganic carbon concentrations changes via a reduction in CO 2 solubility from ocean warming. We show that the small climate change feedback on future surface ocean pH is independent to the amount of ocean warming. Our analysis therefore implies that future projections of surface ocean acidification only need to consider future atmospheric CO 2 levels, not climate change induced modifications in the ocean

Research on Greenhouse-Gas-Induced Climate Change

Energy Technology Data Exchange (ETDEWEB)

Schlesinger, M. E.

2001-07-15

During the 5 years of NSF grant ATM 95-22681 (Research on Greenhouse-Gas-Induced Climate Change, $1,605,000, 9/15/1995 to 8/31/2000) we have performed work which we are described in this report under three topics: (1) Development and Application of Atmosphere, Ocean, Photochemical-Transport, and Coupled Models; (2) Analysis Methods and Estimation; and (3) Climate-Change Scenarios, Impacts and Policy.

The relationship between peak warming and cumulative CO2 emissions, and its use to quantify vulnerabilities in the carbon-climate-human system

International Nuclear Information System (INIS)

Raupach, Michael; Canadell, Josep G.; Ciais, Philippe; Friedlingstein, Pierre; Rayner, Peter J.; Trudinger, Catherine M.

2011-01-01

Interactions between the carbon cycle, climate and human societies are subject to several major vulnerabilities, broadly defined as factors contributing to the risk of harm from human-induced climate change. We assess five vulnerabilities: (1) effects of increasing CO 2 on the partition of anthropogenic carbon between atmospheric, land and ocean reservoirs; (2) effects of climate change (quantified by temperature) on CO 2 fluxes; (3) uncertainty in climate sensitivity; (4) non-CO 2 radiative forcing and (5) anthropogenic CO 2 emissions. Our analysis uses a physically based expression for Tp(Qp), the peak warming Tp associated with a cumulative anthropogenic CO 2 emission Qp to the time of peak warming. The approximations in this expression are evaluated using a non-linear box model of the carbon-climate system, forced with capped emissions trajectories described by an analytic form satisfying integral and smoothness constraints. The first four vulnerabilities appear as parameters that influence Tp(Qp), whereas the last appears through the independent variable. In terms of likely implications for Tp(Qp), the decreasing order of the first four vulnerabilities is: uncertainties in climate sensitivity, effects of non-CO 2 radiative forcing, effects of climate change on CO 2 fluxes and effects of increasing CO 2 on the partition of anthropogenic carbon. (authors)

Model simulations of the competing climatic effects of SO2 and CO2

Science.gov (United States)

Kaufman, Yoram J.; Chou, Ming-Dah

1993-01-01

Sulfur dioxide-derived cloud condensation nuclei are expected to enhance the planetary albedo, thereby cooling the planet. This effect might counteract the global warming expected from enhanced greenhouse gases. A detailed treatment of the relationship between fossil fuel burning and the SO2 effect on cloud albedo is implemented in a two-dimensional model for assessing the climate impact. Using a conservative approach, results show that the cooling induced by the SO2 emission can presently counteract 50 percent of the CO2 greenhouse warming. Since 1980, a strong warming trend has been predicted by the model: 0.15 C during the 1980-1990 period alone. The model predicts that by the year 2060 the SO2 cooling reduces climate warming by 0.5 C or 25 percent for the Intergovernmental Panel on Climate Change (IPCC) business as usual (BAU) scenario and 0.2 C or 20 percent for scenario D (for a slow pace of fossil fuel burning). The hypothesis is examined that the different responses between the Northern Hemisphere and the Southern Hemisphere can be used to validate the presence of the SO2-induced cooling.

CO2 is in the air. Five myths about the role of air transport in climate changes

International Nuclear Information System (INIS)

2015-12-01

This publication discusses and criticises some general opinions on air transport. Thus, it is often said that air transport is a minor contributor to greenhouse effect (whereas air transport emits as much CO 2 as Germany who is the sixth World emitter, and has various impacts on health), that air transport is doing a lot for the climate (whereas it in fact manages not to be affected by policies against climate change), that more air passengers result in less CO 2 (whereas traffic predictions would result in an increased oil consumption, and increased CO 2 emissions despite promised technological improvements), that technical progress is at the service of climate (whereas the sector is notably late to reach its defined objectives in terms of energy efficiency), and that air transport is the only way to travel (whereas other means emit much less CO 2 ). Some recommendations are made for measures to be adopted at the international, European and French levels for a better protection of the environment

Hydrological effects of the increased CO2 and climate change in the Upper Mississippi River Basin using a modified SWAT

Science.gov (United States)

Wu, Y.; Liu, S.; Abdul-Aziz, O. I.

2012-01-01

Increased atmospheric CO2 concentration and climate change may significantly impact the hydrological and meteorological processes of a watershed system. Quantifying and understanding hydrological responses to elevated ambient CO2 and climate change is, therefore, critical for formulating adaptive strategies for an appropriate management of water resources. In this study, the Soil and Water Assessment Tool (SWAT) model was applied to assess the effects of increased CO2 concentration and climate change in the Upper Mississippi River Basin (UMRB). The standard SWAT model was modified to represent more mechanistic vegetation type specific responses of stomatal conductance reduction and leaf area increase to elevated CO2 based on physiological studies. For estimating the historical impacts of increased CO2 in the recent past decades, the incremental (i.e., dynamic) rises of CO2 concentration at a monthly time-scale were also introduced into the model. Our study results indicated that about 1–4% of the streamflow in the UMRB during 1986 through 2008 could be attributed to the elevated CO2 concentration. In addition to evaluating a range of future climate sensitivity scenarios, the climate projections by four General Circulation Models (GCMs) under different greenhouse gas emission scenarios were used to predict the hydrological effects in the late twenty-first century (2071–2100). Our simulations demonstrated that the water yield would increase in spring and substantially decrease in summer, while soil moisture would rise in spring and decline in summer. Such an uneven distribution of water with higher variability compared to the baseline level (1961–1990) may cause an increased risk of both flooding and drought events in the basin.

Changing Amazon biomass and the role of atmospheric CO2 concentration, climate, and land use

Science.gov (United States)

de Almeida Castanho, Andrea D.; Galbraith, David; Zhang, Ke; Coe, Michael T.; Costa, Marcos H.; Moorcroft, Paul

2016-01-01

The Amazon tropical evergreen forest is an important component of the global carbon budget. Its forest floristic composition, structure, and function are sensitive to changes in climate, atmospheric composition, and land use. In this study biomass and productivity simulated by three dynamic global vegetation models (Integrated Biosphere Simulator, Ecosystem Demography Biosphere Model, and Joint UK Land Environment Simulator) for the period 1970-2008 are compared with observations from forest plots (Rede Amazónica de Inventarios Forestales). The spatial variability in biomass and productivity simulated by the DGVMs is low in comparison to the field observations in part because of poor representation of the heterogeneity of vegetation traits within the models. We find that over the last four decades the CO2 fertilization effect dominates a long-term increase in simulated biomass in undisturbed Amazonian forests, while land use change in the south and southeastern Amazonia dominates a reduction in Amazon aboveground biomass, of similar magnitude to the CO2 biomass gain. Climate extremes exert a strong effect on the observed biomass on short time scales, but the models are incapable of reproducing the observed impacts of extreme drought on forest biomass. We find that future improvements in the accuracy of DGVM predictions will require improved representation of four key elements: (1) spatially variable plant traits, (2) soil and nutrients mediated processes, (3) extreme event mortality, and (4) sensitivity to climatic variability. Finally, continued long-term observations and ecosystem-scale experiments (e.g. Free-Air CO2 Enrichment experiments) are essential for a better understanding of the changing dynamics of tropical forests.

Valuation of climate change mitigation co-benefits

DEFF Research Database (Denmark)

Bakhtiari, Fatemeh

a broad range of economic or, more likely, environmental and social issues. Examples of positive environmental impacts that may not be the primary outcome of a climate change mitigation policy include reduced local air pollution or restored ecosystem health. Examples of positive social impacts include......This document describes tools for valuating in monetary terms the co-benefits associated with climate change mitigation actions. The term co-benefits refers to outcomes of those actions other than their primary outcome (reducing greenhouse-gas emissions). Such non-primary outcomes can fall under...... improved human health or increased access to clean energy....

Geologic Carbon Sequestration: Mitigating Climate Change by Injecting CO2 Underground (LBNL Summer Lecture Series)

Energy Technology Data Exchange (ETDEWEB)

Oldenburg, Curtis M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Division

2009-07-21

Summer Lecture Series 2009: Climate change provides strong motivation to reduce CO2 emissions from the burning of fossil fuels. Carbon dioxide capture and storage involves the capture, compression, and transport of CO2 to geologically favorable areas, where its injected into porous rock more than one kilometer underground for permanent storage. Oldenburg, who heads Berkeley Labs Geologic Carbon Sequestration Program, will focus on the challenges, opportunities, and research needs of this innovative technology.

Global climate change and tree nutrition : effects of elevated CO2 and temperature

International Nuclear Information System (INIS)

Lukac, M.; Calfapietra, C.; Lagomarsino, A.; Loreto, F.

2010-01-01

The availability of nutrients for plant uptake can limit the productivity and survival of forest ecosystems. Information about multiple interacting factors regarding the availability of essential nutrients and their roles in plant metabolism is needed in order to understand the full impact of climate change. This paper presented the known effects of elevated carbon dioxide (CO 2 ) and temperature on tree nutrition, with particular reference to the mobilization and immobilization processes instead of pools. Existing gaps in knowledge were identified and future research priorities were suggested. This review focused on the major nutrients, notably nitrogen (N) and phosphorous (P) and how the processes that alter their cycling and availability are influenced by the effects of climate change. 143 refs., 3 figs.

Co-benefits of addressing climate change can motivate action around the world

Science.gov (United States)

Bain, Paul G.; Milfont, Taciano L.; Kashima, Yoshihisa; Bilewicz, Michał; Doron, Guy; Garðarsdóttir, Ragna B.; Gouveia, Valdiney V.; Guan, Yanjun; Johansson, Lars-Olof; Pasquali, Carlota; Corral-Verdugo, Victor; Aragones, Juan Ignacio; Utsugi, Akira; Demarque, Christophe; Otto, Siegmar; Park, Joonha; Soland, Martin; Steg, Linda; González, Roberto; Lebedeva, Nadezhda; Madsen, Ole Jacob; Wagner, Claire; Akotia, Charity S.; Kurz, Tim; Saiz, José L.; Schultz, P. Wesley; Einarsdóttir, Gró; Saviolidis, Nina M.

2016-02-01

Personal and political action on climate change is traditionally thought to be motivated by people accepting its reality and importance. However, convincing the public that climate change is real faces powerful ideological obstacles, and climate change is slipping in public importance in many countries. Here we investigate a different approach, identifying whether potential co-benefits of addressing climate change could motivate pro-environmental behaviour around the world for both those convinced and unconvinced that climate change is real. We describe an integrated framework for assessing beliefs about co-benefits, distinguishing social conditions (for example, economic development, reduced pollution or disease) and community character (for example, benevolence, competence). Data from all inhabited continents (24 countries; 6,196 participants) showed that two co-benefit types, Development (economic and scientific advancement) and Benevolence (a more moral and caring community), motivated public, private and financial actions to address climate change to a similar degree as believing climate change is important. Critically, relationships were similar for both convinced and unconvinced participants, showing that co-benefits can motivate action across ideological divides. These relationships were also independent of perceived climate change importance, and could not be explained by political ideology, age, or gender. Communicating co-benefits could motivate action on climate change where traditional approaches have stalled.

Evaluating the effects of future climate change and elevated CO2 on the water use efficiency in terrestrial ecosystems of China

Science.gov (United States)

Zhu, Q.; Jiang, H.; Peng, C.; Liu, J.; Wei, X.; Fang, X.; Liu, S.; Zhou, G.; Yu, S.

2011-01-01

Water use efficiency (WUE) is an important variable used in climate change and hydrological studies in relation to how it links ecosystem carbon cycles and hydrological cycles together. However, obtaining reliable WUE results based on site-level flux data remains a great challenge when scaling up to larger regional zones. Biophysical, process-based ecosystem models are powerful tools to study WUE at large spatial and temporal scales. The Integrated BIosphere Simulator (IBIS) was used to evaluate the effects of climate change and elevated CO2 concentrations on ecosystem-level WUE (defined as the ratio of gross primary production (GPP) to evapotranspiration (ET)) in relation to terrestrial ecosystems in China for 2009–2099. Climate scenario data (IPCC SRES A2 and SRES B1) generated from the Third Generation Coupled Global Climate Model (CGCM3) was used in the simulations. Seven simulations were implemented according to the assemblage of different elevated CO2 concentrations scenarios and different climate change scenarios. Analysis suggests that (1) further elevated CO2concentrations will significantly enhance the WUE over China by the end of the twenty-first century, especially in forest areas; (2) effects of climate change on WUE will vary for different geographical regions in China with negative effects occurring primarily in southern regions and positive effects occurring primarily in high latitude and altitude regions (Tibetan Plateau); (3) WUE will maintain the current levels for 2009–2099 under the constant climate scenario (i.e. using mean climate condition of 1951–2006 and CO2concentrations of the 2008 level); and (4) WUE will decrease with the increase of water resource restriction (expressed as evaporation ratio) among different ecosystems.

Allowable CO2 concentrations under the United Nations Framework Convention on Climate Change as a function of the climate sensitivity probability distribution function

International Nuclear Information System (INIS)

Harvey, L D Danny

2007-01-01

Article 2 of the United Nations Framework Convention on Climate Change (UNFCCC) calls for stabilization of greenhouse gas (GHG) concentrations at levels that prevent dangerous anthropogenic interference (DAI) in the climate system. Until recently, the consensus viewpoint was that the climate sensitivity (the global mean equilibrium warming for a doubling of atmospheric CO 2 concentration) was 'likely' to fall between 1.5 and 4.5 K. However, a number of recent studies have generated probability distribution functions (pdfs) for climate sensitivity with the 95th percentile of the expected climate sensitivity as large as 10 K, while some studies suggest that the climate sensitivity is likely to fall in the lower half of the long-standing 1.5-4.5 K range. This paper examines the allowable CO 2 concentration as a function of the 95th percentile of the climate sensitivity pdf (ranging from 2 to 8 K) and for the following additional assumptions: (i) the 50th percentile for the pdf of the minimum sustained global mean warming that causes unacceptable harm equal to 1.5 or 2.5 K; and (ii) 1%, 5% or 10% allowable risks of unacceptable harm. For a 1% risk tolerance and the more stringent harm-threshold pdf, the allowable CO 2 concentration ranges from 323 to 268 ppmv as the 95th percentile of the climate sensitivity pdf increases from 2 to 8 K, while for a 10% risk tolerance and the less stringent harm-threshold pdf, the allowable CO 2 concentration ranges from 531 to 305 ppmv. In both cases it is assumed that non-CO 2 GHG radiative forcing can be reduced to half of its present value, otherwise; the allowable CO 2 concentration is even smaller. Accounting for the fact that the CO 2 concentration will gradually fall if emissions are reduced to zero, and that peak realized warming will then be less than the peak equilibrium warming (related to peak radiative forcing) allows the CO 2 concentration to peak at 10-40 ppmv higher than the limiting values given above for a climate

Effects of climate, CO2 concentration, nitrogen deposition, and stand age changes on the carbon budget of China's forests

Science.gov (United States)

Zhang, C.; Ju, W.; Zhang, F.; Mao, D.; Wang, X.

2017-12-01

Forests play an irreplaceable role in the Earth's terrestrial carbon budget which retard the atmospheric CO2 buildup. Understanding the factors controlling forest carbon budget is critical for reducing uncertainties in projections of future climate. The relative importance of climate, atmospheric CO2 concentration, nitrogen deposition, and stand age changes on carbon budget, however, remains unclear for China's forests. In this study, we quantify individual contribution of these drivers to the trends of forest carbon budget in China from 1901 to 2012 by integrating national datasets, the updated Integrated Terrestrial Ecosystem Carbon Cycle (InTEC) model and factorial simulations. Results showed that the average carbon sink in China's forests from 1982 to 2012 was 186.9 Tg C yr-1 with 68% (127.6 Tg C yr-1) of the sink in living biomass because of the integrated effects of climate, atmospheric CO2 concentration, nitrogen deposition, and stand age factors. Compared with the simulation of all factors combined, the estimated carbon sink during 1901-2012 would be reduced by 41.8 Tg C yr-1 if climate change, atmospheric CO2 concentration and nitrogen deposition factors were omitted, and reduced by 25.0 Tg C yr-1 if stand age factor was omitted. In most decades, these factors increased forest carbon sinks with the largest of 101.3, 62.9, and 44.0 Tg C yr-1 from 2000 to 2012 contributed by stand age, CO2 concentration and nitrogen deposition, respectively. During 1901-2012, climate change, CO2 concentration, nitrogen deposition and stand age contributed -13.3, 21.4, 15.4 and 25.0 Tg C yr-1 to the averaged carbon sink of China's forests, respectively. Our study also showed diverse regional patterns of forest carbon budget related to the importance of driving factors. Stand age effect was the largest in most regions, but the effects of CO2 concentration and nitrogen deposition were dominant in southern China.

Carbon Dioxide Effects Research and Assessment Program. Workshop on environmental and societal consequences of a possible CO/sub 2/-induced climate change

Energy Technology Data Exchange (ETDEWEB)

None

1980-10-01

The Workshop was part of a process of elucidating areas of uncertainty where research is needed before meaningful forecasts and sound decisions can be made about the CO/sub 2/ issue. The conferees were divided into five panels dealing with the ocean and the cryosphere: the less managed biosphere; the managed biosphere (chiefly agricultural, forest, and grazing lands); the ways society and its institutions might respond to climate changes; and issues involving the economic and geopolitical consequences of CO/sub 2/ build-up. Also, 28 papers or discussion drafts dealing with a wide variety of topics were contributed to the conference.

Role of CO2 and Southern Ocean winds in glacial abrupt climate change

Directory of Open Access Journals (Sweden)

M. Montoya

2012-06-01

Full Text Available The study of Greenland ice cores revealed two decades ago the abrupt character of glacial millennial-scale climate variability. Several triggering mechanisms have been proposed and confronted against growing proxy-data evidence. Although the implication of North Atlantic deep water (NADW formation reorganisations in glacial abrupt climate change seems robust nowadays, the final cause of these reorganisations remains unclear. Here, the role of CO2 and Southern Ocean winds is investigated using a coupled model of intermediate complexity in an experimental setup designed such that the climate system resides close to a threshold found in previous studies. An initial abrupt surface air temperature (SAT increase over the North Atlantic by 4 K in less than a decade, followed by a more gradual warming greater than 10 K on centennial timescales, is simulated in response to increasing atmospheric CO2 levels and/or enhancing southern westerlies. The simulated peak warming shows a similar pattern and amplitude over Greenland as registered in ice core records of Dansgaard-Oeschger (D/O events. This is accompanied by a strong Atlantic meridional overturning circulation (AMOC intensification. The AMOC strengthening is found to be caused by a northward shift of NADW formation sites into the Nordic Seas as a result of a northward retreat of the sea-ice front in response to higher temperatures. This leads to enhanced heat loss to the atmosphere as well as reduced freshwater fluxes via reduced sea-ice import into the region. In this way, a new mechanism that is consistent with proxy data is identified by which abrupt climate change can be promoted.

Sensitivity of burned area in Europe to climate change, atmospheric CO2 levels, and demography

DEFF Research Database (Denmark)

Wu, Minchao; Knorr, Wolfgang; Thonicke, Kirsten

2015-01-01

model. Applying a range of future projections that combine different scenarios for climate changes, enhanced CO2 concentrations, and population growth, we investigated the individual and combined effects of these drivers on the total area and regions affected by fire in the 21st century. The two models...

Forcings and feedbacks by land ecosystem changes on climate change

Science.gov (United States)

Betts, R. A.

2006-12-01

Vegetation change is involved in climate change through both forcing and feedback processes. Emissions of CO{2} from past net deforestation are estimated to have contributed approximately 0.22 0.51 Wm - 2 to the overall 1.46 Wm - 2 radiative forcing by anthropogenic increases in CO{2} up to the year 2000. Deforestation-induced increases in global mean surface albedo are estimated to exert a radiative forcing of 0 to -0.2 Wm - 2, and dust emissions from land use may exert a radiative forcing of between approximately +0.1 and -0.2 Wm - 2. Changes in the fluxes of latent and sensible heat due to tropical deforestation are simulated to have exerted other local warming effects which cannot be quantified in terms of a Wm - 2 radiative forcing, with the potential for remote effects through changes in atmospheric circulation. With tropical deforestation continuing rapidly, radiative forcing by surface albedo change may become less useful as a measure of the forcing of climate change by changes in the physical properties of the land surface. Although net global deforestation is continuing, future scenarios used for climate change prediction suggest that fossil fuel emissions of CO{2} may continue to increase at a greater rate than land use emissions and therefore continue to increase in dominance as the main radiative forcing. The CO{2} rise may be accelerated by up to 66% by feedbacks arising from global soil carbon loss and forest dieback in Amazonia as a consequence of climate change, and Amazon forest dieback may also exert feedbacks through changes in the local water cycle and increases in dust emissions.

Rain-induced changes in soil CO2 flux and microbial community composition in a tropical forest of China.

Science.gov (United States)

Deng, Qi; Hui, Dafeng; Chu, Guowei; Han, Xi; Zhang, Quanfa

2017-07-17

Rain-induced soil CO 2 pulse, a rapid excitation in soil CO 2 flux after rain, is ubiquitously observed in terrestrial ecosystems, yet the underlying mechanisms in tropical forests are still not clear. We conducted a rain simulation experiment to quantify rain-induced changes in soil CO 2 flux and microbial community composition in a tropical forest. Soil CO 2 flux rapidly increased by ~83% after rains, accompanied by increases in both bacterial (~51%) and fungal (~58%) Phospholipid Fatty Acids (PLFA) biomass. However, soil CO 2 flux and microbial community in the plots without litters showed limited response to rains. Direct releases of CO 2 from litter layer only accounted for ~19% increases in soil CO 2 flux, suggesting that the leaching of dissolved organic carbon (DOC) from litter layer to the topsoil is the major cause of rain-induced soil CO 2 pulse. In addition, rain-induced changes in soil CO 2 flux and microbial PLFA biomass decreased with increasing rain sizes, but they were positively correlated with litter-leached DOC concentration rather than total DOC flux. Our findings reveal an important role of litter-leached DOC input in regulating rain-induced soil CO 2 pulses and microbial community composition, and may have significant implications for CO 2 losses from tropical forest soils under future rainfall changes.

Equality and CO2 emissions distribution in climate change integrated assessment modelling

International Nuclear Information System (INIS)

Cantore, Nicola; Padilla, Emilio

2010-01-01

The equity implications of alternative climate policy measures are an essential issue to be considered in the design of future international agreements to tackle global warming. This paper specifically analyses the future path of emissions and income distribution and its determinants in different scenarios. Whereas our analysis is driven by tools which are typically applied in the income distribution literature and which have recently been applied to the analysis of CO 2 emissions distribution, a new methodological approach is that our study is driven by simulations run with the popular regionalised optimal growth climate change model RICE99 over the 1995-2105 period. We find that the architecture of environmental policies, the implementation of flexible mechanisms and income concentration are key determinants of emissions distribution over time. In particular we find a robust positive relationship between measures of inequalities in the distribution of emissions and income and that their magnitude will essentially depend on technological change. (author)

Plio-Pleistocene climate sensitivity evaluated using high-resolution CO2 records.

Science.gov (United States)

Martínez-Botí, M A; Foster, G L; Chalk, T B; Rohling, E J; Sexton, P F; Lunt, D J; Pancost, R D; Badger, M P S; Schmidt, D N

2015-02-05

Theory and climate modelling suggest that the sensitivity of Earth's climate to changes in radiative forcing could depend on the background climate. However, palaeoclimate data have thus far been insufficient to provide a conclusive test of this prediction. Here we present atmospheric carbon dioxide (CO2) reconstructions based on multi-site boron-isotope records from the late Pliocene epoch (3.3 to 2.3 million years ago). We find that Earth's climate sensitivity to CO2-based radiative forcing (Earth system sensitivity) was half as strong during the warm Pliocene as during the cold late Pleistocene epoch (0.8 to 0.01 million years ago). We attribute this difference to the radiative impacts of continental ice-volume changes (the ice-albedo feedback) during the late Pleistocene, because equilibrium climate sensitivity is identical for the two intervals when we account for such impacts using sea-level reconstructions. We conclude that, on a global scale, no unexpected climate feedbacks operated during the warm Pliocene, and that predictions of equilibrium climate sensitivity (excluding long-term ice-albedo feedbacks) for our Pliocene-like future (with CO2 levels up to maximum Pliocene levels of 450 parts per million) are well described by the currently accepted range of an increase of 1.5 K to 4.5 K per doubling of CO2.

Plio-Pleistocene climate sensitivity evaluated using high-resolution CO2 records

Science.gov (United States)

Martínez-Botí, M. A.; Foster, G. L.; Chalk, T. B.; Rohling, E. J.; Sexton, P. F.; Lunt, D. J.; Pancost, R. D.; Badger, M. P. S.; Schmidt, D. N.

2015-02-01

Theory and climate modelling suggest that the sensitivity of Earth's climate to changes in radiative forcing could depend on the background climate. However, palaeoclimate data have thus far been insufficient to provide a conclusive test of this prediction. Here we present atmospheric carbon dioxide (CO2) reconstructions based on multi-site boron-isotope records from the late Pliocene epoch (3.3 to 2.3 million years ago). We find that Earth's climate sensitivity to CO2-based radiative forcing (Earth system sensitivity) was half as strong during the warm Pliocene as during the cold late Pleistocene epoch (0.8 to 0.01 million years ago). We attribute this difference to the radiative impacts of continental ice-volume changes (the ice-albedo feedback) during the late Pleistocene, because equilibrium climate sensitivity is identical for the two intervals when we account for such impacts using sea-level reconstructions. We conclude that, on a global scale, no unexpected climate feedbacks operated during the warm Pliocene, and that predictions of equilibrium climate sensitivity (excluding long-term ice-albedo feedbacks) for our Pliocene-like future (with CO2 levels up to maximum Pliocene levels of 450 parts per million) are well described by the currently accepted range of an increase of 1.5 K to 4.5 K per doubling of CO2.

Carbon Dioxide Effects Research and Assessment Program. Environmental and societal consequences of a possible CO/sub 2//sup -/ induced climate change: a research agenda

Energy Technology Data Exchange (ETDEWEB)

1980-12-01

In adding carbon dioxide to the atmosphere, mankind is unintentionally conducting a great biological and geophysical experiment. This experiment can be expected to increase scientific understanding of ecological systems and of the processes in the ocean and the atmosphere that partially determine world climate. But from the standpoint of governments and peoples, the major problem to be solved is to understand the nature of the impacts on societies of rising levels of atmospheric carbon dioxide (CO/sub 2/), with the objective of avoiding or ameliorating unfavorable impacts and gaining most benefit from favorable impacts. The research program proposed herein is designed to provide the understanding needed to achieve this objective. It is based on a recognition of the distinctive characteristics of the CO/sub 2/ problem. It is concluded that three kinds of research on the consequences of rising levels of atmospheric carbon dioxide and possible climatic changes are called for: assessment of risks; research to enhance beneficial effects and lessen harmful ones, where this is possible, and to slow down rates of carbon dioxide emission; and study of potential social and institutional responses to projected climatic changes.

Disentangling the effects of land-use change, climate and CO2 on projected future European habitat types

NARCIS (Netherlands)

Lehsten, V; Sykes, M.T.; Scott, A.V.; Tzanopoulis, A.; Kallimanis, A.; Verburg, P.H.; Schulp, C.J.E.; Potts, S.G.; Vogiatzakis, I.

2015-01-01

Aim: To project the potential European distribution of seven broad habitat categories (needle-leaved, broad-leaved, mixed and mediterranean forest, urban, grassland and cropland) in order to assess effects of land use, climate change and increase in CO2 on predicted habitat changes up to

Climatic change and local policy, Amsterdam, Netherlands. Policy options and implementation strategies to reduce emission of CO2

International Nuclear Information System (INIS)

Schol, E.; Van den Bosch, A.; Ligthart, F.A.T.M.; Roemer, J.C.; Ruijg, G.J.; Schaeffer, G.J.; Dinkelman, D.H.; Kok, I.C.; De Paauw, K.F.B.

1998-04-01

Insight is given into the local policy options with respect to climate change, in this case within the sphere of influence of Amsterdam local authorities. A list of new policy options for CO2-reduction has been made with the assistance of local policy makers and representatives of interest groups. These policy options have been divided into three qualitative scenarios: Institutional Cultural Change, Technological Innovation and Least Regrets. The environmental, economic and other effects have been described for each policy option. The three most interesting policy options have been selected by local policy makers and representatives of interest groups during a workshop. Implementation strategies have been developed for the options selected. These strategies have been discussed during a second workshop. The reduction target, stabilization of CO2-emissions in 2015 compared to 1993, can be realized by a combination of all the new policy options. The three selected policy options count for 40% of this total CO2-emission reduction. Finally, a general outline on the methodology to construct local policies for climate protection has been described. This methodology can also be applied to other cities and municipal administrators, e.g. participants of Cities for Climate Protection, an initiative of the International Council for Local Environmental Initiatives, or the Netherlands Climate Association. 136 refs

The Fossil Atmospheres Project: A novel approach for simultaneously refining the Ginkgo paleo-pCO2 barometer & educating citizens about climate change

Science.gov (United States)

Barclay, R. S.; Soul, L.; Bolton, A.; Wilson, J. P.; Megonigal, P.; Wing, S. L.

2017-12-01

During the Late Cretaceous and Paleogene, the Earth's climate was much warmer than today, often punctuated by rapid hyperthermal events. The background warmth and hyperthermals are often attributed to increased atmospheric carbon dioxide (pCO2), yet paleo-pCO2 proxy estimates for this interval often disagree widely, and there are few paired records of temperature and pCO2. Consequently, we have an inadequate understanding of what generated past warm climates, and of the magnitude of pCO2 change associated with hyperthermals. We aim to develop a more reliable stomatal proxy for paleo-pCO2 by quantifying the effect of pCO2 and other environmental variables on stomatal properties of living Ginkgo biloba trees. Herbarium collections of G. biloba demonstrate that the stomatal index proxy for paleo-pCO2 is strongly correlated with pCO2 over the range of 290-400 ppm. However, despite wide application of the Ginkgo paleo-pCO2 barometer, our understanding of pCO2 in the fossil record has been hindered because the morphological and physiological changes in Ginkgo biloba stomata under pCO2 above 400 ppm have been poorly constrained. To address this problem, we are conducting an elevated CO2 experiment that will quantify the response of Ginkgo to elevated pCO2, an experiment we call 'Fossil Atmospheres'. We are growing 15 Ginkgo biloba trees in open-topped chambers in natural field conditions, under atmospheres with ambient (400), 600, 800, and 1,000 ppm of CO2. Each tree is regularly monitored for changes in stomatal frequency, and rates of photosynthesis and transpiration to constrain parameters used in gas exchange models of paleo-pCO2. We have also involved citizen scientists in the process of collecting stomatal index measurements with the Zooniverse platform, utilizing the interaction to educate citizens about modern climate change from the less-menacing viewpoint of deep-time climate change events. Our results can then be used to infer paleo-pCO2 from stomatal features

Assessing the implications of human land-use change for the transient climate response to cumulative carbon emissions

International Nuclear Information System (INIS)

Simmons, C T; Matthews, H D

2016-01-01

Recent research has shown evidence of a linear climate response to cumulative CO 2 emissions, which implies that the source, timing, and amount of emissions does not significantly influence the climate response per unit emission. Furthermore, these analyses have generally assumed that the climate response to land-use CO 2 emissions is equivalent to that of fossil fuels under the assumption that, once in the atmosphere, the radiative forcing induced by CO 2 is not sensitive to the emissions source. However, land-cover change also affects surface albedo and the strength of terrestrial carbon sinks, both of which have an additional climate effect. In this study, we use a coupled climate-carbon cycle model to assess the climate response to historical and future cumulative land-use CO 2 emissions, in order to compare it to the response to fossil fuel CO 2 . We find that when we isolate the CO 2 -induced (biogeochemical) temperature changes associated with land-use change, then the climate response to cumulative land-use emissions is equivalent to that of fossil fuel CO 2 . We show further that the globally-averaged albedo-induced biophysical cooling from land-use change is non-negligible and may be of comparable magnitude to the biogeochemical warming, with the result that the net climate response to land-use change is substantially different from a linear response to cumulative emissions. However, our new simulations suggest that the biophysical cooling from land-use change follows its own independent (negative) linear response to cumulative net land-use CO 2 emissions, which may provide a useful scaling factor for certain applications when evaluating the full transient climate response to emissions. (letter)

The climatic change induced by human activities

International Nuclear Information System (INIS)

Balairon Ruiz, L.

2004-01-01

The climate of the Earth is a changing climate. Along their history many natural climate changes have existed in all time scales. At the present time we use the term climate changes have existed in all time scales. At the present time we use the term climate change in a restricted way, understanding that we have referring to a singular change that has their origin in the modification of the natural composition of the atmosphere. The increase of greenhouse gases from the second half the XVIII century, is due to the human activities of fossil fuels burning to obtain energy and to industrial and agricultural activities needing for the development of a world which population has been duplicated between 1960 and 2000, until overcoming the 6,000 million inhabitants. In particular, the concentrations of carbon dioxide-CO 2 have increased in a 34%. The more recent emission scenarios proposed by the IPCC (SRES, 2000) are based on hypothesis about the population evolution, the energy consumption and the word patterns of development, which are grouped in four families dominated as A1, A2, B1 and B2. The answer for these scenarios from a range of climate models results in an increase of the world average surface atmospheric temperature between 1,4 degree centigrade and 5,8 degree centigrade and a corresponding sea level rise understood between 9 cm and 88 cm. The changes in the precipitation patterns show us that could be above to the current one in high and media latitudes and below in subtropical latitudes, with exceptions highly depending of the model used. (Author)

Co-creation of climate change mitigation policies

DEFF Research Database (Denmark)

Hoff, Jens Villiam

The focus of this paper is on the places where citizens and public authorities meet – possible involving other stakeholders as well – to discuss, formulate and implement climate change mitigation policies at the local level. Through looking at a number of concrete cases stemming from the CIDEA re...... mitigation policies should be aimed at finding ways to support citizen initiated initiatives to a greater extent than is currently the case. Keywords: climate change mitigation, co-creation, behaviour, communities, citizen driven innovation....

Interfacing a one-dimensional lake model with a single-column atmospheric model: 2. Thermal response of the deep Lake Geneva, Switzerland under a 2 × CO2 global climate change

Science.gov (United States)

Perroud, Marjorie; Goyette, StéPhane

2012-06-01

In the companion to the present paper, the one-dimensional k-ɛ lake model SIMSTRAT is coupled to a single-column atmospheric model, nicknamed FIZC, and an application of the coupled model to the deep Lake Geneva, Switzerland, is described. In this paper, the response of Lake Geneva to global warming caused by an increase in atmospheric carbon dioxide concentration (i.e., 2 × CO2) is investigated. Coupling the models allowed for feedbacks between the lake surface and the atmosphere and produced changes in atmospheric moisture and cloud cover that further modified the downward radiation fluxes. The time evolution of atmospheric variables as well as those of the lake's thermal profile could be reproduced realistically by devising a set of adjustable parameters. In a "control" 1 × CO2 climate experiment, the coupled FIZC-SIMSTRAT model demonstrated genuine skills in reproducing epilimnetic and hypolimnetic temperatures, with annual mean errors and standard deviations of 0.25°C ± 0.25°C and 0.3°C ± 0.15°C, respectively. Doubling the CO2 concentration induced an atmospheric warming that impacted the lake's thermal structure, increasing the stability of the water column and extending the stratified period by 3 weeks. Epilimnetic temperatures were seen to increase by 2.6°C to 4.2°C, while hypolimnion temperatures increased by 2.2°C. Climate change modified components of the surface energy budget through changes mainly in air temperature, moisture, and cloud cover. During summer, reduced cloud cover resulted in an increase in the annual net solar radiation budget. A larger water vapor deficit at the air-water interface induced a cooling effect in the lake.

Fast Atmosphere-Ocean Model Runs with Large Changes in CO2

Science.gov (United States)

Russell, Gary L.; Lacis, Andrew A.; Rind, David H.; Colose, Christopher; Opstbaum, Roger F.

2013-01-01

How does climate sensitivity vary with the magnitude of climate forcing? This question was investigated with the use of a modified coupled atmosphere-ocean model, whose stability was improved so that the model would accommodate large radiative forcings yet be fast enough to reach rapid equilibrium. Experiments were performed in which atmospheric CO2 was multiplied by powers of 2, from 1/64 to 256 times the 1950 value. From 8 to 32 times, the 1950 CO2, climate sensitivity for doubling CO2 reaches 8 C due to increases in water vapor absorption and cloud top height and to reductions in low level cloud cover. As CO2 amount increases further, sensitivity drops as cloud cover and planetary albedo stabilize. No water vapor-induced runaway greenhouse caused by increased CO2 was found for the range of CO2 examined. With CO2 at or below 1/8 of the 1950 value, runaway sea ice does occur as the planet cascades to a snowball Earth climate with fully ice covered oceans and global mean surface temperatures near 30 C.

Climate change damage functions in LCA

DEFF Research Database (Denmark)

Callesen, Ingeborg; Beier, Claus; Bagger Jørgensen, Rikke

, their properties, goods and services. In: Climate change 2007. Cambridge, Cambridge University Press, p. 211-272. [2] Mikkelsen TN, Beier C, et al. (2008) Experimental design of multifactor climate change experiments with elevated CO2, warming and drought – the CLIMAITE project. Functional Ecology, 22, 185-195. [3...... will be variable (2). Modeling exercises suggest large-scale range shifts of the major biomes of the world (1). The unknown magnitude of future GHG emissions and the complexity of the climate-carbon system induce large uncertainties in the projected changes. A changed climate may result in new interactions and new...... directions of ecosystem change due to differing adaptive capacities and new species assemblages. Within the framework ‘ecosystem services’ both marketed and non-marketed utilities of the natural environment are formulated (3). Provisioning, cultural, supporting, and regulating ecosystem services have been...

Greenhouse-gas-induced climatic change: A critical appraisal of simulations and observations

International Nuclear Information System (INIS)

Schlesinger, M.E.

1990-01-01

This book is the culmination of a Workshop on Greenhouse-Gas-Induced Climatic Change: A Critical Appraisal of Simulations and Observations which was held at the University of Massachusetts, Amherst, during 8--12 May 1989. The objectives of the Workshop were to: (1) present and evaluate the current status of climate model simulations of greenhouse-gas-induced changes of both the equilibrium and nonequilibrium (transient) climates; (2) present and assess the current status of the observations of global and regional climates from the beginning of the industrial revolution to the present, circa 1850 to 1989; (3) present reconstructions of climatic change during the last millennium to determine the ''natural variability'' of climate on the intra-century time scale; (4) critically evaluate whether or not the climate has changes from circa 1850 to 1989; and (5) compare the observations with the model simulations to ascertain whether a greenhouse-gas-induced climatic change has occurred and, if not, to estimate when in the future such a climatic change will likely become detectable against the background of the ''natural variability.''

CO2-vegetation feedbacks and other climate changes implicated in reducing base flow

Science.gov (United States)

Trancoso, Ralph; Larsen, Joshua R.; McVicar, Tim R.; Phinn, Stuart R.; McAlpine, Clive A.

2017-03-01

Changes in the hydrological cycle have a significant impact in water limited environments. Globally, some of these regions are experiencing declining precipitation yet are simultaneously becoming greener, partly due to vegetation feedbacks associated with increasing atmospheric CO2 concentrations. Reduced precipitation together with increasing rates of actual evapotranspiration diminishes streamflow, especially base flow, a critical freshwater dry-season resource. Here we assess recent changes in base flow in Australia from 1981-2013 and 1950-2013 and separate the contribution of precipitation, potential evapotranspiration, and other factors on base flow trends. Our findings reveal that these other factors influencing the base flow trends are best explained by an increase in photosynthetic activity. These results provide the first robust observational evidence that increasing atmospheric CO2 and its associated vegetation feedbacks are reducing base flow in addition to other climatic impacts. These findings have broad implications for water resource management, especially in the world's water limited regions.

CO2 emission calculations and trends

International Nuclear Information System (INIS)

Boden, T.A.; Marland, G.; Andres, R.J.

1995-01-01

Evidence that the atmospheric CO 2 concentration has risen during the past several decades is irrefutable. Most of the observed increase in atmospheric CO 2 is believed to result from CO 2 releases from fossil-fuel burning. The United Nations (UN) Framework Convention on Climate Change (FCCC), signed in Rio de Janeiro in June 1992, reflects global concern over the increasing CO 2 concentration and its potential impact on climate. One of the convention's stated objectives was the ''stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. '' Specifically, the FCCC asked all 154 signing countries to conduct an inventory of their current greenhouse gas emissions, and it set nonbinding targets for some countries to control emissions by stabilizing them at 1990 levels by the year 2000. Given the importance of CO 2 as a greenhouse gas, the relationship between CO 2 emissions and increases in atmospheric CO 2 levels, and the potential impacts of a greenhouse gas-induced climate change; it is important that comprehensive CO 2 emissions records be compiled, maintained, updated, and documented

Climate change and air quality - measures with co-benefits in China

Energy Technology Data Exchange (ETDEWEB)

Kristin Aunan; Jinghua Fang; Tao Hu; Hans Martin Seip; Haakon Vennemo [Center for International Climate and Environmental Research-Oslo (CICERO) (Norway)

2006-08-15

Several studies carried out in China over the past 5-10 years, including the authors own work, have found that many measures aimed primarily at reducing local air pollution decrease GHG emissions as a co-benefit. Conversely, a range of CO{sub 2} mitigation policies entail reductions in air pollution as a co-benefit. This implies that the real costs of climate policies in China may be lower than anticipated by the government. This article describes the links between climate change and air quality issues as well as the health and environmental benefits accruing from alterative measures and policies for CO{sub 2} mitigation in China where coal is expected to remain a main energy source for many years to come. The tremendous potential to cut GHG emissions while simultaneously reducing air pollution should make cooperation on climate control strategies more attractive to China and other countries in a similar position. 43 refs., 3 figs., 1 tab.

Are forest disturbances amplifying or canceling out climate change-induced productivity changes in European forests?

Science.gov (United States)

Reyer, Christopher P. O.; Bathgate, Stephen; Blennow, Kristina; Borges, Jose G.; Bugmann, Harald; Delzon, Sylvain; Faias, Sonia P.; Garcia-Gonzalo, Jordi; Gardiner, Barry; Gonzalez-Olabarria, Jose Ramon; Gracia, Carlos; Guerra Hernández, Juan; Kellomäki, Seppo; Kramer, Koen; Lexer, Manfred J.; Lindner, Marcus; van der Maaten, Ernst; Maroschek, Michael; Muys, Bart; Nicoll, Bruce; Palahi, Marc; Palma, João HN; Paulo, Joana A.; Peltola, Heli; Pukkala, Timo; Rammer, Werner; Ray, Duncan; Sabaté, Santiago; Schelhaas, Mart-Jan; Seidl, Rupert; Temperli, Christian; Tomé, Margarida; Yousefpour, Rasoul; Zimmermann, Niklaus E.; Hanewinkel, Marc

2017-03-01

Recent studies projecting future climate change impacts on forests mainly consider either the effects of climate change on productivity or on disturbances. However, productivity and disturbances are intrinsically linked because 1) disturbances directly affect forest productivity (e.g. via a reduction in leaf area, growing stock or resource-use efficiency), and 2) disturbance susceptibility is often coupled to a certain development phase of the forest with productivity determining the time a forest is in this specific phase of susceptibility. The objective of this paper is to provide an overview of forest productivity changes in different forest regions in Europe under climate change, and partition these changes into effects induced by climate change alone and by climate change and disturbances. We present projections of climate change impacts on forest productivity from state-of-the-art forest models that dynamically simulate forest productivity and the effects of the main European disturbance agents (fire, storm, insects), driven by the same climate scenario in seven forest case studies along a large climatic gradient throughout Europe. Our study shows that, in most cases, including disturbances in the simulations exaggerate ongoing productivity declines or cancel out productivity gains in response to climate change. In fewer cases, disturbances also increase productivity or buffer climate-change induced productivity losses, e.g. because low severity fires can alleviate resource competition and increase fertilization. Even though our results cannot simply be extrapolated to other types of forests and disturbances, we argue that it is necessary to interpret climate change-induced productivity and disturbance changes jointly to capture the full range of climate change impacts on forests and to plan adaptation measures.

Are forest disturbances amplifying or canceling out climate change-induced productivity changes in European forests?

Science.gov (United States)

Reyer, Christopher P O; Bathgate, Stephen; Blennow, Kristina; Borges, Jose G; Bugmann, Harald; Delzon, Sylvain; Faias, Sonia P; Garcia-Gonzalo, Jordi; Gardiner, Barry; Gonzalez-Olabarria, Jose Ramon; Gracia, Carlos; Hernández, Juan Guerra; Kellomäki, Seppo; Kramer, Koen; Lexer, Manfred J; Lindner, Marcus; van der Maaten, Ernst; Maroschek, Michael; Muys, Bart; Nicoll, Bruce; Palahi, Marc; Palma, João HN; Paulo, Joana A; Peltola, Heli; Pukkala, Timo; Rammer, Werner; Ray, Duncan; Sabaté, Santiago; Schelhaas, Mart-Jan; Seidl, Rupert; Temperli, Christian; Tomé, Margarida; Yousefpour, Rasoul; Zimmermann, Niklaus E; Hanewinkel, Marc

2017-01-01

Recent studies projecting future climate change impacts on forests mainly consider either the effects of climate change on productivity or on disturbances. However, productivity and disturbances are intrinsically linked because 1) disturbances directly affect forest productivity (e.g. via a reduction in leaf area, growing stock or resource-use efficiency), and 2) disturbance susceptibility is often coupled to a certain development phase of the forest with productivity determining the time a forest is in this specific phase of susceptibility. The objective of this paper is to provide an overview of forest productivity changes in different forest regions in Europe under climate change, and partition these changes into effects induced by climate change alone and by climate change and disturbances. We present projections of climate change impacts on forest productivity from state-of-the-art forest models that dynamically simulate forest productivity and the effects of the main European disturbance agents (fire, storm, insects), driven by the same climate scenario in seven forest case studies along a large climatic gradient throughout Europe. Our study shows that, in most cases, including disturbances in the simulations exaggerate ongoing productivity declines or cancel out productivity gains in response to climate change. In fewer cases, disturbances also increase productivity or buffer climate-change induced productivity losses, e.g. because low severity fires can alleviate resource competition and increase fertilization. Even though our results cannot simply be extrapolated to other types of forests and disturbances, we argue that it is necessary to interpret climate change-induced productivity and disturbance changes jointly to capture the full range of climate change impacts on forests and to plan adaptation measures. PMID:28855959

Adaptation, Spatial Heterogeneity, and the Vulnerability of Agricultural Systems to Climate Change and CO2 Fertilization: An Integrated Assessment Approach

International Nuclear Information System (INIS)

Antle, J.M.; Capalbo, S.M.; Elliott, E.T.; Paustian, K.H.

2004-01-01

In this paper we develop economic measures of vulnerability to climate change with and without adaptation in agricultural production systems. We implement these measures using coupled, site-specific ecosystem and economic simulation models. This modeling approach has two key features needed to study the response of agricultural production systems to climate change: it represents adaptation as an endogenous, non-marginal economic response to climate change; and it provides the capability to represent the spatial variability in bio-physical and economic conditions that interact with adaptive responses. We apply this approach to the dryland grain production systems of the Northern Plains region of the United States. The results support the hypothesis that the most adverse impacts on net returns distributions tend to occur in the areas with the poorest resource endowments and when mitigating effects of CO2 fertilization and adaptation are absent. We find that relative and absolute measures of vulnerability depend on complex interactions between climate change, CO2 level, adaptation, and economic conditions such as relative output prices. The relationship between relative vulnerability and resource endowments varies with assumptions about climate change, adaptation, and economic conditions. Vulnerability measured with respect to an absolute threshold is inversely related to resource endowments in all cases investigated

Long-term ecophysiological responses to climate change

DEFF Research Database (Denmark)

Boesgaard, Kristine Stove; Ro-Poulsen, Helge

Plant physiology is affected by climate change. Acclimations of photosynthetic processes are induced by short-term changes in climatic conditions. Further acclimation can be caused by longterm adjustments to climate change due to ecosystem-feedbacks. The aim of this PhD was to investigate plant...... term responses of plant physiology to the climate change factors were investigated. In the CLIMAITE-experiment it has been shown that 2 years of treatment altered physiological responses in Deschampsiaand Calluna. In the work of this PhD similar responses were observed after 6 years of treatment...... physiological responses to climate change in a seasonal and long-term perspective. The effects of elevated CO2, passive night time warming and periodic summer drought as single factor and in combination, on plant physiology were investigated in the long-term multifactorial field experiment CLIMAITE in a Danish...

Regional impacts of climate change and atmospheric CO2 on future ocean carbon uptake: A multi-model linear feedback analysis

OpenAIRE

Roy Tilla; Bopp Laurent; Gehlen Marion; Schneider Birgitt; Cadule Patricia; Frölicher Thomas; Segschneider Jochen; Tijputra Jerry; Heinze Christoph; Joos Fortunat

2011-01-01

The increase in atmospheric CO2 over this century depends on the evolution of the oceanic air–sea CO2 uptake which will be driven by the combined response to rising atmospheric CO2 itself and climate change. Here the future oceanic CO2 uptake is simulated using an ensemble of coupled climate–carbon cycle models. The models are driven by CO2 emissions from historical data and the Special Report on Emissions Scenarios (SRES) A2 high emission scenario. A linear feedback analysis successfully sep...

Ethical implications of co-benefits rationale within climate change mitigation strategy

Directory of Open Access Journals (Sweden)

Rita Vasconcellos Oliveira

2016-10-01

Full Text Available Climate change mitigation effort is being translated into several actions and discourses that make collateral benefits and their rationale increasingly relevant for sustainability, in such a way that they are now a constant part of the political agenda. Taking a border and consensual perspective, co-benefits are considered here to be emerging advantages of the implementation of measures regarding the lowering of greenhouse gases.Departing from the analysis of policy documents referring to two European urban transportation strategies, the emergent co-benefits are problematized and discussed to better understand their moral aspect. Further ethical reflection is conducted after an analysis of some unintended consequences of co-benefits rationale coming from the mentioned examples. The focus is primarily on the challenges of an integrative moral justification for co-benefits and also for their role in the climate change mitigation effort. We also discuss the limitations of the current normative models that frame co-benefits rationale, from a moral viewpoint and in relation to the overall climate change mitigation strategy.In this article, we propose the concepts of well-being and freedom, as portrayed by Capabilities Approach, as possible guiding notions for the moral and social evaluation of goodness of these emergent benefits and their rationale too. Additionally, some preliminary conclusions are drawn regarding the potential of the presented concepts to favour the climate change mitigation action. Finally, a scenario is drawn where Capabilities Approach is the moral guideline for co-benefits rationale showing this way its potential in terms of enhancing climate change mitigation strategy.

CO{sub 2} emission calculations and trends

Energy Technology Data Exchange (ETDEWEB)

Boden, T.A.; Marland, G. [Oak Ridge National Lab., TN (United States); Andres, R.J. [Alaska Univ., Fairbanks, AK (United States). Inst. of Northern Engineering

1995-12-31

Evidence that the atmospheric CO{sub 2} concentration has risen during the past several decades is irrefutable. Most of the observed increase in atmospheric CO{sub 2} is believed to result from CO{sub 2} releases from fossil-fuel burning. The United Nations (UN) Framework Convention on Climate Change (FCCC), signed in Rio de Janeiro in June 1992, reflects global concern over the increasing CO{sub 2} concentration and its potential impact on climate. One of the convention`s stated objectives was the ``stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. `` Specifically, the FCCC asked all 154 signing countries to conduct an inventory of their current greenhouse gas emissions, and it set nonbinding targets for some countries to control emissions by stabilizing them at 1990 levels by the year 2000. Given the importance of CO{sub 2} as a greenhouse gas, the relationship between CO{sub 2} emissions and increases in atmospheric CO{sub 2} levels, and the potential impacts of a greenhouse gas-induced climate change; it is important that comprehensive CO{sub 2} emissions records be compiled, maintained, updated, and documented.

CO{sub 2} Emission Calculations and Trends

Science.gov (United States)

Boden, T. A.; Marland, G.; Andres, R. J.

1995-06-01

Evidence that the atmospheric CO{sub 2}concentration has risen during the past several decades is irrefutable. Most of the observed increase in atmospheric CO{sub 2} is believed to result from CO{sub 2} releases from fossil-fuel burning. The United Nations (UN) Framework Convention on Climate Change (FCCC), signed in Rio de Janeiro in June 1992, reflects global concern over the increasing CO{sub 2} concentration and its potential impact on climate. One of the convention`s stated objectives was the stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. Specifically, the FCCC asked all 154 signing countries to conduct an inventory of their current greenhouse gas emissions, and it set nonbinding targets for some countries to control emissions by stabilizing them at 1990 levels by the year 2000. Given the importance of CO{sub 2} as a greenhouse gas, the relationship between CO{sub 2} emissions and increases in atmospheric CO{sub 2} levels, and the potential impacts of a greenhouse gas-induced climate change; it is important that comprehensive CO{sub 2} emissions records be compiled, maintained, updated, and documented.

Satellite-derived SIF and CO2 Observations Show Coherent Responses to Interannual Climate Variations

Science.gov (United States)

Butterfield, Z.; Hogikyan, A.; Kulawik, S. S.; Keppel-Aleks, G.

2017-12-01

Gross primary production (GPP) is the single largest carbon flux in the Earth system, but its sensitivity to changes in climate is subject to significant uncertainty. Satellite measurements of solar-induced chlorophyll fluorescence (SIF) offer insight into spatial and temporal patterns in GPP at a global scale and, combined with other satellite-derived datasets, provide unprecedented opportunity to explore interactions between atmospheric CO2, GPP, and climate variability. To explore potential drivers of GPP in the Northern Hemisphere (NH), we compare monthly-averaged SIF data from the Global Ozone Monitoring Experiment 2 (GOME-2) with observed anomalies in temperature (T; CRU-TS), liquid water equivalent (LWE) from the Gravity Recovery and Climate Experiment (GRACE), and photosynthetically active radiation (PAR; CERES SYN1deg). Using observations from 2007 through 2015 for several NH regions, we calculate month-specific sensitivities of SIF to variability in T, LWE, and PAR. These sensitivities provide insight into the seasonal progression of how productivity is affected by climate variability and can be used to effectively model the observed SIF signal. In general, we find that high temperatures are beneficial to productivity in the spring, but detrimental in the summer. The influences of PAR and LWE are more heterogeneous between regions; for example, higher LWE in North American temperate forest leads to decreased springtime productivity, while exhibiting a contrasting effect in water-limited regions. Lastly, we assess the influence of variations in terrestrial productivity on atmospheric carbon using a new lower tropospheric CO2 product derived from the Greenhouse Gases Observing Satellite (GOSAT). Together, these data shed light on the drivers of interannual variability in the annual cycle of NH atmospheric CO2, and may provide improved constraints on projections of long-term carbon cycle responses to climate change.

Climate and domestic projects CO{sub 2}: why and how?; Climat et projets domestiques CO{sub 2}: pourquoi et comment?

Energy Technology Data Exchange (ETDEWEB)

NONE

2006-07-01

In order to fight against the climatic change, the France decided to divide by four the greenhouse gases for 2050. With the emission trading, the industrialists and the energy producers progress in this way. But nothing is existing for the emission sectors as the transport, the agriculture, the building and for the greenhouse gases except the CO{sub 2}. The domestic projects CO{sub 2} approach aims to stimulate the realization of projects reducing the greenhouse gases emissions in these sectors, with a remuneration of these reductions. (A.L.B.)

Changes in the probability of co-occurring extreme climate events

Science.gov (United States)

Diffenbaugh, N. S.

2017-12-01

Extreme climate events such as floods, droughts, heatwaves, and severe storms exert acute stresses on natural and human systems. When multiple extreme events co-occur, either in space or time, the impacts can be substantially compounded. A diverse set of human interests - including supply chains, agricultural commodities markets, reinsurance, and deployment of humanitarian aid - have historically relied on the rarity of extreme events to provide a geographic hedge against the compounded impacts of co-occuring extremes. However, changes in the frequency of extreme events in recent decades imply that the probability of co-occuring extremes is also changing, and is likely to continue to change in the future in response to additional global warming. This presentation will review the evidence for historical changes in extreme climate events and the response of extreme events to continued global warming, and will provide some perspective on methods for quantifying changes in the probability of co-occurring extremes in the past and future.

The Political Economy of Health Co-Benefits: Embedding Health in the Climate Change Agenda

Science.gov (United States)

Workman, Annabelle; Blashki, Grant; Bowen, Kathryn J.; Karoly, David J.; Wiseman, John

2018-01-01

A complex, whole-of-economy issue such as climate change demands an interdisciplinary, multi-sectoral response. However, evidence suggests that human health has remained elusive in its influence on the development of ambitious climate change mitigation policies for many national governments, despite a recognition that the combustion of fossil fuels results in pervasive short- and long-term health consequences. We use insights from literature on the political economy of health and climate change, the science–policy interface and power in policy-making, to identify additional barriers to the meaningful incorporation of health co-benefits into climate change mitigation policy development. Specifically, we identify four key interrelated areas where barriers may exist in relation to health co-benefits: discourse, efficiency, vested interests and structural challenges. With these insights in mind, we argue that the current politico-economic paradigm in which climate change is situated and the processes used to develop climate change mitigation policies do not adequately support accounting for health co-benefits. We present approaches for enhancing the role of health co-benefits in the development of climate change mitigation policies to ensure that health is embedded in the broader climate change agenda. PMID:29617317

The Political Economy of Health Co-Benefits: Embedding Health in the Climate Change Agenda.

Science.gov (United States)

Workman, Annabelle; Blashki, Grant; Bowen, Kathryn J; Karoly, David J; Wiseman, John

2018-04-04

A complex, whole-of-economy issue such as climate change demands an interdisciplinary, multi-sectoral response. However, evidence suggests that human health has remained elusive in its influence on the development of ambitious climate change mitigation policies for many national governments, despite a recognition that the combustion of fossil fuels results in pervasive short- and long-term health consequences. We use insights from literature on the political economy of health and climate change, the science–policy interface and power in policy-making, to identify additional barriers to the meaningful incorporation of health co-benefits into climate change mitigation policy development. Specifically, we identify four key interrelated areas where barriers may exist in relation to health co-benefits: discourse, efficiency, vested interests and structural challenges. With these insights in mind, we argue that the current politico-economic paradigm in which climate change is situated and the processes used to develop climate change mitigation policies do not adequately support accounting for health co-benefits. We present approaches for enhancing the role of health co-benefits in the development of climate change mitigation policies to ensure that health is embedded in the broader climate change agenda.

Biodiversity, climate change and complexity: An opportunity for securing co-benefits?

Energy Technology Data Exchange (ETDEWEB)

Roe, Dilys

2006-10-15

Climate change and biodiversity loss are both major environmental concerns, yet the links between them often go unrecognised. Not only does the science of climate change and biodiversity share similar characteristics, but climate change both affects, and is affected by biodiversity. Diversity confers far greater resilience on natural systems, thus reducing their vulnerability – and the vulnerability of the people that depend upon them – to climate change. Yet climate adaptation and mitigation strategies that are blind to biodiversity can undermine this natural and social resilience. Ignoring the links between biodiversity and climate risks exacerbates the problems associated with climate change and represents a missed opportunity for maximising co-benefits.

Multi-model Projection of July-August Climate Extreme Changes over China under CO2 Doubling. Part Ⅰ:Precipitation

Institute of Scientific and Technical Information of China (English)

LI Hongmei; FENG Lei; ZHOU Tianjun

2011-01-01

Potential changes in precipitation extremes in July-August over China in response to CO2 doubling are analyzed based on the output of 24 coupled climate models from the Twentieth-Century Climate in Coupled Models (20C3M) experiment and the 1％ per year CO2 increase experiment (to doubling) (lpctto2x) of phase 3 of the Coupled Model Inter-comparison Project (CMIP3). Evaluation of the models' performance in simulating the mean state shows that the majority of models fairly reproduce the broad spatial pattern of observed precipitation. However, all the models underestimate extreme precipitation by ～50％. The spread among the models over the Tibetan Plateau is ～2-3 times larger than that over the other areas.Models with higher resolution generally perform better than those with lower resolutions in terms of spatial pattern and precipitation amount. Under the lpctto2x scenario, the ratio between the absolute value of MME extreme precipitation change and model spread is larger than that of total precipitation, indicating a relatively robust change of extremes. The change of extreme precipitation is more homogeneous than the total precipitation. Analysis on the output of Geophysical Fluid Dynamics Laboratory coupled climate model version 2.1 (GFDL-CM2.1) indicates that the spatially consistent increase of surface temperature and water vapor content contribute to the large increase of extreme precipitation over contiguous China,which follows the Clausius-Clapeyron relationship. Whereas, the meridionally tri-polar pattern of mean precipitation change over eastern China is dominated by the change of water vapor convergence, which is determined by the response of monsoon circulation to global warming.

CO2-Induced Changes in Wheat Grain Composition: Meta-Analysis and Response Functions

Directory of Open Access Journals (Sweden)

Malin C. Broberg

2017-04-01

Full Text Available Elevated carbon dioxide (eCO2 stimulates wheat grain yield, but simultaneously reduces protein/nitrogen (N concentration. Also, other essential nutrients are subject to change. This study is a synthesis of wheat experiments with eCO2, estimating the effects on N, minerals (B, Ca, Cd, Fe, K, Mg, Mn, Na, P, S, Zn, and starch. The analysis was performed by (i deriving response functions to assess the gradual change in element concentration with increasing CO2 concentration, (ii meta-analysis to test the average magnitude and significance of observed effects, and (iii relating CO2 effects on minerals to effects on N and grain yield. Responses ranged from zero to strong negative effects of eCO2 on mineral concentration, with the largest reductions for the nutritionally important elements of N, Fe, S, Zn, and Mg. Together with the positive but small and non-significant effect on starch concentration, the large variation in effects suggests that CO2-induced responses cannot be explained only by a simple dilution model. To explain the observed pattern, uptake and transport mechanisms may have to be considered, along with the link of different elements to N uptake. Our study shows that eCO2 has a significant effect on wheat grain stoichiometry, with implications for human nutrition in a world of rising CO2.

Rates of consumption of atmospheric CO2 through the weathering of loess during the next 100 yr of climate change

Directory of Open Access Journals (Sweden)

D. Pollard

2013-01-01

Full Text Available Quantifying how C fluxes will change in the future is a complex task for models because of the coupling between climate, hydrology, and biogeochemical reactions. Here we investigate how pedogenesis of the Peoria loess, which has been weathering for the last 13 kyr, will respond over the next 100 yr of climate change. Using a cascade of numerical models for climate (ARPEGE, vegetation (CARAIB and weathering (WITCH, we explore the effect of an increase in CO2 of 315 ppmv (1950 to 700 ppmv (2100 projection. The increasing CO2 results in an increase in temperature along the entire transect. In contrast, drainage increases slightly for a focus pedon in the south but decreases strongly in the north. These two variables largely determine the behavior of weathering. In addition, although CO2 production rate increases in the soils in response to global warming, the rate of diffusion back to the atmosphere also increases, maintaining a roughly constant or even decreasing CO2 concentration in the soil gas phase. Our simulations predict that temperature increasing in the next 100 yr causes the weathering rates of the silicates to increase into the future. In contrast, the weathering rate of dolomite – which consumes most of the CO2 – decreases in both end members (south and north of the transect due to its retrograde solubility. We thus infer slower rates of advance of the dolomite reaction front into the subsurface, and faster rates of advance of the silicate reaction front. However, additional simulations for 9 pedons located along the north–south transect show that the dolomite weathering advance rate will increase in the central part of the Mississippi Valley, owing to a maximum in the response of vertical drainage to the ongoing climate change. The carbonate reaction front can be likened to a terrestrial lysocline because it represents a depth interval over which carbonate dissolution rates increase drastically. However, in contrast to the lower

Climatic impact of aircraft induced ozone changes

Energy Technology Data Exchange (ETDEWEB)

Sausen, R; Feneberg, B; Ponater, M [Deutsche Forschungs- und Versuchsanstalt fuer Luft- und Raumfahrt e.V., Oberpfaffenhofen (Germany). Inst. fuer Physik der Atmosphaere

1998-12-31

The effect of aircraft induced ozone changes on the global climate is studied by means of the general circulation model ECHAM4. The zonal mean temperature signal is considered. In order to estimate the statistical significance of the climatic impact a multivariate statistical test hierarchy combined with the fingerprint method has been applied. Sensitivity experiments show a significant coherent temperature response pattern in the northern extra-tropics for mid-latitude summer conditions. It consists of a tropospheric warming of about 0.2 K with a corresponding stratospheric cooling of the same magnitude. (author) 16 refs.

Climatic impact of aircraft induced ozone changes

Energy Technology Data Exchange (ETDEWEB)

Sausen, R.; Feneberg, B.; Ponater, M. [Deutsche Forschungs- und Versuchsanstalt fuer Luft- und Raumfahrt e.V., Oberpfaffenhofen (Germany). Inst. fuer Physik der Atmosphaere

1997-12-31

The effect of aircraft induced ozone changes on the global climate is studied by means of the general circulation model ECHAM4. The zonal mean temperature signal is considered. In order to estimate the statistical significance of the climatic impact a multivariate statistical test hierarchy combined with the fingerprint method has been applied. Sensitivity experiments show a significant coherent temperature response pattern in the northern extra-tropics for mid-latitude summer conditions. It consists of a tropospheric warming of about 0.2 K with a corresponding stratospheric cooling of the same magnitude. (author) 16 refs.

Nitrogen mediates CO2-induced changes in rhizosphere priming effects in an aggrading forest (Invited)

Science.gov (United States)

Phillips, R.; Bernhardt, E. S.; Finzi, A.

2009-12-01

Root-induced changes in soil organic matter (SOM) decomposition are likely to provide an important feedback to carbon storage in terrestrial ecosystems but to date, there have been few measurements of such “priming effects” in forest soils. Our goal was to estimate the potential magnitude of SOM priming in a 28 year-old loblolly pine stand exposed to elevated atmospheric CO2 (ambient + 200 ppm) and nitrogen fertilization (11 g m-2 yr-1) at the Duke Forest FACE site, NC. We hypothesized that CO2- and nitrogen-induced changes in carbon supply to soil via root exudation would mediate the magnitude and timing of priming effects. Over a two-year period, trees exposed to CO2 enrichment increased dissolved carbon supply to soil by ~50% in nutrient-poor soils, resulting in a doubling of microbial biomass in the rhizosphere in the upper 10 cm of mineral soil (p proteolytic extracellular enzymes involved in SOM depolymerization, with the greatest changes occurring in non-fertilized soils. We interpret the enhanced microbial and enzyme activities in the rhizosphere as evidence of root-induced priming effects. Collectively, our results suggest that although increased carbon flux from to roots to soil may provide a mechanism for trees to accelerate soil nitrogen cycling under elevated CO2, such inputs may also accelerate SOM decomposition and thus reduce storage in the longest lived, most stable pools of carbon in aggrading forests.

Limitation of the CO2 emissions to fight the climatic change. Challenges, prevention at the source and sequestration

International Nuclear Information System (INIS)

Audibert, N.

2003-01-01

In the framework of a climatic change the CO 2 capture and sequestration is considered as an possible way of greenhouse effect gases impact decrease. Meanwhile many other actions in the energy production and consumption must also be implemented. The aim of this study is to offer a global aspect of the problem and a synthesis of bibliographic elements. The first part presents the context of the climatic change, the economical and political aspects. The second deals more specially with the actions possibilities, the energy recovery, the carbon sequestration. (A.L.B.)

Younger Dryas cooling and the Greenland climate response to CO2.

Science.gov (United States)

Liu, Zhengyu; Carlson, Anders E; He, Feng; Brady, Esther C; Otto-Bliesner, Bette L; Briegleb, Bruce P; Wehrenberg, Mark; Clark, Peter U; Wu, Shu; Cheng, Jun; Zhang, Jiaxu; Noone, David; Zhu, Jiang

2012-07-10

Greenland ice-core δ(18)O-temperature reconstructions suggest a dramatic cooling during the Younger Dryas (YD; 12.9-11.7 ka), with temperatures being as cold as the earlier Oldest Dryas (OD; 18.0-14.6 ka) despite an approximately 50 ppm rise in atmospheric CO(2). Such YD cooling implies a muted Greenland climate response to atmospheric CO(2), contrary to physical predictions of an enhanced high-latitude response to future increases in CO(2). Here we show that North Atlantic sea surface temperature reconstructions as well as transient climate model simulations suggest that the YD over Greenland should be substantially warmer than the OD by approximately 5 °C in response to increased atmospheric CO(2). Additional experiments with an isotope-enabled model suggest that the apparent YD temperature reconstruction derived from the ice-core δ(18)O record is likely an artifact of an altered temperature-δ(18)O relationship due to changing deglacial atmospheric circulation. Our results thus suggest that Greenland climate was warmer during the YD relative to the OD in response to rising atmospheric CO(2), consistent with sea surface temperature reconstructions and physical predictions, and has a sensitivity approximately twice that found in climate models for current climate due to an enhanced albedo feedback during the last deglaciation.

Modeling climatic effects of anthropogenic CO2 emissions: Unknowns and uncertainties

Science.gov (United States)

Soon, W.; Baliunas, S.; Idso, S.; Kondratyev, K. Ya.; Posmentier, E. S.

2001-12-01

A likelihood of disastrous global environmental consequences has been surmised as a result of projected increases in anthropogenic greenhouse gas emissions. These estimates are based on computer climate modeling, a branch of science still in its infancy despite recent, substantial strides in knowledge. Because the expected anthropogenic climate forcings are relatively small compared to other background and forcing factors (internal and external), the credibility of the modeled global and regional responses rests on the validity of the models. We focus on this important question of climate model validation. Specifically, we review common deficiencies in general circulation model calculations of atmospheric temperature, surface temperature, precipitation and their spatial and temporal variability. These deficiencies arise from complex problems associated with parameterization of multiply-interacting climate components, forcings and feedbacks, involving especially clouds and oceans. We also review examples of expected climatic impacts from anthropogenic CO2 forcing. Given the host of uncertainties and unknowns in the difficult but important task of climate modeling, the unique attribution of observed current climate change to increased atmospheric CO2 concentration, including the relatively well-observed latest 20 years, is not possible. We further conclude that the incautious use of GCMs to make future climate projections from incomplete or unknown forcing scenarios is antithetical to the intrinsically heuristic value of models. Such uncritical application of climate models has led to the commonly-held but erroneous impression that modeling has proven or substantiated the hypothesis that CO2 added to the air has caused or will cause significant global warming. An assessment of the positive skills of GCMs and their use in suggesting a discernible human influence on global climate can be found in the joint World Meteorological Organisation and United Nations

Deforestation Induced Climate Change: Effects of Spatial Scale.

Science.gov (United States)

Longobardi, Patrick; Montenegro, Alvaro; Beltrami, Hugo; Eby, Michael

2016-01-01

Deforestation is associated with increased atmospheric CO2 and alterations to the surface energy and mass balances that can lead to local and global climate changes. Previous modelling studies show that the global surface air temperature (SAT) response to deforestation depends on latitude, with most simulations showing that high latitude deforestation results in cooling, low latitude deforestation causes warming and that the mid latitude response is mixed. These earlier conclusions are based on simulated large scal land cover change, with complete removal of trees from whole latitude bands. Using a global climate model we examine the effects of removing fractions of 5% to 100% of forested areas in the high, mid and low latitudes. All high latitude deforestation scenarios reduce mean global SAT, the opposite occurring for low latitude deforestation, although a decrease in SAT is simulated over low latitude deforested areas. Mid latitude SAT response is mixed. In all simulations deforested areas tend to become drier and have lower SAT, although soil temperatures increase over deforested mid and low latitude grid cells. For high latitude deforestation fractions of 45% and above, larger net primary productivity, in conjunction with colder and drier conditions after deforestation cause an increase in soil carbon large enough to produce a net decrease of atmospheric CO2. Our results reveal the complex interactions between soil carbon dynamics and other climate subsystems in the energy partition responses to land cover change.

Deforestation Induced Climate Change: Effects of Spatial Scale.

Directory of Open Access Journals (Sweden)

Patrick Longobardi

Full Text Available Deforestation is associated with increased atmospheric CO2 and alterations to the surface energy and mass balances that can lead to local and global climate changes. Previous modelling studies show that the global surface air temperature (SAT response to deforestation depends on latitude, with most simulations showing that high latitude deforestation results in cooling, low latitude deforestation causes warming and that the mid latitude response is mixed. These earlier conclusions are based on simulated large scal land cover change, with complete removal of trees from whole latitude bands. Using a global climate model we examine the effects of removing fractions of 5% to 100% of forested areas in the high, mid and low latitudes. All high latitude deforestation scenarios reduce mean global SAT, the opposite occurring for low latitude deforestation, although a decrease in SAT is simulated over low latitude deforested areas. Mid latitude SAT response is mixed. In all simulations deforested areas tend to become drier and have lower SAT, although soil temperatures increase over deforested mid and low latitude grid cells. For high latitude deforestation fractions of 45% and above, larger net primary productivity, in conjunction with colder and drier conditions after deforestation cause an increase in soil carbon large enough to produce a net decrease of atmospheric CO2. Our results reveal the complex interactions between soil carbon dynamics and other climate subsystems in the energy partition responses to land cover change.

What is the role of historical anthropogenically-induced land-cover change on the surface climate of West Africa? Results from the LUCID intercomparison project

Science.gov (United States)

Souleymane, S.

2015-12-01

West Africa has been highlighted as a hot spot of land surface-atmosphere interactions. This study analyses the outputs of the project Land-Use and Climate, IDentification of Robust Impacts (LUCID) over West Africa. LUCID used seven atmosphere-land models with a common experimental design to explore the impacts of Land Use induced Land Cover Change (LULCC) that are robust and consistent across the climate models. Focusing the analysis on Sahel and Guinea, this study shows that, even though the seven climate models use the same atmospheric and land cover forcing, there are significant differences of West African Monsoon variability across the climate models. The magnitude of that variability differs significantly from model to model resulting two major "features": (1) atmosphere dynamics models; (2) how the land-surface functioning is parameterized in the Land surface Model, in particular regarding the evapotranspiration partitioning within the different land-cover types, as well as the role of leaf area index (LAI) in the flux calculations and how strongly the surface is coupled to the atmosphere. The major role that the models'sensitivity to land-cover perturbations plays in the resulting climate impacts of LULCC has been analysed in this study. The climate models show, however, significant differences in the magnitude and the seasonal partitioning of the temperature change. The LULCC induced cooling is directed by decreases in net shortwave radiation that reduced the available energy (QA) (related to changes in land-cover properties other than albedo, such as LAI and surface roughness), which decreases during most part of the year. The biophysical impacts of LULCC were compared to the impact of elevated greenhouse gases resulting changes in sea surface temperatures and sea ice extent (CO2SST). The results show that the surface cooling (related a decrease in QA) induced by the biophysical effects of LULCC are insignificant compared to surface warming (related an

Climate change research in Canada

International Nuclear Information System (INIS)

Dawson, K.

1994-01-01

The current consensus on climatic change in Canada is briefly summarized, noting the results of modelling of the effects of a doubling of atmospheric CO 2 , the nonuniformity of climate change across the country, the uncertainties in local responses to change, and the general agreement that 2-4 degrees of warming will occur for each doubling of CO 2 . Canadian government response includes programs aimed at reducing the uncertainties in the scientific understanding of climate change and in the socio-economic response to such change. Canadian climate change programs include participation in large-scale experiments on such topics as heat transport in the ocean, and sources and sinks of greenhouse gases; development of next-generation climate models; studying the social and economic effects of climate change in the Great Lakes Basin and Mackenzie River Basin; investigation of paleoclimates; and analysis of climate data for long-term trends

Climate change and agroecosystems: the effect of elevated atmospheric CO2 and temperature on crop growth, development, and yield

Directory of Open Access Journals (Sweden)

Streck Nereu Augusto

2005-01-01

Full Text Available The amount of carbon dioxide (CO2 of the Earths atmosphere is increasing, which has the potential of increasing greenhouse effect and air temperature in the future. Plants respond to environment CO2 and temperature. Therefore, climate change may affect agriculture. The purpose of this paper was to review the literature about the impact of a possible increase in atmospheric CO2 concentration and temperature on crop growth, development, and yield. Increasing CO2 concentration increases crop yield once the substrate for photosynthesis and the gradient of CO2 concentration between atmosphere and leaf increase. C3 plants will benefit more than C4 plants at elevated CO2. However, if global warming will take place, an increase in temperature may offset the benefits of increasing CO2 on crop yield.

Bacteria and Fungi Respond Differently to Multifactorial Climate Change in a Temperate Heathland, Traced with 13C-Glycine and FACE CO2

Science.gov (United States)

Andresen, Louise C.; Dungait, Jennifer A. J.; Bol, Roland; Selsted, Merete B.; Ambus, Per; Michelsen, Anders

2014-01-01

It is vital to understand responses of soil microorganisms to predicted climate changes, as these directly control soil carbon (C) dynamics. The rate of turnover of soil organic carbon is mediated by soil microorganisms whose activity may be affected by climate change. After one year of multifactorial climate change treatments, at an undisturbed temperate heathland, soil microbial community dynamics were investigated by injection of a very small concentration (5.12 µg C g−1 soil) of 13C-labeled glycine (13C2, 99 atom %) to soils in situ. Plots were treated with elevated temperature (+1°C, T), summer drought (D) and elevated atmospheric carbon dioxide (510 ppm [CO2]), as well as combined treatments (TD, TCO2, DCO2 and TDCO2). The 13C enrichment of respired CO2 and of phospholipid fatty acids (PLFAs) was determined after 24 h. 13C-glycine incorporation into the biomarker PLFAs for specific microbial groups (Gram positive bacteria, Gram negative bacteria, actinobacteria and fungi) was quantified using gas chromatography-combustion-stable isotope ratio mass spectrometry (GC-C-IRMS). Gram positive bacteria opportunistically utilized the freshly added glycine substrate, i.e. incorporated 13C in all treatments, whereas fungi had minor or no glycine derived 13C-enrichment, hence slowly reacting to a new substrate. The effects of elevated CO2 did suggest increased direct incorporation of glycine in microbial biomass, in particular in G+ bacteria, in an ecosystem subjected to elevated CO2. Warming decreased the concentration of PLFAs in general. The FACE CO2 was 13C-depleted (δ13C = 12.2‰) compared to ambient (δ13C = ∼−8‰), and this enabled observation of the integrated longer term responses of soil microorganisms to the FACE over one year. All together, the bacterial (and not fungal) utilization of glycine indicates substrate preference and resource partitioning in the microbial community, and therefore suggests a diversified response pattern to future

Bacteria and fungi respond differently to multifactorial climate change in a temperate heathland, traced with 13C-glycine and FACE CO2.

Directory of Open Access Journals (Sweden)

Louise C Andresen

Full Text Available It is vital to understand responses of soil microorganisms to predicted climate changes, as these directly control soil carbon (C dynamics. The rate of turnover of soil organic carbon is mediated by soil microorganisms whose activity may be affected by climate change. After one year of multifactorial climate change treatments, at an undisturbed temperate heathland, soil microbial community dynamics were investigated by injection of a very small concentration (5.12 µg C g(-1 soil of (13C-labeled glycine ((13C2, 99 atom % to soils in situ. Plots were treated with elevated temperature (+1°C, T, summer drought (D and elevated atmospheric carbon dioxide (510 ppm [CO2], as well as combined treatments (TD, TCO2, DCO2 and TDCO2. The (13C enrichment of respired CO2 and of phospholipid fatty acids (PLFAs was determined after 24 h. (13C-glycine incorporation into the biomarker PLFAs for specific microbial groups (Gram positive bacteria, Gram negative bacteria, actinobacteria and fungi was quantified using gas chromatography-combustion-stable isotope ratio mass spectrometry (GC-C-IRMS. Gram positive bacteria opportunistically utilized the freshly added glycine substrate, i.e. incorporated (13C in all treatments, whereas fungi had minor or no glycine derived (13C-enrichment, hence slowly reacting to a new substrate. The effects of elevated CO2 did suggest increased direct incorporation of glycine in microbial biomass, in particular in G(+ bacteria, in an ecosystem subjected to elevated CO2. Warming decreased the concentration of PLFAs in general. The FACE CO2 was (13C-depleted (δ(13C = 12.2‰ compared to ambient (δ(13C = ∼-8‰, and this enabled observation of the integrated longer term responses of soil microorganisms to the FACE over one year. All together, the bacterial (and not fungal utilization of glycine indicates substrate preference and resource partitioning in the microbial community, and therefore suggests a diversified response pattern to

Reversibility in an Earth System model in response to CO2 concentration changes

International Nuclear Information System (INIS)

Boucher, O; Halloran, P R; Burke, E J; Doutriaux-Boucher, M; Jones, C D; Lowe, J; Ringer, M A; Robertson, E; Wu, P

2012-01-01

We use the HadGEM2-ES Earth System model to examine the degree of reversibility of a wide range of components of the Earth System under idealized climate change scenarios where the atmospheric CO 2 concentration is gradually increased to four times the pre-industrial level and then reduced at a similar rate from several points along this trajectory. While some modelled quantities respond almost immediately to the atmospheric CO 2 concentrations, others exhibit a time lag relative to the change in CO 2 . Most quantities also exhibit a lag relative to the global-mean surface temperature change, which can be described as a hysteresis behaviour. The most surprising responses are from low-level clouds and ocean stratification in the Southern Ocean, which both exhibit hysteresis on timescales longer than expected. We see no evidence of critical thresholds in these simulations, although some of the hysteresis phenomena become more apparent above 2 × CO 2 or 3 × CO 2 . Our findings have implications for the parametrization of climate impacts in integrated assessment and simple climate models and for future climate studies of geoengineering scenarios. (letter)

CO{sub 2} and climate protection. Facts, mistakes, policy; CO{sub 2} und Klimaschutz. Fakten, Irrtuemer, Politk

Energy Technology Data Exchange (ETDEWEB)

Luedecke, H.J.

2008-07-01

The author outlines the technical fundamental coherences of the CO{sub 2} problem generally clear and without unnecessary technical details. ''Which measuring methods founds on climate warning, are extrem weather disasters increasing, is the sea level raising, is a warmer climate harmful or useful, are wind turbines solar cells or biofuels meaningful, who is profitting from climate fear, which role play policy and ideology?'' are questions this book dealt with. Expert fundamentals, not political opinions are derived from reports of Intergovernmental Panel on Climate Change (IPCC), the climatic department of the UN, reference items from internet contributions and specialist books. (GL)

Gender and climate change-induced conflict in pastoral communities

African Journals Online (AJOL)

Clitmate change-induced conflict is a major global threat to human security and the environment. It has been projected that there is going to be an increase in climate changes resulting in increased droughts and floods in northern Kenya. Climate change impacts will be differently distributed among different regions, ages, ...

Climate Impacts of Fire-Induced Land-Surface Changes

Science.gov (United States)

Liu, Y.; Hao, X.; Qu, J. J.

2017-12-01

One of the consequences of wildfires is the changes in land-surface properties such as removal of vegetation. This will change local and regional climate through modifying the land-air heat and water fluxes. This study investigates mechanism by developing and a parameterization of fire-induced land-surface property changes and applying it to modeling of the climate impacts of large wildfires in the United States. Satellite remote sensing was used to quantitatively evaluate the land-surface changes from large fires provided from the Monitoring Trends in Burning Severity (MTBS) dataset. It was found that the changes in land-surface properties induced by fires are very complex, depending on vegetation type and coverage, climate type, season and time after fires. The changes in LAI are remarkable only if the actual values meet a threshold. Large albedo changes occur in winter for fires in cool climate regions. The signs are opposite between the first post-fire year and the following years. Summer day-time temperature increases after fires, while nigh-time temperature changes in various patterns. The changes are larger in forested lands than shrub / grassland lands. In the parameterization scheme, the detected post-fire changes are decomposed into trends using natural exponential functions and fluctuations of periodic variations with the amplitudes also determined by natural exponential functions. The final algorithm is a combination of the trends, periods, and amplitude functions. This scheme is used with Earth system models to simulate the local and regional climate effects of wildfires.

Environmental and societal consequences of a possible CO/sub 2/-induced climate change. Volume II, Part 8. Impacts of rising atmospheric carbon dioxide levels on agricultural growing seasons and crop water use efficiencies

Energy Technology Data Exchange (ETDEWEB)

Newman, J. E.

1982-09-01

The researchable areas addressed relate to the possible impacts of climate change on agricultural growing seasons and crop adaptation responses on a global basis. The research activities proposed are divided into the following two main areas of investigation: anticipated climate change impacts on the physical environmental characteristics of the agricultural growing seasons and, the most probable food crop responses to the possible changes in atmospheric CO/sub 2/ levels in plant environments. The main physical environmental impacts considered are the changes in temperature, or more directly, thermal energy levels and the growing season evapotranspiration-precipitation balances. The resulting food crop, commercial forest and rangeland species response impacts addressed relate to potential geographical shifts in agricultural growing seasons as determined by the length in days of the frost free period, thermal energy changes and water balance changes. In addition, the interaction of possible changes in plant water use efficiencies during the growing season in relationship to changing atmospheric CO/sub 2/ concentrations, is also considered under the scenario of global warming due to increases in atmospheric CO/sub 2/ concentration. These proposed research investigations are followed by adaptive response evaluations.

Evaluation of co-benefits from combined climate change and air pollution reduction strategies

Science.gov (United States)

Leitao, Joana; Van Dingenen, Rita; Dentener, Frank; Rao, Shilpa

2014-05-01

The connection of climate change and air pollution is becoming more relevant in the process of policy making and implementation of emission control strategies because of resulting co-benefits and trade-offs. Some sectors, such as fossil fuel combustion, are sources of both pollutants (NOx and PM) as well as greenhouse gas (CO2). Additionally, the use of wood burning as biofuel to reduce climate impact may in fact deteriorate air quality. Furthermore, several air pollutants are important radiative forcers and regulating their emissions impacts on climate. It is evident that both problems need to be undertaken with a common strategy and the existence of cross-policy with co-benefits may encourage their implementation. The LIMITS FP7 project (http://www.feem-project.net/limits/index.html) was designed with the main goal of assessing strategies for reduction of GHG emissions so that the 2°C target can be achieved. The work developed focus on the evaluation of the implementation of strategies analysing several aspects of different scenarios, namely: the feasibility of low carbon scenarios in terms of available technologies and infrastructure, the required financial mechanisms, and also the co-benefits regarding energy security, economic development and air pollution. For the latter, five integrated assessment models (IAMs) provided greenhouse gases and pollutant emission values for several scenarios. These were based on air pollution scenarios defined according to stringency and implementation of future global legislation. They which were also combined with 2 climate policy scenarios (no climate policy and 2.8 W/m2 target). The former are mostly focused on non-climate policies and technical control measures for emissions of air pollutants, such as PM2.5, NOx and SO2, with their emission factors harmonized between the IAMs. With the global air quality source-receptor model TM5-FASST the impact of the resulting emissions was analysed and the co-benefits of combined

Past temperature reconstructions from deep ice cores: relevance for future climate change

Directory of Open Access Journals (Sweden)

V. Masson-Delmotte

2006-01-01

Full Text Available Ice cores provide unique archives of past climate and environmental changes based only on physical processes. Quantitative temperature reconstructions are essential for the comparison between ice core records and climate models. We give an overview of the methods that have been developed to reconstruct past local temperatures from deep ice cores and highlight several points that are relevant for future climate change. We first analyse the long term fluctuations of temperature as depicted in the long Antarctic record from EPICA Dome C. The long term imprint of obliquity changes in the EPICA Dome C record is highlighted and compared to simulations conducted with the ECBILT-CLIO intermediate complexity climate model. We discuss the comparison between the current interglacial period and the long interglacial corresponding to marine isotopic stage 11, ~400 kyr BP. Previous studies had focused on the role of precession and the thresholds required to induce glacial inceptions. We suggest that, due to the low eccentricity configuration of MIS 11 and the Holocene, the effect of precession on the incoming solar radiation is damped and that changes in obliquity must be taken into account. The EPICA Dome C alignment of terminations I and VI published in 2004 corresponds to a phasing of the obliquity signals. A conjunction of low obliquity and minimum northern hemisphere summer insolation is not found in the next tens of thousand years, supporting the idea of an unusually long interglacial ahead. As a second point relevant for future climate change, we discuss the magnitude and rate of change of past temperatures reconstructed from Greenland (NorthGRIP and Antarctic (Dome C ice cores. Past episodes of temperatures above the present-day values by up to 5°C are recorded at both locations during the penultimate interglacial period. The rate of polar warming simulated by coupled climate models forced by a CO2 increase of 1% per year is compared to ice

The role of non-CO2 mitigation within the dairy sector in pursuing climate goals

Science.gov (United States)

Rolph, K.; Forest, C. E.

2017-12-01

Mitigation of non-CO2 climate forcing agents must complement the mitigation of carbon dioxide (CO2) to achieve long-term temperature and climate policy goals. By using multi-gas mitigation strategies, society can limit the rate of temperature change on decadal timescales and reduce the cost of implementing policies that only consider CO2 mitigation. The largest share of global non-CO2 greenhouse gas emissions is attributed to agriculture, with activities related to dairy production contributing the most in this sector. Approximately 4% of global anthropogenic greenhouse gas emissions is released from the dairy sub-sector, primarily through enteric fermentation, feed production, and manure management. Dairy farmers can significantly reduce their emissions by implementing better management practices. This study assesses the potential mitigation of projected climate change if greenhouse gases associated with the dairy sector were reduced. To compare the performance of several mitigation measures under future climate change, we employ a fully coupled earth system model of intermediate complexity, the MIT Integrated Global System Model (IGSM). The model includes an interactive carbon-cycle capable of addressing important feedbacks between the climate and terrestrial biosphere. Mitigation scenarios are developed using estimated emission reductions of implemented management practices studied by the USDA-funded Sustainable Dairy Project (Dairy-CAP). We examine pathways to reach the US dairy industry's voluntary goal of reducing dairy emissions 25% by 2020. We illustrate the importance of ongoing mitigation efforts in the agricultural industry to reduce non-CO2 greenhouse gas emissions towards established climate goals.

Climate and domestic projects CO2: why and how?

International Nuclear Information System (INIS)

2006-01-01

In order to fight against the climatic change, the France decided to divide by four the greenhouse gases for 2050. With the emission trading, the industrialists and the energy producers progress in this way. But nothing is existing for the emission sectors as the transport, the agriculture, the building and for the greenhouse gases except the CO 2 . The domestic projects CO 2 approach aims to stimulate the realization of projects reducing the greenhouse gases emissions in these sectors, with a remuneration of these reductions. (A.L.B.)

Climate Change Mitigation Pathways for Southeast Asia: CO2 Emissions Reduction Policies for the Energy and Transport Sectors

Directory of Open Access Journals (Sweden)

Lew Fulton

2017-07-01

Full Text Available As of June 2017, 150 countries have ratified the Paris Climate Agreement. This agreement calls for, among other things, strong reductions in CO2 emissions by 2030 and beyond. This paper reviews the Nationally Determined Contribution (NDCs plans of six Association of Southeast Asian Nations (ASEAN countries and compares their current and projected future CO2 levels across sectors, and their stated targets in the context of their economic and demographic situations. This comparison reveals wide variations in the types of targets, with the “ambition” level changing as the perspective changes from total CO2 to CO2/capita and per unit gross domestic product (GDP. We also review national plans as stated in NDCs and find that while there are many types of policies listed, few are quantified and no attempts are made to score individual or groups of policies for their likelihood in achieving stated targets. We conclude that more analysis is needed to better understand the possible impacts of current policies and plans on CO2 emissions, and whether current plans are adequate to hit targets. Considerations on better aligning targets are also provided.

Using species co-occurrence networks to assess the impacts of climate change

DEFF Research Database (Denmark)

Bastos Araujo, Miguel; Rozenfeld, Alejandro; Rahbek, Carsten

2011-01-01

Viable populations of species occur in a given place if three conditions are met: the environment at the place is suitable; the species is able to colonize it; co-occurrence is possible despite or because of interactions with other species. Studies investigating the effects of climate change...... on species have mainly focused on measuring changes in climate suitability. Complex interactions among species have rarely been explored in such studies. We extend network theory to the analysis of complex patterns of co-occurrence among species. The framework is used to explore the robustness of networks...... under climate change. With our data, we show that networks describing the geographic pattern of co-occurrence among species display properties shared by other complex networks, namely that most species are poorly connected to other species in the network and only a few are highly connected. In our...

CO2 forcing induces semi-direct effects with consequences for climate feedback interpretations

Science.gov (United States)

Andrews, Timothy; Forster, Piers M.

2008-02-01

Climate forcing and feedbacks are diagnosed from seven slab-ocean GCMs for 2 × CO2 using a regression method. Results are compared to those using conventional methodologies to derive a semi-direct forcing due to tropospheric adjustment, analogous to the semi-direct effect of absorbing aerosols. All models show a cloud semi-direct effect, indicating a rapid cloud response to CO2; cloud typically decreases, enhancing the warming. Similarly there is evidence of semi-direct effects from water-vapour, lapse-rate, ice and snow. Previous estimates of climate feedbacks are unlikely to have taken these semi-direct effects into account and so misinterpret processes as feedbacks that depend only on the forcing, but not the global surface temperature. We show that the actual cloud feedback is smaller than what previous methods suggest and that a significant part of the cloud response and the large spread between previous model estimates of cloud feedback is due to the semi-direct forcing.

Chronic disease and climate change: understanding co-benefits and their policy implications.

Science.gov (United States)

Capon, Anthony G; Rissel, Chris E

2010-01-01

Chronic disease and climate change are major public policy challenges facing governments around the world. An improved understanding of the relationship between chronic disease and climate change should enable improved policy formulation to support both human health and the health of the planet. Chronic disease and climate change are both unintended consequences of our way of life, and are attributable in part to the ready availability of inexpensive fossil fuel energy. There are co-benefits for health from actions to address climate change. For example, substituting physical activity and a vegetable-rich diet for motor vehicle transport and a meat-rich diet is both good for health and good for the planet. We should encourage ways of living that use less carbon as these can be healthy ways of living, for both individuals and society. Quantitative modelling of co-benefits should inform policy responses.

Climate change mitigation in China

Energy Technology Data Exchange (ETDEWEB)

Xu, Bo

2012-07-01

China has been experiencing great economic development and fast urbanisation since its reforms and opening-up policy in 1978. However, these changes are reliant on consumption of primary energy, especially coal, characterised by high pollution and low efficiency. China's greenhouse gas (GHG) emissions, with carbon dioxide (CO{sub 2}) being the most significant contributor, have also been increasing rapidly in the past three decades. Responding to both domestic challenges and international pressure regarding energy, climate change and environment, the Chinese government has made a point of addressing climate change since the early 2000s. This thesis provides a comprehensive analysis of China's CO{sub 2} emissions and policy instruments for mitigating climate change. In the analysis, China's CO{sub 2} emissions in recent decades were reviewed and the Environmental Kuznets Curve (EKC) hypothesis examined. Using the mostly frequently studied macroeconomic factors and time-series data for the period of 1980-2008, the existence of an EKC relationship between CO{sub 2} per capita and GDP per capita was verified. However, China's CO{sub 2} emissions will continue to grow over coming decades and the turning point in overall CO{sub 2} emissions will appear in 2078 according to a crude projection. More importantly, CO{sub 2} emissions will not spontaneously decrease if China continues to develop its economy without mitigating climate change. On the other hand, CO{sub 2} emissions could start to decrease if substantial efforts are made. China's present mitigation target, i.e. to reduce CO{sub 2} emissions per unit of GDP by 40-45 % by 2020 compared with the 2005 level, was then evaluated. Three business-as-usual (BAU) scenarios were developed and compared with the level of emissions according to the mitigation target. The calculations indicated that decreasing the CO{sub 2} intensity of GDP by 40-45 % by 2020 is a challenging but hopeful target. To

Carbon Disulfide (CS2) Mechanisms in Formation of Atmospheric Carbon Dioxide (CO2) Formation from Unconventional Shale Gas Extraction and Processing Operations and Global Climate Change.

Science.gov (United States)

Rich, Alisa L; Patel, Jay T

2015-01-01

Carbon disulfide (CS2) has been historically associated with the production of rayon, cellophane, and carbon tetrachloride. This study identifies multiple mechanisms by which CS2 contributes to the formation of CO2 in the atmosphere. CS2 and other associated sulfide compounds were found by this study to be present in emissions from unconventional shale gas extraction and processing (E&P) operations. The breakdown products of CS2; carbonyl sulfide (COS), carbon monoxide (CO), and sulfur dioxide (SO2) are indirect greenhouse gases (GHGs) that contribute to CO2 levels in the atmosphere. The heat-trapping nature of CO2 has been found to increase the surface temperature, resulting in regional and global climate change. The purpose of this study is to identify five mechanisms by which CS2 and the breakdown products of CS2 contribute to atmospheric concentrations of CO2. The five mechanisms of CO2 formation are as follows: Chemical Interaction of CS2 and hydrogen sulfide (H2S) present in natural gas at high temperatures, resulting in CO2 formation;Combustion of CS2 in the presence of oxygen producing SO2 and CO2;Photolysis of CS2 leading to the formation of COS, CO, and SO2, which are indirect contributors to CO2 formation;One-step hydrolysis of CS2, producing reactive intermediates and ultimately forming H2S and CO2;Two-step hydrolysis of CS2 forming the reactive COS intermediate that reacts with an additional water molecule, ultimately forming H2S and CO2. CS2 and COS additionally are implicated in the formation of SO2 in the stratosphere and/or troposphere. SO2 is an indirect contributor to CO2 formation and is implicated in global climate change.

Biotic and Biogeochemical Feedbacks to Climate Change

Science.gov (United States)

Torn, M. S.; Harte, J.

2002-12-01

Feedbacks to paleoclimate change are evident in ice core records showing correlations of temperature with carbon dioxide, nitrous oxide, and methane. Such feedbacks may be explained by plant and microbial responses to climate change, and are likely to occur under impending climate warming, as evidenced by results of ecosystem climate manipulation experiments and biometeorological observations along ecological and climate gradients. Ecosystems exert considerable influence on climate, by controlling the energy and water balance of the land surface as well as being sinks and sources of greenhouse gases. This presentation will focus on biotic and biogeochemical climate feedbacks on decadal to century time scales, emphasizing carbon storage and energy exchange. In addition to the direct effects of climate on decomposition rates and of climate and CO2 on plant productivity, climate change can alter species composition; because plant species differ in their surface properties, productivity, phenology, and chemistry, climate-induced changes in plant species composition can exert a large influence on the magnitude and sign of climate feedbacks. We discuss the effects of plant species on ecosystem carbon storage that result from characteristic differences in plant biomass and lifetime, allocation to roots vs. leaves, litter quality, microclimate for decomposition and the ultimate stabilization of soil organic matter. We compare the effect of species transitions on transpiration, albedo, and other surface properties, with the effect of elevated CO2 and warming on single species' surface exchange. Global change models and experiments that investigate the effect of climate only on existing vegetation may miss the biggest impacts of climate change on biogeochemical cycling and feedbacks. Quantification of feedbacks will require understanding how species composition and long-term soil processes will change under global warming. Although no single approach, be it experimental

Atmospheric deposition, CO2, and change in the land carbon sink

DEFF Research Database (Denmark)

Martinez-Fernandez, Cristina; Vicca, Sara; Janssens, Ivan A.

2017-01-01

Concentrations of atmospheric carbon dioxide (CO2) have continued to increase whereas atmospheric deposition of sulphur and nitrogen has declined in Europe and the USA during recent decades. Using time series of flux observations from 23 forests distributed throughout Europe and the USA, and gene...... show the need to include the effects of changing atmospheric composition, beyond CO2, to assess future dynamics of carbon-climate feedbacks not currently considered in earth system/climate modelling....

Multi-factor climate change effects on insect herbivore performance

DEFF Research Database (Denmark)

Scherber, Christoph; Gladbach, David J; Stevnbak, Karen

2013-01-01

The impact of climate change on herbivorous insects can have far-reaching consequences for ecosystem processes. However, experiments investigating the combined effects of multiple climate change drivers on herbivorous insects are scarce. We independently manipulated three climate change drivers (CO...... suturalis Thomson), an important herbivore on heather, to ambient versus elevated drought, temperature, and CO2 (plus all combinations) for 5 weeks. Larval weight and survival were highest under ambient conditions and decreased significantly with the number of climate change drivers. Weight was lowest under...... the drought treatment, and there was a three-way interaction between time, CO2, and drought. Survival was lowest when drought, warming, and elevated CO2 were combined. Effects of climate change drivers depended on other co-acting factors and were mediated by changes in plant secondary compounds, nitrogen...

Experimental design of multifactor climate change experiments with elevated CO2, warming and drought: the CLIMAITE project

DEFF Research Database (Denmark)

Mikkelsen, Teis Nørgaard; Beier, Claus; Jonasson, S.

2008-01-01

a larger set of main factors are needed. We describe a new Danish climate change-related field scale experiment, CLIMAITE, in a heath/grassland ecosystem. CLIMAITE is a full factorial combination of elevated CO2, elevated temperature and prolonged summer drought. The manipulations are intended to mimic...... anticipated major environmental changes at the site by year 2075 as closely as possible. The impacts on ecosystem processes and functioning (at ecophysiological levels, through responses by individuals and communities to ecosystem-level responses) are investigated simultaneously. The increase of [CO2] closely...... corresponds with the scenarios for year 2075, while the warming treatment is at the lower end of the predictions and seems to be the most difficult treatment to increase without unwanted side effects on the other variables. The drought treatment follows predictions of increased frequency of drought periods...

Sensitivity of agricultural runoff loads to rising levels of CO2 and climate change in the San Joaquin Valley watershed of California

International Nuclear Information System (INIS)

Ficklin, Darren L.; Luo Yuzhou; Luedeling, Eike; Gatzke, Sarah E.; Zhang Minghua

2010-01-01

The Soil and Water Assessment Tool (SWAT) was used to assess the impact of climate change on sediment, nitrate, phosphorus and pesticide (diazinon and chlorpyrifos) runoff in the San Joaquin watershed in California. This study used modeling techniques that include variations of CO 2 , temperature, and precipitation to quantify these responses. Precipitation had a greater impact on agricultural runoff compared to changes in either CO 2 concentration or temperature. Increase of precipitation by ±10% and ±20% generally changed agricultural runoff proportionally. Solely increasing CO 2 concentration resulted in an increase in nitrate, phosphorus, and chlorpyrifos yield by 4.2, 7.8, and 6.4%, respectively, and a decrease in sediment and diazinon yield by 6.3 and 5.3%, respectively, in comparison to the present-day reference scenario. Only increasing temperature reduced yields of all agricultural runoff components. The results suggest that agricultural runoff in the San Joaquin watershed is sensitive to precipitation, temperature, and CO 2 concentration changes. - Agricultural runoff is significantly affected by changes in precipitation, temperature, and atmospheric CO 2 concentration.

Dangerous anthropogenic interference, dangerous climatic change, and harmful climatic change. Non-trivial distinctions with significant policy implications

International Nuclear Information System (INIS)

Harvey, L.D.D.

2007-01-01

Article 2 of the United Nations Framework Convention on Climate Change (UNFCCC) calls for stabilization of greenhouse gas (GHG) concentrations at levels that prevent dangerous anthropogenic interference (DAI) in the climate system. However, some of the recent policy literature has focused on dangerous climatic change (DCC) rather than on DAI. DAI is a set of increases in GHGs concentrations that has a non-negligible possibility of provoking changes in climate that in turn have a non-negligible possibility of causing unacceptable harm, including harm to one or more of ecosystems, food production systems, and sustainable socio-economic systems, whereas DCC is a change of climate that has actually occurred or is assumed to occur and that has a non-negligible possibility of causing unacceptable harm. If the goal of climate policy is to prevent DAI, then the determination of allowable GHG concentrations requires three inputs: the probability distribution function (pdf) for climate sensitivity, the pdf for the temperature change at which significant harm occurs, and the allowed probability ('risk') of incurring harm previously deemed to be unacceptable. If the goal of climate policy is to prevent DCC, then one must know what the correct climate sensitivity is (along with the harm pdf and risk tolerance) in order to determine allowable GHG concentrations. DAI from elevated atmospheric CO2 also arises through its impact on ocean chemistry as the ocean absorbs CO2. The primary chemical impact is a reduction in the degree of supersaturation of ocean water with respect to calcium carbonate, the structural building material for coral and for calcareous phytoplankton at the base of the marine food chain. Here, the probability of significant harm (in particular, impacts violating the subsidiary conditions in Article 2 of the UNFCCC) is computed as a function of the ratio of total GHG radiative forcing to the radiative forcing for a CO2 doubling, using two alternative pdfs for

Implications of Future Water Use Efficiency for Ecohydrological Responses to Climate Change and Spatial Heterogeneity of Atmospheric CO2 in China

Directory of Open Access Journals (Sweden)

Zhen Zhang

2013-01-01

Full Text Available As the atmospheric carbon dioxide (CO2 increases substantially, the spatial distribution of atmospheric CO2 should be considered when estimating the effects of CO2 on the carbon and water cycle coupling of terrestrial ecosystems. To evaluate this effect on future ecohydrological processes, the spatial-temporal patterns of CO2 were established over 1951 - 2099 according to the IPCC emission scenarios SRES A2 and SRES B1. Thereafter, water use efficiency (WUE was used (i.e., Net Primary Production/Evaportranspiration as an indicator to quantify the effects of climate change and uneven CO2 fertilization in China. We carried out several simulated experiments to estimate WUE under different future scenarios using a land process model (Integrated Biosphere Simulator, IBIS. Results indicated that the geographical distributions of averaged WUE have considerable differences under a heterogeneous atmospheric CO2 condition. Under the SRES A2 scenario, WUE decreased slightly with a 5% value in most areas of the southeastern and northwestern China during the 2050s, while decreasing by approximately 15% in southeastern China during the 2090s. During the period of the 2050s under SRES B1 scenario, the change rate of WUE was similar with that under SRES A2 scenario, but the WUE has a more moderate decreasing trend than that under the SRES A2 scenario. In all, the ecosystems in median and low latitude areas had a weakened effect on resisting extreme climate event such as drought. Conversely, the vegetation in a boreal forest had an enhanced buffering capability to tolerate drought events.

Changes of the climate induced by trace gases. Current state of research

Energy Technology Data Exchange (ETDEWEB)

Grassl, H

1987-02-01

Any attempt of predicting climatic changes is a very different task, because it requires good insight into and knowledge of a complex system whose components respond very differently in terms of time. Hence there remain many uncertainties in efforts towards 'predicting' climatic changes considering the enhancing greenhouse effect. As with all environmental problems, the best reaction is to conserve resources, and systematically explore the interactions. Reducing the CO/sub 2/, for instance, will be highly awarded. (orig./HSCH).

Sensitivity of the Eocene climate to CO2 and orbital variability

Science.gov (United States)

Keery, John S.; Holden, Philip B.; Edwards, Neil R.

2018-02-01

The early Eocene, from about 56 Ma, with high atmospheric CO2 levels, offers an analogue for the response of the Earth's climate system to anthropogenic fossil fuel burning. In this study, we present an ensemble of 50 Earth system model runs with an early Eocene palaeogeography and variation in the forcing values of atmospheric CO2 and the Earth's orbital parameters. Relationships between simple summary metrics of model outputs and the forcing parameters are identified by linear modelling, providing estimates of the relative magnitudes of the effects of atmospheric CO2 and each of the orbital parameters on important climatic features, including tropical-polar temperature difference, ocean-land temperature contrast, Asian, African and South (S.) American monsoon rains, and climate sensitivity. Our results indicate that although CO2 exerts a dominant control on most of the climatic features examined in this study, the orbital parameters also strongly influence important components of the ocean-atmosphere system in a greenhouse Earth. In our ensemble, atmospheric CO2 spans the range 280-3000 ppm, and this variation accounts for over 90 % of the effects on mean air temperature, southern winter high-latitude ocean-land temperature contrast and northern winter tropical-polar temperature difference. However, the variation of precession accounts for over 80 % of the influence of the forcing parameters on the Asian and African monsoon rainfall, and obliquity variation accounts for over 65 % of the effects on winter ocean-land temperature contrast in high northern latitudes and northern summer tropical-polar temperature difference. Our results indicate a bimodal climate sensitivity, with values of 4.36 and 2.54 °C, dependent on low or high states of atmospheric CO2 concentration, respectively, with a threshold at approximately 1000 ppm in this model, and due to a saturated vegetation-albedo feedback. Our method gives a quantitative ranking of the influence of each of the

CO{sub 2} separation

Energy Technology Data Exchange (ETDEWEB)

Hakuta, Toshikatu [National Inst. of Materials and Chemical Research, Ibaraki (Japan)

1993-12-31

The climate change induced by CO{sub 2} and other greenhouse gases is probably the most serious environmental threat that mankind has ever experienced. Nowadays fossil fuels occupy the majority of the world commercial energy supply. Most nations will be dependent on fossil fuels even in the first half of the next century. Around 30 % of CO{sub 2} in the world is emitted from thermal power plants. Recovering CO{sub 2} from energy conversion processes and storing it outside the atmosphere is a promising option for the mitigation of global warming. CO{sub 2} fixation and storage include CO{sub 2} disposal into oceans and underground, and utilization of CO{sub 2}. CO{sub 2} separation process will be used in any CO{sub 2} storage system, and is estimated to consume almost half the energy of the total system. Research and development of highly efficient CO{sub 2} separation process is most important from the viewpoint of practical application of CO{sub 2} fixation system.

Ecosystem service impacts of future changes in CO2, climate, and land use as simulated by a coupled vegetation/land-use model system

Science.gov (United States)

Rabin, S. S.; Alexander, P.; Henry, R.; Anthoni, P.; Pugh, T.; Rounsevell, M.; Arneth, A.

2017-12-01

In a future of increasing atmospheric carbon dioxide (CO2) concentrations, changing climate, increasing human populations, and changing socioeconomic dynamics, the global agricultural system will need to adapt in order to feed the world. Global modeling can help to explore what these adaptations will look like, and their potential impacts on ecosystem services. To do so, however, the complex interconnections among the atmosphere, terrestrial ecosystems, and society mean that these various parts of the Earth system must be examined as an interconnected whole. With the goal of answering these questions, a model system has been developed that couples a biologically-representative global vegetation model, LPJ-GUESS, with the PLUMv2 land use model. LPJ-GUESS first simulates—at 0.5º resolution across the world—the potential yield of various crops and pasture under a range of management intensities for a time step given its atmospheric CO2 level and climatic forcings. These potential yield simulations are fed into PLUMv2, which uses them in conjunction with endogenous agricultural commodity demand and prices to produce land use and management inputs (fertilizer and irrigation water) at a sub-national level for the next time step. This process is performed through 2100 for a range of future climate and societal scenarios—the Representative Concentration Pathways (RCPs) and the Shared Socioeconomic Pathways (SSPs), respectively—providing a thorough exploration of possible trajectories of land use and land cover change. The land use projections produced by PLUMv2 are fed back into LPJ-GUESS to simulate the future impacts of land use change, along with increasing CO2 and climate change, on terrestrial ecosystems. This integrated analysis examines the resulting impacts on regulating and provisioning ecosystem services affecting biophysics (albedo); carbon, nitrogen, and water cycling; and the emission of biogenic volatile organic compounds (BVOCs).

Changing heathlands in a changing climate

DEFF Research Database (Denmark)

Ransijn, Johannes

Atmospheric CO2 concentrations and temperatures are rising and precipitation regimes are changing at global scale. How ecosystem will be affected by global climatic change is dependent on the responses of plants and plant communities. This thesis focuses on how climate change affects heathland...... plant communities. Many heathlands have shifted from dwarf shrub dominance to grass dominance and climatic change might affect the competitive balance between dwarf shrubs and grasses. We looked at heathland vegetation dynamics and heathland plant responses to climatic change at different spatial...... between C. vulgaris and D. flexuosa in the same climate change experiment and 5) a study where we compared the responses of shrubland plant communities to experimental warming and recurrent experimental droughts in seven climate change experiments across Europe. Heathland vegetation dynamics are slow...

Climate dependence of the CO2 fertilization effect on terrestrial net primary production

International Nuclear Information System (INIS)

Alexandrov, G.A.; Yamagata, Y.; Oikawa, T.

2003-01-01

The quantitative formulation of the fertilization effect of CO 2 enrichment on net primary production (NPP) introduced by Keeling and Bacastow in 1970s (known as Keeling's formula) has been recognized as a summary of experimental data and has been used in various assessments of the industrial impact on atmospheric chemistry. Nevertheless, the magnitude of the formula's key coefficient, the so-called growth factor, has remained open to question. Some of the global carbon cycle modelers avoid this question by tuning growth factor and choosing the value that fits the observed course of atmospheric CO 2 changes. However, for mapping terrestrial sinks induced by the CO 2 fertilization effect one needs a geographical pattern of the growth factor rather than its globally averaged value. The earlier approach to this problem involved formulating the climate dependence of the growth factor and the derivation of its global pattern from climatic variables (whose geographical distribution is known). We use a process-based model (TsuBiMo) for this purpose and derive the values of growth factor for major biomes for comparison our approach with the earlier studies. Contrary to the earlier prevailing opinion, TsuBiMo predicts that these values decrease with mean annual temperature (excluding biomes of limited water supply). We attribute this result to the effect of light limitation caused by mutual shading inside a canopy, which was considered earlier as unimportant, and conclude that current hypotheses about CO 2 fertilization effect (and thus projections of the related carbon sink) are very sensitive to the choice of driving forces taken into account

The Role of Sea Ice in 2 x CO2 Climate Model Sensitivity. Part 2; Hemispheric Dependencies

Science.gov (United States)

Rind, D.; Healy, R.; Parkinson, C.; Martinson, D.

1997-01-01

How sensitive are doubled CO2 simulations to GCM control-run sea ice thickness and extent? This issue is examined in a series of 10 control-run simulations with different sea ice and corresponding doubled CO2 simulations. Results show that with increased control-run sea ice coverage in the Southern Hemisphere, temperature sensitivity with climate change is enhanced, while there is little effect on temperature sensitivity of (reasonable) variations in control-run sea ice thickness. In the Northern Hemisphere the situation is reversed: sea ice thickness is the key parameter, while (reasonable) variations in control-run sea ice coverage are of less importance. In both cases, the quantity of sea ice that can be removed in the warmer climate is the determining factor. Overall, the Southern Hemisphere sea ice coverage change had a larger impact on global temperature, because Northern Hemisphere sea ice was sufficiently thick to limit its response to doubled CO2, and sea ice changes generally occurred at higher latitudes, reducing the sea ice-albedo feedback. In both these experiments and earlier ones in which sea ice was not allowed to change, the model displayed a sensitivity of -0.02 C global warming per percent change in Southern Hemisphere sea ice coverage.

A Plan for improving the industrial constitution in Korea for the Convention on Climate Change - concentrated on manufacturing CO{sub 2} unit analysis

Energy Technology Data Exchange (ETDEWEB)

Kang, Sang In; Kim, Tae Wan; Kim, Yong Kun; Sohn, Yang Hoon; Kim, Seung Woo [Korea Environment Institute, Seoul (Korea)

1998-12-01

Due to the implementation of the Convention on Climate Change in future, a policy plan to prepare for the Convention on Climate Change was promoted to improve constitution of domestic economy practically including foreign negotiation strategies, national energy policy and change in consumption pattern. Based on the CO{sub 2} unit analysis in manufacturing, this study proposed an improvement plan of industrial constitution in Korea to prepare for emission trading system. 31 refs., 30 figs., 68 tabs.

Sensitivity of tropical carbon to climate change constrained by carbon dioxide variability.

Science.gov (United States)

Cox, Peter M; Pearson, David; Booth, Ben B; Friedlingstein, Pierre; Huntingford, Chris; Jones, Chris D; Luke, Catherine M

2013-02-21

The release of carbon from tropical forests may exacerbate future climate change, but the magnitude of the effect in climate models remains uncertain. Coupled climate-carbon-cycle models generally agree that carbon storage on land will increase as a result of the simultaneous enhancement of plant photosynthesis and water use efficiency under higher atmospheric CO(2) concentrations, but will decrease owing to higher soil and plant respiration rates associated with warming temperatures. At present, the balance between these effects varies markedly among coupled climate-carbon-cycle models, leading to a range of 330 gigatonnes in the projected change in the amount of carbon stored on tropical land by 2100. Explanations for this large uncertainty include differences in the predicted change in rainfall in Amazonia and variations in the responses of alternative vegetation models to warming. Here we identify an emergent linear relationship, across an ensemble of models, between the sensitivity of tropical land carbon storage to warming and the sensitivity of the annual growth rate of atmospheric CO(2) to tropical temperature anomalies. Combined with contemporary observations of atmospheric CO(2) concentration and tropical temperature, this relationship provides a tight constraint on the sensitivity of tropical land carbon to climate change. We estimate that over tropical land from latitude 30° north to 30° south, warming alone will release 53 ± 17 gigatonnes of carbon per kelvin. Compared with the unconstrained ensemble of climate-carbon-cycle projections, this indicates a much lower risk of Amazon forest dieback under CO(2)-induced climate change if CO(2) fertilization effects are as large as suggested by current models. Our study, however, also implies greater certainty that carbon will be lost from tropical land if warming arises from reductions in aerosols or increases in other greenhouse gases.

Responses of the ocean carbon cycle to climate change: Results from an earth system climate model simulation

Institute of Scientific and Technical Information of China (English)

WANG Shuang-Jing; CAO Long; LI Na

2014-01-01

Based on simulations using the University of Victoria’s Earth System Climate Model, we analyzed the responses of the ocean carbon cycle to increasing atmospheric CO2 levels and climate change from 1800 to 2500 following the RCP 8.5 scenario and its extension. Compared to simulations without climate change, the simulation with a climate sensitivity of 3.0 K shows that in 2100, due to increased atmospheric CO2 concentrations, the simulated sea surface temperature increases by 2.7 K, the intensity of the North Atlantic deep water formation reduces by4.5 Sv, and the oceanic uptake of anthropogenic CO2 decreases by 0.8 Pg C. Climate change is also found to have a large effect on the North Atlantic’s ocean column inventory of anthropogenic CO2. Between the years 1800 and 2500, compared with the simulation with no climate change, the simulation with climate change causes a reduction in the total anthropogenic CO2 column inventory over the entire ocean and in North Atlantic by 23.1% and 32.0%, respectively. A set of simulations with climate sensitivity variations from 0.5 K to 4.5 K show that with greater climate sensitivity climate change would have a greater effect in reducing the ocean’s ability to absorb CO2 from the atmosphere.

Gender and climate change-induced migration: proposing a framework for analysis

International Nuclear Information System (INIS)

Chindarkar, Namrata

2012-01-01

This paper proposes frameworks to analyze the gender dimensions of climate change-induced migration. The experiences, needs and priorities of climate migrants will vary by gender and these differences need to be accounted for if policies are to be inclusive. Among the vulnerable groups, women are likely to be disproportionately affected due to climate change because on average women tend to be poorer, less educated, have a lower health status and have limited direct access to or ownership of natural resources. Both the process (actual movement) and the outcomes (rural–rural or rural–urban migration, out-migration mainly of men) of climate change-induced migration are also likely to be highly gendered. (letter)

Global climate change

International Nuclear Information System (INIS)

Gugele, B.; Radunsky, K.; Spangl, W.

2002-01-01

In the last decade marked changes of climatic factors have been observed, such as increases in average global earth temperatures, the amount of precipitation and the number of extreme weather events. Green house gases influence the energy flow in the atmosphere by absorbing infra-red radiation. An overview of the Austrian greenhouse gas emissions is given, including statistical data and their major sources. In 1999 the emissions of all six Kyoto greenhouse gases ( CO 2 , CH 4 , N 2 O, HFC s , PFC s and SF 6 ) amounted to 79.2 million tonnes of CO 2 equivalents . A comparison between the EC Members states is also presented. Finally the climate change strategy prepared by the Austrian Federal Ministry of Agriculture, Forestry, Environment and Water Management together with other ministries and the federal provinces is discussed, which main aim is to lead to an annual emission reduction of 16 million tonnes of CO 2 . Figs. 2, Tables 1. (nevyjel)

Sensitivity of agricultural runoff loads to rising levels of CO{sub 2} and climate change in the San Joaquin Valley watershed of California

Energy Technology Data Exchange (ETDEWEB)

Ficklin, Darren L.; Luo Yuzhou; Luedeling, Eike; Gatzke, Sarah E. [Department of Land, Air and Water Resources, University of California, Davis, CA 95616 (United States); Zhang Minghua, E-mail: mhzhang@ucdavis.ed [Department of Land, Air and Water Resources, University of California, Davis, CA 95616 (United States)

2010-01-15

The Soil and Water Assessment Tool (SWAT) was used to assess the impact of climate change on sediment, nitrate, phosphorus and pesticide (diazinon and chlorpyrifos) runoff in the San Joaquin watershed in California. This study used modeling techniques that include variations of CO{sub 2}, temperature, and precipitation to quantify these responses. Precipitation had a greater impact on agricultural runoff compared to changes in either CO{sub 2} concentration or temperature. Increase of precipitation by +-10% and +-20% generally changed agricultural runoff proportionally. Solely increasing CO{sub 2} concentration resulted in an increase in nitrate, phosphorus, and chlorpyrifos yield by 4.2, 7.8, and 6.4%, respectively, and a decrease in sediment and diazinon yield by 6.3 and 5.3%, respectively, in comparison to the present-day reference scenario. Only increasing temperature reduced yields of all agricultural runoff components. The results suggest that agricultural runoff in the San Joaquin watershed is sensitive to precipitation, temperature, and CO{sub 2} concentration changes. - Agricultural runoff is significantly affected by changes in precipitation, temperature, and atmospheric CO{sub 2} concentration.

Climate change and the CO2 myth

International Nuclear Information System (INIS)

Boettcher, C.J.F.

1994-01-01

Further increase of the CO 2 concentration in the atmosphere has little effect on the greenhouse effect contrary to the effect of the increase of other greenhouse gases. However, politicians are using targets for the reduction of CO 2 emissions that are unrealistic, taking into account the scientific uncertainties of the applied models, the doubts about the feasibility of quantitative targets and the economic consequences of such drastic measures. Some recommendations are given for a more realistic CO 2 policy. Also attention is paid to the important role that coal will play in the future of the energy supply. 5 figs., 3 ills

Historical effects of CO2 and climate trends on global crop water demand

Science.gov (United States)

Urban, Daniel W.; Sheffield, Justin; Lobell, David B.

2017-12-01

A critical question for agricultural production and food security is how water demand for staple crops will respond to climate and carbon dioxide (CO2) changes1, especially in light of the expected increases in extreme heat exposure2. To quantify the trade-offs between the effects of climate and CO2 on water demand, we use a `sink-strength' model of demand3,4 which relies on the vapour-pressure deficit (VPD), incident radiation and the efficiencies of canopy-radiation use and canopy transpiration; the latter two are both dependent on CO2. This model is applied to a global data set of gridded monthly weather data over the cropping regions of maize, soybean, wheat and rice during the years 1948-2013. We find that this approach agrees well with Penman-Monteith potential evapotranspiration (PM) for the C3 crops of soybean, wheat and rice, where the competing CO2 effects largely cancel each other out, but that water demand in maize is significantly overstated by a demand measure that does not include CO2, such as the PM. We find the largest changes in wheat, for which water demand has increased since 1981 over 86% of the global cropping area and by 2.3-3.6 percentage points per decade in different regions.

Are commercial sweet cherry rootstocks adapted to climate change? Short-term waterlogging and CO2 effects on sweet cherry cv. 'Burlat'.

Science.gov (United States)

Pérez-Jiménez, Margarita; Hernández-Munuera, María; Piñero, M Carmen; López-Ortega, Gregorio; Del Amor, Francisco M

2018-05-01

High CO 2 is able to ameliorate some negative effects due to climate change and intensify others. This study involves the sweet cherry (Prunus avium) cultivar 'Burlat' grafted on the 'Mariana 2624', 'Adara' and 'LC 52' rootstocks. In a climate chamber at two CO 2 concentrations, ambient (400 µmol mol -1 ) and elevated (800 µmol mol -1 ), the plants were submitted to waterlogging for 7 d, followed by 7 d of recovery after drainage. Waterlogging drastically decreased the rate of photosynthesis, significantly endangering plant survival, particularly for the 'LC 52' and 'Adara' rootstocks. 'Mariana 2624' was also clearly affected by waterlogging that increased lipid peroxidation and the Cl - and SO 4 2- concentrations in all the studied plants. Nevertheless, CO 2 was able to overcome this reduction in photosynthesis, augmenting growth, increasing soluble sugars and starch, raising turgor and regulating the concentrations of Cl - and SO 4 2- , while lowering the NO 3 - concentration in leaves of all the studied rootstocks. In concordance with these results, the proline levels indicated a more intense stress at control CO 2 than at high CO 2 for waterlogged plants. 'Mariana 2624' was more resistant to waterlogging than 'Adara', and both were more resistant than 'LC 52' in control CO 2 conditions; this clearly enhanced the chance of survival under hypoxia. © 2017 John Wiley & Sons Ltd.

Functional MRI of CO2 induced increase in cerebral perfusion

DEFF Research Database (Denmark)

Rostrup, Egill; Larsson, H B; Toft, P B

1994-01-01

The sensitivity of MR gradient echo imaging towards CO2 induced changes in cerebral blood flow was investigated in 10 normal subjects. The subjects were inhaling 5% and 7% CO2 and the experiments were carried out at 1.5 T (n = 6) and 2.0 T (n = 5), allowing a comparison of field strengths....... Additional experiments were carried out using a higher spatial resolution. The largest signal increases were noted in areas corresponding to larger vessels, but significant changes were also conspicuous in deeper cortical and central grey matter. The changes appeared linearly related to the arterial CO2...... tension, within the range of PaCO2 studied. In white matter, the changes were not statistically significant....

Evaluating Health Co-Benefits of Climate Change Mitigation in Urban Mobility.

Science.gov (United States)

Wolkinger, Brigitte; Haas, Willi; Bachner, Gabriel; Weisz, Ulli; Steininger, Karl; Hutter, Hans-Peter; Delcour, Jennifer; Griebler, Robert; Mittelbach, Bernhard; Maier, Philipp; Reifeltshammer, Raphael

2018-04-28

There is growing recognition that implementation of low-carbon policies in urban passenger transport has near-term health co-benefits through increased physical activity and improved air quality. Nevertheless, co-benefits and related cost reductions are often not taken into account in decision processes, likely because they are not easy to capture. In an interdisciplinary multi-model approach we address this gap, investigating the co-benefits resulting from increased physical activity and improved air quality due to climate mitigation policies for three urban areas. Additionally we take a (macro-)economic perspective, since that is the ultimate interest of policy-makers. Methodologically, we link a transport modelling tool, a transport emission model, an emission dispersion model, a health model and a macroeconomic Computable General Equilibrium (CGE) model to analyze three climate change mitigation scenarios. We show that higher levels of physical exercise and reduced exposure to pollutants due to mitigation measures substantially decrease morbidity and mortality. Expenditures are mainly born by the public sector but are mostly offset by the emerging co-benefits. Our macroeconomic results indicate a strong positive welfare effect, yet with slightly negative GDP and employment effects. We conclude that considering economic co-benefits of climate change mitigation policies in urban mobility can be put forward as a forceful argument for policy makers to take action.

The sensitivity of stand-scale photosynthesis and transpiration to changes in atmospheric CO2 concentration and climate

Science.gov (United States)

Kruijt, B.; Barton, C.; Rey, A.; Jarvis, P. G.

The 3-dimensional forest model MAESTRO was used to simulate daily and annual photosynthesis and transpiration fluxes of forest stands and the sensitivity of these fluxes to potential changes in atmospheric CO2 concentration ([CO2]), temperature, water stress and phenology. The effects of possible feed-backs from increased leaf area and limitations to leaf nutrition were simulated by imposing changes in leaf area and nitrogen content. Two different tree species were considered: Picea sitchensis (Bong.) Carr., a conifer with long needle longevity and large leaf area, and Betula pendula Roth., a broad-leaved deciduous species with an open canopy and small leaf area. Canopy photosynthetic production in trees was predicted to increase with atmospheric [CO2] and length of the growing season and to decrease with increased water stress. Associated increases in leaf area increased production further only in the B. pendula canopy, where the original leaf area was relatively small. Assumed limitations in N uptake affected B. pendula more than P. sitchensis. The effect of increased temperature was shown to depend on leaf area and nitrogen content. The different sensitivities of the two species were related to their very different canopy structure. Increased [CO2] reduced transpiration, but larger leaf area, early leaf growth, and higher temperature all led to increased water use. These effects were limited by feedbacks from soil water stress. The simulations suggest that, with the projected climate change, there is some increase in stand annual `water use efficiency', but the actual water losses to the atmosphere may not always decrease.

Moderate solar geoengineering greatly reduces the largest changes in climate whilst modestly increasing the changes in climate over a small fraction of the Earth

Science.gov (United States)

Irvine, P. J.; Keith, D.; He, J.; Vecchi, G.; Horowitz, L. W.

2017-12-01

Whilst solar geoengineering reduces global temperature it cannot perfectly offset the climate effects of elevated CO2 concentrations. Solar geoengineering has been shown to have a greater effect on the global hydrological cycle than CO2 and substantial differences in regional precipitation relative to a scenario without elevated CO2­ concentrations have been noted. In this study we evaluate a moderate scenario of solar geoengineering, one which offsets 50% of the forcing from elevated CO2 concentrations, using a 25 Km resolution global climate model and verify these results using the Geoengineering model Intercomparison project ensemble. We calculate the fraction of regions that would be better or worse off after solar geoengineering deployment, defining those which see greater absolute change as worse off and vice versa. We find that 51% of the land area would be statistically significantly better off for precipitation, 33% for Precipitation minus evaporation (P-E), and that less than 3% would be worse off for precipitation, and 1% for P-E. We find that the fraction of the land area experiencing the largest changes in climate, defined as the upper quartile of the CO2 minus control anomaly, is greatly reduced for precipitation, P-E and 5-day maximum precipitation, and eliminated for mean and max annual temperature. The regions which are made worse off in precipitation or P-E by solar geoengineering typically saw relatively little to no CO2 induced climate change and see relatively little to moderate change in the solar geoengineering scenario. There is little overlap between the regions made worse off in terms of precipitation and P-E. In fact, whilst precipitation is reduced in almost all regions made worse off by solar geoengineering, P-E is increased in the majority of regions made worse off. Overall, we find that for each variable considered solar geoengineering greatly reduces the fraction of the world experiencing relatively large change and that those

Response of the global climate to changes in atmospheric chemical composition due to fossil fuel burning

Science.gov (United States)

Hameed, S.; Cess, R. D.; Hogan, J. S.

1980-01-01

Recent modeling of atmospheric chemical processes (Logan et al, 1978; Hameed et al, 1979) suggests that tropospheric ozone and methane might significantly increase in the future as the result of increasing anthropogenic emissions of CO, NO(x), and CH4 due to fossil fuel burning. Since O3 and CH4 are both greenhouse gases, increases in their concentrations could augment global warming due to larger future amounts of atmospheric CO2. To test the possible climatic impact of changes in tropospheric chemical composition, a zonal energy-balance climate model has been combined with a vertically averaged tropospheric chemical model. The latter model includes all relevant chemical reactions which affect species derived from H2O, O2, CH4, and NO(x). The climate model correspondingly incorporates changes in the infrared heating of the surface-troposphere system resulting from chemically induced changes in tropospheric ozone and methane. This coupled climate-chemical model indicates that global climate is sensitive to changes in emissions of CO, NO(x) and CH4, and that future increases in these emissions could augment global warming due to increasing atmospheric CO2.

Transient Atmospheric Circulation Changes in a Grand ensemble of Idealized CO2 Increase Experiments

Science.gov (United States)

Karpechko, A.; Manzini, E.; Kornblueh, L.

2017-12-01

The yearly evolution with increasing forcing of the large-scale atmospheric circulation is examined in a 68-member ensemble of 1pctCO2 scenario experiments performed with the MPI-ESM model. Each member of the experiment ensemble is integrated for 155 years, from initial conditions taken from a 2000-yr long pre-industrial control climate experiment. The 1pctCO2 scenario experiments are conducted following the protocol of including as external forcing only a CO2 concentration increase at 1%/year, till quadrupling of CO2 concentrations. MPI-ESM is the Max-Planck-Institute Earth System Model (including coupling between the atmosphere, ocean and seaice). By averaging over the 68 members (ensemble mean), atmospheric variability is greatly reduced. Thus, it is possible to investigate the sensitivity to the climate state of the atmospheric response to CO2 doubling. Indicators of global change show the expected monotonic evolution with increasing CO2 and a weak dependence of the thermodynamical response to CO2 doubling on the climate state. The surface climate response of the atmospheric circulation, diagnosed for instance by the pressure at sea level, and the eddy-driven jet response show instead a marked dependence to the climate state, for the Northern winter season. We find that as the CO2 concentration increases above doubling, Northern winter trends in some indicators of atmospheric circulation changes decrease or even reverse, posing the question on what are the causes of this nonlinear behavior. The investigation of the role of stationary waves, the meridional overturning circulation, the decrease in Arctic sea ice and the stratospheric vortex points to the latter as a plausible cause of such nonlinear response.

Aviation and the environment, rating airlines on their co2 efficiency

NARCIS (Netherlands)

Van der Zwan, F.M.; Dorland, N.; Ghijs, S.S.A.; Santema, S.C.; Curran, R.

2009-01-01

The aviation industry contributes about 2% to the total global manmade CO2 emissions, which is seen as the main (manmade) greenhouse gas inducing climate change. This paper focuses on the design of a CO2 rating system which makes it possible to make a fair comparison of the environmental performance

CO2 impulse response curves for GWP calculations

International Nuclear Information System (INIS)

Jain, A.K.; Wuebbles, D.J.

1993-01-01

The primary purpose of Global Warming Potential (GWP) is to compare the effectiveness of emission strategies for various greenhouse gases to those for CO 2 , GWPs are quite sensitive to the amount of CO 2 . Unlike all other gases emitted in the atmosphere, CO 2 does not have a chemical or photochemical sink within the atmosphere. Removal of CO 2 is therefore dependent on exchanges with other carbon reservoirs, namely, ocean and terrestrial biosphere. The climatic-induced changes in ocean circulation or marine biological productivity could significantly alter the atmospheric CO 2 lifetime. Moreover, continuing forest destruction, nutrient limitations or temperature induced increases of respiration could also dramatically change the lifetime of CO 2 in the atmosphere. Determination of the current CO 2 sinks, and how these sinks are likely to change with increasing CO 2 emissions, is crucial to the calculations of GWPs. It is interesting to note that the impulse response function is sensitive to the initial state of the ocean-atmosphere system into which CO 2 is emitted. This is due to the fact that in our model the CO 2 flux from the atmosphere to the mixed layer is a nonlinear function of ocean surface total carbon

The energy-climate challenge: Recent trends in CO2 emissions from fuel combustion

International Nuclear Information System (INIS)

Quadrelli, Roberta; Peterson, Sierra

2007-01-01

Fossil fuel combustion is the single largest human influence on climate, accounting for 80% of anthropogenic greenhouse gas emissions. This paper presents trends in world carbon dioxide (CO 2 ) emissions from fossil fuel combustion worldwide, based on the estimates of the International Energy Agency (IEA) [IEA, 2006a. CO 2 Emissions from Fuel Combustion 1971-2004. International Energy Agency, Paris, France]. Analyzing the drivers of CO 2 emissions, the paper considers regions, types of fuel, sectors, and socio-economic indicators. The paper then examines the growing body of climate change mitigation policies and measures, both multinational and federal. Policies discussed include the Kyoto Protocol, the European Union Emissions Trading Scheme, and the potential measures to be implemented in 2012 and beyond. CO 2 emissions of recent years have grown at the highest rates ever recorded, an observed trend incompatible with stabilizing atmospheric concentrations of greenhouse gases and avoiding long-term climate change. Within this aggregate upward trend, a comparison of emissions sources proves dynamic: while industrialized countries have so far dominated historical emissions, rapid growth in energy demand of developing economies, led by China, may soon spur their absolute emissions beyond those of industrialized countries. To provide context for the drivers of CO 2 emissions, the paper examines fuel sources, from coal to biofuels, and fuel use in the production of heat and electricity, in transport, in industrial production and in households. The sectoral analysis illustrates the primacy, in terms of emissions growth and absolute emissions, of two sectors: electricity and heat generation, and transport. A discussion of several socio-economic emissions drivers complements the paper's analysis of mitigation mechanisms. As illustrated, emissions per capita and emissions per unit of economic production, as measured in gross domestic product (GDP), vary widely between

The physics and dynamics of the climate system simulation of climate change

International Nuclear Information System (INIS)

Mitchell, J.F.B.

1991-01-01

The use of climate models is described, using examples related to: the greenhouse effect, the principal absorbers, past, present and future, climate feedbacks in CO2 experiments, equilibrium climate change due to increased CO2, modelling the transient response to increases in trace gases, uncertainties in the simulation and detection of the climatic effect of increased trace gas, simulations for 9000 years before present

Mountain peatlands range from CO2 sinks at high elevations to sources at low elevations: Implications for a changing climate

Science.gov (United States)

David J. Millar; David J. Cooper; Kathleen A. Dwire; Robert M. Hubbard; Joseph. von Fischer

2016-01-01

Mountain fens found in western North America have sequestered atmospheric carbon dioxide (CO2) for millennia, provide important habitat for wildlife, and serve as refugia for regionally-rare plant species typically found in boreal regions. It is unclear how Rocky Mountain fens are responding to a changing climate. It is possible that fens found at lower elevations may...

Engendering climate change-induced migration

Science.gov (United States)

Caretta, Martina Angela; Miletto, Michela

2017-04-01

Climate change leads to increased climate variability, which is manifest in extreme weather events such as floods and droughts. These put at stake agricultural productivity, forestry, inland fisheries, aquaculture, water supply and sanitation which in turn hamper poorest householdś self-sufficiency and capability to cope with risks. Due to the risk of losing or the actual loss of livelihood, farmers in the Global South must look for alternative strategies to diversify risk. Migration is one of those strategies, which that can be seen either as an adaptive measure or an indicator of limits to adaptation to environmental stress. 60% of young migrants live in the Global South (UN, 2013). Many internally displaced people in the world are under the age of 18, some move with their families, other, mostly in South Asia and West Africa, migrate alone. Youth, as all migrants, are seeking better economic opportunities to support themselves and their families. Migration is a gendered process which plays out differently in diverse societies depending on local cultural norms that do not only affect and are affected by gender roles, but also by age, class and ethnicity. Threats to water availability, access and water hazards have diverse impacts on men and women. The link gender and climate-induced migration is still under investigation and few studies provide concrete country specific examples of this phenomenon. Our paper will present a state of the art literature review around climate-induced migration in the Global South from a gender perspective showing how meńs and womeńs migratory decisions, patterns and outcomes differ at the stage pre-during post migration.

Framing Climate Goals in Terms of Cumulative CO2-Forcing-Equivalent Emissions

Science.gov (United States)

Jenkins, S.; Millar, R. J.; Leach, N.; Allen, M. R.

2018-03-01

The relationship between cumulative CO2 emissions and CO2-induced warming is determined by the Transient Climate Response to Emissions (TCRE), but total anthropogenic warming also depends on non-CO2 forcing, complicating the interpretation of emissions budgets based on CO2 alone. An alternative is to frame emissions budgets in terms of CO2-forcing-equivalent (CO2-fe) emissions—the CO2 emissions that would yield a given total anthropogenic radiative forcing pathway. Unlike conventional "CO2-equivalent" emissions, these are directly related to warming by the TCRE and need to fall to zero to stabilize warming: hence, CO2-fe emissions generalize the concept of a cumulative carbon budget to multigas scenarios. Cumulative CO2-fe emissions from 1870 to 2015 inclusive are found to be 2,900 ± 600 GtCO2-fe, increasing at a rate of 67 ± 9.5 GtCO2-fe/yr. A TCRE range of 0.8-2.5°C per 1,000 GtC implies a total budget for 0.6°C of additional warming above the present decade of 880-2,750 GtCO2-fe, with 1,290 GtCO2-fe implied by the Coupled Model Intercomparison Project Phase 5 median response, corresponding to 19 years' CO2-fe emissions at the current rate.

Public willingness to pay for CO2 mitigation and the determinants under climate change: a case study of Suzhou, China.

Science.gov (United States)

Yang, Jie; Zou, Liping; Lin, Tiansheng; Wu, Ying; Wang, Haikun

2014-12-15

This study explored the factors that influence respondents' willingness to pay (WTP) for CO2 mitigation under climate change. A questionnaire survey combined with contingent valuation and psychometric paradigm methods were conducted in the city of Suzhou, Jiangsu Province in China. Respondents' traditional demographic attributes, risk perception of greenhouse gas (GHG), and attitude toward the government's risk management practices were established using a Tobit model to analyze the determinants. The results showed that about 55% of the respondents refused to pay for CO2 mitigation, respondent's WTP increased with increasing CO2 mitigation percentage. Important factors influencing WTP include people's feeling of dread of GHGs, confidence in policy, the timeliness of governmental information disclosure, age, education and income level. Copyright © 2014 Elsevier Ltd. All rights reserved.

Climate-Induced Boreal Forest Change: Predictions versus Current Observations

Science.gov (United States)

Soja, Amber J.; Tchebakova, Nadezda M.; French, Nancy H. F.; Flannigan, Michael D.; Shugart, Herman H.; Stocks, Brian J.; Sukhinin, Anatoly I.; Parfenova, E. I.; Chapin, F. Stuart, III; Stackhouse, Paul W., Jr.

2007-01-01

For about three decades, there have been many predictions of the potential ecological response in boreal regions to the currently warmer conditions. In essence, a widespread, naturally occurring experiment has been conducted over time. In this paper, we describe previously modeled predictions of ecological change in boreal Alaska, Canada and Russia, and then we investigate potential evidence of current climate-induced change. For instance, ecological models have suggested that warming will induce the northern and upslope migration of the treeline and an alteration in the current mosaic structure of boreal forests. We present evidence of the migration of keystone ecosystems in the upland and lowland treeline of mountainous regions across southern Siberia. Ecological models have also predicted a moisture-stress-related dieback in white spruce trees in Alaska, and current investigations show that as temperatures increase, white spruce tree growth is declining. Additionally, it was suggested that increases in infestation and wildfire disturbance would be catalysts that precipitate the alteration of the current mosaic forest composition. In Siberia, five of the last seven years have resulted in extreme fire seasons, and extreme fire years have also been more frequent in both Alaska and Canada. In addition, Alaska has experienced extreme and geographically expansive multi-year outbreaks of the spruce beetle, which had been previously limited by the cold, moist environment. We suggest that there is substantial evidence throughout the circumboreal region to conclude that the biosphere within the boreal terrestrial environment has already responded to the transient effects of climate change. Additionally, temperature increases and warming-induced change are progressing faster than had been predicted in some regions, suggesting a potential non-linear rapid response to changes in climate, as opposed to the predicted slow linear response to climate change.

Mesh climate change data of Japan ver. 2 for climate change impact assessments under IPCC SRES A1B and A2

International Nuclear Information System (INIS)

Okada, M.; Iizumi, T.; Nishimori, M.; Yokozawa, M.

2009-01-01

The Intergovernmental Panel on Climate Change (IPCC) published the Fourth Assessment Report (AR4) in 2007 and stated that recent climate change and variation are induced by increases in the atmospheric greenhouse gases (GHG) concentration due to anthropogenic activities. The report includes the results of impact assessments on a wide range of sectors. These assessments have been conducted based on future climate projections, which refer to aspects of the future climate evaluated by Atmosphere-Ocean Coupled General Circulation Models (CGCMs). The projection data used in the AR4 are archived under the Program for Climate Model Diagnosis and Intercomparison (PCMDI) promoted by the U.S. Department of Energy. We interpolated the projection data around Japan and constructed a dataset entitled the 'Mesh climate change data of Japan Ver. 2' for the climate change impact study. Nine projections performed by seven models under the A1B and A2 of the Special Report on Emissions Scenarios (SRES) were implemented for the dataset. They consist of mesh data with a size of 7.5 min in longitude and 5.0 min in latitude, i.e. approximately 10 X 10 km (45 sec in longitude and 30 sec in latitude, approximately 1 x 1 km, for one high-resolution model). The dataset includes five climatic elements, i.e. the daily mean, maximum, and minimum surface air temperatures, daily total precipitation, and daily accumulated shortwave radiation for three periods, 1981-2000, 2046-2065, and 2081-2100. This article describes the details concerning the construction and characteristics of the data

Climate change feedbacks on future oceanic acidification

OpenAIRE

McNeil, Ben I.; Matear, Richard J.

2011-01-01

Oceanic anthropogenic CO2 uptake will decrease both the pH and the aragonite saturation state (Ωarag) of seawater leading to an oceanic acidification. However, the factors controlling future changes in pH and Ωarag are independent and will respond differently to oceanic climate change feedbacks such as ocean warming, circulation and biological changes. We examine the sensitivity of these two CO2-related parameters to climate change feedbacks within a coupled atmosphere-ocean model. The ocean ...

Projected changes in terrestrial carbon storage in Europe under climate and land-use change, 1990-2100

International Nuclear Information System (INIS)

Zaehle, S.; Bondeau, A.; Cramer, W.; Erhard, M.; Sitch, S.; Smith, P.C.; Zaehle, S.; Smith, P.C.; Carter, T.R.; Erhard, M.; Prentice, C.; Prentice, C.; Reginster, I.; Rounsevell, M.D.A.; Sitch, S.; Smith, B.; Sykes, M

2007-01-01

Changes in climate and land use, caused by socio-economic changes, greenhouse gas emissions, agricultural policies and other factors, are known to affect both natural and managed ecosystems, and will likely impact on the European terrestrial carbon balance during the coming decades. This study presents a comprehensive European Union wide (EU15 plus Norway and Switzerland, EU*) assessment of potential future changes in terrestrial carbon storage considering these effects based on four illustrative IPCC-SRES story-lines (A1FI, A2, B1, B2). A process-based land vegetation model (LPJ-DGVM), adapted to include a generic representation of managed ecosystems, is forced with changing fields of land-use patterns from 1901 to 2100 to assess the effect of land-use and cover changes on the terrestrial carbon balance of Europe. The uncertainty in the future carbon balance associated with the choice of a climate change scenario is assessed by forcing LPJ-DGVM with output from four different climate models (GCMs: CGCM2, CSIRO2, HadCM3, PCM2) for the same SRES story-line. Decrease in agricultural areas and afforestation leads to simulated carbon sequestration for all land-use change scenarios with an average net uptake of 17-38 Tg C/year between 1990 and 2100, corresponding to 1.9-2.9% of the EU*s CO 2 emissions over the same period. Soil carbon losses resulting from climate warming reduce or even offset carbon sequestration resulting from growth enhancement induced by climate change and increasing atmospheric CO 2 concentrations in the second half of the twenty-first century. Differences in future climate change projections among GCMs are the main cause for uncertainty in the cumulative European terrestrial carbon uptake of 4.4-10.1 Pg C between 1990 and 2100. (authors)

The Economics and Ethics of Human Induced Climate Change

OpenAIRE

Spash, Clive L.; Gattringer, Clemens

2016-01-01

Human induced climate change poses a series of ethical challenges to the current political economy, although it has often be regarded by economists as only an ethical issue for those concerned about future generations. The central debate in economics has then concerned the rate at which future costs and benefits should be discounted. Indeed the full range of ethical aspects of climate change are rarely even discussed. Despite recent high profile and lengthy academic papers on t...

Climate impacts of short-lived climate forcers versus CO2 from biodiesel: a case of the EU on-road sector.

Science.gov (United States)

Lund, Marianne T; Berntsen, Terje K; Fuglestvedt, Jan S

2014-12-16

Biofuels are proposed to play an important role in several mitigation strategies to meet future CO2 emission targets for the transport sector but remain controversial due to significant uncertainties in net impacts on environment, society, and climate. A switch to biofuels can also affect short-lived climate forcers (SLCFs), which provide significant contributions to the net climate impact of transportation. We quantify the radiative forcing (RF) and global-mean temperature response over time to EU on-road fossil diesel SLCFs and the impact of 20% (B20) and 100% (B100) replacement of fossil diesel by biodiesel. SLCFs are compared to impacts of on-road CO2 using different approaches from existing literature to account for biodiesel CO2. Given the best estimates for changes in emissions when replacing fossil diesel with biodiesel, the net positive RF from EU on-road fossil diesel SLCFs of 3.4 mW/m(2) is reduced by 15% and 80% in B20 and B100, respectively. Over time the warming of SLCFs is likely small compared to biodiesel CO2 impacts. However, SLCFs may be relatively more important for the total warming than in the fossil fuel case if biodiesel from feedstock with very short rotation periods and low land-use-change impacts replaces a high fraction of fossil diesel.

Climatic change and impacts: a general introduction

International Nuclear Information System (INIS)

Fantechi, R.; Almeida-Teixeira, M.E.; Maracchi, G.

1991-01-01

These proceedings are divided into six parts containing 29 technical papers. 1. An Overview of the Climatic System, 2. Past climate Changes, 3. Climate Processes and Climate Modelling, 4. Greenhouse Gas Induced Climate Change, 5. Climatic Impacts, 6. STUDENTS' PAPERS

Global observation of EKC hypothesis for CO2, SOx and NOx emission: A policy understanding for climate change mitigation in Bangladesh

International Nuclear Information System (INIS)

Danesh Miah, Md.; Farhad Hossain Masum, Md.; Koike, Masao

2010-01-01

Environmental Kuznets Curve (EKC) hypothesis is critical to understanding the developmental path of a nation in relation to its environment. How the effects of economic development processes dictate environmental changes can be found through the study of EKC. To understand the EKC phenomena for climate change, this study was undertaken by reviewing the available literature. As CO 2 , SO x and NO x are the significant greenhouse gases (GHG) responsible for global warming, thus leading to climate change, the study focused on those GHGs for EKC consideration. With an understanding of the different EKC trajectories, an attempt was made to determine the implications for the economic development of Bangladesh in regards to the EKC. It was shown that EKC for CO 2 was following a monotonous straight line in most cases. SO x were shown to follow the full trajectory of the EKC in most situations and NO x was shown the hope only for the developed countries getting the low-income turning point. The type of economic policy that Bangladesh should follow in regards to the discussed pollutants and sources is also revealed. From these discussions, contributions to policy stimulation in Bangladesh are likely to be made.

Decadal changes in CH4 and CO2 emissions on the Alaskan North Slope

Science.gov (United States)

Sweeney, C.; Commane, R.; Wofsy, S.; Dlugokencky, E. J.; Karion, A.; Stone, R. S.; Chang, R.; Tans, P. P.; Wolter, S.

2016-12-01

Large changes in surface air temperature, sea ice cover and permafrost in the Arctic Boreal Ecosystems (ABE) are significantly impacting the critical ecosystem services and human societies that are dependent on the ABE. In order to predict the outcome of continued change in the climate system of the ABE, it is necessary to look at how past changes in climate have affected the ABE. We look at 30 years of CH4 and 42 years of CO2 observations from the NOAA Global Greenhouse Gas Reference Network site in Barrow, Alaska. By eliminating background trends and only looking at data collected when winds are blowing off the North Slope we find very little change in CH4 enhancements, but significant changes in the CO2 enhancements coming off the tundra. The bulk of both CO2 and CH4 emissions appear to be emitted well after the first snow fall on the North Slope. CO2 emissions are a strongly correlation with summer surface temperatures, while CH4 emissions appear insensitive to the large temperature changes that occurred over the measurement period. These results suggest that CO2, and not CH4 emissions, are a likely pathway for the degradation of permafrost carbon.

Potential climate change impacts on temperate forest ecosystem processes

Science.gov (United States)

Peters, Emily B.; Wythers, Kirk R.; Zhang, Shuxia; Bradford, John B.; Reich, Peter B.

2013-01-01

Large changes in atmospheric CO2, temperature and precipitation are predicted by 2100, yet the long-term consequences for carbon, water, and nitrogen cycling in forests are poorly understood. We applied the PnET-CN ecosystem model to compare the long-term effects of changing climate and atmospheric CO2 on productivity, evapotranspiration, runoff, and net nitrogen mineralization in current Great Lakes forest types. We used two statistically downscaled climate projections, PCM B1 (warmer and wetter) and GFDL A1FI (hotter and drier), to represent two potential future climate and atmospheric CO2 scenarios. To separate the effects of climate and CO2, we ran PnET-CN including and excluding the CO2 routine. Our results suggest that, with rising CO2 and without changes in forest type, average regional productivity could increase from 67% to 142%, changes in evapotranspiration could range from –3% to +6%, runoff could increase from 2% to 22%, and net N mineralization could increase 10% to 12%. Ecosystem responses varied geographically and by forest type. Increased productivity was almost entirely driven by CO2 fertilization effects, rather than by temperature or precipitation (model runs holding CO2 constant showed stable or declining productivity). The relative importance of edaphic and climatic spatial drivers of productivity varied over time, suggesting that productivity in Great Lakes forests may switch from being temperature to water limited by the end of the century.

The Co-evolution of Climate Models and the Intergovernmental Panel on Climate Change

Science.gov (United States)

Somerville, R. C.

2010-12-01

been endorsed by many leading scientific professional societies and academies of science worldwide. These reports are considered as definitive summaries of the state of the science. In 2007, in recognition of its exceptional accomplishments, the IPCC shared the Nobel Peace Prize equally with Al Gore. The present era is characterized not only by the reality and seriousness of human-caused climate change, but also by a young yet powerful science that enables us to understand much about the climate change that has occurred already and that awaits in the future. The development of GCMs is a critical part of the scientific story, and the development of the IPCC is a key factor in connecting the science to the perceptions and priorities of the global public and policymakers. GCMs and the IPCC have co-evolved and strongly influenced one another, as both scientists and the world at large have worked to confront the challenge of climate change.

Elevated atmospheric CO2 negatively impacts photosynthesis through radiative forcing and physiology-mediated climate feedback

Science.gov (United States)

Zhu, Peng; Zhuang, Qianlai; Ciais, Philippe; Welp, Lisa; Li, Wenyu; Xin, Qinchuan

2017-02-01

Increasing atmospheric CO2 affects photosynthesis involving directly increasing leaf carboxylation rates, stomatal closure, and climatic effects. The direct effects are generally thought to be positive leading to increased photosynthesis, while its climatic effects can be regionally positive or negative. These effects are usually considered to be independent from each other, but they are in fact coupled through interactions between land surface exchanges of gases and heat and the physical climate system. In particular, stomatal closure reduces evapotranspiration and increases sensible heat emissions from ecosystems, leading to decreased atmospheric moisture and precipitation and local warming. We use a coupled earth system model to attribute the influence of the increase in CO2 on gross primary productivity (GPP) during the period of 1930-2011. In our model, CO2 radiative effects cause climate change that has only a negligible effect on global GPP (a reduction of 0.9 ± 2% during the last 80 years) because of opposite responses between tropical and northern biomes. On the other hand, CO2 physiological effects on GPP are both positive, by increased carboxylation rates and water use efficiency (7.1 ± 0.48% increase), and negative, by vegetation-climate feedback reducing precipitation, as a consequence of decreased transpiration and increased sensible heat in areas without water limitation (2.7 ± 1.76% reduction).When considering the coupled atmosphere-vegetation system, negative climate feedback on photosynthesis and plant growth due to the current level of CO2 opposes 29-38% of the gains from direct fertilization effects.

Astronomical theory of climate change

Energy Technology Data Exchange (ETDEWEB)

Berger, A.; Loutre, M.F. [Universite Catholique de Louvain (UCL), Louvain-la-Neuve (Belgium). Inst. d' Astronomie et de Geophysique G. Lemaitre

2004-12-01

The astronomical theory of paleo-climates aims to explain the climatic variations occurring with quasi-periodicities lying between tens and hundreds of thousands of years. The origin of these quasi-cycles lies in the astronomically driven changes in the latitudinal and seasonal distributions of the energy that the Earth receives from the Sun. These changes are then amplified by the feedback mechanisms which characterize the natural behaviour of the climate system like those involving the albedo-, the water vapor-, and the vegetation- temperature relationships. Climate models of different complexities are used to explain the chain of processes which finally link the long-term variations of three astronomical parameters to the long-term climatic variations at time scale of tens to hundreds of thousands of years. In particular, sensitivity analysis to the astronomically driven insolation changes and to the CO{sub 2} atmospheric concentrations have been performed with the 2-dimension climate model of Louvain-la-Neuve. It could be shown that this model simulates more or less correctly the entrance into glaciation around 2.75 million year (Myr) BP (before present), the late Pliocene-early Pleistocene 41-kyr (thousand years) cycle, the emergence of the 100-kyr cycle around 850 kyr BP and the glacial-interglacial cycles of the last 600 kyr. During the Late Pliocene (in an ice-free - warm world) ice sheets can only develop during times of sufficiently low summer insolation. This occurs during large eccentricity times when climatic precession and obliquity combine to obtain such low values, leading to the 41-kyr period between 3 and 1 million years BP. On the contrary in a glacial world, ice sheets persist most of the time except when insolation is very high in polar latitudes, requiring large eccentricity again, but leading this time to interglacial and finally to the 100-kyr period of the last 1 Myr. Using CO{sub 2} scenarios, it has been shown that stage 11 and stage 1

Oceanic implications for climate change policy

International Nuclear Information System (INIS)

McNeil, Ben I.

2006-01-01

Under the United Nations convention on the law of the sea (1982), each participating country maintains exclusive economic and environmental rights within the oceanic region extending 200 nm from its territorial sea, known as the exclusive economic zone (EEZ). Although the ocean within each EEZ is undoubtedly an anthropogenic CO 2 sink, it has been over-looked within international climate policy. In this paper I use an area-weighted scaling argument to show that the inclusion of the EEZ CO 2 sink within national carbon accounts would have significant implications in tracking national greenhouse commitments to any future climate change policy initiative. The advantages and disadvantages for inclusion of the EEZ CO 2 sink into global climate change policy are also explored. The most compelling argument for including the EEZ CO 2 sink is that it would enhance the equity and resources among coastal nations to combat and adapt against future climate change that will inherently impact coastal nations more so than land locked nations. If included, the funds raised could be used for either monitoring or adaptive coastal infrastructure among the most vulnerable nations. On the other hand, the EEZ anthropogenic CO 2 sink cannot be directly controlled by human activities and could be used as a disincentive for some developed nations to reduce fossil-fuel related greenhouse gas emissions. This may therefore dampen efforts to ultimately reduce atmospheric greenhouse gas concentrations. In consideration of these arguments it is therefore suggested that an 'EEZ clause' be added to Kyoto and any future international climate policy that explicitly excludes its use within national carbon accounts under these international climate frameworks

The role of pCO2 in astronomically-paced climate and carbon cycle variations in the Middle Miocene

Science.gov (United States)

Penman, D. E.; Hull, P. M.; Scher, H.; Kirtland Turner, S.; Ridgwell, A.

2017-12-01

The pace of Earth's background climate variability is known to be driven by the Milankovitch cycles, variations in Earth's orbital parameters and axial tilt. While the Milankovitch (orbital) theory of climate change is very nearly universally accepted, the climate system mechanisms and feedbacks responsible for amplifying orbital cycles preserved in the geologic record remain uncertain. For the late Pleistocene, the ice core-derived record of atmospheric carbon dioxide (pCO2) is strongly coupled with global temperature on orbital time scales, indicating that internal feedbacks involving the carbon cycle amplify or even cause the large changes in global temperature during orbitally driven glacial-interglacial cycles. However, for earlier time periods beyond the range of ice cores (the last 800 kyr), it is not possible to directly compare records of pCO2 to orbital climate cycles because there are no high-resolution (orbitally resolved) records of pCO2 before the Pliocene. We address this deficiency with a high-resolution ( 5-10 kyr spacing) record of planktonic foraminiferal d11B-derived surface seawater pH (as well as d13C and trace metal analyses) over a 500 kyr time window in a sedimentary record with known Milankovitch-scale climate and carbon cycle oscillations: the Middle Miocene (14.0 - 14.5 Ma) at ODP Site 926 (subtropical North Atlantic). The resulting pH record can be used to constrain atmospheric pCO2, allowing comparison of the timescale and magnitude of carbon cycle changes during a period of eccentricity-dominated variability in the response of the global climate system (the Late Pleistocene) with a period of obliquity-dominance (the middle Miocene). These new records of planktic d11B and d13C will then be used to guide simulations of astronomical climate forcing in Earth System models, resulting in refined estimates of pCO2 changes over orbital cycles and providing quantitative constraints on the mechanisms and feedbacks responsible for the

Siple Dome ice reveals two modes of millennial CO2 change during the last ice age

Science.gov (United States)

Ahn, Jinho; Brook, Edward J.

2014-01-01

Reconstruction of atmospheric CO2 during times of past abrupt climate change may help us better understand climate-carbon cycle feedbacks. Previous ice core studies reveal simultaneous increases in atmospheric CO2 and Antarctic temperature during times when Greenland and the northern hemisphere experienced very long, cold stadial conditions during the last ice age. Whether this relationship extends to all of the numerous stadial events in the Greenland ice core record has not been clear. Here we present a high-resolution record of atmospheric CO2 from the Siple Dome ice core, Antarctica for part of the last ice age. We find that CO2 does not significantly change during the short Greenlandic stadial events, implying that the climate system perturbation that produced the short stadials was not strong enough to substantially alter the carbon cycle. PMID:24781344

The impact of CO2 fertilization and historical land use/land cover change on regional climate extremes

Science.gov (United States)

Findell, Kirsten; Berg, Alexis; Gentine, Pierre; Krasting, John; Lintner, Benjamin; Malyshev, Sergey; Santanello, Joseph; Shevliakova, Elena

2017-04-01

Recent research highlights the role of land surface processes in heat waves, droughts, and other extreme events. Here we use an earth system model (ESM) from the Geophysical Fluid Dynamics Laboratory (GFDL) to investigate the regional impacts of historical anthropogenic land use/land cover change (LULCC) and the vegetative response to changes in atmospheric CO2 on combined extremes of temperature and humidity. A bivariate assessment allows us to consider aridity and moist enthalpy extremes, quantities central to human experience of near-surface climate conditions. We show that according to this model, conversion of forests to cropland has contributed to much of the upper central US and central Europe experiencing extreme hot, dry summers every 2-3 years instead of every 10 years. In the tropics, historical patterns of wood harvesting, shifting cultivation and regrowth of secondary vegetation have enhanced near surface moist enthalpy, leading to extensive increases in the occurrence of humid conditions throughout the tropics year round. These critical land use processes and practices are not included in many current generation land models, yet these results identify them as critical factors in the energy and water cycles of the midlatitudes and tropics. Current work is targeted at understanding how CO2 fertilization of plant growth impacts water use efficiency and surface flux partitioning, and how these changes influence temperature and humidity extremes. We use this modeling work to explore how remote sensing can be used to determine how different forest ecosystems in different climatological regimes are responding to enhanced CO2 and a warming world.

Climate change scenarios in Mexico from models results under the assumption of a doubling in the atmospheric CO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Mendoza, V.M.; Villanueva, E.E.; Garduno, R.; Adem, J. [Centro de Ciencias de la Atmosfera, Mexico (Mexico)

1995-12-31

General circulation models (GCMs) and energy balance models (EBMs) are the best way to simulate the complex large-scale dynamic and thermodynamic processes in the atmosphere. These models have been used to estimate the global warming due to an increase of atmospheric CO{sub 2}. In Japan Ohta with coworkers has developed a physical model based on the conservation of thermal energy applied to pounded shallow water, to compute the change in the water temperature, using the atmospheric warming and the precipitation due to the increase in the atmospheric CO{sub 2} computed by the GISS-GCM. In this work, a method similar to the Ohta`s one is used for computing the change in ground temperature, soil moisture, evaporation, runoff and dryness index in eleven hydrological zones, using in this case the surface air temperature and precipitation due to CO{sub 2} doubling, computed by the GFDLR30-GCM and the version of the Adem thermodynamic climate model (CTM-EBM), which contains the three feedbacks (cryosphere, clouds and water vapor), and does not include water vapor in the CO{sub 2} atmospheric spectral band (12-19{mu})

Climate change scenarios in Mexico from models results under the assumption of a doubling in the atmospheric CO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Mendoza, V M; Villanueva, E E; Garduno, R; Adem, J [Centro de Ciencias de la Atmosfera, Mexico (Mexico)

1996-12-31

General circulation models (GCMs) and energy balance models (EBMs) are the best way to simulate the complex large-scale dynamic and thermodynamic processes in the atmosphere. These models have been used to estimate the global warming due to an increase of atmospheric CO{sub 2}. In Japan Ohta with coworkers has developed a physical model based on the conservation of thermal energy applied to pounded shallow water, to compute the change in the water temperature, using the atmospheric warming and the precipitation due to the increase in the atmospheric CO{sub 2} computed by the GISS-GCM. In this work, a method similar to the Ohta`s one is used for computing the change in ground temperature, soil moisture, evaporation, runoff and dryness index in eleven hydrological zones, using in this case the surface air temperature and precipitation due to CO{sub 2} doubling, computed by the GFDLR30-GCM and the version of the Adem thermodynamic climate model (CTM-EBM), which contains the three feedbacks (cryosphere, clouds and water vapor), and does not include water vapor in the CO{sub 2} atmospheric spectral band (12-19{mu})

Co-production of knowledge: recipe for success in land-based climate change adaptation?

Science.gov (United States)

Coninx, Ingrid; Swart, Rob

2015-04-01

After multiple failures of scientists to trigger policymakers and other relevant actors to take action when communicating research findings, the request for co-production (or co-creation) of knowledge and stakeholder involvement in climate change adaptation efforts has rapidly increased over the past few years. In particular for land-based adaptation, on-the-ground action is often met by societal resistance towards solutions proposed by scientists, by a misfit of potential solutions with the local context, leading to misunderstanding and even rejection of scientific recommendations. A fully integrative co-creation process in which both scientists and practitioners discuss climate vulnerability and possible responses, exploring perspectives and designing adaptation measures based on their own knowledge, is expected to prevent the adaptation deadlock. The apparent conviction that co-creation processes result in successful adaptation, has not yet been unambiguously empirically demonstrated, but has resulted in co-creation being one of basic principles in many new research and policy programmes. But is co-creation that brings knowledge of scientists and practitioners together always the best recipe for success in climate change adaptation? Assessing a number of actual cases, the authors have serious doubts. The paper proposes additional considerations for adaptively managing the environment that should be taken into account in the design of participatory knowledge development in which climate scientists play a role. These include the nature of the problem at stake; the values, interests and perceptions of the actors involved; the methods used to build trust, strengthen alignment and develop reciprocal relationships among scientists and practitioners; and the concreteness of the co-creation output.

Olivine and climate change

NARCIS (Netherlands)

Schuiling, R.D.

2012-01-01

The greenhouse effect, thanks mainly to the water vapor in our atmosphere, has created a livable climate on Earth. Climate change, however, may potentially have dire consequences. It is generally assumed that the rise in CO2 levels in the atmosphere is the main culprit, although several other

Forest Biomass for Climate Change Mitigation

DEFF Research Database (Denmark)

Nielsen, Anders Tærø

Awareness of elevated CO2 levels in the atmosphere and resulting climate change has increased focus on renewable energy sources during recent decades. Biomass for energy has been predicted to have the greatest potential for CO2 reductions in the short term and the IPCC assumes that the use...... of biomass for energy is CO2 neutral. Several studies have however criticized this CO2 neutrality assumption and questioned whether CO2 reductions actually are achieved through use of biomass for energy. The purpose of this thesis is to investigate the biomass production potential of poplar plantations...... on southern Scandinavian sites, managed under different systems both in agriculture and in forests. In addition, the objective is to assess the potential of the poplar plantations to mitigate climate change by using poplar biomass for substitution of fossil fuels in comparison to a traditional product...

Soil ecosystem functioning under climate change: plant species and community effects

Energy Technology Data Exchange (ETDEWEB)

Kardol, Paul [ORNL; Cregger, Melissa [ORNL; Campany, Courtney E [ORNL; Classen, Aimee T [ORNL

2010-01-01

Feedbacks of terrestrial ecosystems to climate change depend on soil ecosystem dynamics. Soil ecosystems can directly and indirectly respond to climate change. For example, warming directly alters microbial communities by increasing their activity. Climate change may also alter plant community composition, thus indirectly altering the microbial communities that feed on their inputs. To better understand how climate change may directly and indirectly alter soil ecosystem functioning, we investigated old-field plant community and soil ecosystem responses to single and combined effects of elevated [CO2], warming, and water availability. Specifically, we collected soils at the plot level (plant community soils), and beneath dominant plant species (plant-specific soils). We used microbial enzyme activities and soil nematodes as indicators for soil ecosystem functioning. Our study resulted in two main findings: 1) Overall, while there were some interactions, water, relative to increases in [CO2] and warming, had the largest impact on plant community composition, soil enzyme activities, and soil nematodes. Multiple climate change factors can interact to shape ecosystems, but in this case, those interactions were largely driven by changes in water availability. 2) Indirect effects of climate change, via changes in plant communities, had a significant impact on soil ecosystem functioning and this impact was not obvious when looking at plant community soils. Climate change effects on enzyme activities and soil nematode abundance and community structure strongly differed between plant community soils and plant-specific soils, but also within plant-specific soils. In sum, these results indicate that accurate assessments of climate change impacts on soil ecosystem functioning require incorporating the concurrent changes in plant function and plant community composition. Climate change-induced shifts in plant community composition will likely modify or counteract the direct

The CO2nnect activities

Science.gov (United States)

Eugenia, Marcu

2014-05-01

Climate change is one of the biggest challenges we face today. A first step is the understanding the problem, more exactly what is the challenge and the differences people can make. Pupils need a wide competencies to meet the challenges of sustainable development - including climate change. The CO2nnect activities are designed to support learning which can provide pupils the abilities, skills, attitudes and awareness as well as knowledge and understanding of the issues. The project "Together for a clean and healthy world" is part of "The Global Educational Campaign CO2nnect- CO2 on the way to school" and it was held in our school in the period between February and October 2009. It contained a variety of curricular and extra-curricular activities, adapted to students aged from 11 to 15. These activities aimed to develop in students the necessary skills to understanding man's active role in improving the quality of the environment, putting an end to its degrading process and to reducing the effects of climate changes caused by the human intervention in nature, including transport- a source of CO2 pollution. The activity which I propose can be easily adapted to a wide range of age groups and linked to the curricula of many subjects: - Investigate CO2 emissions from travel to school -Share the findings using an international database -Compare and discuss CO2 emissions -Submit questions to a climate- and transport expert -Partner with other schools -Meet with people in your community to discuss emissions from transport Intended learning outcomes for pupils who participate in the CO2nnect campaign are: Understanding of the interconnected mobility- and climate change issue climate change, its causes and consequences greenhouse-gas emissions from transport and mobility the interlinking of social, environmental, cultural and economic aspects of the local transport system how individual choices and participation can contribute to creating a more sustainable development

Thermodynamics of climate change: generalized sensitivities

Directory of Open Access Journals (Sweden)

V. Lucarini

2010-10-01

Full Text Available Using a recent theoretical approach, we study how global warming impacts the thermodynamics of the climate system by performing experiments with a simplified yet Earth-like climate model. The intensity of the Lorenz energy cycle, the Carnot efficiency, the material entropy production, and the degree of irreversibility of the system change monotonically with the CO₂ concentration. Moreover, these quantities feature an approximately linear behaviour with respect to the logarithm of the CO₂ concentration in a relatively wide range. These generalized sensitivities suggest that the climate becomes less efficient, more irreversible, and features higher entropy production as it becomes warmer, with changes in the latent heat fluxes playing a predominant role. These results may be of help for explaining recent findings obtained with state of the art climate models regarding how increases in CO₂ concentration impact the vertical stratification of the tropical and extratropical atmosphere and the position of the storm tracks.

Climate conditions, and changes, affect microalgae communities… should we worry?

Science.gov (United States)

Gimenez Papiol, Gemma

2018-03-01

Microalgae play a pivotal role in the regulation of Earth's climate and its cycles, but are also affected by climate change, mainly by changes in temperature, light, ocean acidification, water stratification, and precipitation-induced nutrient inputs. The changes and impacts on microalgae communities are difficult to study, predict, and manage, but there is no doubt that there will be changes. These changes will have impacts beyond microalgae communities, and many of them will be negative. Some actions are currently ongoing for the mitigation of some of the negative impacts, such as harmful algal blooms and water quality, but global efforts for reducing CO 2 emissions, temperature rises, and ocean acidification are paramount for reducing the impact of climate change on microalgae communities, and eventually, on human well-being. Integr Environ Assess Manag 2018;14:181-184. © 2018 SETAC. © 2018 SETAC.

Detecting the climatic effects of increasing carbon dioxide

Energy Technology Data Exchange (ETDEWEB)

MacCracken, M C; Luther, F M [eds.

1985-12-01

This report documents what is known about detecting the CO2-induced changes in climate, and describes the uncertainties and unknowns associated with this monitoring and analysis effort. The various approaches for detecting CO2-induced climate changes are discussed first, followed by a review of applications of these strategies to the various climatic variables that are expected to be changing. Recommendations are presented for research and analysis activities. Separate abstracts have been prepared for the individual papers. (ACR)

Predicting impacts of increased CO2 and climate change on the water cycle and water quality in the semiarid James River Basin of the Midwestern USA

International Nuclear Information System (INIS)

Wu, Yiping; Liu, Shuguang; Gallant, Alisa L.

2012-01-01

Emissions of greenhouse gases and aerosols from human activities continue to alter the climate and likely will have significant impacts on the terrestrial hydrological cycle and water quality, especially in arid and semiarid regions. We applied an improved Soil and Water Assessment Tool (SWAT) to evaluate impacts of increased atmospheric CO 2 concentration and potential climate change on the water cycle and nitrogen loads in the semiarid James River Basin (JRB) in the Midwestern United States. We assessed responses of water yield, soil water content, groundwater recharge, and nitrate nitrogen (NO 3 –N) load under hypothetical climate-sensitivity scenarios in terms of CO 2 , precipitation, and air temperature. We extended our predictions of the dynamics of these hydrological variables into the mid-21st century with downscaled climate projections integrated across output from six General Circulation Models. Our simulation results compared against the baseline period 1980 to 2009 suggest the JRB hydrological system is highly responsive to rising levels of CO 2 concentration and potential climate change. Under our scenarios, substantial decrease in precipitation and increase in air temperature by the mid-21st century could result in significant reduction in water yield, soil water content, and groundwater recharge. Our model also estimated decreased NO 3 –N load to streams, which could be beneficial, but a concomitant increase in NO 3 –N concentration due to a decrease in streamflow likely would degrade stream water and threaten aquatic ecosystems. These results highlight possible risks of drought, water supply shortage, and water quality degradation in this basin. - Highlights: ► We used a modified version of SWAT to more accurately simulate the effects of CO 2 . ► Our sensitivity analysis indicated this basin is very responsive to climate change. ► Downscaled GCM outputs showed decreased precipitation and increased temperature. ► There may be large

Using the CLM Crop Model to assess the impacts of changes in Climate, Atmospheric CO2, Irrigation, Fertilizer and Geographic Distribution on Historical and Future Crop Yields

Science.gov (United States)

Lawrence, P.

2015-12-01

Since the start of the green revolution global crop yields have increased linearly for most major cereal crops, so that present day global values are around twice those of the 1960s. The increase in crop yields have allowed for large increases in global agricultural production without correspondingly large increases in cropping area. Future projections under the Shared Socio-economic Pathways (SSP) framework and other assessments result in increases of global crop production of greater than 100% by the year 2050. In order to meet this increased agricultural demand within the available arable land, future production gains need to be understood in terms of the yield changes due to changes in climate, atmospheric CO2, and adaptive management such as irrigation and fertilizer application. In addition to the changes in crop yield, future agricultural demand will need to be met through increasing cropping areas into what are currently marginal lands at the cost of existing forests and other natural ecosystems. In this study we assess the utility of the crop model within the Community Land Model (CLM Crop) to provide both historical and future guidance on changes in crop yields under a range of global idealized crop modeling experiments. The idealized experiments follow the experimental design of the AgMIP Global Gridded Crop Model Intercomparison (GGCMI) in which CLM Crop is a participating model. The idealized experiments consist of global crop simulations for Cotton, Maize, Rice, Soy, Sugarcane, and Wheat under various climate, atmospheric CO2 levels, irrigation prescription, and nitrogen fertilizer application. The time periods simulated for the experiments are for the Historical period (1901 - 2005), and for the two Representative Concentration Pathways of RCP 4.5 and RCP 8.5 (2006 - 2100). Each crop is simulated on all land grid cells globally for each time period with atmospheric forcing that is a combination of: 1. transient climate and CO2; 2. transient climate

Enchytraeidae (Oligochaeta) in a changing climate

DEFF Research Database (Denmark)

Maraldo, Kristine

The background for this thesis was to investigate the effect of climate change (increased CO2, temperature and prolonged drought) on field communities of enchytraeids dominated by the species Cognettia sphagnetorum. In the short-term, enchytraeids appear to be unaffected by the climate change when...

Water Resources Response to Changes in Temperature, Rainfall and CO2 Concentration: A First Approach in NW Spain

Directory of Open Access Journals (Sweden)

Ricardo Arias

2014-10-01

Full Text Available Assessment of the diverse responses of water resources to climate change and high concentrations of CO2 is crucial for the appropriate management of natural ecosystems. Despite numerous studies on the impact of climate change on different regions, it is still necessary to evaluate the impact of these changes at the local scale. In this study, the Soil and Water Assessment Tool (SWAT model was used to evaluate the potential impact of changes in temperature, rainfall and CO2 concentration on water resources in a rural catchment in NW Spain for the periods 2031–2060 and 2069–2098, using 1981–2010 as a reference period. For the simulations we used compiled regional climate models of the ENSEMBLES project for future climate input data and two CO2 concentration scenarios (550 and 660 ppm. The results showed that changes in the concentration of CO2 and climate had a significant effect on water resources. Overall, the results suggest a decrease in streamflow of 16% for the period 2031–2060 (intermediate future and 35% by the end of the 21st century as a consequence of decreasing rainfall (2031–2060: −6%; 2069–2098: −15% and increasing temperature (2031–2060: 1.1 °C; 2069–2098: 2.2 °C.

CO2 and CH4 exchange by Phragmites australis under different climates

Science.gov (United States)

Serrano Ortiz, Penélope; Chojnickic, Bogdan H.; Sánchez-Cañete, Enrique P.; Kowalska, Natalia; López-Ballesteros, Ana; Fernández, Néstor; Urbaniak, Marek; Olejnik, Janusz; Kowalski, Andrew S.

2015-04-01

The key role of wetlands regarding global warming is the resulting balance between net CO2 assimilation, via photosynthesis, and CO2 and CH4 emissions, given the potential to release stored carbon, because of the high temperature sensitivity of heterotrophic soil respiration and anoxic conditions. However, it is still unknown whether wetlands will convert from long-term carbon sinks to sources as a result of climate change and other anthropogenic effects such as land use changes. Phragmites australis is one of the most common species found in wetlands and is considered the most globally widespread and productive plant species in this type of ecosystem. In this context, the main objective of this study is to analyse the GHG exchange (CO2 and CH4) of two wetlands with Phragmites australis as the dominant species under different climates using the eddy covariance (EC) technique. The first site, Padul, is located in southern Spain, with a sub-humid warm climate, characterised by a mean annual temperature of 16°C and annual precipitation of ca. 470 mm, with a very dry summer. The second site, Rzecin is located in Poland with a mean annual temperature of 8°C, and annual precipitation around 600mm with no dry season. The Padul EC station is equipped with two infrared gas analysers to measure CO2 and CH4 fluxes (LI-7200 and LI-7700 respectively) while the Rzecin EC station has the same CH4 sensor as Padul, but also a sensor measuring both GHG fluxes (DLT-100 Fast Methane Analyser, Los Gatos). In this study, we present: i) the results of a CH4 analyser inter-comparison campaign (LI-7700 vs. Los Gatos), ii) a comparative analysis of the functional behaviour of respiration and photosynthesis in both sites testing relationships between CO2 fluxes measured with the EC technique and meteorological variables such as temperature and direct or diffuse radiation and iii) the CH4 dynamicsat both sites by identifying, when possible, annual, seasonal and diurnal patterns.

Adaptation responses of crops to climate change

Energy Technology Data Exchange (ETDEWEB)

Seino, Hiroshi [National Inst. of Agro-Environmental Sciences, Tsukuba, Ibaraki (Japan)

1993-12-31

Appreciable global climatic responses to increasing levels of atmospheric CO{sub 2} and other trace gases are expected to take place over the next 50 to 80 years. Increasing atmospheric concentrations of carbon dioxide and other greenhouse gases are producing or will produce changes in the climate of the Earth. In particular, numerous efforts of climate modeling project very substantial increase of surface air temperature. In addition to a general warming of the atmosphere, the possibility of increased summer dryness in the continental mid-latitudes has been suggested on the basis of both historical analogues and some General Circulation Model (GCM) studies. There are three types of effect of climatic change on agriculture: (1) the physiological (direct) effect of elevated levels of atmospheric CO{sub 2} on crop plants and weeds, (2) the effect of changes in parameters of climate (e.g., temperature, precipitation, and solar radiation) on plants and animals, and (3) the effects of climate-related rises in sea-level on land use. The direct effects of elevated CO{sub 2} are on photosynthesis and respiration and thereby on growth, and there are additional effects of increased CO{sub 2} on development, yield quality and stomatal aperture and water use. A doubling of CO{sub 2} increases the instantaneous photosynthetic rate by 30% to 100%, depending on the other environmental conditions, and reduce water requirements of plants by reducing transpiration (per unit leaf area) through reductions in stomatal aperture. A doubling of CO{sub 2} causes partial stomatal closure on both C{sub 3} and C{sub 4} plants (approximately a 40% decrease in aperture). In many experiments this results in reductions of transpiration of about 23% to 46%. However. there is considerable uncertainty over the magnitude of this in natural conditions.

Climate effect of ozone changes caused by present and future air traffic

Energy Technology Data Exchange (ETDEWEB)

Ponater, M.; Sausen, R.; Feneberg, B. [DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Wessling (Germany). Inst. fuer Physik der Atmosphaere; Roeckner, E. [Max-Planck-Institut fuer Meteorologie, Hamburg (Germany)

1998-08-01

The potential of aircraft-induced ozone changes to significantly enhance the climate impact of air traffic due to CO{sub 2}-emissions is investigated by means of simulations with an atmospheric general circulation model, coupled to a mixed layer ocean model. Results from several numerical experiments are presented, based on ozone increase patterns for 1992 aviation and on a future scenario for the year 2015. The climate signal is statistically significant for both time slices. Its strength is of comparable magnitude to that arising from aircraft CO{sub 2} emissions, thus meaning a nonnegligible contribution to the total effect. There are indications of a characteristic signature of the aircraft ozone related temperature response pattern, distinctly different from that typically associated with the increase of a well-mixed greenhouse gas. Likewise, the climate sensitivity to nonuniform ozone changes including a strong concentration perturbation at the tropopause appears to he higher than the climate sensitivity to uniform changes of a greenhouse gas. In a hierarchy of experiments based on an aircraft-related ozone perturbation with fixed structure (but increasing amplitude), the climate signal depends in a nonlinear way from the radiative forcing. (orig.) 44 refs.

The changing world of climate change: Oregon leads the states

International Nuclear Information System (INIS)

Carver, P.H.; Sadler, S.; Kosloff, L.H.; Trexler, M.C.

1997-01-01

Following on the heels of recent national and international developments in climate change policy, Oregon's open-quote best-of-batch close-quote proceeding has validated the use of CO 2 offsets as a cost-effective means of advancing climate change mitigation goals. The proceeding was a first in several respects and represents a record commitment of funds to CO 2 mitigation by a private entity. In December 1995, the Intergovernmental Panel on Climate Change (IPCC), issued its Second Assessment Report. The IPCC's conclusion that open-quotes[t]he balance of evidence suggests a discernible human influence on global climateclose quotes fundamentally changed the tenor of the policy debate regarding potential threats associated with global climate change. At the Climate Change Convention's Conference of the Parties (COP) in Geneva in July 1996, most countries, including the United States, advocated adopting the IPCC report as the basis for swift policy movement toward binding international emissions targets. The next COP, in December 1997, is scheduled to be the venue for the signing of a treaty protocol incorporating such targets. Binding targets would have major consequences for power plant operators in the US and around the world. Recent developments in the state of Oregon show the kinds of measures that may become commonplace at the state level in addressing climate change mitigation. First, Oregon recently completed the first administrative proceeding in the US aimed at offsetting the greenhouse gas emissions of a new power plant. Second, a legislatively mandated energy facility siting task force recently recommended that Oregon adopt a carbon dioxide (CO 2 ) standard for new power plant construction and drop use of the open-quotes need for powerclose quotes standard. This article reviews these two policy milestones and their implications for climate change mitigation in the United States

Regional pattern and interannual variations in global terrestrial carbon uptake in response to changes in climate and atmospheric CO2

International Nuclear Information System (INIS)

Cao, Mingkui; Tao, B.; Li, Kerang; Prince, Stephen D.; Small, J.

2005-01-01

Atmospheric measurements indicate that the terrestrial carbon sink increased substantially from the 1980s to the 1990s, but which factors and regions were responsible for the increase are not well identified yet. Using process- and remote sensing-based ecosystem models, we show that changes in climate and atmospheric CO 2 in the period 1981-2000 enhanced net ecosystem production (NEP) and caused major geographical changes in the global distribution of NEP. In the 1980s the Americas accounted for almost all of the global NEP, but in the 1990s NEP in Eurasia and Africa became higher than that of the Americas. The year-to-year variation in global NEP was up to 2.5 Pg C (1 Pg = 10 15 g), in which 1.4 Pg C was attributable to the El Nino Southern Oscillation cycle (ENSO). NEP clearly decreased in El Nino and increased in La Nina in South America and Africa, but the response in North America and Eurasia was mixed. The estimated NEP increases accounted for only 30% of the global terrestrial carbon sink but can explain almost all of the increase from the 1980s to the 1990s. Because a large part of the increase in NEP was driven by the long-term trend of climate and atmospheric CO 2 , the increase in the global terrestrial carbon sink from the 1980s to the 1990s was a continuation of the trend since the middle of the twentieth century, rather than merely a consequence of short-time climate variability

Fast Cloud Adjustment to Increasing CO2 in a Superparameterized Climate Model

Directory of Open Access Journals (Sweden)

Marat Khairoutdinov

2012-05-01

Full Text Available Two-year simulation experiments with a superparameterized climate model, SP-CAM, are performed to understand the fast tropical (30S-30N cloud response to an instantaneous quadrupling of CO2 concentration with SST held fixed at present-day values.The greenhouse effect of the CO2 perturbation quickly warms the tropical land surfaces by an average of 0.5 K. This shifts rising motion, surface precipitation, and cloud cover at all levels from the ocean to the land, with only small net tropical-mean cloud changes. There is a widespread average reduction of about 80 m in the depth of the trade inversion capping the marine boundary layer (MBL over the cooler subtropical oceans.One apparent contributing factor is CO2-enhanced downwelling longwave radiation, which reduces boundary-layer radiative cooling, a primary driver of turbulent entrainment through the trade inversion. A second contributor is a slight CO2-induced heating of the free troposphere above the MBL, which strengthens the trade inversion and also inhibits entrainment. There is a corresponding downward displacement of MBL clouds with a very slight decrease in mean cloud cover and albedo.Two-dimensional cloud-resolving model (CRM simulations of this MBL response are run to steady state using composite SP-CAM simulated thermodynamic and wind profiles from a representative cool subtropical ocean regime, for the control and 4xCO2 cases. Simulations with a CRM grid resolution equal to that of SP-CAM are compared with much finer resolution simulations. The coarse-resolution simulations maintain a cloud fraction and albedo comparable to SP-CAM, but the fine-resolution simulations have a much smaller cloud fraction. Nevertheless, both CRM configurations simulate a reduction in inversion height comparable to SP-CAM. The changes in low cloud cover and albedo in the CRM simulations are small, but both simulations predict a slight reduction in low cloud albedo as in SP-CAM.

Evasion of CO2 injected into the ocean in the context of CO2 stabilization

International Nuclear Information System (INIS)

Kheshgi, Haroon S.

2004-01-01

The eventual evasion of injected CO 2 to the atmosphere is one consideration when assessing deep-sea disposal of CO 2 as a potential response option to climate change concerns. Evasion estimated using an ocean carbon cycle model is compared to long-term trajectories for future CO 2 emissions, including illustrative cases leading to stabilization of CO 2 concentration at various levels. Modeled residence time for CO 2 injected into the deep ocean exceeds the 100-year time-scale usually considered in scenarios for future emissions, and the potential impacts of climate change. Illustrative cases leading monotonically to constant CO 2 concentration have been highlighted by the Intergovernmental Panel on Climate Change to give guidance on possible timing of emission reductions that may be required to stabilize greenhouse gas concentrations at various levels. For stabilization cases considered, significant modeled evasion does not occur until long after CO 2 emissions have reached a maximum and begun to decline. Illustrative cases can also lead to a maximum in CO 2 concentration followed by a decline to slowly decreasing concentrations. In such cases, future injection of emissions into the deep ocean leads to lower maximum CO 2 concentration, with less effect on concentration later on in time

CO/sub 2/ carbon cycle and climate interactions

Energy Technology Data Exchange (ETDEWEB)

Grassl, H; Maier-Reimer, E; Degens, E T; Kempe, S; Spitzy, A

1984-03-01

Past and expected emissions of anthropogenic CO/sub 2/ stimulate carbon cycle and climate research. Prognoses of future CO/sub 2/ levels depend on energy scenarios and on the reaction of the biosphere and hydrosphere to elevated atmospheric CO/sub 2/ concentrations. The reaction of the reservoirs vegetation, freshwater and oceans to disturbances of the carbon cycle is reviewed. For the oceans first results of a simple carbon cycle model implanted in a three-dimensional general circulation model are presented. This model allows experiments not possible with previous box models.

Transient simulations of historical climate change including interactive carbon emissions from land-use change.

Science.gov (United States)

Matveev, A.; Matthews, H. D.

2009-04-01

Carbon fluxes from land conversion are among the most uncertain variables in our understanding of the contemporary carbon cycle, which limits our ability to estimate both the total human contribution to current climate forcing and the net effect of terrestrial biosphere changes on atmospheric CO2 increases. The current generation of coupled climate-carbon models have made significant progress in simulating the coupled climate and carbon cycle response to anthropogenic CO2 emissions, but do not typically include land-use change as a dynamic component of the simulation. In this work we have incorporated a book-keeping land-use carbon accounting model into the University of Victoria Earth System Climate Model (UVic ESCM), and intermediate-complexity coupled climate-carbon model. The terrestrial component of the UVic ESCM allows an aerial competition of five plant functional types (PFTs) in response to climatic conditions and area availability, and tracks the associated changes in affected carbon pools. In order to model CO2 emissions from land conversion in the terrestrial component of the model, we calculate the allocation of carbon to short and long-lived wood products following specified land-cover change, and use varying decay timescales to estimate CO2 emissions. We use recently available spatial datasets of both crop and pasture distributions to drive a series of transient simulations and estimate the net contribution of human land-use change to historical carbon emissions and climate change.

The Influence of Climate Change on CO2 and CH4 Concentration Near Closed Shaft - Numerical Simulations

Science.gov (United States)

Wrona, Paweł

2017-09-01

Given the scientific consensus pointing to climate change, the more extreme weather events associated with this will lead to deeper pressure drops. As has already been stated, pressure drops are the main cause of gas flow from underground sites to the surface. This article presents the results of numerical simulations of the change in distribution of CO2 and CH4 near a closed mining shaft under the predicted baric tendency. Simulations have been undertaken by means of the FDS software package with the Pyrosim graphical interface - a CFD tool for fire and ventilation analysis. Assumptions have been based on previous results of in-situ measurements. The results (determined for a height of 1m above the ground) were compared to the following levels (later in the text comparison levels): for CO2 0.1%vol. according to Pettenkoffer's scale and 2.5%vol. for CH4 as the half of Lower Explosive Limit (LEL). The results show that the deeper baric drops anticipated could lead to a wider spread of both greenhouse gases in the vicinity of the shaft, especially along the prevailing wind direction. According to the results obtained, CO2 and CH4 with concentrations above their comparison levels are expected at a distance greater than 50m from the shaft when wind is present for CO2 and at a distance of 4.5m for CH4. Subsequent analysis of the results enabled the determination of functions for describing the concentration of gases along the wind direction line under the projected pressure drop. The results relate to a particular case, although the model could easily be modified to any other example of gas emissions from underground sites.

Elevated CO2 induces changes in the ecohydrological functions of forests - from mechanisms to models

Science.gov (United States)

Pötzelsberger, Elisabeth; Warren, Jeffrey M.; Wullschleger, Stan D.; Thornton, Peter E.; Norby, Richard J.; Hasenauer, Hubert

2010-05-01

Forests are known to considerably influence ecosystem water balance as a result of the many dynamic interactions between the plant physiology, morphology, phenology and other biophysical properties and environmental conditions. A changing climate will exert a new environmental setting for the forests and the biological feedbacks will be considerable. With the mechanistic ecosystem model Biome-BGC the dense net of cause-response relationships among carbon, nitrogen, water and energy cycles at a free-air CO2 enrichment (FACE) site in a North American deciduous broadleaved forest can be represented. At the Oak Ridge National Laboratory (ORNL) closed canopy sweetgum plantation elevated CO2 caused a decrease in stomatal conductance, and concurrent changes in daily transpiration were observed. This is in agreement with data from other FACE experiments. At the ORNL FACE site average transpiration reduction in a growing season was 10-16%, with 7-16% during mid summer, depending on the year. After parameterization of the model for this ecosystem the observed transpiration patterns could be well represented. Most importantly, the complete water budget at the site could be described and increased outflow could be observed (~15%). This yields crucial information for broader scale future water budget simulations. Changes in the water balance of deciduous forests will affect a wide range of ecosystem functions, from decomposition, over carbon and nutrient cycling to plant-plant competition and species composition.

Modeling the impacts of temperature and precipitation changes on soil CO2 fluxes from a Switchgrass stand recently converted from cropland.

Science.gov (United States)

Lai, Liming; Kumar, Sandeep; Chintala, Rajesh; Owens, Vance N; Clay, David; Schumacher, Joseph; Nizami, Abdul-Sattar; Lee, Sang Soo; Rafique, Rashad

2016-05-01

Switchgrass (Panicum virgatum L.) is a perennial C4 grass native to North America and successfully adapted to diverse environmental conditions. It offers the potential to reduce soil surface carbon dioxide (CO2) fluxes and mitigate climate change. However, information on how these CO2 fluxes respond to changing climate is still lacking. In this study, CO2 fluxes were monitored continuously from 2011 through 2014 using high frequency measurements from Switchgrass land seeded in 2008 on an experimental site that has been previously used for soybean (Glycine max L.) in South Dakota, USA. DAYCENT, a process-based model, was used to simulate CO2 fluxes. An improved methodology CPTE [Combining Parameter estimation (PEST) with "Trial and Error" method] was used to calibrate DAYCENT. The calibrated DAYCENT model was used for simulating future CO2 emissions based on different climate change scenarios. This study showed that: (i) the measured soil CO2 fluxes from Switchgrass land were higher for 2012 which was a drought year, and these fluxes when simulated using DAYCENT for long-term (2015-2070) provided a pattern of polynomial curve; (ii) the simulated CO2 fluxes provided different patterns with temperature and precipitation changes in a long-term, (iii) the future CO2 fluxes from Switchgrass land under different changing climate scenarios were not significantly different, therefore, it can be concluded that Switchgrass grown for longer durations could reduce changes in CO2 fluxes from soil as a result of temperature and precipitation changes to some extent. Copyright © 2015. Published by Elsevier B.V.

Uncertainty in projected climate change arising from uncertain fossil-fuel emission factors

Science.gov (United States)

Quilcaille, Y.; Gasser, T.; Ciais, P.; Lecocq, F.; Janssens-Maenhout, G.; Mohr, S.

2018-04-01

Emission inventories are widely used by the climate community, but their uncertainties are rarely accounted for. In this study, we evaluate the uncertainty in projected climate change induced by uncertainties in fossil-fuel emissions, accounting for non-CO2 species co-emitted with the combustion of fossil-fuels and their use in industrial processes. Using consistent historical reconstructions and three contrasted future projections of fossil-fuel extraction from Mohr et al we calculate CO2 emissions and their uncertainties stemming from estimates of fuel carbon content, net calorific value and oxidation fraction. Our historical reconstructions of fossil-fuel CO2 emissions are consistent with other inventories in terms of average and range. The uncertainties sum up to a ±15% relative uncertainty in cumulative CO2 emissions by 2300. Uncertainties in the emissions of non-CO2 species associated with the use of fossil fuels are estimated using co-emission ratios varying with time. Using these inputs, we use the compact Earth system model OSCAR v2.2 and a Monte Carlo setup, in order to attribute the uncertainty in projected global surface temperature change (ΔT) to three sources of uncertainty, namely on the Earth system’s response, on fossil-fuel CO2 emission and on non-CO2 co-emissions. Under the three future fuel extraction scenarios, we simulate the median ΔT to be 1.9, 2.7 or 4.0 °C in 2300, with an associated 90% confidence interval of about 65%, 52% and 42%. We show that virtually all of the total uncertainty is attributable to the uncertainty in the future Earth system’s response to the anthropogenic perturbation. We conclude that the uncertainty in emission estimates can be neglected for global temperature projections in the face of the large uncertainty in the Earth system response to the forcing of emissions. We show that this result does not hold for all variables of the climate system, such as the atmospheric partial pressure of CO2 and the

Climate-society feedbacks and the avoidance of dangerous climate change

Science.gov (United States)

Jarvis, A. J.; Leedal, D. T.; Hewitt, C. N.

2012-09-01

The growth in anthropogenic CO2 emissions experienced since the onset of the Industrial Revolution is the most important disturbance operating on the Earth's climate system. To avoid dangerous climate change, future greenhouse-gas emissions will have to deviate from business-as-usual trajectories. This implies that feedback links need to exist between climate change and societal actions. Here, we show that, consciously or otherwise, these feedbacks can be represented by linking global mean temperature change to the growth dynamics of CO2 emissions. We show that the global growth of new renewable sources of energy post-1990 represents a climate-society feedback of ~0.25%yr-1 per degree increase in global mean temperature. We also show that to fulfil the outcomes negotiated in Durban in 2011, society will have to become ~ 50 times more responsive to global mean temperature change than it has been since 1990. If global energy use continues to grow as it has done historically then this would result in amplification of the long-term endogenous rate of decarbonization from -0.6%yr-1 to ~-13%yr-1. It is apparent that modest levels of feedback sensitivity pay large dividends in avoiding climate change but that the marginal return on this effort diminishes rapidly as the required feedback strength increases.

Directed technical change and differentiation of climate policy

International Nuclear Information System (INIS)

Otto, Vincent M.; Loeschel, Andreas; Reilly, John

2008-01-01

This paper studies the cost effectiveness of climate policy if there are technology externalities. For this purpose, we develop a forward looking model that captures empirical links between CO 2 emissions associated with energy use, directed technical change and the economy. We find our most cost effective climate policy to include a combination of R and D subsidies and CO 2 emission constraints, although R and D subsidies raise the shadow value of the CO 2 constraint (i.e. CO 2 price) because of a strong rebound effect from stimulating innovation. Furthermore, we find that cost effectiveness of climate policy improves if it is differentiated between technologies. Even our rudimentary distinction between CO 2 intensive technologies and non-CO 2 intensive technologies lead to this result. Such differentiated climate policy encourages growth in the non-CO 2 intensive sectors and discourages growth in CO 2 intensive sectors by harnessing positive effects of technology externalities on total factor productivity in the former and letting the latter bear relatively more of the abatement burden. This result is robust to whether emission constraints, R and D subsidies or combinations of both are used as climate policy instruments. (author)

Uncertainty in Simulating Wheat Yields Under Climate Change

Science.gov (United States)

Asseng, S.; Ewert, F.; Rosenzweig, Cynthia; Jones, J. W.; Hatfield, J. W.; Ruane, A. C.; Boote, K. J.; Thornburn, P. J.; Rotter, R. P.; Cammarano, D.;

Effects of climatic variability and change

Science.gov (United States)

Michael G. Ryan; James M. Vose

2012-01-01

Climate profoundly shapes forests. Forest species composition, productivity, availability of goods and services, disturbance regimes, and location on the landscape are all regulated by climate. Much research attention has focused on the problem of projecting the response of forests to changing climate, elevated atmospheric carbon dioxide (CO2)...

Climate Change Adaptation

DEFF Research Database (Denmark)

Hudecz, Adriána

The European Union ROADEX Project 1998 – 2012 was a trans-national roads co-operation aimed at developing ways for interactive and innovative management of low traffic volume roads throughout the cold climate regions of the Northern Periphery Area of Europe. Its goals were to facilitate co......-operation and research into the common problems of the Northern Periphery. This report is an output of the ROADEX “Implementing Accessibility” project (2009-2012). It gives a summary of the results of research into adaptation measures to combat climate change effects on low volume roads in the Northern Periphery...... causes changes in other climatic variables such as rainfall, humidity and wind speed that impact on the functioning of infrastructure such road networks. This paper discusses the climate changes predicted by the world’s meteorological organisations and considers how these may impact on the public...

10 CFR 960.4-2-4 - Climatic changes.

Science.gov (United States)

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Climatic changes. 960.4-2-4 Section 960.4-2-4 Energy... REPOSITORY Postclosure Guidelines § 960.4-2-4 Climatic changes. (a) Qualifying condition. The site shall be... years would not adversely affect waste isolation. (2) A geologic setting in which climatic changes have...

Agriculture and climate change

International Nuclear Information System (INIS)

Abelson, P.H.

1992-01-01

How will increases in levels of CO 2 and changes in temperature affect food production? A recently issued report analyzes prospects for US agriculture 1990 to 2030. The report, prepared by a distinguished Task Force, first projects the evolution of agriculture assuming increased levels of CO 2 but no climate change. Then it deals with effects of climate change, followed by a discussion of how greenhouse emissions might be diminished by agriculture. Economic and policy matters are also covered. How the climate would respond to more greenhouse gases is uncertain. If temperatures were higher, there would be more evaporation and more precipitation. Where would the rain fall? That is a good question. Weather in a particular locality is not determined by global averages. The Dust Bowl of the 1930s could be repeated at its former site or located in another region such as the present Corn Belt. But depending on the realities at a given place, farmers have demonstrated great flexibility in choosing what they may grow. Their flexibility has been increased by the numerous varieties of seeds of major crops that are now available, each having different characteristics such as drought resistance and temperature tolerance. In past, agriculture has contributed about 5% of US greenhouse gases. Two large components have involved emissions of CO 2 from farm machinery and from oxidation of organic matter in soil due to tillage. Use of diesel fuel and more efficient machinery has reduced emissions from that source by 40%. In some areas changed tillage practices are now responsible for returning carbon to the soil. The report identifies an important potential for diminishing net US emissions of CO 2 by growth and utilization of biomass. Large areas are already available that could be devoted to energy crops

Direct and indirect climate change effects on carbon dioxide fluxes in a thawing boreal forest-wetland landscape.

Science.gov (United States)

Helbig, Manuel; Chasmer, Laura E; Desai, Ankur R; Kljun, Natascha; Quinton, William L; Sonnentag, Oliver

2017-08-01

In the sporadic permafrost zone of northwestern Canada, boreal forest carbon dioxide (CO 2 ) fluxes will be altered directly by climate change through changing meteorological forcing and indirectly through changes in landscape functioning associated with thaw-induced collapse-scar bog ('wetland') expansion. However, their combined effect on landscape-scale net ecosystem CO 2 exchange (NEE LAND ), resulting from changing gross primary productivity (GPP) and ecosystem respiration (ER), remains unknown. Here, we quantify indirect land cover change impacts on NEE LAND and direct climate change impacts on modeled temperature- and light-limited NEE LAND of a boreal forest-wetland landscape. Using nested eddy covariance flux towers, we find both GPP and ER to be larger at the landscape compared to the wetland level. However, annual NEE LAND (-20 g C m -2 ) and wetland NEE (-24 g C m -2 ) were similar, suggesting negligible wetland expansion effects on NEE LAND . In contrast, we find non-negligible direct climate change impacts when modeling NEE LAND using projected air temperature and incoming shortwave radiation. At the end of the 21st century, modeled GPP mainly increases in spring and fall due to reduced temperature limitation, but becomes more frequently light-limited in fall. In a warmer climate, ER increases year-round in the absence of moisture stress resulting in net CO 2 uptake increases in the shoulder seasons and decreases during the summer. Annually, landscape net CO 2 uptake is projected to decline by 25 ± 14 g C m -2 for a moderate and 103 ± 38 g C m -2 for a high warming scenario, potentially reversing recently observed positive net CO 2 uptake trends across the boreal biome. Thus, even without moisture stress, net CO 2 uptake of boreal forest-wetland landscapes may decline, and ultimately, these landscapes may turn into net CO 2 sources under continued anthropogenic CO 2 emissions. We conclude that NEE LAND changes are more likely to be

Predicting Impacts of Increased CO2 and Climate Change on the Water Cycle and Water Quality in the Semiarid James River Basin of the Midwestern USA

Science.gov (United States)

Wu, Yiping; Liu, Shu-Guang; Gallant, Alisa L.

2012-01-01

Emissions of greenhouse gases and aerosols from human activities continue to alter the climate and likely will have significant impacts on the terrestrial hydrological cycle and water quality, especially in arid and semiarid regions. We applied an improved Soil and Water Assessment Tool (SWAT) to evaluate impacts of increased atmospheric CO2 concentration and potential climate change on the water cycle and nitrogen loads in the semiarid James River Basin (JRB) in the Midwestern United States. We assessed responses of water yield, soil water content, groundwater recharge, and nitrate nitrogen (NO3–N) load under hypothetical climate-sensitivity scenarios in terms of CO2, precipitation, and air temperature. We extended our predictions of the dynamics of these hydrological variables into the mid-21st century with downscaled climate projections integrated across output from six General Circulation Models. Our simulation results compared against the baseline period 1980 to 2009 suggest the JRB hydrological system is highly responsive to rising levels of CO2 concentration and potential climate change. Under our scenarios, substantial decrease in precipitation and increase in air temperature by the mid-21st century could result in significant reduction in water yield, soil water content, and groundwater recharge. Our model also estimated decreased NO3–N load to streams, which could be beneficial, but a concomitant increase in NO3–N concentration due to a decrease in streamflow likely would degrade stream water and threaten aquatic ecosystems. These results highlight possible risks of drought, water supply shortage, and water quality degradation in this basin.

Modeled climate-induced glacier change in Glacier National Park, 1850-2100

Science.gov (United States)

Hall, M.H.P.; Fagre, D.B.

2003-01-01

The glaciers in the Blackfoot-Jackson Glacier Basin of Glacier National Park, Montana, decreased in area from 21.6 square kilometers (km2) in 1850 to 7.4 km2 in 1979. Over this same period global temperatures increased by 0.45??C (?? 0. 15??C). We analyzed the climatic causes and ecological consequences of glacier retreat by creating spatially explicit models of the creation and ablation of glaciers and of the response of vegetation to climate change. We determined the melt rate and spatial distribution of glaciers under two possible future climate scenarios, one based on carbon dioxide-induced global warming and the other on a linear temperature extrapolation. Under the former scenario, all glaciers in the basin will disappear by the year 2030, despite predicted increases in precipitation; under the latter, melting is slower. Using a second model, we analyzed vegetation responses to variations in soil moisture and increasing temperature in a complex alpine landscape and predicted where plant communities are likely to be located as conditions change.

Predicting pan-tropical climate change induced forest stock gains and losses-implications for REDD

International Nuclear Information System (INIS)

Gumpenberger, Marlies; Vohland, Katrin; Heyder, Ursula; Poulter, Benjamin; Rammig, Anja; Popp, Alexander; Cramer, Wolfgang; Macey, Kirsten

2010-01-01

Deforestation is a major threat to tropical forests worldwide, contributing up to one-fifth of global carbon emissions into the atmosphere. Despite protection efforts, deforestation of tropical forests has continued in recent years. Providing incentives to reducing deforestation has been proposed in the United Nations Framework Convention on Climate Change (UNFCCC) Bali negotiations in 2007 to decelerate emissions from deforestation (REDD-reduced emissions from deforestation and forest degradation). A number of methodological issues such as ensuring permanence, establishing reference emissions levels that do not reward business-as-usual and having a measuring, reporting and verification system in place are essential elements in implementing successful REDD schemes. To assess the combined impacts of climate and land-use change on tropical forest carbon stocks in the 21st century, we use a dynamic global vegetation model (LPJ DGVM) driven by five different climate change projections under a given greenhouse gas emission scenario (SRES A2) and two contrasting land-use change scenarios. We find that even under a complete stop of deforestation after the period of the Kyoto Protocol (post-2012) some countries may continue to lose carbon stocks due to climate change. Especially at risk is tropical Latin America, although the presence and magnitude of the risk depends on the climate change scenario. By contrast, strong protection of forests could increase carbon uptake in many tropical countries, due to CO 2 fertilization effects, even under altered climate regimes.

Abiotic and seasonal control of soil-produced CO2 efflux in karstic ecosystems located in Oceanic and Mediterranean climates

Science.gov (United States)

Garcia-Anton, Elena; Cuezva, Soledad; Fernandez-Cortes, Angel; Alvarez-Gallego, Miriam; Pla, Concepcion; Benavente, David; Cañaveras, Juan Carlos; Sanchez-Moral, Sergio

2017-09-01

This study characterizes the processes involved in seasonal CO2 exchange between soils and shallow underground systems and explores the contribution of the different biotic and abiotic sources as a function of changing weather conditions. We spatially and temporally investigated five karstic caves across the Iberian Peninsula, which presented different microclimatic, geologic and geomorphologic features. The locations present Mediterranean and Oceanic climates. Spot air sampling of CO2 (g) and δ13CO2 in the caves, soils and outside atmospheric air was periodically conducted. The isotopic ratio of the source contribution enhancing the CO2 concentration was calculated using the Keeling model. We compared the isotopic ratio of the source in the soil (δ13Cs-soil) with that in the soil-underground system (δ13Cs-system). Although the studied field sites have different features, we found common seasonal trends in their values, which suggests a climatic control over the soil air CO2 and the δ13CO2 of the sources of CO2 in the soil (δ13Cs-soil) and the system (δ13Cs-system). The roots respiration and soil organic matter degradation are the main source of CO2 in underground environments, and the inlet of the gas is mainly driven by diffusion and advection. Drier and warmer conditions enhance soil-exterior CO2 interchange, reducing the CO2 concentration and increasing the δ13CO2 of the soil air. Moreover, the isotopic ratio of the source of CO2 in both the soil and the system tends to heavier values throughout the dry and warm season. We conclude that seasonal variations of soil CO2 concentration and its 13C/12C isotopic ratio are mainly regulated by thermo-hygrometric conditions. In cold and wet seasons, the increase of soil moisture reduces soil diffusivity and allows the storage of CO2 in the subsoil. During dry and warm seasons, the evaporation of soil water favours diffusive and advective transport of soil-derived CO2 to the atmosphere. The soil CO2 diffusion is

Co-benefits of climate policies: a potential keystone of climate negotiations?

International Nuclear Information System (INIS)

Cassen, Christophe; Guivarch, Celine; Lecocq, Franck

2015-01-01

This paper analyzes the challenges related to the assessment of co-benefits of climate policies underpinned by the implementation of multi-objective policies which seek synergies between climate policies and other development objectives (poverty alleviation, employment, health etc.). The analysis highlights the increasing interest in co-benefits in the latest 5. IPCC report, in particular by integrated models. Nevertheless, the quantified evaluation of co-benefits is still confronted to several methodological limitations which reduce the scope of co-benefits, particularly at the global level. In a growing context of climate-development approaches in climate negotiations, this article insists on the need to also assess co-benefits of other policies which induce a significant part of GHG emissions. Considering climate policies focused only on Greenhouse Gases emissions reduction limits the range of policy instruments to carbon taxation, tradable carbon emissions permits or dedicated mitigation and adaptation funds. This also hinders the integration of climate objectives in non-climate policies. Analyzing impacts of development policies on Green Gases emissions in the form of co-benefits requires to broaden the range of policy instruments and to take into account other drivers of emissions such as land dynamics. Including these mechanisms in integrated models therefore represents new scientific frontiers for integrated models in the coming years

The impact on atmospheric CO2 of iron fertilization induced changes in the ocean's biological pump

Science.gov (United States)

Jin, X.; Gruber, N.; Frenzel, H.; Doney, S. C.; McWilliams, J. C.

2008-03-01

Using numerical simulations, we quantify the impact of changes in the ocean's biological pump on the air-sea balance of CO2 by fertilizing a small surface patch in the high-nutrient, low-chlorophyll region of the eastern tropical Pacific with iron. Decade-long fertilization experiments are conducted in a basin-scale, eddy-permitting coupled physical/biogeochemical/ecological model. In contrast to previous studies, we find that most of the dissolved inorganic carbon (DIC) removed from the euphotic zone by the enhanced biological export is replaced by uptake of CO2 from the atmosphere. Atmospheric uptake efficiencies, the ratio of the perturbation in air-sea CO2 flux to the perturbation in export flux across 100 m, integrated over 10 years, are 0.75 to 0.93 in our patch size-scale experiments. The atmospheric uptake efficiency is insensitive to the duration of the experiment. The primary factor controlling the atmospheric uptake efficiency is the vertical distribution of the enhanced biological production and export. Iron fertilization at the surface tends to induce production anomalies primarily near the surface, leading to high efficiencies. In contrast, mechanisms that induce deep production anomalies (e.g. altered light availability) tend to have a low uptake efficiency, since most of the removed DIC is replaced by lateral and vertical transport and mixing. Despite high atmospheric uptake efficiencies, patch-scale iron fertilization of the ocean's biological pump tends to remove little CO2 from the atmosphere over the decadal timescale considered here.

High fitness costs of climate change-induced camouflage mismatch.

Science.gov (United States)

Zimova, Marketa; Mills, L Scott; Nowak, J Joshua

2016-03-01

Anthropogenic climate change has created myriad stressors that threaten to cause local extinctions if wild populations fail to adapt to novel conditions. We studied individual and population-level fitness costs of a climate change-induced stressor: camouflage mismatch in seasonally colour molting species confronting decreasing snow cover duration. Based on field measurements of radiocollared snowshoe hares, we found strong selection on coat colour molt phenology, such that animals mismatched with the colour of their background experienced weekly survival decreases up to 7%. In the absence of adaptive response, we show that these mortality costs would result in strong population-level declines by the end of the century. However, natural selection acting on wide individual variation in molt phenology might enable evolutionary adaptation to camouflage mismatch. We conclude that evolutionary rescue will be critical for hares and other colour molting species to keep up with climate change. © 2016 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

Evasion of CO{sub 2} injected into the ocean in the content of CO{sub 2} stabilization

Energy Technology Data Exchange (ETDEWEB)

Kheshgi, H.S. [ExxonMobil Research and Engineering Co., Annandale, NJ (United States)

2004-08-01

The eventual evasion of injected CO{sub 2} to the atmosphere is one consideration when assessing deep-sea disposal of CO{sub 2} as a potential response option to climate change concerns. Evasion estimated using an ocean carbon cycle model is compared to long-term trajectories for future CO{sub 2} emissions, including illustrative cases leading to stabilization of CO{sub 2} concentration at various levels. Modeled residence time for CO{sub 2} injected into the deep ocean exceeds the 100-year time-scale usually considered in scenarios for future emissions, and the potential impacts of climate change. Illustrative cases leading monotonically to constant CO{sub 2} concentration have been highlighted by the Intergovernmental Panel on Climate Change to give guidance on possible timing of emission reductions that may be required to stabilize greenhouse gas concentrations at various levels. For stabilization cases considered, significant modeled evasion does not occur until long after CO{sub 2} emissions have reached a maximum and begun to decline. Illustrative cases can also lead to a maximum in CO{sub 2} concentration followed by a decline to slowly decreasing concentrations. In such cases, future injection of emissions into the deep ocean leads to lower maximum CO{sub 2} concentration, with less effect on concentration later on in time. (author)

Evasion of CO{sub 2} injected into the ocean in the context of CO{sub 2} stabilization

Energy Technology Data Exchange (ETDEWEB)

Kheshgi, Haroon S

2004-08-01

The eventual evasion of injected CO{sub 2} to the atmosphere is one consideration when assessing deep-sea disposal of CO{sub 2} as a potential response option to climate change concerns. Evasion estimated using an ocean carbon cycle model is compared to long-term trajectories for future CO{sub 2} emissions, including illustrative cases leading to stabilization of CO{sub 2} concentration at various levels. Modeled residence time for CO{sub 2} injected into the deep ocean exceeds the 100-year time-scale usually considered in scenarios for future emissions, and the potential impacts of climate change. Illustrative cases leading monotonically to constant CO{sub 2} concentration have been highlighted by the Intergovernmental Panel on Climate Change to give guidance on possible timing of emission reductions that may be required to stabilize greenhouse gas concentrations at various levels. For stabilization cases considered, significant modeled evasion does not occur until long after CO{sub 2} emissions have reached a maximum and begun to decline. Illustrative cases can also lead to a maximum in CO{sub 2} concentration followed by a decline to slowly decreasing concentrations. In such cases, future injection of emissions into the deep ocean leads to lower maximum CO{sub 2} concentration, with less effect on concentration later on in time.

Surface CO2 Exchange Dynamics across a Climatic Gradient in McKenzie Valley: Effect of Landforms, Climate and Permafrost

Directory of Open Access Journals (Sweden)

Natalia Startsev

2016-11-01

Full Text Available Northern regions are experiencing considerable climate change affecting the state of permafrost, peat accumulation rates, and the large pool of carbon (C stored in soil, thereby emphasizing the importance of monitoring surface C fluxes in different landform sites along a climate gradient. We studied surface net C exchange (NCE and ecosystem respiration (ER across different landforms (upland, peat plateau, collapse scar in mid-boreal to high subarctic ecoregions in the Mackenzie Valley of northwestern Canada for three years. NCE and ER were measured using automatic CO2 chambers (ADC, Bioscientific LTD., Herts, England, and soil respiration (SR was measured with solid state infrared CO2 sensors (Carbocaps, Vaisala, Vantaa, Finland using the concentration gradient technique. Both NCE and ER were primarily controlled by soil temperature in the upper horizons. In upland forest locations, ER varied from 583 to 214 g C·m−2·year−1 from mid-boreal to high subarctic zones, respectively. For the bog and peat plateau areas, ER was less than half that at the upland locations. Of SR, nearly 75% was generated in the upper 5 cm layer composed of live bryophytes and actively decomposing fibric material. Our results suggest that for the upland and bog locations, ER significantly exceeded NCE. Bryophyte NCE was greatest in continuously waterlogged collapsed areas and was negligible in other locations. Overall, upland forest sites were sources of CO2 (from 64 g·C·m−2·year−1 in the high subarctic to 588 g C·m−2·year−1 in mid-boreal zone; collapsed areas were sinks of C, especially in high subarctic (from 27 g·C·m−2 year−1 in mid-boreal to 86 g·C·m−2·year−1 in high subarctic and peat plateaus were minor sources (from 153 g·C·m−2·year−1 in mid-boreal to 6 g·C·m−2·year−1 in high subarctic. The results are important in understanding how different landforms are responding to climate change and would be useful in modeling the

Climate Change Modelling and Its Roles to Chinese Crops Yield

Institute of Scientific and Technical Information of China (English)

JU Hui; LIN Er-da; Tim Wheeler; Andrew Challinor; JIANG Shuai

2013-01-01

Climate has been changing in the last fifty years in China and will continue to change regardless any efforts for mitigation. Agriculture is a climate-dependent activity and highly sensitive to climate changes and climate variability. Understanding the interactions between climate change and agricultural production is essential for society stable development of China. The first mission is to fully understand how to predict future climate and link it with agriculture production system. In this paper, recent studies both domestic and international are reviewed in order to provide an overall image of the progress in climate change researches. The methods for climate change scenarios construction are introduced. The pivotal techniques linking crop model and climate models are systematically assessed and climate change impacts on Chinese crops yield among model results are summarized. The study found that simulated productions of grain crop inherit uncertainty from using different climate models, emission scenarios and the crops simulation models. Moreover, studies have different spatial resolutions, and methods for general circulation model (GCM) downscaling which increase the uncertainty for regional impacts assessment. However, the magnitude of change in crop production due to climate change (at 700 ppm CO2 eq correct) appears within ±10%for China in these assessments. In most literatures, the three cereal crop yields showed decline under climate change scenarios and only wheat in some region showed increase. Finally, the paper points out several gaps in current researches which need more studies to shorten the distance for objective recognizing the impacts of climate change on crops. The uncertainty for crop yield projection is associated with climate change scenarios, CO2 fertilization effects and adaptation options. Therefore, more studies on the fields such as free air CO2 enrichment experiment and practical adaptations implemented need to be carried out.

assessing climate change impacts on river hydrology

Indian Academy of Sciences (India)

71

model, Soil and Water Assessment Tool (SWAT), in order to evaluate the effect of climate. 24 change on rainfall ... to project future climate data based on the CO2 emission scenarios.The RCMs are of finer ..... Springer Science+Business. 2.

Europeans' attitudes towards climate change

International Nuclear Information System (INIS)

2009-07-01

This report presents the results of a survey on Europeans' attitudes towards climate change which was carried out in January and February 2009. The survey focuses on: Citizens' perceptions of climate change in relation to other world problems; Citizens' perceptions of the seriousness of climate change; The extent to which citizens feel informed about climate change - its causes, consequences and ways of fighting it; Citizens' attitudes towards alternative fuels and CO2 emissions; Whether citizens feel that climate change is stoppable or has been exaggerated, and what impact it has on the European economy; Whether citizens have taken personal action to fight climate change. This Eurobarometer survey was carried out by TNS Opinion and Social network between 16 January and 22 February 2009. The interviews were conducted among 26,718 citizens in the 27 Member States of the European Union, the three candidate countries for accession to the European Union (Croatia, Turkey and the Former Yugoslav Republic of Macedonia) and in the Turkish Cypriot Community.

CO2-Induced ATP-Dependent Release of Acetylcholine on the Ventral Surface of the Medulla Oblongata.

Science.gov (United States)

Huckstepp, Robert T R; Llaudet, Enrique; Gourine, Alexander V

2016-01-01

Complex mechanisms that detect changes in brainstem parenchymal PCO2/[H+] and trigger adaptive changes in lung ventilation are responsible for central respiratory CO2 chemosensitivity. Previous studies of chemosensory signalling pathways suggest that at the level of the ventral surface of the medulla oblongata (VMS), CO2-induced changes in ventilation are (at least in part) mediated by the release and actions of ATP and/or acetylcholine (ACh). Here we performed simultaneous real-time biosensor recordings of CO2-induced ATP and ACh release from the VMS in vivo and in vitro, to test the hypothesis that central respiratory CO2 chemosensory transduction involves simultaneous recruitment of purinergic and cholinergic signalling pathways. In anaesthetised and artificially ventilated rats, an increase in inspired CO2 triggered ACh release on the VMS with a peak amplitude of ~5 μM. Release of ACh was only detected after the onset of CO2-induced activation of the respiratory activity and was markedly reduced (by ~70%) by ATP receptor blockade. In horizontal slices of the VMS, CO2-induced release of ATP was reliably detected, whereas CO2 or bath application of ATP (100 μM) failed to trigger release of ACh. These results suggest that during hypercapnia locally produced ATP induces or potentiates the release of ACh (likely from the medullary projections of distal groups of cholinergic neurones), which may also contribute to the development and/or maintenance of the ventilatory response to CO2.

Groundwater Chemistry Changes as a Result of CO2 Injection at the ZERT Field Site in Bozeman, Montana

Energy Technology Data Exchange (ETDEWEB)

Apps, J.A.; Birkholzer, J.T.; Spycher, N.; Zheng, L.; Herkelrath, W.N.; Kharaka, Y.K.; Thordsen, J.J.; Kakouros, E.; Beers, S; Gullickson, K.S.; Spangler, L.H.; Ambats, G.

2009-11-01

Combustion of fossil fuels produces CO{sub 2}, a common greenhouse gas linked to global climate change. Separation of CO{sub 2}from emissions produced by large industrial point sources like power plants, cement kilns and refineries, and injection deep nderground into geologic formations is one method of preventing CO{sub 2} releases into the atmosphere. This process is referred to as Carbon Capture and Storage (CCS). CCS is one of several solutions being considered to mitigate global climate change. Other solutions nclude increased energy efficiency, renewables, nuclear power, advanced coal, and plug-in hybrid electric vehicles.

Interactions between above- and belowground organisms modified in climate change experiments

Science.gov (United States)

Stevnbak, Karen; Scherber, Christoph; Gladbach, David J.; Beier, Claus; Mikkelsen, Teis N.; Christensen, Søren

2012-11-01

Climate change has been shown to affect ecosystem process rates and community composition, with direct and indirect effects on belowground food webs. In particular, altered rates of herbivory under future climate can be expected to influence above-belowground interactions. Here, we use a multifactor, field-scale climate change experiment and independently manipulate atmospheric CO2 concentration, air and soil temperature and drought in all combinations since 2005. We show that changes in these factors modify the interaction between above- and belowground organisms. We use an insect herbivore to experimentally increase aboveground herbivory in grass phytometers exposed to all eight combinations of climate change factors for three years. Aboveground herbivory increased the abundance of belowground protozoans, microbial growth and microbial nitrogen availability. Increased CO2 modified these links through a reduction in herbivory and cascading effects through the soil food web. Interactions between CO2, drought and warming can affect belowground protozoan abundance. Our findings imply that climate change affects aboveground-belowground interactions through changes in nutrient availability.

Abrupt climate change:Debate or action

Institute of Scientific and Technical Information of China (English)

CHENG Hai

2004-01-01

Global abrupt climate changes have been documented by various climate records, including ice cores,ocean sediment cores, lake sediment cores, cave deposits,loess deposits and pollen records. The climate system prefers to be in one of two stable states, i.e. interstadial or stadial conditions, but not in between. The transition between two states has an abrupt character. Abrupt climate changes are,in general, synchronous in the northern hemisphere and tropical regions. The timescale for abrupt climate changes can be as short as a decade. As the impacts may be potentially serious, we need to take actions such as reducing CO2emissions to the atmosphere.

Climate change – a critical emerging issue

CSIR Research Space (South Africa)

Archer van Garderen, Emma RM

2010-01-01

Full Text Available amount of what are termed 'greenhouse gases', including carbon dioxide (CO2) (the best known); but also water vapour and methane (amongst others). Without the presence of greenhouse gases in the atmosphere, the planet would be unable to sustain life... critical emerging issue 1 Climate Change ? a critical emerging issue 1. Introduction We inhabit a dynamic and changing planet, and a changing climate is, clearly, nothing new. In fact, the earth has undergone significant climatic change...

The Role of Health Co-Benefits in the Development of Australian Climate Change Mitigation Policies

Science.gov (United States)

Workman, Annabelle; Blashki, Grant; Karoly, David; Wiseman, John

2016-01-01

Reducing domestic carbon dioxide and other associated emissions can lead to short-term, localized health benefits. Quantifying and incorporating these health co-benefits into the development of national climate change mitigation policies may facilitate the adoption of stronger policies. There is, however, a dearth of research exploring the role of health co-benefits on the development of such policies. To address this knowledge gap, research was conducted in Australia involving the analysis of several data sources, including interviews carried out with Australian federal government employees directly involved in the development of mitigation policies. The resulting case study determined that, in Australia, health co-benefits play a minimal role in the development of climate change mitigation policies. Several factors influence the extent to which health co-benefits inform the development of mitigation policies. Understanding these factors may help to increase the political utility of future health co-benefits studies. PMID:27657098

The Role of Health Co-Benefits in the Development of Australian Climate Change Mitigation Policies

Directory of Open Access Journals (Sweden)

Annabelle Workman

2016-09-01

Full Text Available Reducing domestic carbon dioxide and other associated emissions can lead to short-term, localized health benefits. Quantifying and incorporating these health co-benefits into the development of national climate change mitigation policies may facilitate the adoption of stronger policies. There is, however, a dearth of research exploring the role of health co-benefits on the development of such policies. To address this knowledge gap, research was conducted in Australia involving the analysis of several data sources, including interviews carried out with Australian federal government employees directly involved in the development of mitigation policies. The resulting case study determined that, in Australia, health co-benefits play a minimal role in the development of climate change mitigation policies. Several factors influence the extent to which health co-benefits inform the development of mitigation policies. Understanding these factors may help to increase the political utility of future health co-benefits studies.

Chemistry and climate change

International Nuclear Information System (INIS)

Bernier, Jean-Claude; Brasseur, Guy; Brechet, Yves; Candel, Sebastien; Cazenave, Anny; Courtillot, Vincent; Fontecave, Marc; Garnier, Emmanuel; Goebel, Philippe; Legrand, Jack; Legrand, Michel; Le Treut, Herve; Mauberger, Pascal; Dinh-Audouin, Minh-Thu; Olivier, Daniele; Rigny, Paul; Bigot, Bernard

2016-01-01

In its first part, this collective publication addresses the decennial and centuries-old variations of climate: perspectives and implications of climate change for the 21. century, questions remaining about the understanding of climate change from its sources to its modelling, extreme climate variations and societies during the last millennium. The contributions of the second part outline how chemistry is a tool to study climate change: ice chemistry as an archive of our past environment, observations and predictions on sea level rise, relationship between atmosphere chemistry and climate. The third set of contributions discusses the transformation of the energy system for a cleaner atmosphere and the management of the climate risk: the chemical processing of CO_2, actions of chemical companies to support the struggle against climate change, relationship between barrel price and renewable energies, relationship between grid complexity and green energy. The last part outlines the role chemistry can have to be able to do without fossil fuels: chemistry in front of challenges of transformation of the energy system, the use of micro-algae, the use of hydrogen as a vector of energy transition

Predicting impacts of increased CO{sub 2} and climate change on the water cycle and water quality in the semiarid James River Basin of the Midwestern USA

Energy Technology Data Exchange (ETDEWEB)

Wu, Yiping, E-mail: ywu@usgs.gov [ASRC Research and Technology Solutions, contractor to the U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center, Sioux Falls, SD 57198 (United States); Liu, Shuguang, E-mail: sliu@usgs.gov [U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center, Sioux Falls, SD 57198 (United States); Geographic Information Science Center of Excellence, South Dakota State University, Brookings, SD 57007 (United States); Gallant, Alisa L., E-mail: gallant@usgs.gov [U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center, Sioux Falls, SD 57198 (United States); Geographic Information Science Center of Excellence, South Dakota State University, Brookings, SD 57007 (United States)

2012-07-15

Emissions of greenhouse gases and aerosols from human activities continue to alter the climate and likely will have significant impacts on the terrestrial hydrological cycle and water quality, especially in arid and semiarid regions. We applied an improved Soil and Water Assessment Tool (SWAT) to evaluate impacts of increased atmospheric CO{sub 2} concentration and potential climate change on the water cycle and nitrogen loads in the semiarid James River Basin (JRB) in the Midwestern United States. We assessed responses of water yield, soil water content, groundwater recharge, and nitrate nitrogen (NO{sub 3}-N) load under hypothetical climate-sensitivity scenarios in terms of CO{sub 2}, precipitation, and air temperature. We extended our predictions of the dynamics of these hydrological variables into the mid-21st century with downscaled climate projections integrated across output from six General Circulation Models. Our simulation results compared against the baseline period 1980 to 2009 suggest the JRB hydrological system is highly responsive to rising levels of CO{sub 2} concentration and potential climate change. Under our scenarios, substantial decrease in precipitation and increase in air temperature by the mid-21st century could result in significant reduction in water yield, soil water content, and groundwater recharge. Our model also estimated decreased NO{sub 3}-N load to streams, which could be beneficial, but a concomitant increase in NO{sub 3}-N concentration due to a decrease in streamflow likely would degrade stream water and threaten aquatic ecosystems. These results highlight possible risks of drought, water supply shortage, and water quality degradation in this basin. - Highlights: Black-Right-Pointing-Pointer We used a modified version of SWAT to more accurately simulate the effects of CO{sub 2}. Black-Right-Pointing-Pointer Our sensitivity analysis indicated this basin is very responsive to climate change. Black

Preliminary study on impact assessment of climate change on building risks induced by typhoons in Japan

DEFF Research Database (Denmark)

Nishijima, Kazuyoshi; Maruyama, Takashi; Graf, Mathias

The present paper investigates possible impacts of the climate change on building risks caused by typhoons. The inputs to this investigation are: (1) outcomes from the numerical simulations with a Global Climate Model (GCM) developed under the framework of the KAKUSHIN program, (2) statistics...... and the future climate subject to the climate change, whereas the other inputs are utilized to develop a model for structural performance of buildings. Taking basis in these models, changes of building risks under the climate change are investigated. The result shows that the building risks slightly decrease...... on building damage in the event of Typhoon Songda, and (3) numerical simulation of the wind field induced by the typhoon Songda with the JMA Non- Hydrostatic Model (JMA-NHM). The first input is utilized to develop two sets of probabilistic typhoon models; i.e. corresponding to the current climate...

Climate induced changes in the circulation and dispersal patterns of ...

Indian Academy of Sciences (India)

C dated box cores from the eastern, the central and the western regions were studied to determine climate induced changes in the hydrography. Clay assemblages have spatial and temporal changes and are markedly different in the eastern and the western bay. From a high abundance of the clay smectite, which has its ...

Global warming and climate change in Amazonia: Climate-vegetation feedback and impacts on water resources

Science.gov (United States)

Marengo, José; Nobre, Carlos A.; Betts, Richard A.; Cox, Peter M.; Sampaio, Gilvan; Salazar, Luis

This chapter constitutes an updated review of long-term climate variability and change in the Amazon region, based on observational data spanning more than 50 years of records and on climate-change modeling studies. We start with the early experiments on Amazon deforestation in the late 1970s, and the evolution of these experiments to the latest studies on greenhouse gases emission scenarios and land use changes until the end of the twenty-first century. The "Amazon dieback" simulated by the HadCM3 model occurs after a "tipping point" of CO2 concentration and warming. Experiments on Amazon deforestation and change of climate suggest that once a critical deforestation threshold (or tipping point) of 40-50% forest loss is reached in eastern Amazonia, climate would change in a way which is dangerous for the remaining forest. This may favor a collapse of the tropical forest, with a substitution of the forest by savanna-type vegetation. The concept of "dangerous climate change," as a climate change, which induces positive feedback, which accelerate the change, is strongly linked to the occurrence of tipping points, and it can be explained as the presence of feedback between climate change and the carbon cycle, particularly involving a weakening of the current terrestrial carbon sink and a possible reversal from a sink (as in present climate) to a source by the year 2050. We must, therefore, currently consider the drying simulated by the Hadley Centre model(s) as having a finite probability under global warming, with a potentially enormous impact, but with some degree of uncertainty.

The climatic change induced by human activities; El cambio climatico inducido por actividades humanas

Energy Technology Data Exchange (ETDEWEB)

Balairon Ruiz, L.

2004-07-01

The climate of the Earth is a changing climate. Along their history many natural climate changes have existed in all time scales. At the present time we use the term climate changes have existed in all time scales. At the present time we use the term climate change in a restricted way, understanding that we have referring to a singular change that has their origin in the modification of the natural composition of the atmosphere. The increase of greenhouse gases from the second half the XVIII century, is due to the human activities of fossil fuels burning to obtain energy and to industrial and agricultural activities needing for the development of a world which population has been duplicated between 1960 and 2000, until overcoming the 6,000 million inhabitants. In particular, the concentrations of carbon dioxide-CO{sub 2} have increased in a 34%. The more recent emission scenarios proposed by the IPCC (SRES, 2000) are based on hypothesis about the population evolution, the energy consumption and the word patterns of development, which are grouped in four families dominated as A1, A2, B1 and B2. The answer for these scenarios from a range of climate models results in an increase of the world average surface atmospheric temperature between 1,4 degree centigree and 5,8 degree centigree and a corresponding sea level rise understood between 9 cm and 88 cm. The changes in the precipitation patterns show us that could be above to the current one in high and media latitudes and below in subtropical latitudes, with exceptions highly depending of the model used. (Author)

Estimated migration rates under scenarios of global climate change.

Science.gov (United States)

Jay R. Malcolm; Adam Markham; Ronald P. Neilson; Michael. Oaraci

2002-01-01

Greefihouse-induced warming and resulting shifts in climatic zones may exceed the migration capabilities of some species. We used fourteen combinations of General Circulation Models (GCMs) and Global Vegetation Models (GVMs) to investigate possible migration rates required under CO2 doubled climatic forcing.

The impact on atmospheric CO2 of iron fertilization induced changes in the ocean's biological pump

Directory of Open Access Journals (Sweden)

J. C. McWilliams

2008-03-01

Full Text Available Using numerical simulations, we quantify the impact of changes in the ocean's biological pump on the air-sea balance of CO2 by fertilizing a small surface patch in the high-nutrient, low-chlorophyll region of the eastern tropical Pacific with iron. Decade-long fertilization experiments are conducted in a basin-scale, eddy-permitting coupled physical/biogeochemical/ecological model. In contrast to previous studies, we find that most of the dissolved inorganic carbon (DIC removed from the euphotic zone by the enhanced biological export is replaced by uptake of CO2 from the atmosphere. Atmospheric uptake efficiencies, the ratio of the perturbation in air-sea CO2 flux to the perturbation in export flux across 100 m, integrated over 10 years, are 0.75 to 0.93 in our patch size-scale experiments. The atmospheric uptake efficiency is insensitive to the duration of the experiment. The primary factor controlling the atmospheric uptake efficiency is the vertical distribution of the enhanced biological production and export. Iron fertilization at the surface tends to induce production anomalies primarily near the surface, leading to high efficiencies. In contrast, mechanisms that induce deep production anomalies (e.g. altered light availability tend to have a low uptake efficiency, since most of the removed DIC is replaced by lateral and vertical transport and mixing. Despite high atmospheric uptake efficiencies, patch-scale iron fertilization of the ocean's biological pump tends to remove little CO2 from the atmosphere over the decadal timescale considered here.

CO{sub 2} and energy France and world indicators 2007; CO{sub 2} et energie France et Monde reperes edition 2007

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-07-01

In the framework of a sustainable development, the carbon dioxide is a very controlled greenhouse effect gases to limit the climatic change. This paper presents and explains the greenhouse effect, the consequences of the climatic change, the other greenhouse effect gases as the CO{sub 2}, the CO{sub 2} emissions from the energy production, the emission factors of CO{sub 2}, the sectorial emissions of CO{sub 2}, the Kyoto protocol and the european market of the CO{sub 2} quotas. (A.L.B.)

How positive is the feedback between climate change and the carbon cycle?

International Nuclear Information System (INIS)

Friedlingstein, P.; Rayner, P.

2003-01-01

Future climate change induced by atmospheric emissions of greenhouse gases is believed to have a large impact on the global carbon cycle. Several offline studies focusing either on the marine or on the terrestrial carbon cycle highlighted such potential effects. Two recent online studies, using ocean-atmosphere general circulation models coupled to land and ocean carbon cycle models, investigated in a consistent way the feedback between the climate change and the carbon cycle. These two studies used observed anthropogenic CO 2 emissions for the 1860-1995 period and IPCC scenarios for the 1995-2100 period to force the climate - carbon cycle models. The study from the Hadley Centre group showed a very large positive feedback, atmospheric CO 2 reaching 980 ppmv by 2100 if future climate impacts on the carbon cycle, but only about 700 ppmv if the carbon cycle is included but assumed to be insensitive to the climate change. The IPSL coupled climate - carbon cycle model simulated a much smaller positive feedback: climate impact on the carbon cycle leads by 2100 to an addition of less than 100 ppmv in the atmosphere. Here we perform a detailed feedback analysis to show that such differences are due to two key processes that are still poorly constrained in these coupled models: first Southern Ocean circulation, which primarily controls the geochemical uptake of CO 2 , and second vegetation and soil carbon response to global warming. Our analytical analysis reproduces remarkably the results obtained by the fully coupled models. Also it allows us to identify that, amongst the two processes mentioned above, the latter (the land response to global warming) is the one that essentially explains the differences between the IPSL and the Hadley results

Evasion of CO{sub 2} injected into the ocean in the context of CO{sub 2} stabilization

Energy Technology Data Exchange (ETDEWEB)

Haroon S. Kheshgi [ExxonMobil Research and Engineering Company, Annandale, NJ (United States)

2003-07-01

The eventual evasion of injected CO{sub 2} to the atmosphere is one consideration when assessing deep sea disposal of CO{sub 2} as a potential response option to climate change concerns. Evasion estimated using an ocean carbon cycle model is compared to long-term trajectories for future CO{sub 2} emissions, including illustrative cases leading to stabilization of CO{sub 2} concentration at various levels. Modeled residence time for CO{sub 2} injected into the deep ocean exceeds the 100-year time scale usually considered in scenarios for future emissions, and the potential impacts of climate change. Illustrative cases leading monotonically to constant CO{sub 2} concentration have been highlighted by the Intergovernmental Panel on Climate Change to give guidance on possible timing of emission reductions that may be required to stabilize greenhouse gas concentrations at various levels. For stabilization cases considered, significant modeled evasion does not occur until long after CO{sub 2} emissions have reached a maximum and begun to decline. Illustrative cases can also lead to a maximum in CO{sub 2} concentration followed by a decline to slowly decreasing concentrations. In such cases, future injection of emissions into the deep ocean leads to lower maximum CO{sub 2} concentration, with less effect on concentration later on in time. 20 refs., 4 figs.

Soil Carbon in the Time of Climate Change

Science.gov (United States)

Amundson, R.

2017-12-01

The Earth is in the midst of human induced climate change driven by the emission of greenhouse gases largely through fossil fuels and land conversion. Drastically and rapidly reducing the net emissions are critical to avoid societally disruptive climate changes by the end of the Century. In the midst of this change are soils, that have a vast store of C and for a given change in conditions, can either rapidly add or remove C from the atmosphere. Mainstream soil and agricultural science has focused on the former for nearly two decades, conducting research and estimates of the potential global C sequestration potential of soils due to changed land management. This has culminated with the French 4 per mille initiative. While it is possible that in some countries, at some times, economic or political forces may drive farming practices one way or another, the estimated requirement that 30 to 70% of all farms on Earth adopt the best practices needed to achieve this goal is simply unrealistic. In addition, it diverts attention and resources from much more viable alternatives, and is clouding the growing need for climate adaption strategies that soil and environmental science will need to provide. Soil C sequestration will never be a significant "bridge" to C-free energy during the next few decades, which is the time frame of critical importance. Most likely, soil will be part of the CO2 sources. Few agricultural sequestration studies explicitly consider the positive feedback between soil C and temperature, and on-going loss of soil C to the atmosphere. Truly comprehensive studies of the combined management vs. climate feedback effects on soil C are few, but tend to conclude that even managed soils will continue to be a net source of CO2 this century. Only by reducing fossil fuel C emissions will we successfully, and in a time frame required by the Earth's climate system, contend with the greenhouse gas issue. Better soil C management is unlikely to slow or hold off

Diverse perspectives on governance on the very long term. Biodiversity, climatic change, CO2 storage, radioactive wastes, space wastes

International Nuclear Information System (INIS)

Boeuf, Gilles; Gouyon, Pierre Henry; Rollinger, Francois; Besnus, Francois; Heriard Dubreuil, Gilles; Dahan, Amy; Alby, Fernand; Arnould, Jacques; Fabriol, Hubert; Hoummady, Moussa; Demarcq, Francois; Farret, Regis; Hubert, Philippe; Weber, Jacques; Charton, Patrick; Boissier, Fabrice; Lopez, Mirelle; Devisse, Jean-Jacques; Mathy, Sandrine; Hourcade, Jean-Charles; Le Roux, Xavier; Bourcier, Danielle; Roure, Francoise; Henry, Claude; Bartet, Jean Hughes; Calame, Mathieu; Biteau, Benoit; Kastler, Guy; Ducret, Pierre; Berest, Pierre; Charron, Sylvie; Clin, Francois; Gadbois, Serge; Gueritte, Michel; Heriard-Dubreuil, Bertrand; Laville, Bettina; Marie, Michel; Marignac, Yves; Ollagnon, Henry; Pelegrin, Flora; Roure, Francoise; Rouyer, Michel; Schellenberger, Thomas; Toussaint, Jean-Francois

2013-03-01

This bibliographical note contains the program of a workshop and a presentation of a book based on the contributions to this workshop proposed by experts, representatives of institutional bodies and associations, or local representatives. This workshop addressed the issue of the governance on the very long term with respect to the management of resources such as climate, geology, biodiversity or space. How to make a possible usage of these resources while ensuring their protection and durability? What are the solutions or new challenges are raising these usages on the very long term? The first part addresses the main challenges and ethical issues for governance on the very long term for each of the examined topics: biodiversity, climatic change, CO 2 storage, radioactive waste storage, and space debris). The next parts propose contributions from different origins and disciplines, present relevant data, and report evidences

Obesity and climate change mitigation in Australia: overview and analysis of policies with co-benefits.

Science.gov (United States)

Lowe, Melanie

2014-02-01

To provide an overview of the shared structural causes of obesity and climate change, and analyse policies that could be implemented in Australia to both equitably reduce obesity rates and contribute to mitigating climate change. Informed by the political economy of health theoretical framework, a review was conducted of the literature on the shared causes of, and solutions to, obesity and climate change. Policies with potential co-benefits for climate change and obesity were then analysed based upon their feasibility and capacity to reduce greenhouse gas emissions and equitably reduce obesity rates in Australia. Policies with potential co-benefits fit within three broad categories: those to replace car use with low-emissions, active modes of transport; those to improve diets and reduce emissions from the food system; and macro-level economic policies to reduce the over-consumption of food and fossil fuel energy. Given the complex causes of both problems, it is argued that a full spectrum of complementary strategies across different sectors should be utilised. Such an approach would have significant public health, social and environmental benefits. © 2014 The Authors. ANZJPH © 2014 Public Health Association of Australia.

Influence of CO2 on the climate

International Nuclear Information System (INIS)

Junod, A.

1989-01-01

The earth's climate is subject to long and short term fluctuations. The recent ones are being caused by mankind. The most important result is the increase in the CO 2 -content of the atmosphere, caused by burning of fossil fuels. This leads to the so-called greenhouse effect. It is judged that the average temperature of the earth's surface will rise by 2 o C between the years 2030 and 2050

Biological and physical controls in the Southern Ocean on past millennial-scale atmospheric CO2 changes.

Science.gov (United States)

Gottschalk, Julia; Skinner, Luke C; Lippold, Jörg; Vogel, Hendrik; Frank, Norbert; Jaccard, Samuel L; Waelbroeck, Claire

2016-05-17

Millennial-scale climate changes during the last glacial period and deglaciation were accompanied by rapid changes in atmospheric CO2 that remain unexplained. While the role of the Southern Ocean as a 'control valve' on ocean-atmosphere CO2 exchange has been emphasized, the exact nature of this role, in particular the relative contributions of physical (for example, ocean dynamics and air-sea gas exchange) versus biological processes (for example, export productivity), remains poorly constrained. Here we combine reconstructions of bottom-water [O2], export production and (14)C ventilation ages in the sub-Antarctic Atlantic, and show that atmospheric CO2 pulses during the last glacial- and deglacial periods were consistently accompanied by decreases in the biological export of carbon and increases in deep-ocean ventilation via southern-sourced water masses. These findings demonstrate how the Southern Ocean's 'organic carbon pump' has exerted a tight control on atmospheric CO2, and thus global climate, specifically via a synergy of both physical and biological processes.

Relationship between sea level and climate forcing by CO2 on geological timescales.

Science.gov (United States)

Foster, Gavin L; Rohling, Eelco J

2013-01-22

On 10(3)- to 10(6)-year timescales, global sea level is determined largely by the volume of ice stored on land, which in turn largely reflects the thermal state of the Earth system. Here we use observations from five well-studied time slices covering the last 40 My to identify a well-defined and clearly sigmoidal relationship between atmospheric CO(2) and sea level on geological (near-equilibrium) timescales. This strongly supports the dominant role of CO(2) in determining Earth's climate on these timescales and suggests that other variables that influence long-term global climate (e.g., topography, ocean circulation) play a secondary role. The relationship between CO(2) and sea level we describe portrays the "likely" (68% probability) long-term sea-level response after Earth system adjustment over many centuries. Because it appears largely independent of other boundary condition changes, it also may provide useful long-range predictions of future sea level. For instance, with CO(2) stabilized at 400-450 ppm (as required for the frequently quoted "acceptable warming" of 2 °C), or even at AD 2011 levels of 392 ppm, we infer a likely (68% confidence) long-term sea-level rise of more than 9 m above the present. Therefore, our results imply that to avoid significantly elevated sea level in the long term, atmospheric CO(2) should be reduced to levels similar to those of preindustrial times.

Climate induced changes in the circulation and dispersal patterns of ...

Indian Academy of Sciences (India)

Climate induced changes in the circulation and dispersal patterns of the fluvial sources during late Quaternary in the middle Bengal Fan ... in 14C dated box cores from the eastern, the central and the western regions were studied to determine ...

Chapter 1. Impacts of the oceans on climate change.

Science.gov (United States)

Reid, Philip C; Fischer, Astrid C; Lewis-Brown, Emily; Meredith, Michael P; Sparrow, Mike; Andersson, Andreas J; Antia, Avan; Bates, Nicholas R; Bathmann, Ulrich; Beaugrand, Gregory; Brix, Holger; Dye, Stephen; Edwards, Martin; Furevik, Tore; Gangstø, Reidun; Hátún, Hjálmar; Hopcroft, Russell R; Kendall, Mike; Kasten, Sabine; Keeling, Ralph; Le Quéré, Corinne; Mackenzie, Fred T; Malin, Gill; Mauritzen, Cecilie; Olafsson, Jón; Paull, Charlie; Rignot, Eric; Shimada, Koji; Vogt, Meike; Wallace, Craig; Wang, Zhaomin; Washington, Richard

2009-01-01

The oceans play a key role in climate regulation especially in part buffering (neutralising) the effects of increasing levels of greenhouse gases in the atmosphere and rising global temperatures. This chapter examines how the regulatory processes performed by the oceans alter as a response to climate change and assesses the extent to which positive feedbacks from the ocean may exacerbate climate change. There is clear evidence for rapid change in the oceans. As the main heat store for the world there has been an accelerating change in sea temperatures over the last few decades, which has contributed to rising sea-level. The oceans are also the main store of carbon dioxide (CO2), and are estimated to have taken up approximately 40% of anthropogenic-sourced CO2 from the atmosphere since the beginning of the industrial revolution. A proportion of the carbon uptake is exported via the four ocean 'carbon pumps' (Solubility, Biological, Continental Shelf and Carbonate Counter) to the deep ocean reservoir. Increases in sea temperature and changing planktonic systems and ocean currents may lead to a reduction in the uptake of CO2 by the ocean; some evidence suggests a suppression of parts of the marine carbon sink is already underway. While the oceans have buffered climate change through the uptake of CO2 produced by fossil fuel burning this has already had an impact on ocean chemistry through ocean acidification and will continue to do so. Feedbacks to climate change from acidification may result from expected impacts on marine organisms (especially corals and calcareous plankton), ecosystems and biogeochemical cycles. The polar regions of the world are showing the most rapid responses to climate change. As a result of a strong ice-ocean influence, small changes in temperature, salinity and ice cover may trigger large and sudden changes in regional climate with potential downstream feedbacks to the climate of the rest of the world. A warming Arctic Ocean may lead to

Linking models of human behaviour and climate alters projected climate change

Science.gov (United States)

Beckage, Brian; Gross, Louis J.; Lacasse, Katherine; Carr, Eric; Metcalf, Sara S.; Winter, Jonathan M.; Howe, Peter D.; Fefferman, Nina; Franck, Travis; Zia, Asim; Kinzig, Ann; Hoffman, Forrest M.

2018-01-01

Although not considered in climate models, perceived risk stemming from extreme climate events may induce behavioural changes that alter greenhouse gas emissions. Here, we link the C-ROADS climate model to a social model of behavioural change to examine how interactions between perceived risk and emissions behaviour influence projected climate change. Our coupled climate and social model resulted in a global temperature change ranging from 3.4-6.2 °C by 2100 compared with 4.9 °C for the C-ROADS model alone, and led to behavioural uncertainty that was of a similar magnitude to physical uncertainty (2.8 °C versus 3.5 °C). Model components with the largest influence on temperature were the functional form of response to extreme events, interaction of perceived behavioural control with perceived social norms, and behaviours leading to sustained emissions reductions. Our results suggest that policies emphasizing the appropriate attribution of extreme events to climate change and infrastructural mitigation may reduce climate change the most.

Climatic significance of stable isotope characteristics of air-CO2 and rainfall in Delhi area water-plant-air system

International Nuclear Information System (INIS)

Datta, P.S.; Tyagi, S.K.

2002-01-01

In recent years, there is a global concern on the role of carbon dioxide in atmosphere in affecting the climate. The present models of global atmospheric circulation suggest that oceans sequester about one-third of the CO 2 released by anthropogenic activities, and biospheric productivity is the primary cause of the interannual fluctuations in the atmospheric CO 2 . However, most of the times, the excess of CO 2 in air is associated with the presence of anthropogenic pollutants from urbanised centres. Therefore, the studies on the pattern of local variations in the isotopic composition of air CO 2 and rainfall in urban areas are expected to provide important information on the atmospheric circulation processes which affect the climate on a regional scale. Internationally, aspects of climate change have been so far demonstrated using isotopic data mainly from temperate climates, and there is limited understanding of the factors controlling stable isotopic composition of air-CO 2 and rainfall in tropical regions. In this context, to assess the magnitude of the above mentioned effects, analysis of the data on the variations in the 13 C/ 12 C and 18 O/ 16 O signatures of air-CO 2 in Delhi area water-plant-air system is presented here