WorldWideScience

Sample records for abrupt climate change

  1. Abrupt climate change:Debate or action

    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.

  2. Abrupt climate change and extinction events

    Crowley, Thomas J.

    1988-01-01

    There is a growing body of theoretical and empirical support for the concept of instabilities in the climate system, and indications that abrupt climate change may in some cases contribute to abrupt extinctions. Theoretical indications of instabilities can be found in a broad spectrum of climate models (energy balance models, a thermohaline model of deep-water circulation, atmospheric general circulation models, and coupled ocean-atmosphere models). Abrupt transitions can be of several types and affect the environment in different ways. There is increasing evidence for abrupt climate change in the geologic record and involves both interglacial-glacial scale transitions and the longer-term evolution of climate over the last 100 million years. Records from the Cenozoic clearly show that the long-term trend is characterized by numerous abrupt steps where the system appears to be rapidly moving to a new equilibrium state. The long-term trend probably is due to changes associated with plate tectonic processes, but the abrupt steps most likely reflect instabilities in the climate system as the slowly changing boundary conditions caused the climate to reach some threshold critical point. A more detailed analysis of abrupt steps comes from high-resolution studies of glacial-interglacial fluctuations in the Pleistocene. Comparison of climate transitions with the extinction record indicates that many climate and biotic transitions coincide. The Cretaceous-Tertiary extinction is not a candidate for an extinction event due to instabilities in the climate system. It is quite possible that more detailed comparisons and analysis will indicate some flaws in the climate instability-extinction hypothesis, but at present it appears to be a viable candidate as an alternate mechanism for causing abrupt environmental changes and extinctions.

  3. The Arctic Grand Challenge: Abrupt Climate Change

    Wilkniss, P. E.

    2003-12-01

    Trouble in polar paradise (Science, 08/30/02), significant changes in the Arctic environment are scientifically documented (R.E. Moritz et al. ibid.). More trouble, lots more, "abrupt climate change," (R. B. Alley, et al. Science 03/28/03). R. Corell, Arctic Climate Impact Assessment team (ACIA), "If you want to see what will happen in the rest of the world 25 years from now just look what's happening in the Arctic," (Arctic Council meeting, Iceland, 08/03). What to do? Make abrupt Arctic climate change a grand challenge for the IPY-4 and beyond! Scientifically:Describe the "state" of the Arctic climate system as succinctly as possible and accept it as the point of departure.Develop a hypothesis and criteria what constitutes "abrupt climate change," in the Arctic that can be tested with observations. Observations: Bring to bear existing observations and coordinate new investments in observations through an IPY-4 scientific management committee. Make the new Barrow, Alaska, Global Climate Change Research Facility a major U.S. contribution and focal point for the IPY-4 in the U.S Arctic. Arctic populations, Native peoples: The people of the North are living already, daily, with wrenching change, encroaching on their habitats and cultures. For them "the earth is faster now," (I. Krupnik and D. Jolly, ARCUS, 2002). From a political, economic, social and entirely realistic perspective, an Arctic grand challenge without the total integration of the Native peoples in this effort cannot succeed. Therefore: Communications must be established, and the respective Native entities must be approached with the determination to create well founded, well functioning, enduring partnerships. In the U.S. Arctic, Barrow with its long history of involvement and active support of science and with the new global climate change research facility should be the focal point of choice Private industry: Resource extraction in the Arctic followed by oil and gas consumption, return the combustion

  4. Abrupt climate change in the computer: Is it real?

    Stocker, Thomas F.; Marchal, Olivier

    2000-01-01

    Models suggest that dramatic changes in the ocean circulation are responsible for abrupt climate changes during the last ice age and may possibly alter the relative climate stability of the last 10,000 years.

  5. Sensitivity and Thresholds of Ecosystems to Abrupt Climate Change

    Peteet, D. M.; Peteet, D. M.

    2001-12-01

    Rapid vegetational change is a hallmark of past abrupt climate change, as evidenced from Younger Dryas records in Europe, eastern North America, and the Pacific North American rim. The potential response of future ecosystems to abrupt climate change is targeted, with a focus on particular changes in the hydrological cycle. The vulnerability of ecosystems is notable when particular shifts cross thresholds of precipitation and temperature, as many plants and animals are adapted to specific climatic "windows". Significant forest species compositional changes occur at ecotonal boundaries, which are often the first locations to record a climatic response. Historical forest declines have been linked to stress, and even Pleistocene extinctions have been associated with human interaction at times of rapid climatic shifts. Environmental extremes are risky for reproductive stages, and result in nonlinearities. The role of humans in association with abrupt climate change suggests that many ecosystems may cross thresholds from which they will find it difficult to recover. Sectors particularly vulnerable will be reviewed.

  6. The Role of the Tropics in Abrupt Climate Changes

    Fedorov, Alexey [Yale University

    2013-12-07

    Topics addressed include: abrupt climate changes and ocean circulation in the tropics; what controls the ocean thermal structure in the tropics; a permanent El Niño in paleoclimates; the energetics of the tropical ocean.

  7. AbruptChangesInClimateInTheTwentiethCentury

    Narisma, G. T.; Foley, J. A.; Ramankutty, N.; Licker, R.

    2005-12-01

    Complex interactions in the climate system can give rise to strong positive feedback mechanisms that may lead to sudden changes in climate. These abrupt climate changes are almost impossible to predict. As a result, human and environmental systems are often caught unaware and without the necessary mechanisms for adaptation. The well-studied abrupt and prolonged drought in the Sahel, for example, has vastly affected the region and its people. Apart from the Sahel, however, studies on abrupt climatic changes in other regions of the world especially in the 20th century are limited. Here we analyze historical temperature and rainfall observation data using wavelet analysis to detect regions that may have undergone sudden changes in climate. We isolate regions wherein anomalous climate changes deviate persistently from the 1901-2000 time series average. Our results show that in the 20th century, many regions in the world aside from the Sahel may have experienced sudden changes in rainfall. Our results also indicate numerous large, abrupt changes in temperature that are globally widespread in the last two decades of the 20th century. Identifying these regions of large, sudden climate changes is a good first step in analyzing the underlying dynamics of a system's loss of resilience and may complement current and future modeling studies. Further, knowing that these regions are particularly vulnerable to abrupt climate change may help in the development of strategies not only for adaptation but also for resilience management in these environmental systems. Lastly, these maps give us a hint of the magnitude of global abrupt changes in climate in the 20th century. They give us a picture of what has happened and what can happen. With the projected changes in climate in the next 100 years, the possibility of increasing loss of resilience in these regions as well as other regions that were not previously vulnerable is almost undeniable. These maps reiterate the need for

  8. Abrupt climate change and collapse of deep-sea ecosystems

    Yasuhara, Moriaki; Cronin, T. M.; Demenocal, P.B.; Okahashi, H.; Linsley, B.K.

    2008-01-01

    We investigated the deep-sea fossil record of benthic ostracodes during periods of rapid climate and oceanographic change over the past 20,000 years in a core from intermediate depth in the northwestern Atlantic. Results show that deep-sea benthic community "collapses" occur with faunal turnover of up to 50% during major climatically driven oceanographic changes. Species diversity as measured by the Shannon-Wiener index falls from 3 to as low as 1.6 during these events. Major disruptions in the benthic communities commenced with Heinrich Event 1, the Inter-Aller??d Cold Period (IACP: 13.1 ka), the Younger Dryas (YD: 12.9-11.5 ka), and several Holocene Bond events when changes in deep-water circulation occurred. The largest collapse is associated with the YD/IACP and is characterized by an abrupt two-step decrease in both the upper North Atlantic Deep Water assemblage and species diversity at 13.1 ka and at 12.2 ka. The ostracode fauna at this site did not fully recover until ???8 ka, with the establishment of Labrador Sea Water ventilation. Ecologically opportunistic slope species prospered during this community collapse. Other abrupt community collapses during the past 20 ka generally correspond to millennial climate events. These results indicate that deep-sea ecosystems are not immune to the effects of rapid climate changes occurring over centuries or less. ?? 2008 by The National Academy of Sciences of the USA.

  9. Abrupt climate change and the decline of Indus urbanism

    Hodell, D. A.; Dixit, Y.; Petrie, C. A.

    2012-12-01

    Climate change has been suggested as a cause for the decline of the cities of the Indus Civilization, which is believed to have begun ~4.0 to 3.9 ky B.P. Previous studies have centered on paleoclimatic records obtained from areas outside the geographic limits of the Indus Civilization, raising questions about their suitability for evaluating past climate-cultural linkages. Here we report a detailed climate record from paleolake Kotla Dahar, Haryana (28°00'095'' N, 76°57'173'' E), located at the eastern edge of the distribution of Indus settlements and ~100km to the east of the city-site of Rakhigarhi in NW India. Regional hydrologic changes are inferred using oxygen-isotope measurements of gastropod aragonite from a 2.88-m sediment section. A permanent ~4‰ increase in δ18O of shell aragonite occurred at ~4.1±0.1 ky B.P., marking an abrupt increase in evaporation/precipitation in the lake catchment. These data provide evidence for a weakening of the monsoon and shift toward drier climate on the plains of northwest (NW) India at ~4.1±0.1 ky B.P. Decreased monsoon rainfall at this time may have been linked to increased ENSO variability, and supports a possible role of climate in the transformation of the Indus Civilization from an urbanized (mature or urban Indus) to a rural (post-urban) society.

  10. Catalogue of abrupt shifts in Intergovernmental Panel on Climate Change climate models

    Drijfhout, Sybren; Bathiany, Sebastian; Beaulieu, Claudie; Brovkin, Victor; Claussen, Martin; Huntingford, Chris; Scheffer, Marten; Sgubin, Giovanni; Swingedouw, Didier

    2015-10-01

    Abrupt transitions of regional climate in response to the gradual rise in atmospheric greenhouse gas concentrations are notoriously difficult to foresee. However, such events could be particularly challenging in view of the capacity required for society and ecosystems to adapt to them. We present, to our knowledge, the first systematic screening of the massive climate model ensemble informing the recent Intergovernmental Panel on Climate Change report, and reveal evidence of 37 forced regional abrupt changes in the ocean, sea ice, snow cover, permafrost, and terrestrial biosphere that arise after a certain global temperature increase. Eighteen out of 37 events occur for global warming levels of less than 2°, a threshold sometimes presented as a safe limit. Although most models predict one or more such events, any specific occurrence typically appears in only a few models. We find no compelling evidence for a general relation between the overall number of abrupt shifts and the level of global warming. However, we do note that abrupt changes in ocean circulation occur more often for moderate warming (less than 2°), whereas over land they occur more often for warming larger than 2°. Using a basic proportion test, however, we find that the number of abrupt shifts identified in Representative Concentration Pathway (RCP) 8.5 scenarios is significantly larger than in other scenarios of lower radiative forcing. This suggests the potential for a gradual trend of destabilization of the climate with respect to such shifts, due to increasing global mean temperature change.

  11. Arctic Ocean freshwater as a trigger for abrupt climate change

    Bradley, Raymond; Condron, Alan; Coletti, Anthony

    2016-04-01

    The cause of the Younger Dryas cooling remains unresolved despite decades of debate. Current arguments focus on either freshwater from Glacial Lake Agassiz drainage through the St Lawrence or the MacKenzie river systems. High resolution ocean modeling suggests that freshwater delivered to the North Atlantic from the Arctic Ocean through Fram Strait would have had more of an impact on Atlantic Meridional Overturning Circulation (AMOC) than freshwater from the St Lawrence. This has been interpreted as an argument for a MacKenzie River /Lake Agassiz freshwater source. However, it is important to note that although the modeling identifies Fram Strait as the optimum location for delivery of freshwater to disrupt the AMOC, this does not mean the freshwater source came from Lake Agassiz. Another potential source of freshwater is the Arctic Ocean ice cover itself. During the LGM, ice cover was extremely thick - many tens of meters in the Canada Basin (at least), resulting in a hiatus in sediment deposition there. Extreme ice thickness was related to a stagnant circulation, very low temperatures and continuous accumulation of snow on top of a base of sea-ice. This resulted in a large accumulation of freshwater in the Arctic Basin. As sea-level rose and a more modern circulation regime became established in the Arctic, this freshwater was released from the Arctic Ocean through Fram Strait, leading to extensive sea-ice formation in the North Atlantic (Greenland Sea) and a major reduction in the AMOC. Here we present new model results and a review of the paleoceanographic evidence to support this hypothesis. The bottom line is that the Arctic Ocean was likely a major player in causing abrupt climate change in the past, via its influence on the AMOC. Although we focus here on the Younger Dryas, the Arctic Ocean has been repeatedly isolated from the world ocean during glacial periods of the past. When these periods of isolation ended, it is probable that there were significant

  12. Modeling geologically abrupt climate changes in the Miocene

    B. J. Haupt

    2010-12-01

    Full Text Available The gradual cooling of the Cenozoic, including the Miocene epoch, was punctuated by many geologically abrupt warming and cooling episodes – strong deviations from the cooling trend with time span of ten to hundred thousands of years. Our working hypothesis is that some of those warming episodes at least partially might have been caused by dynamics of the emerging Antarctic Ice Sheet, which, in turn, might have caused strong changes of sea surface salinity in the Miocene Southern Ocean. Feasibility of this hypothesis is explored in a series of coupled ocean-atmosphere computer experiments. The results suggest that relatively small and geologically short-lived changes in freshwater balance in the Southern Ocean could have significantly contributed to at least two prominent warming episodes in the Miocene. Importantly, the experiments also suggest that the Southern Ocean was more sensitive to the salinity changes in the Miocene than today, which can attributed to the opening of the Central American Isthmus as a major difference between the Miocene and the present-day ocean-sea geometry.

  13. Phase relationship between sea level and abrupt climate change

    Sierro Sánchez, Francisco Javier; Andersen, Nils; Bassetti, Maria A.; Berné, Serge,; Canals, Miquel; Curtis, Jason H.; Dennielou, Bernard; Flores Villarejo, José Abel; Frigola, Jaime; González-Mora, Beatriz; Grimalt, Joan O.; Hodell, David A.; Jouet, Gwenael; Pérez Folgado, Marta; Schneider, Ralph

    2009-01-01

    Direct traces of past sea levels are based on the elevation of old coral reefs at times of sea level high-stands. However, these measurements are discontinuous and cannot be easily correlated with climate records from ice cores. In this study we show a new approach to recognizing the imprint of sea level changes in continuous sediment records taken from the continental slope at locations that were continuously submerged, even during periods of sea level lowstand. By using a sediment core prec...

  14. Abrupt climate change in southeast tropical Africa influenced by Indian monsoon variability and ITCZ migration

    Tierney, Jessica E.; Russell, James M.

    2007-08-01

    The timing and magnitude of abrupt climate change in tropical Africa during the last glacial termination remains poorly understood. High-resolution paleolimnological data from Lake Tanganyika, Southeast Africa show that wind-driven seasonal mixing in the lake was reduced during the Younger Dryas, Inter-Allerød Cool Period, Older Dryas, and Heinrich Event 1, suggesting a weakened southwest Indian monsoon and a more southerly position of the Inter-Tropical Convergence Zone over Africa during these intervals. These events in Lake Tanganyika, coeval with millennial and centennial-scale climate shifts in the high latitudes, suggest that changes in ITCZ location and Indian monsoon strength are important components of abrupt global climate change and that their effects are felt south of the equator in Africa. However, we observe additional events in Lake Tanganyika of equal magnitude that are not correlated with high-latitude changes, indicating the potential for abrupt climate change to originate from within tropical systems.

  15. Abrupt climate change and transient climates during the Paleogene: a marine perspective

    Zachos, J. C.; Lohmann, K. C.; Walker, J. C.; Wise, S. W.

    1993-01-01

    Detailed investigations of high latitude sequences recently collected by the Ocean Drilling Program (ODP) indicate that periods of rapid climate change often culminated in brief transient climates, with more extreme conditions than subsequent long term climates. Two examples of such events have been identified in the Paleogene; the first in latest Paleocene time in the middle of a warming trend that began several million years earlier: the second in earliest Oligocene time near the end of a Middle Eocene to Late Oligocene global cooling trend. Superimposed on the earlier event was a sudden and extreme warming of both high latitude sea surface and deep ocean waters. Imbedded in the latter transition was an abrupt decline in high latitude temperatures and the brief appearance of a full size continental ice-sheet on Antarctica. In both cases the climate extremes were not stable, lasting for less than a few hundred thousand years, indicating a temporary or transient climate state. Geochemical and sedimentological evidence suggest that both Paleogene climate events were accompanied by reorganizations in ocean circulation, and major perturbations in marine productivity and the global carbon cycle. The Paleocene-Eocene thermal maximum was marked by reduced oceanic turnover and decreases in global delta 13C and in marine productivity, while the Early Oligocene glacial maximum was accompanied by intensification of deep ocean circulation and elevated delta 13C and productivity. It has been suggested that sudden changes in climate and/or ocean circulation might occur as a result of gradual forcing as certain physical thresholds are exceeded. We investigate the possibility that sudden reorganizations in ocean and/or atmosphere circulation during these abrupt transitions generated short-term positive feedbacks that briefly sustained these transient climatic states.

  16. Paleoclimate from ice cores : abrupt climate change and the prolonged Holocene

    Ice cores provide valuable information about the Earth's past climates and past environments. They can also help in predicting future climates and the nature of climate change. Recent findings in ice cores have shown large and abrupt climate changes in the past. This paper addressed abrupt climate changes and the peculiar nature of the Holocene. An abrupt climate change is a shift of 5 degrees C in mean annual temperature in less than 50 years. This is considered to be the most threatening aspect of potential future climate change since it leaves very little time for adaptation by humans or any other part of the Earth's ecosystem. This paper also discussed the arrival of the next glacial period. In the past 50 years, scientists have recognized the importance of the Earth's orbit around the sun in pacing the occurrence of large ice sheets. The timing of orbital forcing suggests that the Earth is overdue for the next major glaciation. The reason for this anomaly was discussed. Abrupt climate shifts seem to be caused by mode changes in sensitive points in the climate system, such as the North Atlantic Deep Water Formation and its impact on sea ice cover in the North Atlantic. These changes have been observed in ice cores in Greenland but they are not restricted to Greenland. Evidence from Antarctic ice cores suggest that abrupt climate change may also occur in the Southern Hemisphere. The Vostok ice core in Antarctica indicates that the 11,000 year long interglacial period that we are in right now is longer than the previous four interglacial periods. The Holocene epoch is unique because both methane and carbon dioxide rise in the last 6,000 years, an atypical response from these greenhouse gases during an interglacial period. It was suggested that the rise in methane can be attributed to human activities. 13 refs., 2 figs

  17. Detection and attribution of abrupt climate changes in the last one hundred years

    Based on physical backgrounds, the four time series of the Guliya (Tibetan plateau) ice core (GIC) δ18O, and three natural factors, i.e. the rotation rate of earth, sunspots, and El Nino–Southern Oscillation (ENSO) signals, are decomposed into two hierarchies, i.e. more and less than 10-year hierarchies respectively, and then the running t-test is used to reanalyse the data before and after filtering with the purpose of investigating the contribution of natural factors to the abrupt climate changes in the last one hundred years. The results show that the GIC δ18O evolved with a quasi-period of 7–9 years, and the abrupt climate changes in the early 1960s and in the period from the end of the 1970s to the beginning of the 1980s resulted from the joint effect of the two hierarchies, in other words, the two interdecadal abrupt changes of climate in the last one hundred years were global. The interannual variations of ENSO and sunspots were the important triggering factors for the abrupt climate changes in the last one hundred years. At the same time, the method of Information Transfer (IT) is employed to estimate the contributions of ENSO signals and sunspots activities to the abrupt climate changes, and it is found that the contribution of the interannual variation of ENSO signals is relatively large

  18. Detection and attribution of abrupt climate changes in the last one hundred years

    Zhang Wen; Wan Shi-Quan

    2008-01-01

    Based on physical backgrounds, the four time series of the Guliya (Tibetan plateau) ice core (GIC) δ18O, and three natural factors, I.e. The rotation rate of earth, sunspots, and El Nino-Southern Oscillation (ENSO) signals, are decomposed into two hierarchies, I.e. More and less than 10-year hierarchies respectively, and then the running t-test is used to reanalyse the data before and after filtering with the purpose of investigating the contribution of natural factors to the abrupt climate changes in the last one hundred years. The results show that the GIC δ18O evolved with a quasi-period of 7-9 years, and the abrupt climate changes in the early 1960s and in the period from the end of the 1970s to the beginning of the 1980s resulted from the joint effect of the two hierarchies, in other words, the two interdecadal abrupt changes of climate in the last one hundred years were global. The interannual variations of ENSO and sunspots were the important triggering factors for the abrupt climate changes in the last one hundred years. At the same time, the method of Information Transfer (IT) is employed to estimate the contributions of ENSO signals and sunspots activities to the abrupt climate changes, and it is found that the contribution of the interannual variation of ENSO signals is relatively large.

  19. The applicability of research on moving cut data-approximate entropy on abrupt climate change detection

    Jin, Hongmei; He, Wenping; Liu, Qunqun; Wang, Jinsong; Feng, Guolin

    2016-04-01

    In this study, the performance of moving cut data-approximate entropy (MC-ApEn) to detect abrupt dynamic changes was investigated. Numerical tests in a time series model indicate that the MC-ApEn method is suitable for the detection of abrupt dynamic changes for three types of meteorological data: daily maximum temperature, daily minimum temperature, and daily precipitation. Additionally, the MC-ApEn method was used to detect abrupt climate changes in daily precipitation data from Northwest China and the Pacific Decadal Oscillation (PDO) index. The results show an abrupt dynamic change in precipitation in 1980 and in the PDO index in 1976. The times indicated for the abrupt changes are identical to those from previous results. Application of the analysis to observational data further confirmed the performance of the MC-ApEn method. Moreover, MC-ApEn outperformed the moving t test (MTT) and the moving detrended fluctuation analysis (MDFA) methods for the detection of abrupt dynamic changes in a simulated 1000-point daily precipitation dataset.

  20. Abrupt climate change and collapse of ancient civilizations at 2200BC-2000BC

    WANG Shaowu

    2005-01-01

    Plentiful evidence of historical, archaeological and palaeoclimatic studies proved that an abrupt change from wetter to drier climate occurred over the Nile Valley, the Mesopotamia, the Indus Valley and Huanghe River Valley at 2200BC-2000BC. The abrupt change was developed based on the general lowering of temperature in the middle latitudes, and was a strong cold event since the beginning of the Megathermal (8.5-3.0 kaBP). Collapse of Nile civilization appeared at the First Intermediate Period (2181BC-2040BC). Civilization of Mesopotamia began collapse following the disintegration of Akkadian Empire. This process lasted to the foundation of Babylon Kingdom from 2200BC to 1900BC. Indus civilization abruptly fell off at 1800BC. A widespread alternation of archaeological cultures happened in China at ca. 2000BC except only in its central part. Longsheng culture was replaced by the Erlitou culture, which is now acknowledged in China as Xia Culture. Foundation of Xia Dynasty at 2070BC opened a new chapter in the development of Chinese civilization. Studies indicated that abrupt climate change may be caused by the weakening of the Thermohaline Circulation (THC).

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

    M. Montoya

    2011-10-01

    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 seems robust nowadays, their final cause 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 abrupt surface air temperature (SAT increase over the North Atlantic is simulated in response to increasing atmospheric CO2 levels and/or enhancing southern westerlies. The simulated abrupt 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 an increase in sea surface salinity in the Northeastern Atlantic. The latter is caused by a northward retreat of the sea-ice front in response to higher temperatures. In this way, a new mechanism that is consistent with proxy data is identified by which abrupt climate change can be promoted.

  2. What if ... abrupt and extreme climate change? Programme of VAM (Vulnerability, Adaptation, Mitigation)

    A number of researchers from different social scientific disciplines present a view in response to the question 'what will happen in our society if the climate suddenly changes?'. They answer questions such as: How will people respond to real risks such as imminent flooding? What are the economic consequences? How will it affect sectors such as inland shipping and coastal tourism? What are the costs of adapting our country to rising sea levels or sudden cold? As a society what do we consider to be socially and publicly acceptable? Can we still insure ourselves? Who will assume responsibility and what are the tasks of the various parties involved? The book merely sets the scene. Social sciences research into climate change has only just started. Besides providing answers to the question about the social and public implications of abrupt climate change, the book calls for a greater involvement of social scientists in climate change issues

  3. Transition process of abrupt climate change based on global sea surface temperature over the past century

    Yan, Pengcheng; Hou, Wei; Feng, Guolin

    2016-05-01

    A new detection method has been proposed to study the transition process of abrupt climate change. With this method, the climate system transiting from one stable state to another can be verified clearly. By applying this method to the global sea surface temperature over the past century, several climate changes and their processes are detected, including the start state (moment), persist time, and end state (moment). According to the spatial distribution, the locations of climate changes mainly have occurred in the Indian Ocean and western Pacific before the middle twentieth century, in the 1970s in the equatorial middle-eastern Pacific, and in the middle and southern Pacific since the end of the twentieth century. In addition, the quantitative relationship between the transition process parameters is verified in theory and practice: (1) the relationship between the rate and stability parameters is linear, and (2) the relationship between the rate and change amplitude parameters is quadratic.

  4. Simulating the vegetation response in western Europe to abrupt climate changes under glacial background conditions

    Woillez, M.-N.; Kageyama, M.; Combourieu-Nebout, N.; Krinner, G.

    2013-03-01

    The last glacial period has been punctuated by two types of abrupt climatic events, the Dansgaard-Oeschger (DO) and Heinrich (HE) events. These events, recorded in Greenland ice and in marine sediments, involved changes in the Atlantic Meridional Overturning Circulation (AMOC) and led to major changes in the terrestrial biosphere. Here we use the dynamical global vegetation model ORCHIDEE to simulate the response of vegetation to abrupt changes in the AMOC strength. We force ORCHIDEE offline with outputs from the IPSL_CM4 general circulation model, in which the AMOC is forced to change by adding freshwater fluxes in the North Atlantic. We investigate the impact of a collapse and recovery of the AMOC, at different rates, and focus on Western Europe, where many pollen records are available for comparison. The impact of an AMOC collapse on the European mean temperatures and precipitations simulated by the GCM is relatively small but sufficient to drive an important regression of forests and expansion of grasses in ORCHIDEE, in qualitative agreement with pollen data for an HE event. On the contrary, a run with a rapid shift of the AMOC to a hyperactive state of 30 Sv, mimicking the warming phase of a DO event, does not exhibit a strong impact on the European vegetation compared to the glacial control state. For our model, simulating the impact of an HE event thus appears easier than simulating the abrupt transition towards the interstadial phase of a DO. For both a collapse or a recovery of the AMOC, the vegetation starts to respond to climatic changes immediately but reaches equilibrium about 200 yr after the climate equilibrates, suggesting a possible bias in the climatic reconstructions based on pollen records, which assume equilibrium between climate and vegetation. However, our study does not take into account vegetation feedbacks on the atmosphere.

  5. Simulating the vegetation response in western Europe to abrupt climate changes under glacial background conditions

    M.-N. Woillez

    2013-03-01

    Full Text Available The last glacial period has been punctuated by two types of abrupt climatic events, the Dansgaard–Oeschger (DO and Heinrich (HE events. These events, recorded in Greenland ice and in marine sediments, involved changes in the Atlantic Meridional Overturning Circulation (AMOC and led to major changes in the terrestrial biosphere. Here we use the dynamical global vegetation model ORCHIDEE to simulate the response of vegetation to abrupt changes in the AMOC strength. We force ORCHIDEE offline with outputs from the IPSL_CM4 general circulation model, in which the AMOC is forced to change by adding freshwater fluxes in the North Atlantic. We investigate the impact of a collapse and recovery of the AMOC, at different rates, and focus on Western Europe, where many pollen records are available for comparison. The impact of an AMOC collapse on the European mean temperatures and precipitations simulated by the GCM is relatively small but sufficient to drive an important regression of forests and expansion of grasses in ORCHIDEE, in qualitative agreement with pollen data for an HE event. On the contrary, a run with a rapid shift of the AMOC to a hyperactive state of 30 Sv, mimicking the warming phase of a DO event, does not exhibit a strong impact on the European vegetation compared to the glacial control state. For our model, simulating the impact of an HE event thus appears easier than simulating the abrupt transition towards the interstadial phase of a DO. For both a collapse or a recovery of the AMOC, the vegetation starts to respond to climatic changes immediately but reaches equilibrium about 200 yr after the climate equilibrates, suggesting a possible bias in the climatic reconstructions based on pollen records, which assume equilibrium between climate and vegetation. However, our study does not take into account vegetation feedbacks on the atmosphere.

  6. Deep-Sea Biodiversity Response to Abrupt Deglacial and Holocene Climate Changes

    Yasuhara, M.

    2014-12-01

    High-resolution records of microfossil assemblages from deep-sea sediment cores covering the last 20,000 years in the North Atlantic Ocean were investigated to understand biotic responses to abrupt climate changes over decadal-centennial timescales. The results show pervasive control of deep-sea benthic species diversity by rapidly changing climate. Species diversity rapidly increased during abrupt stadial events during the last deglacial and the Holocene interglacial periods. These included the well-known Heinrich 1, the Younger Dryas, and the 8.2 ka events when the strength of Atlantic Meridional Overturning Circulation (AMOC) decreased. In addition, there is evidence for quasi-cyclic changes in biodiversity at a ~1500-year periodicity. Statistical analyses revealed that AMOC-driven bottom-water-temperature variability is a primary influence on deep-sea biodiversity. Our results may portend pervasive, synchronous and sudden ecosystem responses to human-induced changes to climate and ocean circulation in this century. Exceptionally highly resolved fossil records help us to understand past, present and future ecosystem responses to climate changes by bridging the gap between biological and palaeontological time-scales.

  7. Response of terrestrial N2O and NOx emissions to abrupt climate change

    Being a potent greenhouse gas, N2O emitted by the terrestrial biosphere during abrupt climate change events could have amplified externally forced warming. To investigate this possibility, we tested the sensitivity of terrestrial N2O emissions to an abrupt warming event by applying the ARVE-DGVM in combination with a novel scheme for process-based simulation of terrestrial N2O and NOx emissions at the Gerzensee site in Switzerland. In this study, we aim to quantify the magnitude of change in emissions for the abrupt climate change event that occurred at the transition from Oldest Dryas to Boel-ling during the last deglaciation. Using high-resolution multiproxy records obtained from the Gerzensee that cover the Late Glacial, we apply a prescribed vegetation change derived from the pollen record and temperature and precipitation reconstructions derived from δ18O in lake sediments. Changes in soil temperature and moisture are simulated by the ARVE-DGVM using the reconstructed paleoclimate as a driver. Our results show a pronounced increase in mean annual N2O and NOx emissions for the transition (by factor 2.55 and 1.97, respectively), with highest amounts generally being emitted during summer. Our findings suggest that summertime emissions are limited by soil moisture, while temperature controls emissions during winter. For the time between 14670 and 14620 cal. years BP, our simulated N2O emissions show increase rates as high as 1% per year, indicating that local reactions of emissions to changing climate could have been considerably faster than the atmospheric concentration changes observed in polar ice.

  8. Consistent simulations of multiple proxy responses to an abrupt climate change event

    LeGrande, A. N.; Schmidt, G. A.; Shindell, D. T.; Field, C. V.; Miller, R. L.; Koch, D. M.; Faluvegi, G.; Hoffmann, G.

    2006-01-01

    Isotope, aerosol, and methane records document an abrupt cooling event across the Northern Hemisphere at 8.2 kiloyears before present (kyr), while separate geologic lines of evidence document the catastrophic drainage of the glacial Lakes Agassiz and Ojibway into the Hudson Bay at approximately the same time. This melt water pulse may have been the catalyst for a decrease in North Atlantic Deep Water formation and subsequent cooling around the Northern Hemisphere. However, lack of direct evidence for ocean cooling has lead to speculation that this abrupt event was purely local to Greenland and called into question this proposed mechanism. We simulate the response to this melt water pulse using a coupled general circulation model that explicitly tracks water isotopes and with atmosphere-only experiments that calculate changes in atmospheric aerosol deposition (specifically 10Be and dust) and wetland methane emissions. The simulations produce a short period of significantly diminished North Atlantic Deep Water and are able to quantitatively match paleoclimate observations, including the lack of isotopic signal in the North Atlantic. This direct comparison with multiple proxy records provides compelling evidence that changes in ocean circulation played a major role in this abrupt climate change event. PMID:16415159

  9. Antarctic Forcing of Abrupt Global Climate Change During Isotope Stage 3

    Turney, Christian; Jones, Richard; Phipps, Steven; Thomas, Zoë; Hogg, Alan; Kershaw, Peter; Fogwill, Christopher; Palmer, Jonathan; Bronk Ramsey, Christopher; Adolphi, Florian; Muscheler, Raimund; Hughen, Konrad; Staff, Richard; Grosvenor, Mark; Golledge, Nicholas; Haberle, Simon

    2016-04-01

    Contrasting Greenland and Antarctic temperature trends during the late Pleistocene (60,000 to 11,650 years ago) are thought to be driven by imbalances in the rate of formation of North Atlantic and Antarctic Deep Water (the 'bipolar seesaw'), with millennial-scale cooling Dansgaard-Oeschger (D-O) events in the north leading warming in the south. An alternative origin for these abrupt climate shifts, however, is the Southern Hemisphere whereby changes are transmitted globally via atmospheric and/or oceanic teleconnections. Testing these competing hypotheses is challenging given the relatively large uncertainties associated with dating terrestrial, marine and ice core chronologies. Here we use a fully coupled climate system model to investigate whether freshening of the Southern Ocean has extra-regional climate impacts. Focusing on an Isotope Stage 3 cooling event preserved in Antarctic ice cores immediately prior to Antarctic Isotope Maximum 4 (AIM 4; around 29,000 years ago) we undertook an ensemble of transient meltwater simulations. We observe no impact on the Atlantic Meridional Overturning Circulation (AMOC) from freshwater hosing in the Southern Ocean but a dramatic warming over the North Atlantic and contrasting precipitation patterns across the low latitudes. Exploiting a new bidecadally-resolved 14C calibration dataset obtained from New Zealand kauri (Agathis australis) we undertook intensive radiocarbon dating and high-resolution multiproxy analysis of the tropical Australia Lynch's Crater terrestrial peat sequence spanning this same period and find a synchronous change in hydroclimate to the purported meltwater event in the Southern Ocean. Our results imply Southern Ocean dynamics played a significant role in driving global climate change across this period via atmospheric teleconnections, with implications for other abrupt events through the late Pleistocene.

  10. Laurentide Ice Sheet meltwater and abrupt climate change during the last glaciation

    Hill, H W; Flower, B P; Quinn, T M; Hollander, D J; Guilderson, T P

    2005-10-02

    A leading hypothesis to explain abrupt climate change during the last glacial cycle calls on fluctuations in the margin of the North American Laurentide Ice Sheet (LIS), which may have routed freshwater between the Gulf of Mexico (GOM) and North Atlantic, affecting North Atlantic Deep Water (NADW) variability and regional climate. Paired measurements of {delta}O and Mg/Ca of foraminiferal calcite from GOM sediments reveal five episodes of LIS meltwater input from 28-45 thousand years ago (ka) that do not match the millennial-scale Dansgaard-Oeschger (D/O) warmings recorded in Greenland ice. We suggest that summer melting of the LIS may occur during Antarctic warming and likely contributed to sea-level variability during Marine Isotope Stage 3 (MIS 3).

  11. Melt-Water-Pulse (MWP) events and abrupt climate change of the last deglaciation

    HUANG EnQing; TIAN Jun

    2008-01-01

    The last deglaciation is characterized by massive ice sheet melting, which results in an average sea-level rise of ~120-140 m. At least three major Melt-Water-Pulse (MWP) events (19ka-MWP, MWP-1A and MWP-1B) are recognizable for the last deglaciation, of which MWP-1A event lasting from ~14.2 to ~13.7 ka B.P. is of the most significance. However, the accurate timing and source of MWP-1A event remain debatable and controversial. It has long been postulated that meltwater of the last deglaciation pouring into the North Atlantic resulted in a slowdown or even a shutdown of the thermohaline circula-tion (THC) which subsequently affected the global climate change. Accordingly, the focus of this debate consists in establishing a reasonable relationship between MWP events and abrupt climate change. Here we summarize a variety of geological and model results for the last deglaciation, reaching a con-clusion that the major MWP events did not correspond with the rigorous stadials, nor always happened within climate reversal intervals. MWP events of the last deglaciation had very weak influences on the intensity of the THC and were not able to trigger a collapse of the global climate. We need to reevaluate the influences of the temporal meltwater variability on the global climate system.

  12. The Response of First Flowering Dates to Abrupt Climate Change in Beijing

    2011-01-01

    Phenological data on the First Flowering Date(FFD) of woody plants in Beijing from 1963-2007 are analyzed.The correlation between each species' yearly FFD and the mean monthly temperatures for every year over a 45-year period is used to identify the month in which temperature has the most effect on FFD. Through further analysis,the FFDs of 48 woody plant species are shown to have advanced an average of 5.4 days from 1990-2007 compared to 1963-1989.The results indicate that 70.8%of species flowered significantly earlier(7 days on average) during the period 1990-2007,while only one species(2.1%) flowered significantly later.Moreover,the responses of FFD to climate change are shown to be different in two climatic stages, defined by an abrupt climate change point.Thirty-three species which first flower in March and April are sensitive to temperature are examined.The correlation coefficients between FFD and temperature for 20 species during the latter period(1990-2007) are shown to be larger than during the former period(1963- 1989),with a difference of around -0.87 days per 1℃on average.The paper concludes that with the warming of climate,the linear trend of FFD variation,as well as its responsiveness to temperature,became more prominent during 1990-2007 than 1963-1989.The data analyzed in this study present a strong biological indicator of climate change in Beijing,and provide further confirmation of previous results from regional and local studies across the Northern Hemisphere.Phenophase variations indicate that the climate is changing rapidly.

  13. The Response of First Flowering Dates to Abrupt Climate Change in Beijing

    BAI Jie; GE Quansheng; DAI Junhu

    2011-01-01

    Phenological data on the First Flowering Date (FFD) of woody plants in Beijing from 1963-2007 are analyzed. The correlation between each species' yearly FFD and the mean monthly temperatures for every year over a 45-year period is used to identify the month in which temperature has the most effect on FFD.Through further analysis, the FFDs of 48 woody plant species are shown to have advanced an average of 5.4days from 1990-2007 compared to 1963-1989. The results indicate that 70.8% of species flowered significantly earlier (7 days on average) during the period 1990 2007, while only one species (2.1%) flowered significantly later. Moreover, the responses of FFD to climate change are shown to be different in two climatic stages,defined by an abrupt climate change point. Thirty-three species which first flower in March and April are sensitive to temperature are examined. The correlation coefficients between FFD and temperature for 20species during the latter period (1990-2007) are shown to be larger than during the former period (1963-1989), with a difference of around -0.87 days per 1℃ on average. The paper concludes that with the warming of climate, the linear trend of FFD variation, as well as its responsiveness to temperature, became more prominent during 1990-2007 than 1963-1989. The data analyzed in this study present a strong biological indicator of climate change in Beijing, and provide further confirmation of previous results from regional and local studies across the Northern Hemisphere. Phenophase variations indicate that the climate is changing rapidly.

  14. Links between early Holocene ice-sheet decay, sea-level rise and abrupt climate change

    Törnqvist, Torbjörn E.; Hijma, Marc P.

    2012-09-01

    The beginning of the current interglacial period, the Holocene epoch, was a critical part of the transition from glacial to interglacial climate conditions. This period, between about 12,000 and 7,000 years ago, was marked by the continued retreat of the ice sheets that had expanded through polar and temperate regions during the preceding glacial. This meltdown led to a dramatic rise in sea level, punctuated by short-lived jumps associated with catastrophic ice-sheet collapses. Tracking down which ice sheet produced specific sea-level jumps has been challenging, but two events between 8,500 and 8,200 years ago have been linked to the final drainage of glacial Lake Agassiz in north-central North America. The release of the water from this ice-dammed lake into the ocean is recorded by sea-level jumps in the Mississippi and Rhine-Meuse deltas of approximately 0.4 and 2.1 metres, respectively. These sea-level jumps can be related to an abrupt cooling in the Northern Hemisphere known as the 8.2 kyr event, and it has been suggested that the freshwater release from Lake Agassiz into the North Atlantic was sufficient to perturb the North Atlantic meridional overturning circulation. As sea-level rise on the order of decimetres to metres can now be detected with confidence and linked to climate records, it is becoming apparent that abrupt climate change during the early Holocene associated with perturbations in North Atlantic circulation required sustained freshwater release into the ocean.

  15. Agriculture, Settlement, and Abrupt Climate Change: The 4.2ka BP event in Northern Mesopotamia

    Ristvet, L.

    2003-12-01

    An abrupt aridification event at 4200 BP has been recorded in 41 paleoclimate proxies in the Old World, from Kilmanjaro, Tanzania to Rajasthan, India, East Asia and the Pacific. This event is particularly well defined for Western Asia, where it has been associated with the abandonment of settlements across the Fertile Crescent and the collapse of states on the Levantine coast and in the dry-farming plains of Northern Mesopotamia, including the Akkadian Empire. Adaptations to climate change are constrained by both local environmental and social factors. Agriculturalists, especially those living in pre-industrial societies, are particularly susceptible to changes in precipitation. The Tell Leilan Regional Survey, which systematically studied sites in a 1650km2 area of Northeastern Syria, records one set of adaptations to this event in an area where dry-farming provided the subsistence base. The survey transect crosses ecotones, from the present 500mm isohyet in the North to the 250mm isohyet in the South, and contains diverse wadi systems, ground water resources, soil profiles, and an ancient marsh/lake-- all of which allow this region to be taken as a microcosm of Northern Mesopotamia. In order to contextualize our study of human response to abrupt climate change, it is necessary to consider how the economic and social systems that were previously in place were transformed by this event. This study attempts to quantify climate change and model its effects on agricultural, pastoral, and settlement systems in Northeastern Syria from 2400-1700 BC. From 2400-2300 BC, optimal climate conditions coincided with the consolidation of an indigenous state. The next century witnessed the Akkadian conquest and imperialization of the Habur plains, which resulted in both the intensification and extensification of agro-production. During the next 300 years, (2200-1900 BC), rainfall plummeted to 70% of the climatic optimum, triggering the abandonment of cities along with their

  16. A comparison of two methods for detecting abrupt changes in the variance of climatic time series

    Rodionov, Sergei

    2016-01-01

    Two methods for detecting abrupt shifts in the variance, Integrated Cumulative Sum of Squares (ICSS) and Sequential Regime Shift Detector (SRSD), have been compared on both synthetic and observed time series. In Monte Carlo experiments, SRSD outperformed ICSS in the overwhelming majority of the modelled scenarios with different sequences of variance regimes. The SRSD advantage was particularly apparent in the case of outliers in the series. When tested on climatic time series, in most cases both methods detected the same change points in the longer series (252-787 monthly values). The only exception was the Arctic Ocean SST series, when ICSS found one extra change point that appeared to be spurious. As for the shorter time series (66-136 yearly values), ICSS failed to detect any change points even when the variance doubled or tripled from one regime to another. For these time series, SRSD is recommended. Interestingly, all the climatic time series tested, from the Arctic to the Tropics, had one thing in commo...

  17. EVIDENCE FOR ABRUPT CLIMATIC CHANGES ON NORTHWESTERN MARGIN OF EAST ASIAN MONSOON REGION DURING LAST DEGLACIATION

    QIANG Ming-rui; LI Sen; GAO Shang-yu

    2004-01-01

    Based on investigations of the Zhongwei Nanshan aeolian section situated in the southeastern margin of Tcngger Desert, carbon-14 and TL (thermoluminescence) dating results and paleoclimatic proxies such as magnetic susceptibility and grain size, we inferred that the northwestern margin of East Asian monsoon region experienced abrupt climatic changes during the last deglaciation. Six oscillation events were identified: Oldest Dryas, B¢lling, Older Dryas, Aller¢d, Intra-Aller¢d Cold Period (IACP) and Younger Dryas (YD). The summer monsoon was weaker during Oldest Dryas and Younger Dryas when the winter monsoon was stronger. However, during the B/A (B¢lling/Aller¢d)period, the summer monsoon strengthened, reflected by magnetic susceptibility, when the winter monsoon also became strong, which is different from the paleoclimatic pattern established in the East Asian monsoon region. Furthermore,the summer monsoon was nearly in phase with the climate changes inferred from the oxygen isotopic records of Greenland ice cores. It could be speculated that the variations of the sea ice cover in the high latitudes of the North Hemisphere affected the high pressure of Asian continent and the changes of the winter monsoon inland. On the other hand,the sea ice cover variations might have indirectly caused the occurrence of ENSO events that has tightly been related to the summer monsoon in northwest margin of East Asian monsoon region.

  18. Reducing The Risk Of Abrupt Climate Change: Emission Corridors Preserving The Thermohaline Circulation

    Zickfeld, K.

    Paleo-reconstructions have shown that large and abrupt climate changes have occurred throughout the last ice-age cycles. This evidence, supplemented by insights into the complex and nonlinear nature of the climate system, gives raise to the concern that anthropogenic forcing may trigger such events in the future. A prominent example for such a potential climatic shift is the collapse of the North Atlantic thermohaline circu- lation (THC), which would cause a major cooling of the northern North Atlantic and north-western Europe and considerable regional sea level rise, with possibly severe consequences on, e.g., fisheries, agriculture and ecosystems. In this paper we present emission corridors for the 21st century preserving the THC. Emission corridors embrace the range of future emissions beyond which either the THC collapses or the mitigation burden becomes intolerable. They are calculated along the conceptual and methodological lines of the tolerable windows approach. We investigate the sensitivity of the emission corridors to the main uncertain parame- ters (climate and North Atlantic hydrological sensitivities as well as emissions of non CO_2 greenhouse gases). Results show a high dependence of the size of the emis- sion corridors on hydrological and climate sensitivities. For the best-guess values of both parameters we find that the emission corridors are wider than the range spanned by the SRES emissions scenarios. Thus, no immediate mitigation seems necessary in order to preserve the THC. For high but still realistic values of the sensitivities, however, even the low SRES emissions scenarios transgress the corridor boundaries. These findings imply that under 'business as usual' a non-negligible risk of either a THC collapse or an intolerable mitigation burden exists.

  19. Long-Term Trend and Abrupt Change for Major Climate Variables in the Upper Yellow River Basin

    2007-01-01

    On the basis of the mean air temperature, precipitation, sunshine duration, and pan evaporation from 23 meteorological stations in the upper Yellow River Basin from 1960 to 2001, the feasibility of using hypothesis test techniques to detect the long-term trend for major climate variables has been investigated.Parametric tests are limited by the assumptions such as the normality and constant variance of the error terms. Nonparametric tests have not these additional assumptions and are better adapted to the trend test for hydro-meteorological time series. The possible trends of annual and monthly climatic time series are detected by using a non-parametric method and the abrupt changes have been examined in terms of 5-yr moving averaged seasonal and annual series by using moving T-test (MTT) method, Yamamoto method,and Mann-Kendall method. The results show that the annual mean temperature has increased by 0.8℃ in the upper Yellow River Basin during the past 42 years. The warmest center was located in the northern part of the basin. The nonlinear tendency for annual precipitation was negative during the same period.The declining center for annual precipitation was located in the eastern part and the center of the basin.The variation of annual precipitation in the upper Yellow River Basin during the past 42 years exhibited an increasing tendency from 1972 to 1989 and a decreasing tendency from 1990 to 2001. The nonlinear tendencies for annual sunshine duration and pan evaporation were also negative. They have decreased by 125.6 h and 161.3 mm during the past 42 years, respectively. The test for abrupt changes by using MTT method shows that an abrupt warming occurred in the late 1980s. An abrupt change of the annual mean precipitation occurred in the middle 1980s and an abrupt change of the mean sunshine duration took place in the early 1980s. For the annual mean pan evaporation, two abrupt changes took place in the 1980s and the early 1990s. The test results of the

  20. Precise interpolar phasing of abrupt climate change during the last ice age

    WAIS Divide Project Members; Buizert, Christo; Adrian, Betty M.; Ahn, Jinho; Albert, Mary; Alley, Richard B.; Baggenstos, Daniel; Bauska, Thomas K.; Bay, Ryan C.; Bencivengo, Brian B.; Bentley, Charles R.; Brook, Edward J.; Chellman, Nathan J.; Clow, Gary D.; Cole-Dai, Jihong; Conway, Howard; Cravens, Eric; Cuffey, Kurt M.; Dunbar, Nelia W.; Edwards, Jon S.; Fegyveresi, John M.; Ferris, Dave G.; Fitzpatrick, Joan J.; Fudge, T. J.; Gibson, Chris J.; Gkinis, Vasileios; Goetz, Joshua J.; Gregory, Stephanie; Hargreaves, Geoffrey Mill; Iverson, Nels; Johnson, Jay A.; Jones, Tyler R.; Kalk, Michael L.; Kippenhan, Matthew J.; Koffman, Bess G.; Kreutz, Karl; Kuhl, Tanner W.; Lebar, Donald A.; Lee, James E.; Marcott, Shaun A.; Markle, Bradley R.; Maselli, Olivia J.; McConnell, Joseph R.; McGwire, Kenneth C.; Mitchell, Logan E.; Mortensen, Nicolai B.; Neff, Peter D.; Nishiizumi, Kunihiko; Nunn, Richard M.; Orsi, Anais J.; Pasteris, Daniel R.; Pedro, Joel B.; Pettit, Erin C.; Price, P. Buford; Priscu, John C.; Rhodes, Rachael H.; Rosen, Julia L.; Schauer, Andrew J.; Schoenemann, Spruce W.; Sendelbach, Paul J.; Severinghaus, Jeffrey P.; Shturmakov, Alexander J.; Sigl, Michael; Slawny, Kristina R.; Souney, Joseph M.; Sowers, Todd A.; Spencer, Matthew K.; Steig, Eric J.; Taylor, Kendrick C.; Twickler, Mark S.; Vaughn, Bruce H.; Voigt, Donald E.; Waddington, Edwin D.; Welten, Kees C.; Wendricks, Anthony W.; White, James W. C.; Winstrup, Mai; Wong, Gifford J.; Woodruff, Thomas E.

    2015-01-01

    The last glacial period exhibited abrupt Dansgaard–Oeschger climatic oscillations, evidence of which is preserved in a variety of Northern Hemisphere palaeoclimate archives1. Ice cores show that Antarctica cooled during the warm phases of the Greenland Dansgaard–Oeschger cycle and vice versa2, 3, suggesting an interhemispheric redistribution of heat through a mechanism called the bipolar seesaw4, 5, 6. Variations in the Atlantic meridional overturning circulation (AMOC) strength are thought to have been important, but much uncertainty remains regarding the dynamics and trigger of these abrupt events7, 8, 9. Key information is contained in the relative phasing of hemispheric climate variations, yet the large, poorly constrained difference between gas age and ice age and the relatively low resolution of methane records from Antarctic ice cores have so far precluded methane-based synchronization at the required sub-centennial precision2, 3,10. Here we use a recently drilled high-accumulation Antarctic ice core to show that, on average, abrupt Greenland warming leads the corresponding Antarctic cooling onset by 218 ± 92 years (2σ) for Dansgaard–Oeschger events, including the Bølling event; Greenland cooling leads the corresponding onset of Antarctic warming by 208 ± 96 years. Our results demonstrate a north-to-south directionality of the abrupt climatic signal, which is propagated to the Southern Hemisphere high latitudes by oceanic rather than atmospheric processes. The similar interpolar phasing of warming and cooling transitions suggests that the transfer time of the climatic signal is independent of the AMOC background state. Our findings confirm a central role for ocean circulation in the bipolar seesaw and provide clear criteria for assessing hypotheses and model simulations of Dansgaard–Oeschger dynamics.

  1. High-resolution Greenland Ice Core data show abrupt climate change happens in few years

    Steffensen, Jørgen Peder; Andersen, Katrine Krogh; Bigler, Matthias;

    2008-01-01

    source, switched mode within 1 to 3 years over these transitions and initiated a more gradual change (over 50 years) of the Greenland air temperature, as recorded by stable water isotopes. The onsets of both abrupt Greenland warmings were slightly preceded by decreasing Greenland dust deposition...

  2. An Abrupt Centennial-Scale Drought Event and Mid-Holocene Climate Change Patterns in Monsoon Marginal Zones of East Asia

    LI Yu; Wang, Nai'ang; Zhang, Chengqi

    2014-01-01

    The mid-latitudes of East Asia are characterized by the interaction between the Asian summer monsoon and the westerly winds. Understanding long-term climate change in the marginal regions of the Asian monsoon is critical for understanding the millennial-scale interactions between the Asian monsoon and the westerly winds. Abrupt climate events are always associated with changes in large-scale circulation patterns; therefore, investigations into abrupt climate changes provide clues for response...

  3. Simulating the vegetation response to abrupt climate changes under glacial conditions with the ORCHIDEE/IPSL models

    Woillez, M.-N.; Kageyama, M.; Combourieu-Nebout, N.; Krinner, G.

    2012-09-01

    The last glacial period has been punctuated by two types of abrupt climatic events, the Dansgaard-Oeschger (DO) and Heinrich (HE) events. These events, recorded in Greenland ice and in marine sediments, involved changes in the Atlantic Meridional Overturning Circulation (AMOC) and led to major changes in the terrestrial biosphere. Here we use the dynamical global vegetation model ORCHIDEE to simulate the response of vegetation to abrupt changes in the AMOC strength. To do so, we force ORCHIDEE off-line with outputs from the IPSL_CM4 general circulation model, in which we have forced the AMOC to change by adding freshwater fluxes in the North Atlantic. We investigate the impact of a collapse and recovery of the AMOC, at different rates, and focus on Western Europe, where many pollen records are available to compare with. The impact of an AMOC collapse on the European mean temperatures and precipitations simulated by the GCM is relatively small but sufficient to drive an important regression of forests and expansion of grasses in ORCHIDEE, in qualitative agreement with pollen data for an HE event. On the contrary, a run with a rapid shift of the AMOC to an hyperactive state of 30 Sv, mimicking the warming phase of a DO event, does not exhibit a strong impact on the European vegetation compared to the glacial control state. For our model, simulating the impact of an HE event thus appears easier than simulating the abrupt transition towards the interstadial phase of a DO. For both a collapse or a recovery of the AMOC the vegetation starts to respond to climatic changes immediately but reaches equilibrium about 200 yr after the climate equilibrates, suggesting a possible bias in the climatic reconstructions based on pollen records, which assume equilibrium between climate and vegetation. However, our study does not take into account vegetation feedbacks on the atmosphere.

  4. Simulating the vegetation response to abrupt climate changes under glacial conditions with the ORCHIDEE/IPSL models

    M.-N. Woillez

    2012-09-01

    Full Text Available The last glacial period has been punctuated by two types of abrupt climatic events, the Dansgaard-Oeschger (DO and Heinrich (HE events. These events, recorded in Greenland ice and in marine sediments, involved changes in the Atlantic Meridional Overturning Circulation (AMOC and led to major changes in the terrestrial biosphere.

    Here we use the dynamical global vegetation model ORCHIDEE to simulate the response of vegetation to abrupt changes in the AMOC strength. To do so, we force ORCHIDEE off-line with outputs from the IPSL_CM4 general circulation model, in which we have forced the AMOC to change by adding freshwater fluxes in the North Atlantic. We investigate the impact of a collapse and recovery of the AMOC, at different rates, and focus on Western Europe, where many pollen records are available to compare with.

    The impact of an AMOC collapse on the European mean temperatures and precipitations simulated by the GCM is relatively small but sufficient to drive an important regression of forests and expansion of grasses in ORCHIDEE, in qualitative agreement with pollen data for an HE event. On the contrary, a run with a rapid shift of the AMOC to an hyperactive state of 30 Sv, mimicking the warming phase of a DO event, does not exhibit a strong impact on the European vegetation compared to the glacial control state. For our model, simulating the impact of an HE event thus appears easier than simulating the abrupt transition towards the interstadial phase of a DO.

    For both a collapse or a recovery of the AMOC the vegetation starts to respond to climatic changes immediately but reaches equilibrium about 200 yr after the climate equilibrates, suggesting a possible bias in the climatic reconstructions based on pollen records, which assume equilibrium between climate and vegetation. However, our study does not take into account vegetation feedbacks on the atmosphere.

  5. "What Controls the Structure and Stability of the Ocean Meridional Overturning Circulation: Implications for Abrupt Climate Change?"

    Fedorov, Alexey [Yale University

    2013-11-23

    The central goal of this research project is to understand the properties of the ocean meridional overturning circulation (MOC) – a topic critical for understanding climate variability and stability on a variety of timescales (from decadal to centennial and longer). Specifically, we have explored various factors that control the MOC stability and decadal variability in the Atlantic and the ocean thermal structure in general, including the possibility abrupt climate change. We have also continued efforts on improving the performance of coupled ocean-atmosphere GCMs.

  6. Abrupt climate-induced changes in carbonate burial in the Arabian Sea: Causes and consequences.

    Naidu, P.D.; Singh, A.D.; Ganeshram, R.S.; Bharti, S.K.

    experienced large declines in monsoon-driven productivity and greater penetration of Antarctica Intermediate Water (AAIW). Thus, pteropod preservation in the Arabian Sea appears to be linked to rapid climate change through atmospheric and oceanic...

  7. A Generalized Stability Analysis of the AMOC in Earth System Models: Implication for Decadal Variability and Abrupt Climate Change

    Fedorov, Alexey V. [Yale University; Fedorov, Alexey

    2015-01-14

    The central goal of this research project was to understand the mechanisms of decadal and multi-decadal variability of the Atlantic Meridional Overturning Circulation (AMOC) as related to climate variability and abrupt climate change within a hierarchy of climate models ranging from realistic ocean models to comprehensive Earth system models. Generalized Stability Analysis, a method that quantifies the transient and asymptotic growth of perturbations in the system, is one of the main approaches used throughout this project. The topics we have explored range from physical mechanisms that control AMOC variability to the factors that determine AMOC predictability in the Earth system models, to the stability and variability of the AMOC in past climates.

  8. A statistical modelling study of the abrupt millennial-scale climate changes focusing on the influence of external forcings

    Mitsui, Takahito

    2015-01-01

    Dansgaard-Oeschger (DO) events are abrupt millennial-scale climate changes mainly detected in the North Atlantic region during the last glacial cycle. The frequency of the DO events varied in time, supposedly because of changes in background climate conditions. Here, we investigate the influences of external forcings on DO events with statistical modelling. We assume two types of generic stochastic dynamical systems models (double-well potential-type and oscillator-type), forced by the northern hemisphere summer insolation change and/or the global ice volume change. The models are calibrated by maximizing their likelihood and compared using the Bayesian Information Criterion (BIC). Among the models, the stochastic oscillator model forced by both insolation and ice volume changes is favored by the NGRIP calcium ion data. The BIC scores provide positive evidence for the ice volume forcing in the presence of the insolation forcing but weak evidence for the insolation forcing in the presence of the ice volume for...

  9. Abrupt Holocene climate change as an important factor for human migration in West Greenland

    D’Andrea, William J.; Huang, Yongsong; Sherilyn C Fritz; Anderson, N. John

    2011-01-01

    West Greenland has had multiple episodes of human colonization and cultural transitions over the past 4,500 y. However, the explanations for these large-scale human migrations are varied, including climatic factors, resistance to adaptation, economic marginalization, mercantile exploration, and hostile neighborhood interactions. Evaluating the potential role of climate change is complicated by the lack of quantitative paleoclimate reconstructions near settlement areas and by the relative stab...

  10. Quantifying Climate Feedbacks from Abrupt Changes in High-Latitude Trace-Gas Emissions

    Schlosser, Courtney Adam [MIT; Walter-Anthony, Katey [University of Alaska; Zhuang, Qianlai [Purdue University; Melillo, Jerry [Marine Biological Laboratory

    2013-04-26

    Our overall goal was to quantify the potential for threshold changes in natural emission rates of trace gases, particularly methane and carbon dioxide, from pan-arctic terrestrial systems under the spectrum of anthropogenically forced climate warming, and the extent to which these emissions provide a strong feedback mechanism to global climate warming. This goal is motivated under the premise that polar amplification of global climate warming will induce widespread thaw and degradation of the permafrost, and would thus cause substantial changes in the extent of wetlands and lakes, especially thermokarst (thaw) lakes, over the Arctic. Through a coordinated effort of field measurements, model development, and numerical experimentation with an integrated assessment model framework, we have investigated the following hypothesis: There exists a climate-warming threshold beyond which permafrost degradation becomes widespread and thus instigates strong and/or sharp increases in methane emissions (via thermokarst lakes and wetland expansion). These would outweigh any increased uptake of carbon (e.g. from peatlands) and would result in a strong, positive feedback to global climate warming.

  11. A Collaborative Proposal: Simulating and Understanding Abrupt Climate-Ecosystem Changes During Holocene with NCAR-CCSM3.

    Zhengyu Liu, Bette Otto-Bliesner

    2013-02-01

    We have made significant progress in our proposed work in the last 4 years (3 years plus 1 year of no cost extension). In anticipation of the next phase of study, we have spent time on the abrupt changes since the last glacial maximum. First, we have performed further model-data comparison based on our baseline TRACE-21 simulation and made important progress towards the understanding of several major climate transitions. Second, we have made a significant effort in processing the model output of TRACE-21 and have put this output on a website for access by the community. Third, we have completed many additional sensitivity experiments. In addition, we have organized synthesis workshops to facilitate and promote transient model-data comparison for the international community. Finally, we have identified new areas of interest for Holocene climate changes.

  12. Variations in atmospheric N{sub 2}O concentration during abrupt climatic changes

    Flueckiger, J.; Daellenbach, A.; Blunier, T.; Stauffer, B.; stocker, T.F.; Raynaud, D.; Barnola, J.-M. [University of Bern, Bern (Switzerland). Physics Inst.

    1999-07-09

    Nitrous oxide (N{sub 2}O) is an important greenhouse gas that is presently increasing at a rate of 0.25% per year. Records measured along two ice cores from Summit in Central Greenland provide information about variations in atmospheric N{sub 2}O concentration in the past. The record covering the past millennium reduces the uncertainty regarding the preindustrial concentration. Records covering the last glacial-interglacial transition and a fast climatic change during the last ice age show that the N{sub 2}O concentration changed in parallel with fast temperature variations in the Northern Hemisphere. This provides important information about the response of the environment to global climatic changes. 18 refs., 3 figs.

  13. Abrupt Climate Change around 4 ka BP:Role of the Thermohaline Circulation as Indicated by a GCM Experiment

    王绍武; 周天军; 蔡静宁; 朱锦红; 谢志辉; 龚道溢

    2004-01-01

    A great deal of palaeoenvironmental and palaeoclimatic evidence suggests that a predominant temperature drop and an aridification occurred at ca. 4.0 ka BP. Palaeoclimate studies in China support this dedution. The collapse of ancient civilizations at ca. 4.0 ka BP in the Nile Valley and Mesopotamia has been attributed to climate-induced aridification. A widespread alternation of the ancient cultures was also found in China at ca. 4.0 ka BP in concert with the collapse of the civilizations in the Old World. Palaeoclimatic studies indicate that the abrupt climate change at 4.0 ka BP is one of the realizations of the cold phase in millennial scale climate oscillations, which may be related to the modulation of the Thermohaline Circulation (THC) over the Atlantic Ocean. Therefore, this study conducts a numerical experiment of a GCM with SST forcing to simulate the impact of the weakening of the THC. Results show a drop in temperature from North Europe, the northern middle East Asia, and northern East Asia and a significant reduction of precipitation in East Africa, the Middle East, the Indian Peninsula, and the Yellow River Valley. This seems to support the idea that coldness and aridification at ca. 4.0 ka BP was caused by the weakening of the THC.

  14. Abrupt climate change around 4 ka BP: Role of the Thermohaline circulation as indicated by a GCM experiment

    Wang, Shaowu; Zhou, Tianjun; Cai, Jingning; Zhu, Jinhong; Xie, Zhihui; Gong, Daoyi

    2004-04-01

    A great deal of palaeoenvironmental and palaeoclimatic evidence suggests that a predominant temperature drop and an aridification occurred at ca. 4.0 ka BP. Palaeoclimate studies in China support this dedution. The collapse of ancient civilizations at ca. 4.0 ka BP in the Nile Valley and Mesopotamia has been attributed to climate-induced aridification. A widespread alternation of the ancient cultures was also found in China at ca. 4.0 ka BP in concert with the collapse of the civilizations in the Old World. Palaeoclimatic studies indicate that the abrupt climate change at 4.0 ka BP is one of the realizations of the cold phase in millennial scale climate oscillations, which may be related to the modulation of the Thermohaline Circulation (THC) over the Atlantic Ocean. Therefore, this study conducts a numerical experiment of a GCM with SST forcing to simulate the impact of the weakening of the THC. Results show a drop in temperature from North Europe, the northern middle East Asia, and northern East Asia and a significant reduction of precipitation in East Africa, the Middle East, the Indian Peninsula, and the Yellow River Valley. This seems to support the idea that coldness and aridification at ca. 4.0 ka BP was caused by the weakening of the THC.

  15. Direct north-south synchronization of abrupt climate change record in ice cores using Beryllium 10

    Raisbeck, G.M.; Yiou, F.; Jouzel, J.; Stocker, T.F.

    2007-01-01

    A new, decadally resolved record of the 10Be peak at 41 kyr from the EPICA Dome C ice core (Antarctica) is used to match it with the same peak in the GRIP ice core (Greenland). This permits a direct synchronisation of the climatic variations around this time period, independent of uncertainties related to the ice age-gas age difference in ice cores. Dansgaard-Oeschger event 10 is in the period of best synchronisation and is found to be coeval with an Antarctic temperature ma...

  16. Direct north-south synchroniszation of abrupt climate change record in ice cores using Beryllium 10

    Raisbeck, G.M.; Yiou, F.; Jouzel, J.; Stocker, Thomas

    2007-01-01

    A new, decadally resolved record of the 10Be peak at 41 kyr from the EPICA Dome C ice core (Antarctica) is used to match it with the same peak in the GRIP ice core (Greenland). This permits a direct synchronisation of the climatic variations around this time period, independent of uncertainties related to the ice age-gas age difference in ice cores. Dansgaard-Oeschger event 10 is in the period of best synchronisation and is found to be coeval with an Antarctic temperature maximum. Simulations...

  17. An abrupt centennial-scale drought event and mid-holocene climate change patterns in monsoon marginal zones of East Asia.

    Li, Yu; Wang, Nai'ang; Zhang, Chengqi

    2014-01-01

    The mid-latitudes of East Asia are characterized by the interaction between the Asian summer monsoon and the westerly winds. Understanding long-term climate change in the marginal regions of the Asian monsoon is critical for understanding the millennial-scale interactions between the Asian monsoon and the westerly winds. Abrupt climate events are always associated with changes in large-scale circulation patterns; therefore, investigations into abrupt climate changes provide clues for responses of circulation patterns to extreme climate events. In this paper, we examined the time scale and mid-Holocene climatic background of an abrupt dry mid-Holocene event in the Shiyang River drainage basin in the northwest margin of the Asian monsoon. Mid-Holocene lacustrine records were collected from the middle reaches and the terminal lake of the basin. Using radiocarbon and OSL ages, a centennial-scale drought event, which is characterized by a sand layer in lacustrine sediments both from the middle and lower reaches of the basin, was absolutely dated between 8.0-7.0 cal kyr BP. Grain size data suggest an abrupt decline in lake level and a dry environment in the middle reaches of the basin during the dry interval. Previous studies have shown mid-Holocene drought events in other places of monsoon marginal zones; however, their chronologies are not strong enough to study the mechanism. According to the absolutely dated records, we proposed a new hypothesis that the mid-Holocene dry interval can be related to the weakening Asian summer monsoon and the relatively arid environment in arid Central Asia. Furthermore, abrupt dry climatic events are directly linked to the basin-wide effective moisture change in semi-arid and arid regions. Effective moisture is affected by basin-wide precipitation, evapotranspiration, lake surface evaporation and other geographical settings. As a result, the time scales of the dry interval could vary according to locations due to different geographical

  18. Quantifying Climate Feedbacks from Abrupt Changes in High-Latitude Trace-Gas Emissions

    Qianlai Zhuang

    2012-11-16

    During the three-year project period, Purdue University has specifically accomplished the following: revised the existing Methane Dynamics Model (MDM) to consider the effects of changes of atmospheric pressure; applied the methane dynamics model (MDM) to Siberian region to demonstrate that ebullition estimates could increase previous estimates of regional terrestrial CH{sub 4} emissions 3- to 7-fold in Siberia; Conducted an analysis of the carbon balance of the Arctic Basin from 1997 to 2006 to show that terrestrial areas of the Arctic were a net source of 41.5 Tg CH{sub 4} yr{sup −1} that increased by 0.6 Tg CH{sub 4} yr{sup −1} during the decade of analysis, a magnitude that is comparable with an atmospheric inversion of CH{sub 4}; improved the quantification of CH{sub 4} fluxes in the Arctic with inversion methods; evaluated AIRS CH4 retrieval data with a transport and inversion model and surface flux and aircraft data; to better quantify methane emissions from wetlands, we extended the MDM within a biogeochemistry model, the Terrestrial Ecosystem Model (TEM), to include a large-scale hydrology model, the variable infiltration capacity (VIC) model; more recently, we developed a single box atmospheric chemistry model involving atmospheric methane (CH{sub 4}), carbon monoxide (CO) and radical hydroxyl (OH) to analyze atmospheric CH{sub 4} concentrations from 1984 to 2008.

  19. Past migrations of the Intertropical convergence zone in NE Australia during Heinrich events: a tropical perspective on abrupt climate change

    Muller, J.; Kylander, M.; Wüst, R.; Weiss, D.; Martinez-Cortizas, A.; Legrande, A.; Turney, C.; Kershaw, P.; Jennerjahn, T.; Behling, H.

    2006-12-01

    This study presents evidence for an extended southward migrations of the Intertropical Convergence Zone (ITCZ) in the Southern Hemisphere Pacific region during major climate perturbations of the last 55 kyr. The peat deposits of Lynch's Crater, NE Australia, show several periods with synchronous high ash yield, high Si/Al ratios, high Cyperaceae/Poaceae ratios and heavier delta 15N isotopes. These intervals span the following periods: 34-37 kyr, 28-30 kyr, 22-25 kyr, 14.5-16 kyr, 12.5-13.5 kyr and 8.5 kyr which are contemporaneous with Heinrich events, the Younger Dryas and the 8.2 kyr event characterised in the Northern Hemisphere as abrupt climate events. Our record allows us to determine the impact on climate shifts in the Southern Hemisphere and more specifically the western Pacific Ocean during these millennial-scale climate perturbations in the low latitudes. Simulations of past ITCZ positions indicate that an increase in the temperature gradient between the Northern and Southern Hemispheres is a driving mechanism for its southern displacement. The trigger for the initial increase in this gradient is debatable and its relation to increased warming of the equatorial hemisphere or cooling of the northern hemisphere is still in question. It is possible that an initial warming of the equatorial latitudes increased the inter-hemispheric temperature gradient and triggered ITCZ migration before ice-rafting episodes. Interestingly, the records of ITCZ migrations in sediments from the western tropical Atlantic predate the timing of ice rafting in the northern high latitudes. It is possible that the western tropical Atlantic record shows the initial warming in the Southern Hemisphere tropics. Consequently, the role and migration of the ITCZ may be more important than previously thought and may even play an important role in the current debate about drivers and feedbacks of abrupt climate.

  20. Abrupt Climate Change and the Atlantic Meridional Overturning Circulation: sensitivity and non-linear response to Arctic/sub-Arctic freshwater pulses. Collaborative research. Final report

    Hill, Christopher [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States)

    2015-06-15

    This project investigated possible mechanisms by which melt-water pulses can induce abrupt change in the Atlantic Meridional Overturning Circulation (AMOC) magnitude. AMOC magnitude is an important ingredient in present day climate. Previous studies have hypothesized abrupt reduction in AMOC magnitude in response to influxes of glacial melt water into the North Atlantic. Notable fresh-water influxes are associated with the terminus of the last ice age. During this period large volumes of melt water accumulated behind retreating ice sheets and subsequently drained rapidly when the ice weakened sufficiently. Rapid draining of glacial lakes into the North Atlantic is a possible origin of a number of paleo-record abrupt climate shifts. These include the Younger-Dryas cooling event and the 8,200 year cooling event. The studies undertaken focused on whether the mechanistic sequence by which glacial melt-water impacts AMOC, which then impacts Northern Hemisphere global mean surface temperature, is dynamically plausible. The work has implications for better understanding past climate stability. The work also has relevance for today’s environment, in which high-latitude ice melting in Greenland appears to be driving fresh water outflows at an accelerating pace.

  1. An abrupt stochastic damage function to analyse climate policy benefits

    Ha-Duong, Minh; Dumas, Patrice

    2004-01-01

    Chapter in Alain Haurie and Laurent Viguier (eds.) 2005, The coupling of climate and economic dynamics, Essays on Integrated Assessment. Series: Advances in Global Change Research, Vol. 22 , Kluwerhttp://www.centre-cired.fr/perso/haduong/files/Dumas.ea-2004-AbruptStochasticDamage.pdf This paper studies uncertainty about the non-linearity of climate change impact. The DIAM 2.3 model is used to compute the sensitivity of optimal CO2 emissions paths with respect to damage function parameters....

  2. Application of nonlinear dynamical metho ds in abrupt climate change detection%非线性动力学方法在气候突变检测中的应用∗

    2015-01-01

    The research of abrupt climate change is an important field in the climate change. The rapid and accurate detection of the abrupt climate change has important practical significance and major economic-social costs, which will help us understand climate change and forecast the future evolutionary trend of the climate system. The detection results of most traditional abrupt climate change depend on the selection of the time scale concerned, which may result in the fact that we cannot identify an abrupt climate change until the event has been past for a long time. Moreover, these detection methods cannot extract the dynamical changes from the observational data of the climate system. As the rapid development in nonlinear science, the abrupt climate change detection technology has also been improved gradually. This article briefly reviews several new progresses in abrupt dynamical detection methods developed on the basis of recent nonlinear technologies, and some applications in the real observational data. These new methods mainly contain the technologies based on the long-range correlation of climate systems, such as moving detrended fluctuation analysis, moving cut data-detrended fluctuation analysis, moving cut data-R/S analysis, degenerate fingerprinting, and red noise. Moreover, some abrupt dynamical detection methods developed by the complexity of the time series, namely, entropy, such as approximate entropy, moving cutting data-approximate entropy, Fisher information, and wavelet Fisher’s information measure. Furthermore, there are some other abrupt dynamical detection methods based on the theory of phase space, such as the dynamics exponent Q. Climate system is a complex dynamical system with nonlinear and interactive nature, which has long-range persistence in spatio-temporal variation, thus the abrupt detection method on spatial field change is pointed out to be a promising direction for further research in future. Because the spatial field contains

  3. Abrupt climate change: Past, present and the search for precursors as an aid to predicting events in the future (Hans Oeschger Medal Lecture)

    Mayewski, Paul Andrew

    2016-04-01

    The demonstration using Greenland ice cores that abrupt shifts in climate, Dansgaard-Oeschger (D-O) events, existed during the last glacial period has had a transformational impact on our understanding of climate change in the naturally forced world. The demonstration that D-O events are globally distributed and that they operated during previous glacial periods has led to extensive research into the relative hemispheric timing and causes of these events. The emergence of civilization during our current interglacial, the Holocene, has been attributed to the "relative climate quiescence" of this period relative to the massive, abrupt shifts in climate that characterized glacial periods in the form of D-O events. But, everything is relative and climate change is no exception. The demise of past civilizations, (eg., Mesopatamian, Mayan and Norse) is integrally tied to abrupt climate change (ACC) events operating at regional scales. Regionally to globally distributed ACC events have punctuated the Holocene and extreme events have always posed significant challenges to humans and ecosystems. Current warming of the Arctic, in terms of length of the summer season, is as abrupt and massive, albeit not as extensive, as the transition from the last major D-O event, the Younger Dryas into the Holocene (Mayewski et al., 2013). Tropospheric source greenhouse gas rise and ozone depletion in the stratosphere over Antarctica are triggers for the modern advent of human emission instigated ACCs. Arctic warming and Antarctic ozone depletion have resulted in significance changes to the atmospheric circulation systems that transport heat, moisture, and pollutants in both hemispheres. Climate models offer a critical tool for assessing trends, but they cannot as yet predict ACC events, as evidenced by the inability of these models to predict the rapid onset of Arctic warming and resulting changes in atmospheric circulation; and in the model vs past analog differences in projections for

  4. Abrupt climatic changes on the Tibetan Plateau during the Last Ice Age——Comparative study of the Guliya ice core with the Greenland GRIP ice core

    姚檀栋

    1999-01-01

    Based on a comparative study of the Gtdiya ice core with the Greenland GRIP ice core, the abrupt climatic changes on the Tibetan Plateau during the Last Ice Age have been examined. The major stadial-interstadial events and 7 warm events (BrΦrump, Odderade, Oerel, Glinde, Hengelo, Denekamp, BΦlling) are consistent in the two ice cores. However, there are some unique features in the Guliya ice core records. The transition from warm to cold periods in the Guliya ice core is faster than that in the Greenland GRIP ice core. The magnitude of the climatic changes in the Guliya ice core is also larger than that in the Greenland GRIP ice core. Another significant feature of the Guliya ice core records is that there is a series of cycles of about 200 a from 18 to 35 kaBP. 22 warm events and 20 cold events with a fluctuation magnitude of 7℃ have been distinguished. The warm and cold events with a fluctuation magnitude within 3℃ are as high as 100. It is speculated that the abrupt climatic changes in different

  5. The abrupt climate change near 4,400 yr BP on the cultural transition in Yuchisi, China and its global linkage

    Wang, Jianjun; Sun, Liguang; Chen, Liqi; Xu, Libin; Wang, Yuhong; Wang, Xinming

    2016-06-01

    Extreme climatic events have profound impacts on human society. Here we present the results of a study of organic biomarkers within a sedimentary section at the archaeological site of Yuchisi, eastern China, in order to reconstruct climatic variability during the Dawenkou (5,050–4,400 yr BP) and Longshan (4,400–4,000 yr BP) cultures. At ~4,400 yr BP, within the cultural transition horizon, abrupt changes in biomarkers, such as the fatty acid ratio C18:2/C18:0, 2C31/(C27 + C29), n-C18-ol and n-C30-ol, indicate the occurrence of local climate changes over the course of a few decades. These changes occurred during the transition from the Holocene warm period to a subsequent cold period which lasted for the following 600 years. This climatic shift has been recorded at numerous sites worldwide, and it is likely to have been the main cause of the widespread collapse of many isolated cultures at that time. The palaeoclimatic and archaeological data from the Yuchisi sediments may provide new insights into the relationship between climate change and prehistoric cultural transitions.

  6. Work More? The 8.2 kaBP Abrupt Climate Change Event and the Origins of Irrigation Agriculture and Surplus Agro-Production in Mesopotamia

    Weiss, H.

    2003-12-01

    The West Asian archaeological record is of sufficient transparency and resolution to permit observation of the social responses to the major Holocene abrupt climate change events at 8.2, 5.2 and 4.2 kaBP. The 8.2kaBP abrupt climate change event in West Asia was a three hundred year aridification and cooling episode. During this period rain-fed agriculture, established for over a millennium in northern Mesopotamia, suddenly collapsed. Irrigation agriculture, pastoral nomadism, or migration were the only subsistence alternatives for populations previously supported by cereal dry-farming. Irrigation agriculture was not, however, possible along the northern alluvial plains of the Tigris and Euphrates Rivers, where incised riverbeds were several meters below plain level. Exploitable plain-level levees were only accessible in southern-most alluvial plain, at the head of the present-day Persian Gulf. The archaeological data from this region documents the first irrigation agriculture settlement of the plain during the 8.2 kaBP event. Irrigation agriculture provides about twice the yield of dry-farming in Mesopotamia, but at considerable labor costs relative to dry-farming. With irrigation agriculture surplus production was now available for deployment. But why work more? The 8.2 kaBP event provided the natural force for Mesopotamian irrigation agriculture and surplus production that were essential for the earliest class-formation and urban life.

  7. The fluvial system response to abrupt climate change during the last cold stage: the Upper Pleistocene River Thames fluvial succession at Ashton Keynes, UK

    Lewis, S. G.; Maddy, D.; Scaife, R. G.

    2001-02-01

    The last interglacial-glacial cycle (125-10 ka BP) is characterised by numerous rapid shifts in global climate on sub-Milankovitch timescales, recorded in the ocean and ice core records. These climatic fluctuations are clearly recorded in those European terrestrial sedimentary sequences that span this time period without interruption. In the UK, only fragmentary Upper Pleistocene sequences exist, mainly within the fluvial archive of the major river systems such as the Thames. The response of the upper River Thames to abrupt fluctuations in climate is documented in the fluvial sediments beneath the Floodplain Terrace (Northmoor Member of the Upper Thames Formation) at Ashton Keynes, Wiltshire. A number of criteria are set out by which significant changes in the fluvial system may be established from the sedimentological, palaeoecological and geochronological information contained within the succession. The sedimentary succession is divisible into four facies associations, on the basis of their sedimentology and bounding surface characteristics. These represent distinct phases of fluvial activity at the site and allow changes in fluvial style to be inferred. Palaeoecological reconstructions from pollen analysis of peats within the sequence provides an indication of the nature and direction of Late Glacial environmental change and optically stimulated luminescence and radiocarbon dating methods provide chronological control on the sequence. These data suggest that major changes in fluvial style are recorded within the succession, which can be related to the climatic fluctuations that took place on the oxygen isotope stage 5a/4 transition (approximately 70 ka BP) and the Devensian Late Glacial climatic warm-cold-warm oscillation (13-11 ka BP). The changes in fluvial style are a result of variations in sediment supply to the river resulting from changes in slope stability, vegetation cover and cold-climate mass movement processes and variations in discharge regime

  8. Abrupt change of the mid-summer climate in central east China by the influence of atmospheric pollution

    Following the great flooding of summer 1998, the mid-lower Yangtze Basin further suffered from another large flooding in summer 1999. Successive droughts through three recent summers (1997-1999) appeared in north China in addition, leading to an abnormal summer climate pattern of ''north drought with south flooding''. Such southward move of the summer monsoon rainy belt in east China started in the late 1970s-early 1980s. Its main cause may not be a purely natural climate change, but the acceleration of industrialization in east China could play a major role by emitting large volumes of SO2, especially from the rapidly growing rural factories of east China. The annual release of SO2 in China exceeded 20Tg during 1992-1998, so dense sulfate aerosols covered the central east China which significantly reduced the sunlight. Although present estimates for the changes of clear sky global solar radiation may include some error, they show that the negative radiative forcing of sulfate aerosols in central east China by far exceeds the effect of greenhouse warming in summer. Hence the mid-summer monsoon rainy belt of east China has a trend moving southward in 21 recent years (1979-1999), showing the very sensitive characteristic of the summer monsoon system to the change in heat equilibrium of the land surface. The occurrence rate of summer climate pattern of ''north drought with south flooding'' in east China during 21 recent years is the largest since AD 950; such anomalous climate has brought large losses to China. The only possible way to reverse this southward trend of summer monsoon rainy belt is to significantly reduce air pollution by using more clean energy. Recently, the PRC has paid serious attention to this problem by adopting a series of countermeasures. (author)

  9. Abrupt change of the mid-summer climate in central east China by the influence of atmospheric pollution

    Xu, Qun

    Following the great flooding of summer 1998, the mid-lower Yangtze Basin further suffered from another large flooding in summer 1999. Successive droughts through 3 recent summers (1997-1999) appeared in north China in addition, leading to an abnormal summer climate pattern of "north drought with south flooding". Such southward move of the summer monsoon rainy belt in east China started in the late 1970s-early 1980s. Its main cause may not be a purely natural climate change, but the acceleration of industrialization in east China could play a major role by emitting large volumes of SO 2, especially from the rapidly growing rural factories of east China. The annual release of SO 2 in China exceeded 20 Tg during 1992-1998, so dense sulfate aerosols covered the central east China which significantly reduced the sunlight. Although present estimates for the changes of clear sky global solar radiation may include some error, they show that the negative radiative forcing of sulfate aerosols in central east China by far exceeds the effect of greenhouse warming in summer. Hence the mid-summer monsoon rainy belt of east China has a trend moving southward in 21 recent years (1979-1999), showing the very sensitive characteristic of the summer monsoon system to the change in heat equilibrium of the land surface. The occurrence rate of summer climate pattern of "north drought with south flooding" in east China during 21 recent years is the largest since AD 950; such anomalous climate has brought large losses to China. The only possible way to reverse this southward trend of summer monsoon rainy belt is to significantly reduce air pollution by using more clean energy. Recently, the PRC has paid serious attention to this problem by adopting a series of countermeasures.

  10. Abrupt climate change of East Asian Monsoon at 130 kaBP inferred from a high resolution stalagmite δ18O record

    JIANG Xiuyang; WANG Yongjin; KONG Xinggong; WU Jiangying; SHAO Xiaohua; XIA Zhifeng; CHENG Hai

    2005-01-01

    230Th ages and oxygen isotope data of a stalagmite from Shanbao Cave in Hubei Province characterize the East Asian Monsoon precipitation from 133 to127 ka. The decadal-scale high-resolution δ18O record reveals a detailed transitional process from the Penultimate Glaciation to the Last Interglaciation. As established with 230Th dates, the age of the Termination II is determined to be 129.5±1.0 kaBP, which supports the Northern Hemisphere insolation as the triggers for the ice-age cycles. In our δ18O record, the glacial/ interglacial fluctuation reaches about 4‰, almost the same level as in other Asian Monsoon cave stalagmite δ18O records. The transition of the glacial/interglacial period in our record can be recognized as four stepwise stages, among which, a rapid rise of monsoon precipitation follows the stage of "Termination II pause". The rapid rise is synchronous with the abrupt change of global methane concentration, which reflects that an increase in both Asian Monsoon precipitation and tropical wetland plays an important role in the global climate changes.

  11. Abrupt climate shift in the Western Mediterranean Sea

    Schroeder, K.; Chiggiato, J.; Bryden, H. L.; Borghini, M.; Ben Ismail, S.

    2016-03-01

    One century of oceanographic measurements has evidenced gradual increases in temperature and salinity of western Mediterranean water masses, even though the vertical stratification has basically remained unchanged. Starting in 2005, the basic structure of the intermediate and deep layers abruptly changed. We report here evidence of reinforced thermohaline variability in the deep western basin with significant dense water formation events producing large amounts of warmer, saltier and denser water masses than ever before. We provide a detailed chronological order to these changes, giving an overview of the new water masses and following their route from the central basin interior to the east (toward the Tyrrhenian) and toward the Atlantic Ocean. As a consequence of this climate shift, new deep waters outflowing through Gibraltar will impact the North Atlantic in terms of salt and heat input. In addition, modifications in the Mediterranean abyssal ecosystems and biogeochemical cycles are to be expected.

  12. Abrupt shifts in phenology and vegetation productivity under climate extremes

    Ma, Xuanlong; Huete, Alfredo; Moran, Susan; Ponce-Campos, Guillermo; Eamus, Derek

    2015-10-01

    Amplification of the hydrologic cycle as a consequence of global warming is predicted to increase climate variability and the frequency and severity of droughts. Recent large-scale drought and flooding over numerous continents provide unique opportunities to understand ecosystem responses to climatic extremes. In this study, we investigated the impacts of the early 21st century extreme hydroclimatic variations in southeastern Australia on phenology and vegetation productivity using Moderate Resolution Imaging Spectroradiometer Enhanced Vegetation Index and Standardized Precipitation-Evapotranspiration Index. Results revealed dramatic impacts of drought and wet extremes on vegetation dynamics, with abrupt between year changes in phenology. Drought resulted in widespread reductions or collapse in the normal patterns of seasonality such that in many cases there was no detectable phenological cycle during drought years. Across the full range of biomes examined, we found semiarid ecosystems to exhibit the largest sensitivity to hydroclimatic variations, exceeding that of arid and humid ecosystems. This result demonstrated the vulnerability of semiarid ecosystems to climatic extremes and potential loss of ecosystem resilience with future mega-drought events. A skewed distribution of hydroclimatic sensitivity with aridity is of global biogeochemical significance because it suggests that current drying trends in semiarid regions will reduce hydroclimatic sensitivity and suppress the large carbon sink that has been reported during recent wet periods (e.g., 2011 La Niña).

  13. A simple conceptual model of abrupt glacial climate events

    Braun, H; Christl, M; Chialvo, D R

    2008-01-01

    Here we use a very simple conceptual model in an attempt to reduce essential parts of the complex nonlinearity of abrupt glacial climate changes (the so-called Dansgaard-Oeschger events) to a few simple principles, namely (i) a threshold process, (ii) an overshooting in the stability of the system and (iii) a millennial-scale relaxation. By comparison with a so-called Earth system model of intermediate complexity (CLIMBER-2), in which the events represent oscillations between two climate states corresponding to two fundamentally different modes of deep-water formation in the North Atlantic, we demonstrate that the conceptual model captures fundamental aspects of the nonlinearity of the events in that model. We use the conceptual model in order to reproduce and reanalyse nonlinear resonance mechanisms that were already suggested in order to explain the characteristic time scale of Dansgaard-Oeschger events. In doing so we identify a new form of stochastic resonance (i.e. an overshooting stochastic resonance) a...

  14. Neanderthal and Anatomically Modern Human interaction with Abrupt Late Pleistocene Environments - the data is finally good enough to talk about climate change!

    Blockley, Simon; Schreve, Danielle

    2015-04-01

    The timing and nature of the appearance of Anatomically Modern Humans (AMH) in Europe, their interaction with, and eventual morphological replacement of Neanderthals (despite some shared genetic heritage) has been a matter of intense debate within archaeology for a generation. This period, often termed the Middle to Upper Palaeolithic transition occurs in the latter part of Marine Isotope Stage Three and in recent decades archaeological interest has been complemented by the input of palaeoclimate scientists, over the role of abrupt climate change in this process. This was due to the recognition from ice core and marine proxy archives, in particular, of periods if intense cooling, correlated to the marine record of Heinrich ice rafted debris layers from the Atlantic. As a result of these collaborations between the archaeological and palaeoenvironmental communities various drivers have been proposed for the Middle to Upper Palaeolithic Transition that include: (1) resource competition between two species occupying similar niches; (2) the impact of repeated cycles of Heinrich event cooling, leading to the decline and eventual disappearance of the Neanderthal populations, leaving a new region open for AMH exploitation; and (3) catastrophic impacts of large volcanic eruptions on Neanderthal populations. Attempts to address the above hypotheses have been dogged by the chronological precision available for a number of key archives. The accuracy of many of the radiocarbon ages that underpin the chronology for both Neanderthal and AMH archaeological sites has been questioned1. This has been exacerbated by uncertainties over the influence of variability in the radiocarbon marine reservoir effect on marine palaeoclimate records and a marine dominated radiocarbon calibration curve. Additionally, the counting uncertainties of the master Greenland palaeoclimate archives are also large by this time, meaning palaeoclimate interpretation can be equivocal. However, several research

  15. A GCM study on the mechanism of seasonal abrupt changes

    Wang, Huijun; Zeng, Qingcun

    1994-02-01

    In this paper the observational studies and some related dynamical and numerical researches on seasonal abrupt changes were reviewed first. Then a speculation that the seasonal variation of insolation and the nonlinear dynamic interaction account for the abrupt changes was put forward and was asserted by a set of GCM sensitivity experiments. The results show that the abrupt changes would exist in case that all the earth surface was grass land and there was no topography. However, many factors may have influences on the abrupt changes. Hence this phenomenon is quite complicated and needs further investigations.

  16. Gradual onset and recovery of the Younger Dryas abrupt climate event in the tropics.

    Partin, J W; Quinn, T M; Shen, C-C; Okumura, Y; Cardenas, M B; Siringan, F P; Banner, J L; Lin, K; Hu, H-M; Taylor, F W

    2015-01-01

    Proxy records of temperature from the Atlantic clearly show that the Younger Dryas was an abrupt climate change event during the last deglaciation, but records of hydroclimate are underutilized in defining the event. Here we combine a new hydroclimate record from Palawan, Philippines, in the tropical Pacific, with previously published records to highlight a difference between hydroclimate and temperature responses to the Younger Dryas. Although the onset and termination are synchronous across the records, tropical hydroclimate changes are more gradual (>100 years) than the abrupt (10-100 years) temperature changes in the northern Atlantic Ocean. The abrupt recovery of Greenland temperatures likely reflects changes in regional sea ice extent. Proxy data and transient climate model simulations support the hypothesis that freshwater forced a reduction in the Atlantic meridional overturning circulation, thereby causing the Younger Dryas. However, changes in ocean overturning may not produce the same effects globally as in Greenland. PMID:26329911

  17. Climate change: a primer

    Khanna, Dr. Perminder; Aneja, Reenu

    2011-01-01

    Abstract Climate has inherent variability manifesting in gradual changes in temperature, precipitation and sea-level rise. The paper entitled “Climate Change: A Primer” attempts to analyse the policy response and adaptation to the need to address climate change at the international and domestic level both. Intense variations in climate would increase the risk of abrupt and non-linear changes in the ecosystem, impacting their function, biodiversity and productivity. The policy initiations and ...

  18. A stratigraphic framework for abrupt climatic changes during the Last Glacial period based on three synchronized Greenland ice-core records: refining and extending the INTIMATE event stratigraphy

    Rasmussen, Sune O.; Bigler, Matthias; Blockley, Simon P.; Blunier, Thomas; Buchardt, Susanne L.; Clausen, Henrik B.; Cvijanovic, Ivana; Dahl-Jensen, Dorthe; Johnsen, Sigfus J.; Fischer, Hubertus; Gkinis, Vasileios; Guillevic, Myriam; Hoek, Wim Z.; Lowe, J. John; Pedro, Joel B.; Popp, Trevor; Seierstad, Inger K.; Steffensen, Jørgen Peder; Svensson, Anders M.; Vallelonga, Paul; Vinther, Bo M.; Walker, Mike J.C.; Wheatley, Joe J.; Winstrup, Mai

    2014-01-01

    Due to their outstanding resolution and well-constrained chronologies, Greenland ice-core records provide a master record of past climatic changes throughout the Last Interglacial–Glacial cycle in the North Atlantic region. As part of the INTIMATE (INTegration of Ice-core, MArine and TErrestrial r

  19. Abrupt climate shift in the Western Mediterranean Sea

    K. Schroeder; J. Chiggiato; H. L. Bryden; Borghini, M.; Ben Ismail, S.

    2016-01-01

    One century of oceanographic measurements has evidenced gradual increases in temperature and salinity of western Mediterranean water masses, even though the vertical stratification has basically remained unchanged. Starting in 2005, the basic structure of the intermediate and deep layers abruptly changed. We report here evidence of reinforced thermohaline variability in the deep western basin with significant dense water formation events producing large amounts of warmer, saltier and denser w...

  20. Causes and projections of abrupt climate-driven ecosystem shifts in the North Atlantic

    Beaugrand, G.; Edwards, M.; Brander, Keith;

    2008-01-01

    Warming of the global climate is now unequivocal and its impact on Earth' functional units has become more apparent. Here, we show that marine ecosystems are not equally sensitive to climate change and reveal a critical thermal boundary where a small increase in temperature triggers abrupt...... ecosystem shifts seen across multiple trophic levels. This large-scale boundary is located in regions where abrupt ecosystem shifts have been reported in the North Atlantic sector and thereby allows us to link these shifts by a global common phenomenon. We show that these changes alter the biodiversity and...... carrying capacity of ecosystems and may, combined with fishing, precipitate the reduction of some stocks of Atlantic cod already severely impacted by exploitation. These findings offer a way to anticipate major ecosystem changes and to propose adaptive strategies for marine exploited resources such as cod...

  1. Climate Change

    ... in a place over a period of time. Climate change is major change in temperature, rainfall, snow, or ... by natural factors or by human activities. Today climate changes are occurring at an increasingly rapid rate. Climate ...

  2. Paleoclimate. Synchronization of North Pacific and Greenland climates preceded abrupt deglacial warming.

    Praetorius, Summer K; Mix, Alan C

    2014-07-25

    Some proposed mechanisms for transmission of major climate change events between the North Pacific and North Atlantic predict opposing patterns of variations; others suggest synchronization. Resolving this conflict has implications for regulation of poleward heat transport and global climate change. New multidecadal-resolution foraminiferal oxygen isotope records from the Gulf of Alaska (GOA) reveal sudden shifts between intervals of synchroneity and asynchroneity with the North Greenland Ice Core Project (NGRIP) δ(18)O record over the past 18,000 years. Synchronization of these regions occurred 15,500 to 11,000 years ago, just prior to and throughout the most abrupt climate transitions of the last 20,000 years, suggesting that dynamic coupling of North Pacific and North Atlantic climates may lead to critical transitions in Earth's climate system. PMID:25061208

  3. Gradual and abrupt changes during the Mid-Pleistocene Transition

    Ford, Heather L.; Sosdian, Sindia M.; Rosenthal, Yair; Raymo, Maureen E.

    2016-09-01

    During the Mid-Pleistocene Transition (MPT), the dominant glacial-interglacial cyclicity as inferred from the marine δ18O records of benthic foraminifera (δ18Obenthic) changed from 41 kyr to 100 kyr years in the absence of a comparable change in orbital forcing. Currently, only two Mg/Ca-derived, high-resolution bottom water temperature (BWT) records exist that can be used with δ18Obenthic records to separate temperature and ice volume signals over the Pleistocene. However, these two BWT records suggest a different pattern of climate change occurred over the MPT-a record from North Atlantic DSDP Site 607 suggests BWT decreased with no long-term trend in ice volume over the MPT, while South Pacific ODP Site 1123 suggests that BWT has been relatively stable over the last 1.5 Myr but that there was an abrupt increase in ice volume at ∼900 kyr. In this paper we attempt to reconcile these two views of climate change across the MPT. Specifically, we investigated the suggestion that the secular BWT trend obtained from Mg/Ca measurements on Cibicidoides wuellerstorfi and Oridorsalis umbonatus species from N. Atlantic Site 607 is biased by the possible influence of Δ[CO32-] on Mg/Ca values in these species by generating a low-resolution BWT record using Uvigerina spp., a genus whose Mg/Ca values are not thought to be influenced by Δ[CO32-]. We find a long-term BWT cooling of ∼2-3°C occurred from 1500 to ∼500 kyr in the N. Atlantic, consistent with the previously generated C. wuellerstorfi and O. umbonatus BWT record. We also find that changes in ocean circulation likely influenced δ18Obenthic, BWT, and δ18Oseawater records across the MPT. N. Atlantic BWT cooling starting at ∼1.2 Ma, presumably driven by high-latitude cooling, may have been a necessary precursor to a threshold response in climate-ice sheet behavior at ∼900 ka. At that point, a modest increase in ice volume and thermohaline reorganization may have caused enhanced sensitivity to the 100 kyr

  4. Climate Change

    ... can be caused by natural factors or by human activities. Today climate changes are occurring at an increasingly rapid rate. Climate change can affect our health. It can lead to More heat-related illness ...

  5. Could massive Arctic sea ice export to the North Atlantic be the real cause of abrupt climate change during the last deglaciation?

    Coletti, A. J.; Condron, A.

    2015-12-01

    Using a coupled ocean-sea ice model (MITgcm), we investigate whether the break-up and mobilization of thick, multiyear, Arctic sea ice might have supplied enough freshwater to the Nordic Seas to reduce North Atlantic Deep Water (NADW) formation and weaken the Atlantic Meridional Overturning Circulation (AMOC). Numerical simulations of a Last Glacial Maximum (LGM) environment show the potential for sea ice to grow to ~30m thick, storing ~1.41x105 km3 of freshwater as sea ice in the Arctic (this is ~10 times the volume of freshwater stored in the modern-day Arctic). Releasing this volume of sea ice from the Arctic in 1-yr is equivalent to a high-latitude freshwater forcing of ~4.5 Sv, which is comparable (or larger) in magnitude to most meltwater floods emanating from land-based glacial lakes (e.g. Agassiz) during the last deglaciation. Opening of the Bering Strait and Barents Sea are two plausible mechanisms that may have initiated sea ice mobilization. Opening Bering Strait increases sea ice transport through the Fram Strait by 7% and results in a 22% weakening of AMOC for 2000 years and a >3°C warming in the Arctic basin at 800 m depth. Opening Barents Sea to simulate a collapse of the Fennoscandian ice sheet has little impact on Arctic sea ice and freshwater export to the North Atlantic, but weakens AMOC ~8%. In a simulation with both straits open there is a transition to near-modern sea ice circulation pattern and a 24% reduction in AMOC. Experiments with the Bering Strait open and sea ice artificially capped to 10 m show barely any difference to those when sea ice can grow to ~30m, suggesting that changes in topography have a much greater impact on AMOC than the freshwater forcing from sea ice melting in the Nordic Seas.

  6. Climate Change

    Rasmussen, Torben Valdbjørn; Hansen, Ernst Jan de Place

    2011-01-01

    This paper presents the effects of climate change relevant for Denmark, including the change in mean year values as well as the extent of maximum and minimum extremes. Described by the Intergovernmental Panel on Climate Change, the assumptions that the scenarios are based on were outlined...... and evaluated in a Danish context. The uncertainty of the scenarios leaves major challenges that, if not addressed and taken into account in building design, will grow far more serious as climate change progresses. Cases implemented in the Danish building stock illustrate adaptation to climate change...... and illustrate how building design can include mitigating measures to counteract climate change. Cases studied were individual buildings as well as the urban environment. Furthermore the paper describes some of the issues that must be addressed, as the building sector is investing in measures to adapt to climate...

  7. Climate Change

    Rasmussen, Torben Valdbjørn; Hansen, Ernst Jan de Place

    2011-01-01

    This paper presents the effects of climate change relevant for Denmark, including the change in mean year values as well as the extent of maximum and minimum extremes. Described by the Intergovernmental Panel on Climate Change, the assumptions that the scenarios are based on were outlined and...... evaluated in a Danish context. The uncertainty of the scenarios leaves major challenges that, if not addressed and taken into account in building design, will grow far more serious as climate change progresses. Cases implemented in the Danish building stock illustrate adaptation to climate change and...... illustrate how building design can include mitigating measures to counteract climate change. Cases studied were individual buildings as well as the urban environment. Furthermore the paper describes some of the issues that must be addressed, as the building sector is investing in measures to adapt to climate...

  8. Abrupt changes in the southern extent of North Atlantic Deep Water during Dansgaard-Oeschger events

    Gottschalk, Julia; Skinner, Luke C.; Misra, Sambuddha; Waelbroeck, Claire; Menviel, Laurie; Timmermann, Axel

    2015-12-01

    The glacial climate system transitioned rapidly between cold (stadial) and warm (interstadial) conditions in the Northern Hemisphere. This variability, referred to as Dansgaard-Oeschger variability, is widely believed to arise from perturbations of the Atlantic Meridional Overturning Circulation. Evidence for such changes during the longer Heinrich stadials has been identified, but direct evidence for overturning circulation changes during Dansgaard-Oeschger events has proven elusive. Here we reconstruct bottom water [CO32-] variability from B/Ca ratios of benthic foraminifera and indicators of sedimentary dissolution, and use these reconstructions to infer the flow of northern-sourced deep water to the deep central sub-Antarctic Atlantic Ocean. We find that nearly every Dansgaard-Oeschger interstadial is accompanied by a rapid incursion of North Atlantic Deep Water into the deep South Atlantic. Based on these results and transient climate model simulations, we conclude that North Atlantic stadial-interstadial climate variability was associated with significant Atlantic overturning circulation changes that were rapidly transmitted across the Atlantic. However, by demonstrating the persistent role of Atlantic overturning circulation changes in past abrupt climate variability, our reconstructions of carbonate chemistry further indicate that the carbon cycle response to abrupt climate change was not a simple function of North Atlantic overturning.

  9. A study of the early warning signals of abrupt change in the Pacific decadal oscillation

    Wu, Hao; Hou, Wei; Yan, Peng-Cheng; Zhang, Zhi-Sen; Wang, Kuo

    2015-08-01

    In recent years, the phenomenon of a critical slowing down has demonstrated its major potential in discovering whether a complex dynamic system tends to abruptly change at critical points. This research on the Pacific decadal oscillation (PDO) index has been made on the basis of the critical slowing down principle in order to analyze its early warning signal of abrupt change. The chaotic characteristics of the PDO index sequence at different times are determined by using the largest Lyapunov exponent (LLE). The relationship between the regional sea surface temperature (SST) background field and the early warning signal of the PDO abrupt change is further studied through calculating the variance of the SST in the PDO region and the spatial distribution of the autocorrelation coefficient, thereby providing the experimental foundation for the extensive application of the method of the critical slowing down phenomenon. Our results show that the phenomenon of critical slowing down, such as the increase of the variance and autocorrelation coefficient, will continue for six years before the abrupt change of the PDO index. This phenomenon of the critical slowing down can be regarded as one of the early warning signals of an abrupt change. Through calculating the LLE of the PDO index during different times, it is also found that the strongest chaotic characteristics of the system occurred between 1971 and 1975 in the early stages of an abrupt change (1976), and the system was at the stage of a critical slowing down, which proves the reliability of the early warning signal of abrupt change discovered in 1970 from the mechanism. In addition, the variance of the SST, along with the spatial distribution of the autocorrelation coefficient in the corresponding PDO region, also demonstrates the corresponding relationship between the change of the background field of the SST and the change of the PDO. Project supported by the National Natural Science Foundation of China (Grant Nos

  10. Abrupt Climatic Events Observed in Organic-Rich Sediments From Lake Tanganyika, Tropical East Africa, Over the Past 50 kyr

    Burnett, A. P.; Weyhenmeyer, C. E.; Scholz, C. A.; Swart, P. K.

    2006-12-01

    Abrupt climate changes such as Dansgaard-Oeschger Cycles and Heinrich Events were first detected in high- latitude records, but an increasing number of studies suggest that these rapid changes are actually global events. The degree to which the tropics drive, control and/or respond to such rapid changes is still poorly understood due to a scarcity of data from low-latitude regions. A recently acquired sediment core from Lake Tanganyika, East Africa, provides a unique archive to study abrupt climate events in the tropics throughout the last glaciation. The core provides a continuous, undisturbed and high resolution climate record over the past 100 kyr. An age-depth model based on 25 new radiocarbon dates provides a solid, high-resolution chronology for the past 50 kyr. Throughout this time, several rapid changes in paleoclimate proxy data are observed along the core. Sedimentation rates remained fairly constant from the Holocene until the Last Glacial Maximum (LGM) but increased abruptly from ~80 mm/1000 yr to ~150 mm/1000 yr around 18 kyr BP. At the same time, the sediment record reveals a sudden increase in total organic carbon (TOC) from 4% to 12% indicating a rapid increase in organic matter contributions at the end of the LGM. Abrupt changes in TOC and δ13C values are also found at ~38 kyr, ~30 kyr and ~16 kyr BP, suggesting a possible link to Heinrich events 4, 3 and 1, respectively. Forthcoming very high-resolution analyses, to augment existing low-resolution data, include δ13C, δ15N, C/N ratios and TOC values. Furthermore, TEX86 measurements will be carried out to determine whether the observed changes in organic matter contributions are associated with changes in water temperatures. In combination with the solid 14C chronology, the new data will allow us to precisely determine the onset, timing and nature of abrupt changes and evaluate them in the global context.

  11. Greenland climate change

    Masson-Delmotte, Valerie; Swingedouw, D.; Landais, A.;

    2012-01-01

    Climate archives available from deep-sea and marine shelf sediments, glaciers, lakes and ice cores in and around Greenland allow us to place the current trends in regional climate, ice sheet dynamics, and land surface changes in a broader perspective. We show that during the last decade (2000s......), atmospheric and sea-surface temperatures are reaching levels last encountered millennia ago when northern high latitude summer insolation was higher due to a different orbital configuration. Concurrently, records from lake sediments in southern Greenland document major environmental and climatic conditions...... regional climate and ice sheet dynamics. The magnitude and rate of future changes in Greenland temperature, in response to increasing greenhouse gas emissions, may be faster than any past abrupt events occurring under interglacial conditions. Projections indicate that within one century Greenland may...

  12. Climate change

    Marchal, V.; Dellink, R.; Vuuren, D.P. van; Clapp, C.; Chateau, J.; Magné, B.; Lanzi, E.; Vliet, J. van

    2012-01-01

    This chapter analyses the policy implications of the climate change challenge. Are current emission reduction pledges made in Copenhagen/Cancun enough to stabilise the climate and limit global average temperature increase to 2 oC? If not, what will the consequences be? What alternative growth pathwa

  13. Climate change

    Based on contributions on 120 French and foreign scientists representing different disciplines (mathematics, physics, mechanics, chemistry, biology, medicine, and so on), this report proposes an overview of the scientific knowledge and debate about climate change. It discusses the various indicators of climate evolution (temperatures, ice surfaces, sea level, biological indicators) and the various factors which may contribute to climate evolution (greenhouse gases, solar radiation). It also comments climate evolutions in the past as they can be investigated through some geological, thermal or geochemical indicators. Then, the authors describe and discuss the various climate mechanisms: solar activity, oceans, ice caps, greenhouse gases. In a third part, the authors discuss the different types of climate models which differ by the way they describe processes, and the current validation process for these models

  14. Detection of Abrupt Changes in Runoff in the Weihe River Basin

    Yanling Li

    2016-01-01

    Full Text Available Climate change and human activities are two major driving factors for variations in hydrological patterns globally, and it is of significant importance to distinguish their effects on the change of hydrological regime in order to formulate robust water management strategies. Hilbert-Huang transform-based time-frequency analysis is employed in this study to detect abrupt changes and periods of the runoff at five hydrological stations in the Weihe River Basin, China, from 1951 to 2010. The key part of the method is the empirical decomposition mode with which any complicated data set can be decomposed into small number of intrinsic mode functions that admit well adaptive Hilbert transforms. Moreover, an attempt has been made to find out the specific reason for the abrupt point at the five hydrological stations in the Weihe River Basin. The results are presented as follows: (1 annual runoff significantly declined in the basin in intervals of 8~15 years; (2 abrupt changes occurred in 1971, 1982, and 1994 at Huaxian, 1972 and 1982 at Xianyang, 1992 at Zhangjiashan, 1990 at Zhuangtou, and 1984 at Beidao; (3 changes were more frequent and complex in the mainstream and downstream reaches than in tributaries and upstream reaches, respectively.

  15. As climate changes, so do glaciers

    Lowell, Thomas V.

    2000-01-01

    Understanding abrupt climate changes requires detailed spatial/temporal records of such changes, and to make these records, we need rapidly responding, geographically widespread climate trackers. Glacial systems are such trackers, and recent additions to the stratigraphic record show overall synchronous response of glacial systems to climate change reflecting global atmosphere conditions.

  16. Modeling Abrupt Change in Global Sea Level Arising from Ocean - Ice-Sheet Interaction

    David M Holland

    2011-09-24

    It is proposed to develop, validate, and apply a coupled ocean ice-sheet model to simulate possible, abrupt future change in global sea level. This research is to be carried out collaboratively between an academic institute and a Department of Energy Laboratory (DOE), namely, the PI and a graduate student at New York University (NYU) and climate model researchers at the Los Alamos National Laboratory (LANL). The NYU contribution is mainly in the area of incorporating new physical processes into the model, while the LANL efforts are focused on improved numerics and overall model development. NYU and LANL will work together on applying the model to a variety of modeling scenarios of recent past and possible near-future abrupt change to the configuration of the periphery of the major ice sheets. The project's ultimate goal is to provide a robust, accurate prediction of future global sea level change, a feat that no fully-coupled climate model is currently capable of producing. This proposal seeks to advance that ultimate goal by developing, validating, and applying a regional model that can simulate the detailed processes involved in sea-level change due to ocean“ ice-sheet interaction. Directly modeling ocean ice-sheet processes in a fully-coupled global climate model is not a feasible activity at present given the near-complete absence of development of any such causal mechanism in these models to date.

  17. Climatic change

    In spite of man's remarkable advances in technology, ultimately he is still dependent on the Earth's climatic system for food and fresh water. The recent occurrences in certain regions of the world of climatic extremes such as excessive rain or droughts and unseasonably high or low temperatures have led to speculation that a major climatic change is occurring on a global scale. Some point to the recent drop in temperatures in the northern hemisphere as an indication that the Earth is entering a new ice age. Others see a global warming trend that may be due to a build-up of carbon dioxide in the atmosphere. An authoritative report on the subject has been prepared by a World Meteorological Organization Panel of Experts on Climatic Change. Excerpts from the report are given. (author)

  18. Climatic change

    This book proposes both a scientific and societal approach of a phenomenon which is today the object of lot of debates. Climates perception is illustrated with examples taken in various modern civilizations and in the history of mankind. The Sahara example illustrates the notion of climate evolution. The last chapters are devoted to forecasting and scenarios for the future, taking into account the share of uncertainty. The controversies generated by these forecasts and the Kyoto protocol stakes demonstrate the tight links between the scientific, economical and political aspects in climatic change debates. (J.S.)

  19. Climate change

    NONE

    2006-07-01

    This paper presented indicators of climate change for British Columbia (BC) with an emphasis on the coastal region. An overview of global effects of climate change was presented, as well as details of BC's current climate change action plan. Indicators examined in the paper for the BC coastal region included long-term trends in air temperature; long-term trends in precipitation; coastal ocean temperatures; sea levels on the BC coast; and the sensitivity of the BC coast to sea level rise and erosion. Data suggested that average air temperatures have become higher in many areas, and that Springtime temperatures have become warmer over the whole province. Winters have become drier in many areas of the province. Sea surface temperature has risen over the entire coast, with the North Coast and central Strait of Georgia showing the largest increases. Deep-water temperatures have also increased in 5 inlets on the South Coast. Results suggested that the direction and spatial pattern of the climate changes reported for British Columbia are consistent with broader trends in North America and the type of changes predicted by climate models for the region. Climate change will likely result in reduced snow-pack in southern BC. An earlier spring freshet on many snow-dominated river systems is anticipated as well as glacial retreat and disappearance. Warmer temperatures in some lakes and rivers are expected, as well as the increased frequency and severity of natural disturbances such as the pine mountain beetle. Large-scale shifts in ecosystems and the loss of certain ecosystems may also occur. BC's current climate plan includes cost effective actions that address GHG emissions and support efficient infrastructure and opportunities for innovation. Management programs for forest and agricultural lands have been initiated, as well as programs to reduce emissions from government operations. Research is also being conducted to understand the impacts of climate change on

  20. Climate change

    This paper presented indicators of climate change for British Columbia (BC) with an emphasis on the coastal region. An overview of global effects of climate change was presented, as well as details of BC's current climate change action plan. Indicators examined in the paper for the BC coastal region included long-term trends in air temperature; long-term trends in precipitation; coastal ocean temperatures; sea levels on the BC coast; and the sensitivity of the BC coast to sea level rise and erosion. Data suggested that average air temperatures have become higher in many areas, and that Springtime temperatures have become warmer over the whole province. Winters have become drier in many areas of the province. Sea surface temperature has risen over the entire coast, with the North Coast and central Strait of Georgia showing the largest increases. Deep-water temperatures have also increased in 5 inlets on the South Coast. Results suggested that the direction and spatial pattern of the climate changes reported for British Columbia are consistent with broader trends in North America and the type of changes predicted by climate models for the region. Climate change will likely result in reduced snow-pack in southern BC. An earlier spring freshet on many snow-dominated river systems is anticipated as well as glacial retreat and disappearance. Warmer temperatures in some lakes and rivers are expected, as well as the increased frequency and severity of natural disturbances such as the pine mountain beetle. Large-scale shifts in ecosystems and the loss of certain ecosystems may also occur. BC's current climate plan includes cost effective actions that address GHG emissions and support efficient infrastructure and opportunities for innovation. Management programs for forest and agricultural lands have been initiated, as well as programs to reduce emissions from government operations. Research is also being conducted to understand the impacts of climate change on water

  1. Extreme temperatures, foundation species, and abrupt ecosystem change: an example from an iconic seagrass ecosystem.

    Thomson, Jordan A; Burkholder, Derek A; Heithaus, Michael R; Fourqurean, James W; Fraser, Matthew W; Statton, John; Kendrick, Gary A

    2015-04-01

    Extreme climatic events can trigger abrupt and often lasting change in ecosystems via the reduction or elimination of foundation (i.e., habitat-forming) species. However, while the frequency/intensity of extreme events is predicted to increase under climate change, the impact of these events on many foundation species and the ecosystems they support remains poorly understood. Here, we use the iconic seagrass meadows of Shark Bay, Western Australia--a relatively pristine subtropical embayment whose dominant, canopy-forming seagrass, Amphibolis antarctica, is a temperate species growing near its low-latitude range limit--as a model system to investigate the impacts of extreme temperatures on ecosystems supported by thermally sensitive foundation species in a changing climate. Following an unprecedented marine heat wave in late summer 2010/11, A. antarctica experienced catastrophic (>90%) dieback in several regions of Shark Bay. Animal-borne video footage taken from the perspective of resident, seagrass-associated megafauna (sea turtles) revealed severe habitat degradation after the event compared with a decade earlier. This reduction in habitat quality corresponded with a decline in the health status of largely herbivorous green turtles (Chelonia mydas) in the 2 years following the heat wave, providing evidence of long-term, community-level impacts of the event. Based on these findings, and similar examples from diverse ecosystems, we argue that a generalized framework for assessing the vulnerability of ecosystems to abrupt change associated with the loss of foundation species is needed to accurately predict ecosystem trajectories in a changing climate. This includes seagrass meadows, which have received relatively little attention in this context. Novel research and monitoring methods, such as the analysis of habitat and environmental data from animal-borne video and data-logging systems, can make an important contribution to this framework. PMID:25145694

  2. Climate Change: Basic Information

    ... are here: EPA Home Climate Change Basic Information Climate Change: Basic Information On This Page Climate change ... We can make a difference How is the climate changing in the U.S.? Observations across the United ...

  3. Climate change

    The indicators in this bulletin are part of a national set of environmental indicators designed to provide a profile of the state of Canada's environment and measure progress towards sustainable development. A review of potential impacts on Canada shows that such changes would have wide-ranging implications for its economic sectors, social well-being including human health, and ecological systems. This document looks at the natural state of greenhouse gases which help regulate the Earth's climate. Then it looks at human influence and what is being done about it. The document then examines some indicators: Carbon dioxide emissions from fossil fuel use; global atmospheric concentrations of greenhouse gases; and global and Canadian temperature variations

  4. Abrupt decadal-to-centennial hydroclimate changes in the Mediterranean region since the mid-Holocene

    Hu, Hsun-Ming; Shen, Chuan-Chou; Jiang, Xiuyang; Wang, Yongjin; Mii, Horng-Sheng; Michel, Véronique

    2016-04-01

    A series of severe drought events in the Mediterranean region over the past two decades has posed a threat on both human society and biosystem. Holocene hydrological dynamics can offer valuable clues for understanding future climate and making proper adaption strategy. Here, we present a decadal-resolved stalagmite record documenting various hydroclimatic fluctuations in the north central Mediterranean region since the middle Holocene. The stalagmite δ18O sequence shows dramatic instability, characterized by abrupt shifts between dry and wet conditions Greece, Akkadian Empire, Egyptian Old Kingdom, and Uruk, occurred during the drought events, suggesting an important role of climate impact on human civilization. The unstable hydroclimate evolution is related to transferred North Atlantic Oscillation states. Rate of rapid transfer of precipitation patterns, which can be pin-pointed by our good chronology, improves the prediction to future climate changes in North Atlantic region. We also found that a strong correlation between this stalagmite δ18O and sea surface temperatures especially in Pacific Ocean. This agreement suggests a distant interregional climate teleconnection.

  5. Holocene megathermal abrupt environmental changes derived from 14C dating of a coral reef at Leizhou Peninsula, South China Sea

    A depth profile of a Goniopora coral reef at Leizhou Peninsula, South China Sea, was radiocarbon dated using liquid scintillation counting (LSC) and accelerator mass spectrometry (AMS). The time of formation, during 6600-7400 cal BP, can be divided into nine stages, each terminated by abrupt growth cessation of Goniopora and appearance of Ostrea shells. The results show that, during the Holocene megathermal (8.2-3.3 ka BP), large climatic changes have occurred in the South China Sea area

  6. Spatiotemporal Variation and Abrupt Change Analysis of Temperature from 1960 to 2012 in the Huang-Huai-Hai Plain, China

    Yanyu Yin

    2015-01-01

    Full Text Available Based on a monthly dataset of temperature time series (1960–2012 in the Huang-Huai-Hai Plain of China (HHHPC, spatiotemporal variation and abrupt change analysis of temperature were examined by moving average, linear regression, spline interpolation, Mann-Kendall test, and moving t-test. Major conclusions were listed as follows. (1 Annual and seasonal temperature increased with different rates on the process of fluctuating changes during 1960~2012. The upward trend was 0.22°C 10a−1 for annual temperature, while it was very significant in winter (0.34°C 10a−1 and spring (0.31°C 10a−1, moderately significant in autumn (0.21°C 10a−1, and nonsignificant in summer (0.05°C 10a−1. (2 The spatial changes of annual and seasonal temperature were similar. The temperature increased significantly in Beijing and its adjacent regions, while it was nonsignificant in the central and southern regions. (3 The spring, autumn, winter, and annual temperature had warm abrupt change. The abrupt change time for winter temperature was in the late 1970s, while it was in the late 1980s and early 1990s for spring, autumn, and annual temperature. (4 Macroscopic effects of global and regional climate warming and human activities were probably responsible for the temperature changes. The climate warming would influence the hydrological cycle and agricultural crops in the study area.

  7. Changing climate, changing frames

    Highlights: ► We show development of flood policy frames in context of climate change attention. ► Rising attention on climate change influences traditional flood policy framing. ► The new framing employs global-scale scientific climate change knowledge. ► With declining attention, framing disregards climate change, using local knowledge. ► We conclude that frames function as sensemaking devices selectively using knowledge. -- Abstract: Water management and particularly flood defence have a long history of collective action in low-lying countries like the Netherlands. The uncertain but potentially severe impacts of the recent climate change issue (e.g. sea level rise, extreme river discharges, salinisation) amplify the wicked and controversial character of flood safety policy issues. Policy proposals in this area generally involve drastic infrastructural works and long-term investments. They face the difficult challenge of framing problems and solutions in a publicly acceptable manner in ever changing circumstances. In this paper, we analyse and compare (1) how three key policy proposals publicly frame the flood safety issue, (2) the knowledge referred to in the framing and (3) how these frames are rhetorically connected or disconnected as statements in a long-term conversation. We find that (1) framings of policy proposals differ in the way they depict the importance of climate change, the relevant timeframe and the appropriate governance mode; (2) knowledge is selectively mobilised to underpin the different frames and (3) the frames about these proposals position themselves against the background of the previous proposals through rhetorical connections and disconnections. Finally, we discuss how this analysis hints at the importance of processes of powering and puzzling that lead to particular framings towards the public at different historical junctures

  8. Climate Change

    2005-01-01

    According to the National Academy of Sciences in American,the Earth's surface temperature has risen by about 1 degree Fahrenheit in the past century, with accelerated warming during the past two decades. There is new and stronger evidence that most of the warming over the last 50 years is attributable to human activities.Human activities have altered the chemical composition of the atmosphere through the buildup of greenhouse gases-primarily carbon dioxide, methane, and nitrous oxide. The heat-trapping property of these gases is undisputed although uncertainties exist about exactly how earth's climate responds to them.

  9. Bayesian analysis to detect abrupt changes in extreme hydrological processes

    Jo, Seongil; Kim, Gwangsu; Jeon, Jong-June

    2016-07-01

    In this study, we develop a new method for a Bayesian change point analysis. The proposed method is easy to implement and can be extended to a wide class of distributions. Using a generalized extreme-value distribution, we investigate the annual maximum of precipitations observed at stations in the South Korean Peninsula, and find significant changes in the considered sites. We evaluate the hydrological risk in predictions using the estimated return levels. In addition, we explain that the misspecification of the probability model can lead to a bias in the number of change points and using a simple example, show that this problem is difficult to avoid by technical data transformation.

  10. GEOMAGNETIC REVERSALS DRIVEN BY ABRUPT SEA LEVEL CHANGES

    Muller, R.A.; Morris, D.E.

    1986-10-01

    Changes in the moment of inertia of the earth, brought about by the redistribution of ocean water from the tropics to ice at high latitudes, couple energy from the spin of the earth into convection in the liquid core. This mechanism may help provide the driving energy for the earth's dynamo. Sufficiently rapid ocean level changes can disrupt the dynamo, resulting (in half of the cases) in a geomagnetic field reversal. The model can account for the previously mysterious correlation reported between geomagnetic reversals and mass extinctions.

  11. Climate variability and climate change

    Changes of variability with climate change are likely to have a substantial impact on vegetation and society, rivaling the importance of changes in the mean values themselves. A variety of paleoclimate and future climate simulations performed with the GISS global climate model is used to assess how the variabilities of temperature and precipitation are altered as climate warms or cools. In general, as climate warms, temperature variability decreases due to reductions in the latitudinal temperature gradient and precipitation variability increases together with the intensity of the hydrologic cycle. If future climate projections are accurate, the reduction in temperature variability will be minimized by the rapid change in mean temperatures, but the hydrologic variability will be amplified by increased evapotranspiration. Greater hydrologic variability would appear to pose a potentially severe problem for the next century. 19 refs.; 3 figs.; 2 tabs

  12. Climate variability and climate change

    Changes of variability with climate change are likely to have a substantial impact on vegetation and society, rivaling the importance of changes in the mean values themselves. A variety of paleoclimate and future climate simulations performed with the GISS global climate model is used to assess how the variabilities of temperature and precipitation are altered as climate warms or cools. In general, as climate warms, temperature variability decreases due to reductions in the latitudinal temperature gradient and precipitation variability increases together with the intensity of the hydrologic cycle. If future climate projections are accurate, the reduction in temperature variability will be minimized by the rapid change in mean temperatures, but the hydrologic variability will be amplified by increased evapotranspiration. Greater hydrologic variability would appear to pose a potentially severe problem for the next century

  13. Climatic changes

    Majgaard Krarup, Jonna

    2014-01-01

    are now ques-tioning this. Measurements as dykes will changes or cut off the spatial and func-tional coherence between the city structure and the sea. Questions regarding the status and the appropriation of these ‘new’ adaptive func-tions in landscapes and open urban spaces by ordinary people must...

  14. Climate changes your business

    Businesses face much bigger climate change costs than they realise. That is the conclusion of Climate Changes Your Business. The climate change risks that companies should be paying more attention to are physical risks, regulatory risks as well as risk to reputation and the emerging risk of litigation, says the report. It argues that the risks associated with climate change tend to be underestimated

  15. Climate Change Schools Project...

    McKinzey, Krista

    2010-01-01

    This article features the award-winning Climate Change Schools Project which aims to: (1) help schools to embed climate change throughout the national curriculum; and (2) showcase schools as "beacons" for climate change teaching, learning, and positive action in their local communities. Operating since 2007, the Climate Change Schools Project…

  16. CLIMATE CHANGE, Change International Negociations?

    Gao Xiaosheng

    2009-01-01

    @@ Climate change is one of key threats to human beings who have to deal with.According to Bali Action Plan released after the 2007 Bali Climate Talk held in Indonesia,the United Nations Framework on Climate Change(UNFCCC) has launched a two-year process to negotiate a post-2012 climate arrangement after the Kyoto Protocol expires in 2012 and the Copenhagen Climate Change Conference will seal a final deal on post-2012 climate regime in December,2009.For this,the United Nation Chief Ban Ki Moon called 2009"the year ofclimate change".

  17. Use of abrupt strain path change for determining subsequent yield surface

    Kuwabara, T.; Kuroda, M.; Tvergaard, Viggo;

    2000-01-01

    biaxial tensile testing apparatus, a cruciform specimen is used, with the strains measured by a biaxial-strain gauge. Then, with the hydraulic pressure of two sets of opposing hydraulic cylinders servo-controlled independently, the testing apparatus can be used to prescribe an abrupt change of the strain...

  18. Glass heat capacity and its abrupt change in glass transition region

    Yue, Yuanzheng; Smedskjær, Morten Mattrup; Mauro, John C.

    Glass transition (GT) has been a fascinating, but challenging subject in the condensed matter science over decades. Despite progress in understanding GT, many crucial problems still need to be clarified. One of the problems deals with the microscopic origin of abrupt change of heat capacity (Cp...

  19. Climate change and climate policy

    The climate issue is a great political and scientific challenge for several reasons: (1) There are many uncertain aspects of the climate problem, such as future emission of climate gases, the response of the climate system upon these gases, and the effects of climate changes. (2) It is probable, however, that anthropogenic emission of climate gases, deforestation etc. will cause noticeable climate changes in the future. This might be observed as increased frequency of extreme weather situations. This appears to be a greater threat than a gradual increase of temperature and precipitation. (3) Since the climate system is large and react only relatively slowly on changes in for instance the emission of climate gases, the climate problem can only be solved by means of long-term measures. (4) The climate changes may be irreversible. A rational short-term strategy is to ensure maximum flexibility, which can be done by ''slowing down'' (curtailing emissions) and by avoiding irreversible actions as much as possible. The long-term challenge is to develop an economically responsible alternative to the present fossil-based energy system that permits carbon-efficient technologies to compete on price with coal and unconventional oil and gas. Norway is in a special position by being a large exporter of fossil fuel and at the same time wanting to appear responsible in environmental matters. This combination may incur considerable expenses upon Norway and it is therefore important that environmental commitments like the Kyoto agreement can be honoured to the lowest possible cost. The costs can be minimized by: (1) minimizing the measure costs in Norway, (2) working to make the international quota price as low as possible, and (3) reducing the loss of petroleum income as much as possible. This report describes the earth's climate history, the forces behind climatic changes and what the prospects for the future look like. It also reviews what is being done to curtail the emission of

  20. Climate engineering and the risk of rapid climate change

    Recent research has highlighted risks associated with the use of climate engineering as a method of stabilizing global temperatures, including the possibility of rapid climate warming in the case of abrupt removal of engineered radiative forcing. In this study, we have used a simple climate model to estimate the likely range of temperature changes associated with implementation and removal of climate engineering. In the absence of climate engineering, maximum annual rates of warming ranged from 0.015 to 0.07 deg. C/year, depending on the model's climate sensitivity. Climate engineering resulted in much higher rates of warming, with the temperature change in the year following the removal of climate engineering ranging from 0.13 to 0.76 deg. C. High rates of temperature change were sustained for two decades following the removal of climate engineering; rates of change of 0.5 (0.3,0.1) deg. C/decade were exceeded over a 20 year period with 15% (75%, 100%) likelihood. Many ecosystems could be negatively affected by these rates of temperature change; our results suggest that climate engineering in the absence of deep emissions cuts could arguably constitute increased risk of dangerous anthropogenic interference in the climate system under the criteria laid out in the United Nations Framework Convention on Climate Change.

  1. Late Oligocene sedimentary environments and provenance abrupt change event in the northern South China Sea

    2008-01-01

    A significant change in composition was recorded in late Oligocene sediments from the northern South China Sea.This abrupt event coincided with the seafloor spreading axis jump across the Oligocene/Miocene boundary,leading to sedimentation breaks and slumps as well as obvious changes in sediment geochemical composition,and representing the greatest tectonic activity in the South China Sea region since the Oligocene.Through this tectonic event,the sedimentary environment in the Baiyun sag area transformed from a continental shelf in the late Oligocene to a continental slope since the early Miocene,the provenance of the sediments changed from neighboring areas to the hinterland of the South China block,and the sea level rose since the early Miocene in the area.Therefore,this abrupt change event has a profound influence on the evolution of petroleum offshore in the northern South China Sea.

  2. Residual strength of WC-Co cemented carbides after being subjected to abrupt temperature changes

    Tarragó Cifre, Jose María; Serra, Ignacio; Al-Dawery, Ihsan; Llanes Pitarch, Luis Miguel

    2014-01-01

    Thermal shock and thermal fatigue are recognized as common failure modes for WC - Co cemented carbides (hardmetals) in several applications in volving service temperature changes. However, information on microstructure - performance for these materials when subjected to abrupt changes in temper ature is rather limited. In this investigation, the thermal shock resistance of two WC - Co cemented carbides is studied on the basis of their resi...

  3. Climate Change and Health

    ... 2014 Fact sheets Features Commentaries 2014 Multimedia Contacts Climate change and health Fact sheet Reviewed June 2016 ... in improved health, particularly through reduced air pollution. Climate change Over the last 50 years, human activities – ...

  4. Use of abrupt strain path change for determining subsequent yield surface

    Kuwabara, T.; Kuroda, M.; Tvergaard, Viggo; Nomura, K.

    2000-01-01

    biaxial tensile testing apparatus, a cruciform specimen is used, with the strains measured by a biaxial-strain gauge. Then, with the hydraulic pressure of two sets of opposing hydraulic cylinders servo-controlled independently, the testing apparatus can be used to prescribe an abrupt change of the strain......A basic idea for a method for determining the subsequent yield surface in the vicinity of a current loading point by using an abrupt strain path change has been proposed recently by Kuroda and Tvergaard (Acta mater., 1999, 47, 3879). The proposed method is applied to real experimental studies. In a...... path. Both a cold-rolled steel sheet and an aluminum alloy sheet are investigated. The differences between the yield surface shapes found by the strain path change procedure and the shapes found by probing the yield points from the elastic region are shown and discussed for different cases. (C) 2000...

  5. Climate and Change

    Roger S. Pulwarty

    2011-01-01

    A presentation about the basics of climate change - the science, the impacts, and the consequences. The focus is on water and the Caribbean in particular but the information is general. It includes information about climate change mitigation and climate change adaptation.

  6. Rethinking species’ ability to cope with rapid climate change

    Hof, Christian; Levinsky, Irina; Bastos Araujo, Miguel;

    2011-01-01

    Ongoing climate change is assumed to be exceptional because of its unprecedented velocity. However, new geophysical research suggests that dramatic climatic changes during the Late Pleistocene occurred extremely rapid, over just a few years. These abrupt climatic changes may have been even faster...... species' ability to cope with climate change, and that lessons must be learned for modelling future impacts of climate change on species....... than contemporary ones, but relatively few continent-wide extinctions of species have been documented for these periods. This raises questions about the ability of extant species to adapt to ongoing climate change. We propose that the advances in geophysical research challenge current views about...

  7. A Fast Framework for Abrupt Change Detection Based on Binary Search Trees and Kolmogorov Statistic

    Qi, Jin-Peng; Qi, Jie; Zhang, Qing

    2016-01-01

    Change-Point (CP) detection has attracted considerable attention in the fields of data mining and statistics; it is very meaningful to discuss how to quickly and efficiently detect abrupt change from large-scale bioelectric signals. Currently, most of the existing methods, like Kolmogorov-Smirnov (KS) statistic and so forth, are time-consuming, especially for large-scale datasets. In this paper, we propose a fast framework for abrupt change detection based on binary search trees (BSTs) and a modified KS statistic, named BSTKS (binary search trees and Kolmogorov statistic). In this method, first, two binary search trees, termed as BSTcA and BSTcD, are constructed by multilevel Haar Wavelet Transform (HWT); second, three search criteria are introduced in terms of the statistic and variance fluctuations in the diagnosed time series; last, an optimal search path is detected from the root to leaf nodes of two BSTs. The studies on both the synthetic time series samples and the real electroencephalograph (EEG) recordings indicate that the proposed BSTKS can detect abrupt change more quickly and efficiently than KS, t-statistic (t), and Singular-Spectrum Analyses (SSA) methods, with the shortest computation time, the highest hit rate, the smallest error, and the highest accuracy out of four methods. This study suggests that the proposed BSTKS is very helpful for useful information inspection on all kinds of bioelectric time series signals. PMID:27413364

  8. Characterizing abrupt changes in the stock prices using a wavelet decomposition method

    Caetano, Marco Antonio Leonel; Yoneyama, Takashi

    2007-09-01

    Abrupt changes in the stock prices, either upwards or downwards, are usually preceded by an oscillatory behavior with frequencies that tend to increase as the moment of transition becomes closer. The wavelet decomposition methods may be useful for analysis of this oscillations with varying frequencies, because they provide simultaneous information on the frequency (scale) and localization in time (translation). However, in order to use the wavelet decomposition, certain requirements have to be satisfied, so that the linear and cyclic trends are eliminated by standard least squares techniques. The coefficients obtained by the wavelet decomposition can be represented in a graphical form. A threshold can then be established to characterize the likelihood of a short-time abrupt change in the stock prices. Actual data from the São Paulo Stock Exchange (Bolsa de Valores de São Paulo) were used in this work to illustrate the proposed method.

  9. Climate for Change?

    Wejs, Anja

    Cities rather than national governments take the lead in acting on climate change. Several cities have voluntarily created climate change plans to prevent and prepare for the effects of climate change. In the literature climate change has been examined as a multilevel governance area taking place...... around international networks. Despite the many initiatives taken by cities, existing research shows that the implementation of climate change actions is lacking. The reasons for this scarcity in practice are limited to general explanations in the literature, and studies focused on explaining...... the constraints on climate change planning at the local level are absent. To understand these constraints, this PhD thesis investigates the institutional dynamics that influence the process of the integration of climate change into planning practices at the local level in Denmark. The examination of integration...

  10. Our changing climate

    The author presents an overview of the changing climate. Attention is focused on the following: meteorology; weather; climate anomalies; changes in atmospheric composition and global warming; ozone; mathematical models; and climate and politics. In its conclusion, it asks researchers to stay out of a game in which, ultimately, neither science nor politics stands to gain anything

  11. Final Scientific Report for "The Interhemispheric Pattern in 20th Century and Future Abrupt Change in Regional Tropical Rainfall"

    Chiang, John C. H. [University of California, Berkeley, CA (United States); Wehner, Michael F. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-10-29

    This is the final scientific report for grant DOE-FG02-08ER64588, "The Interhemispheric Pattern in 20th Century and Future Abrupt Change in Regional Tropical Rainfall."The project investigates the role of the interhemispheric pattern in surface temperature – i.e. the contrast between the northern and southern temperature changes – in driving rapid changes to tropical rainfall changes over the 20th century and future climates. Previous observational and modeling studies have shown that the tropical rainband – the Intertropical Convergence Zone (ITCZ) over marine regions, and the summer monsoonal rainfall over land – are sensitive to the interhemispheric thermal contrast; but that the link between the two has not been applied to interpreting long-term tropical rainfall changes over the 20th century and future.The specific goals of the project were to i) develop dynamical mechanisms to explain the link between the interhemispheric pattern to abrupt changes of West African and Asian monsoonal rainfall; ii) Undertake a formal detection and attribution study on the interhemispheric pattern in 20th century climate; and iii) assess the likelihood of changes to this pattern in the future. In line with these goals, our project has produced the following significant results: 1.We have developed a case that suggests that the well-known abrupt weakening of the West African monsoon in the late 1960s was part of a wider co-ordinated weakening of the West African and Asian monsoons, and driven from an abrupt cooling in the high latitude North Atlantic sea surface temperature at the same time. Our modeling work suggests that the high-latitude North Atlantic cooling is effective in driving monsoonal weakening, through driving a cooling of the Northern hemisphere that is amplified by positive radiative feedbacks. 2.We have shown that anthropogenic sulfate aerosols may have partially contributed to driving a progressively southward displacement of the Atlantic Intertropical

  12. Mathematics of Climate Change

    Halstadtrø, Ida

    2013-01-01

    Mathematics in climate research is rarely mentioned in the everyday conversations or in the media when talking about climate changes. This thesis therefore focus on the central role mathematics plays in climate research, through describing the different models used in predicting future weather and climate. In Chapter 1, a general introduction to climate, its components and feedbacks, and today's status is given. Chapter 2 concentrates on the dynamical models represented by ordinary differenti...

  13. Abrupt changes in photospheric magnetic and Lorentz-force vectors during neutral-line flares

    Petrie, Gordon

    2012-01-01

    We analyze the spatial and temporal variations of the abrupt photospheric magnetic changes associated with six major flares using 12-minute, 0.5-arcsec vector magnetograms from NASA's Helioseismic and Magnetic Imager instrument (HMI) on the Solar Dynamics Observatory satellite. The six major flares occurred near the main magnetic neutral lines of four active regions, NOAA 11158, 11166, 11283 and 11429. During all six flares the neutral line field vectors became stronger and more horizontal, in each case almost entirely due to strengthening of the horizontal field components parallel to the neutral line. In all six cases the neutral line pre-flare fields were more vertical than the reference potential fields, and collapsed abruptly and permanently closer to potential field tilt angles during every flare, implying that the relaxation of magnetic stress associated with non-potential tilt angles plays a major role during major flares. The shear angle with respect to the reference potential field did not show such...

  14. Climate Change Policy

    Jepma, Catrinus J.; Munasinghe, Mohan; Bolin, Foreword By Bert; Watson, Robert; Bruce, James P.

    1998-03-01

    There is increasing scientific evidence to suggest that humans are gradually but certainly changing the Earth's climate. In an effort to prevent further damage to the fragile atmosphere, and with the belief that action is required now, the scientific community has been prolific in its dissemination of information on climate change. Inspired by the results of the Intergovernmental Panel on Climate Change's Second Assessment Report, Jepma and Munasinghe set out to create a concise, practical, and compelling approach to climate change issues. They deftly explain the implications of global warming, and the risks involved in attempting to mitigate climate change. They look at how and where to start action, and what organization is needed to be able to implement the changes. This book represents a much needed synopsis of climate change and its real impacts on society. It will be an essential text for climate change researchers, policy analysts, university students studying the environment, and anyone with an interest in climate change issues. A digestible version of the IPCC 1995 Economics Report - written by two of IPCC contributors with a Foreword by two of the editors of Climate Change 1995: Economics of Climate Change: i.e. has unofficial IPCC approval Focusses on policy and economics - important but of marginal interest to scientists, who are more likely to buy this summary than the full IPCC report itself Has case-studies to get the points across Separate study guide workbook will be available, mode of presentation (Web or book) not yet finalized

  15. Asking about climate change

    Nielsen, Jonas Østergaard; D'haen, Sarah Ann Lise

    2014-01-01

    There is increasing evidence that climate change will strongly affect people across the globe. Likely impacts of and adaptations to climate change are drawing the attention of researchers from many disciplines. In adaptation research focus is often on perceptions of climate change...... and on vulnerability and adaptation strategies in a particular region or community. But how do we research the ways in which people experience changing climatic conditions, the processes of decision-making, the actual adaptation strategies carried out and the consequences of these for actors living and dealing...... with climate change? On the basis of a literature review of all articles published in Global Environmental Change between 2000 and 2012 that deal with human dimensions of climate change using qualitative methods this paper provides some answers but also raises some concerns. The period and length of fieldwork...

  16. Liquid concentration distribution and planar interface instability at an abruptly changing pulling velocity in directional solidification

    LI ShuangMing; FU HengZhi

    2007-01-01

    Liquid concentration distribution is seriously affected by an abruptly changing pulling velocity under directional solidification. Theoretical and numerical investigations indicate that at the pulling velocity jumping from V0 to V, the solidification system does not achieve the pulling velocity V immediately, and it goes through a non-steady-state transition zone. As the pulling velocity abruptly increases (V/V0 > 1), interface liquid concentration firstly increases to the maximum and then decreases to the steady-state value. The magnitude of interface liquid concentration at the beginning increases with V/V0, the initial pulling velocity V0 and the temperature gradient GL in the liquid. At the same time, solute diffusion length reduces with V/V0 and GL. In contrast, the minimum of interface liquid concentration falls with V/V0 at the pulling velocity decreasing abruptly. As the interface liquid concentration enriched at V/V0 > 1 is more than the value required for the planar interface to keep stable, the solid/liquid interface may become unstable. The analytical results are in agreement with the numerical calculation results of Al-2%Cu alloy.

  17. Liquid concentration distribution and planar interface instability at an abruptly changing pulling velocity in directional solidification

    2007-01-01

    Liquid concentration distribution is seriously affected by an abruptly changing pulling velocity under directional solidification. Theoretical and numerical investi-gations indicate that at the pulling velocity jumping from V0 to V, the solidification system does not achieve the pulling velocity V immediately, and it goes through a non-steady-state transition zone. As the pulling velocity abruptly increases (V/V0 > 1), interface liquid concentration firstly increases to the maximum and then de-creases to the steady-state value. The magnitude of interface liquid concentration at the beginning increases with V/V0, the initial pulling velocity V0 and the tem-perature gradient GL in the liquid. At the same time, solute diffusion length reduces with V/V0 and GL. In contrast, the minimum of interface liquid concentration falls with V/V0 at the pulling velocity decreasing abruptly. As the interface liquid con-centration enriched at V/V0 > 1 is more than the value required for the planar inter-face to keep stable, the solid/liquid interface may become unstable. The analytical results are in agreement with the numerical calculation results of Al-2%Cu alloy.

  18. Forecasting abrupt changes in foreign exchange markets: method using dynamical network marker

    We apply the idea of dynamical network markers (Chen et al 2012 Sci. Rep. 2 342) to foreign exchange markets so that early warning signals can be provided for any abrupt changes. The dynamical network marker constructed achieves a high odds ratio for forecasting these sudden changes. In addition, we also extend the notion of the dynamical network marker by using recurrence plots so that the notion can be applied to delay coordinates and point processes. Thus, the dynamical network marker is useful in a variety of contexts in science, technology, and society. (paper)

  19. Abrupt changes in air temperature and precipitation - do they matter for organic matter?

    Temnerud, Johan; Weyhenmeyer, Gesa

    2007-01-01

    We analyzed 120 years long time series of air temperature and precipitation from 29 respective 44 sites distributed all over Sweden and determined abrupt changes (regime shifts) by using three different methods. The used methods are the Excel add-in ‘Sequential Regime Shift Detection version 3.2’ (SRSD), the software Change-Point Analyzer version 2.3 and the manually performed CUSUM/Pettit-test. Since all three methods revealed similar results we focused on the first method. The SRSD use year...

  20. Global vs climate change

    The various agents of global change that will affect the state of natural resources 50-100 years from now are discussed. These include economic and population growth, technological progress, and climatic change. The importance of climatic change lies in its effects on natural resources and on human activities that depend on those resources. Other factors affecting those resources include the demand on those resources from an increasing population and from a growing economy, and a more efficient use of those resources that comes from technological changes and from the consequences of economic growth itself. It is shown that there is a considerable ability to adapt to climatic change, since humans already have an intrinsic ability to adapt to the wide variations in climates that already exist and since technological developments can make it easier to cope with climatic variability. It appears that agents other than climatic change are more significant to the future state of natural resources than climatic change. Criteria for selecting options for addressing climatic change are outlined. Technological change and economic growth are seen to be key response options, since the vulnerability to climatic change depends on economic resources and technological progress. Specific options to stimulate sustainable economic growth and technological progress are listed. 16 refs., 1 fig., 2 tabs

  1. Our Changing Climate

    Newhouse, Kay Berglund

    2007-01-01

    In this article, the author discusses how global warming makes the leap from the headlines to the classroom with thought-provoking science experiments. To teach her fifth-grade students about climate change, the author starts with a discussion of the United States' local climate. They extend this idea to contrast the local climate with others,…

  2. Climate-driven shifts in continental net primary production implicated as a driver of a recent abrupt increase in the land carbon sink

    Buermann, Wolfgang; Beaulieu, Claudie; Parida, Bikash; Medvigy, David; Collatz, George J.; Sheffield, Justin; Sarmiento, Jorge L.

    2016-03-01

    The world's ocean and land ecosystems act as sinks for anthropogenic CO2, and over the last half century their combined sink strength grew steadily with increasing CO2 emissions. Recent analyses of the global carbon budget, however, have uncovered an abrupt, substantial ( ˜ 1 PgC yr-1) and sustained increase in the land sink in the late 1980s whose origin remains unclear. In the absence of this prominent shift in the land sink, increases in atmospheric CO2 concentrations since the late 1980s would have been ˜ 30 % larger than observed (or ˜ 12 ppm above current levels). Global data analyses are limited in regards to attributing causes to changes in the land sink because different regions are likely responding to different drivers. Here, we address this challenge by using terrestrial biosphere models constrained by observations to determine if there is independent evidence for the abrupt strengthening of the land sink. We find that net primary production significantly increased in the late 1980s (more so than heterotrophic respiration), consistent with the inferred increase in the global land sink, and that large-scale climate anomalies are responsible for this shift. We identify two key regions in which climatic constraints on plant growth have eased: northern Eurasia experienced warming, and northern Africa received increased precipitation. Whether these changes in continental climates are connected is uncertain, but North Atlantic climate variability is important. Our findings suggest that improved understanding of climate variability in the North Atlantic may be essential for more credible projections of the land sink under climate change.

  3. Climate change and forest ecosystem dynamics

    Effects of climate change on water relations in forests were studied using several modelling approaches. Of several models tested, the FORGRO model had the highest potential for a reliable estimation of effects of climate change on forests. An evaluation of process-based models of forest growth showed that several models, including FORGRO, were able to produce accurate estimates of carbon and water fluxes at several forest sites of Europe. Responses were in relatively good agreement with the expected responses obtained by experimental studies, and models were able to deal with new conditions and explore the likely effects of climate change. The effect of climate change on forest development was assessed for three forests stands in the Netherlands using a gap model which was made climate sensitive by including the effects of climate change scenario IPCC IS92A on growth (FORGRO results), phenology (FORGRO results), and seed production (regression analysis). Results showed that climate change is likely to cause subtle changes rather than abrupt changes in forest development in the Netherlands, and that forest development on sandy soils in the Netherlands is not likely to be influenced significantly by climate change over the coming 50 years. The impact of climate change on the production, nature and recreation values of forests was studied using a simple economic model, and showed that response are likely to be relatively small during the first century, and are related to the successional status of the forest. Linking of detailed process-based models with gap models enables interpretation of climate change effects beyond a change in tree growth only, and is an important tool for investigating the effects of climate change on the development of mixed forests. The modelling approach presented in this project (process-based growth models -> gap models -> economic model) is a useful tool to support policy decisions in the light of climate change and forests. refs

  4. Changes in extreme regional sea surface height due to an abrupt weakening of the Atlantic MOC

    S.-E. Brunnabend

    2014-04-01

    Full Text Available As an extreme scenario of dynamical sea level changes, regional sea surface height (SSH changes that occur in the North Atlantic due to an abrupt weakening of the Atlantic Meridional Overturning Circulation (AMOC are simulated. Two versions of the same ocean-only model are used to study the effect of ocean model resolution on these SSH changes: a high-resolution (HR strongly eddying version and a low-resolution (LR version in which the effect of eddies are parameterized. The weakening of the AMOC is induced in both model versions by applying strong freshwater perturbations around Greenland. A rapid decrease of the AMOC in the HR version induces much shorter return times of several specific regional and coastal extremes in North Atlantic SSH than in the LR version. This effect is caused by a change in main eddy pathways associated with a change in separation latitude of the Gulf Stream.

  5. Responses to abrupt changes in feeding and illumination in laying hens

    TAKEDA, ichi

    2010-01-01

    This study aimed to investigate the responses to abrupt changes in feeding and illumination during the egg-laying period. Six hens were housed individually in cages under constant environmental conditions, with a photoperiod of 15 h (0400-1900) and ad libitum access to food for 10 days. Then the same hens were subjected to a feed withdrawal trial (between 1200 and 0830), followed by a 5-h reduction in the photoperiod (0400-1400). The heart rate (HR), body temperature (BT), and locomotor activ...

  6. Climate and Global Change

    The present volume contains the lessons delivered at the course held in Arles, France, on the subject Climate and Global Change: natural variability of the geosphere and biosphere systems, biogeochemical cycles and their perturbation by human activities, monitoring and forecasting global changes (satellite observations, modelling,...). Short presentations of students' own research activities are also proposed (climatic fluctuation in the Mediterranean area, climate/vegetation relations, etc.)

  7. The changing climate

    A historical outline of climate changes is followed by a discussion of the problem of predictability. The main section goes into anthropogenic changes of the local (urban) and global climate, with particular regard to the greenhouse effect and its consequences in terms of human action. The author points out that today's climate problems should be discussed in a subject-centered and objective manner. (KW)

  8. Climate Change Crunch Time

    Xie Zhenhua

    2011-01-01

    CLIMATE change is a severe challenge facing humanity in the 21st century and thus the Chinese Government always attaches great importance to the problem.Actively dealing with climate change is China's important strategic policy in its social and economic development.China will make a positive contribution to the world in this regard.

  9. Climate for change

    Climate for Change: Non-State Actors and the Global Politics of the Greenhouse provides a challenging explanation of the forces that have shaped the international global warming debate. Unlike existing books on the politics of climate change, this book concentrates on how non-stage actors, such as scientific, environmental and industry groups, as opposed to governmental organisations, affect political outcomes in global fora on climate change. It also provides insights in to the role of the media in influencing the agenda. The book draws on a range of analytical approaches to assess and explain the influence of these non-governmental organisations in the course of global climate change politics. The book will be of interest to all researchers and policy-makers associated with climate change, and will be used on university courses in international relations, politics and environmental studies. (Author)

  10. Trade and climate change

    Tamiotti, L.; Teh, R.; Kulacoglu, V. (World Trade Organization (WTO), Geneva (Switzerland)); Olhoff, A.; Simmons, B.; Abaza, H. (United Nations Environment Programme (UNEP) (Denmark))

    2009-06-15

    The Report aims to improve understanding about the linkages between trade and climate change. It shows that trade intersects with climate change in a multitude of ways. For example, governments may introduce a variety of policies, such as regulatory measures and economic incentives, to address climate change. This complex web of measures may have an impact on international trade and the multilateral trading system. The Report begins with a summary of the current state of scientific knowledge on climate change and on the options available for responding to the challenge of climate change. The scientific review is followed by a part on the economic aspects of the link between trade and climate change, and these two parts set the context for the subsequent parts of the Report, which looks at the policies introduced at both the international and national level to address climate change. The part on international policy responses to climate change describes multilateral efforts to reduce greenhouse gas emissions and to adapt to the effects of climate change, and also discusses the role of the current trade and environment negotiations in promoting trade in technologies that aim to mitigate climate change. The final part of the Report gives an overview of a range of national policies and measures that have been used in a number of countries to reduce greenhouse gas emissions and to increase energy efficiency. It presents key features in the design and implementation of these policies, in order to draw a clearer picture of their overall effect and potential impact on environmental protection, sustainable development and trade. It also gives, where appropriate, an overview of the WTO rules that may be relevant to such measures. (author)

  11. Influence of the abrupt area change on the pressure pulse expansion

    The sudden valve closure in the pipeline system causes a large pressure pulse. The pulse expands along the pipe and reflects from the obstruction such as, close end, valve, water tank, ... Every such obstruction can be described as abrupt area change and has different effects on pressure pulse expansion. In certain circumstances phase transition and two phase flow appears which complicates the problem. Two phase flow surface is a new object for pressure pulse reflection and deformation and also it appears to be a source of new pressure pulses. A fluid flow is described with conservative equations (continuity, momentum and energy equation) which are completed with state equation. The problem was calculated as one-dimensional with the excluded gravitational force, neglected friction force and heat transfer. The problem is calculated by method of characteristics (MOC).In the model the pipe system is separated into two parts which each one has constant cross section. Each part has its own nodalization. Those parts are gathered in the abrupt area change point with special conservative equations in the integral form. When phase transition occurs the supposition that all vapour gathers in one bubble across the whole cross section is used. That simplifies the problem and it is further calculated as single-phase. For controlling and comparing the results the same problem was calculated with the RELAP5 program, which calculates on two-phase base with semi implicit scheme. (author)

  12. Struggle against climate change

    This document first proposes a presentation of the cross-cutting policy defined for the struggle against climate change. It notably presents its various programs. It describes the implemented strategy which aims at reducing on a short term greenhouse gas emissions with the available technologies, at making the climate challenge a driver for economic competitiveness, at developing the knowledge on climatic change and at preparing the necessary adaptation measures, and at stating on the international scene the French commitment and its dynamic role in front of the climate challenge

  13. Theory and Design Tools For Studies of Reactions to Abrupt Changes in Noise Exposure

    Fields, James M.; Ehrlich, Gary E.; Zador, Paul; Shepherd, Kevin P. (Technical Monitor)

    2000-01-01

    Study plans, a pre-tested questionnaire, a sample design evaluation tool, a community publicity monitoring plan, and a theoretical framework have been developed to support combined social/acoustical surveys of residents' reactions to an abrupt change in environmental noise, Secondary analyses of more than 20 previous surveys provide estimates of three parameters of a study simulation model; within individual variability, between study wave variability, and between neighborhood variability in response to community noise. The simulation model predicts the precision of the results from social surveys of reactions to noise, including changes in noise. When the study simulation model analyzed the population distribution, noise exposure environments and feasible noise measurement program at a proposed noise change survey site, it was concluded that the site could not yield sufficient precise estimates of human reaction model to justify conducting a survey. Additional secondary analyses determined that noise reactions are affected by the season of the social survey.

  14. Communities under climate change

    Nogues, David Bravo; Rahbek, Carsten

    2011-01-01

    The distribution of species on Earth and the interactions among them are tightly linked to historical and contemporary climate, so that global climate change will transform the world in which we live. Biological models can now credibly link recent decadal trends in field data to climate change......, but predicting future impacts on biological communities is a major challenge. Attempts to move beyond general macroecological predictions of climate change impact on one hand, and observations from specific, local-scale cases, small-scale experiments, or studies of a few species on the other, raise a plethora...... of unanswered questions. On page 1124 of this issue, Harley (1) reports results that cast new light on how biodiversity, across different trophic levels, responds to climate change....

  15. Evidence for abrupt geomagnetic field intensity changes in Europe between 200 and 1400 AD

    Gomez-Paccard, M.; Chauvin, A.; Lanos, P.

    2013-05-01

    Available archaeomagnetic data indicate that during the past 2500 yr there have been periods of rapid geomagnetic field intensity fluctuations interspersed with periods of almost constant field strength. Despite Europe being the most widely covered region in terms of archaeomagnetic data the occurrence and the behaviour of these rapid geomagnetic field intensity changes is under discussion and the challenge now is to precisely describe them. Here we present an improved description of the sharp intensity change that took place in Europe around 800 AD. For this purpose 13 precisely dated early medieval Spanish pottery fragments, four archaeological French kilns and three collections of bricks used for the construction of different French historical buildings with ages ranging between 335 and 1260 AD have been studied. Classical Thellier experiments performed on 164 specimens, and including anisotropy of thermoremanent magnetisation and cooling rate corrections, gave 119 reliable results. The 10 new high-quality mean archaeointensities obtained confirm the existence of an intensity maximum of about 85 μT (at the latitude of Paris) centred at ~800 AD and suggest that a previous abrupt intensity change occurred around 600 AD. Western European data also suggest the occurrence of abrupt geomagnetic field intensity changes during the 12th century AD and around the second half of the 13th century AD. Reliable selected eastern European data show a similar variation of geomagnetic field intensity with the occurrence of two intensity bumps (up to 75 μT at the latitude of Sofia) at ages around 650 and 950 AD and two periods of rapid intensity changes during the 12th century AD and 1300 AD. The results suggest that the described features of the geomagnetic field are observed at a continental scale and that very rapid intensity changes (of at least of 20 μT/century) took place in the recent history of the Earth's magnetic field.

  16. PERCEPTIONS OF CLIMATE CHANGE

    WAITHAKA, E.; OGENDI, KIMANI; MORARA, G.; MUTUA, MAKENZI P.

    2014-01-01

    There is evidence of climate change related events in arid and semi-arid lands. People living in Arid and Semi-arid Lands are particularly vulnerable to the change. Previous studies have revealed great wealth of adaptation mechanisms developed by communities residing in therein over the course of history for their survival. Despite this, there is little or no evidence whether these developed indigenous strategies by the vulnerable communities are based on perception of climate change. The obj...

  17. Climate Change and Mitigation

    Nibleus, Kerstin; Lundin, Rickard

    2010-01-01

    Planet Earth has experienced repeated changes of its climate throughout time. Periods warmer than today as well as much colder, during glacial episodes, have alternated. In our time, rapid population growth with increased demand for natural resources and energy, has made society increasingly vulnerable to environmental changes, both natural and those caused by man; human activity is clearly affecting the radiation balance of the Earth. In the session “Climate Change and Mitigation” the speake...

  18. Climate change and skin.

    Balato, N; Ayala, F; Megna, M; Balato, A; Patruno, C

    2013-02-01

    Global climate appears to be changing at an unprecedented rate. Climate change can be caused by several factors that include variations in solar radiation received by earth, oceanic processes (such as oceanic circulation), plate tectonics, and volcanic eruptions, as well as human-induced alterations of the natural world. Many human activities, such as the use of fossil fuel and the consequent accumulation of greenhouse gases in the atmosphere, land consumption, deforestation, industrial processes, as well as some agriculture practices are contributing to global climate change. Indeed, many authors have reported on the current trend towards global warming (average surface temperature has augmented by 0.6 °C over the past 100 years), decreased precipitation, atmospheric humidity changes, and global rise in extreme climatic events. The magnitude and cause of these changes and their impact on human activity have become important matters of debate worldwide, representing climate change as one of the greatest challenges of the modern age. Although many articles have been written based on observations and various predictive models of how climate change could affect social, economic and health systems, only few studies exist about the effects of this change on skin physiology and diseases. However, the skin is the most exposed organ to environment; therefore, cutaneous diseases are inclined to have a high sensitivity to climate. For example, global warming, deforestation and changes in precipitation have been linked to variations in the geographical distribution of vectors of some infectious diseases (leishmaniasis, lyme disease, etc) by changing their spread, whereas warm and humid environment can also encourage the colonization of the skin by bacteria and fungi. The present review focuses on the wide and complex relationship between climate change and dermatology, showing the numerous factors that are contributing to modify the incidence and the clinical pattern of many

  19. Witnesses of climate change

    After having evoked the process of climate change, the effect of greenhouse gas emissions, the evolution of average temperatures in France since 1900, and indicated the various interactions and impacts of climate change regarding air quality, water resources, food supply, degradation and loss of biodiversity, deforestation, desertification, this publication, while quoting various testimonies (from a mountain refuge guardian, a wine maker, a guide in La Reunion, an IFREMER bio-statistician engineer, and a representative of health professionals), describes the various noticed impacts of climate change on the environment in mountain chains, on agriculture, on sea level rise, on overseas biodiversity, and on health

  20. Biodiversity and Climate Change

    Biological diversity or biodiversity is crucial for ecological stability including regulation of climate change, recreational and medicinal use; and scientific advancement. Kenya like other developing countries, especially, those in Sub-Saharan Africa, will continue to depend greatly on her biodiversity for present and future development. This important resource must, therefore be conserved. This chapter presents an overview of Kenya's biodiversity; its importance and initiatives being undertaken for its conservation; and in detail, explores issues of climate change and biodiversity, concentrating on impacts of climate change

  1. Global climate change and international security.

    Karas, Thomas H.

    2003-11-01

    This report originates in a workshop held at Sandia National Laboratories, bringing together a variety of external experts with Sandia personnel to discuss 'The Implications of Global Climate Change for International Security.' Whatever the future of the current global warming trend, paleoclimatic history shows that climate change happens, sometimes abruptly. These changes can severely impact human water supplies, agriculture, migration patterns, infrastructure, financial flows, disease prevalence, and economic activity. Those impacts, in turn, can lead to national or international security problems stemming from aggravation of internal conflicts, increased poverty and inequality, exacerbation of existing international conflicts, diversion of national and international resources from international security programs (military or non-military), contribution to global economic decline or collapse, or international realignments based on climate change mitigation policies. After reviewing these potential problems, the report concludes with a brief listing of some research, technology, and policy measures that might mitigate them.

  2. Adapting to climate change

    Arndt, Channing; Strzepek, Kenneth; Tarp, Finn;

    2011-01-01

    Mozambique, like many African countries, is already highly susceptible to climate variability and extreme weather events. Climate change threatens to heighten this vulnerability. In order to evaluate potential impacts and adaptation options for Mozambique, we develop an integrated modeling...... framework that translates atmospheric changes from general circulation model projections into biophysical outcomes via detailed hydrologic, crop, hydropower and infrastructure models. These sector models simulate a historical baseline and four extreme climate change scenarios. Sector results are then passed...... down to a dynamic computable general equilibrium model, which is used to estimate economy-wide impacts on national welfare, as well as the total cost of damages caused by climate change. Potential damages without changes in policy are significant; our discounted estimates range from US2.3 to US2.3toUS7...

  3. Live cell tracking of symmetry break in actin cytoskeleton triggered by abrupt changes in micromechanical environments.

    Inoue, S; Frank, V; Hörning, M; Kaufmann, S; Yoshikawa, H Y; Madsen, J P; Lewis, A L; Armes, S P; Tanaka, M

    2015-12-01

    With the aid of stimulus-responsive hydrogel substrates composed of ABA triblock copolymer micelles, we monitored the morphological dynamics of myoblast (C2C12) cells in response to an abrupt change in the substrate elasticity by live cell imaging. The remodeling of actin cytoskeletons could be monitored by means of transient transfection with LifeAct-GFP. Dynamic changes in the orientational order of actin filaments were characterized by an order parameter, which enables one to generalize the mechanically induced actin cytoskeletons as a break of symmetry. The critical role that acto-myosin complexes play in the morphological transition was verified by the treatment of cells with myosin II inhibitor (blebbistatin) and the fluorescence localization of focal adhesion contacts. Such dynamically tunable hydrogels can be utilized as in vitro cellular micro-environments that can exert time-dependent stimuli to mechanically regulate target cells. PMID:26347909

  4. Climate change governance

    Knieling, Joerg [HafenCity Univ. Hamburg (Germany). Urban Planning and Regional Development; Leal Filho, Walter (eds.) [HAW Hamburg (Germany). Research and Transfer Centre Applications of Life Science

    2013-07-01

    Climate change is a cause for concern both globally and locally. In order for it to be tackled holistically, its governance is an important topic needing scientific and practical consideration. Climate change governance is an emerging area, and one which is closely related to state and public administrative systems and the behaviour of private actors, including the business sector, as well as the civil society and non-governmental organisations. Questions of climate change governance deal both with mitigation and adaptation whilst at the same time trying to devise effective ways of managing the consequences of these measures across the different sectors. Many books have been produced on general matters related to climate change, such as climate modelling, temperature variations, sea level rise, but, to date, very few publications have addressed the political, economic and social elements of climate change and their links with governance. This book will address this gap. Furthermore, a particular feature of this book is that it not only presents different perspectives on climate change governance, but it also introduces theoretical approaches and brings these together with practical examples which show how main principles may be implemented in practice.

  5. Olivine and climate change

    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 greenh

  6. Understanding climate change

    Topics covered in this book are: include volcanism; biogeochemistry; land hydrology; modeling climate; past and present; cryosphere; paleoclimates; land-surface processes; tropical oceans and the global atmosphere; clouds and atmospheric radiation; aeronomy and planetary atmospheres; and modeling future climate changes. The papers presented include uptake by the Atlantic Ocean of excess atmospheric carbon dioxide and radiocarbon

  7. Abrupt climate variability of eastern Anatolia vegetation during the last glacial

    N. Pickarski

    2015-07-01

    Full Text Available Detailed analyses of the Lake Van pollen and stable oxygen isotope record allow the identification of millennial-scale vegetation and environmental changes in eastern Anatolia throughout the last glacial. The climate within the last glacial period (∼75–15 ka BP was cold and dry, with low arboreal pollen (AP levels. The driest and coldest period corresponds to Marine Isotope Stage (MIS 2 (∼28–14.5 ka BP dominated by the highest values of xerophytic steppe vegetation. Our high-resolution multi proxy record shows rapid expansions and contractions that mimic the stadial-interstadial pattern of the Dansgaard–Oeschger (DO events as recorded in the Greenland ice cores, and thus, provide a linkage to North Atlantic climate oscillations. Periods of reduced moisture availability characterized at Lake Van by enhanced xerophytic species correlates well with increase in ice-rafted debris (IRD and a decrease of sea surface temperature (SST in the North Atlantic. Furthermore, comparison with the marine realm reveals that the complex atmosphere–ocean interaction can be recognized by the strength and position of the westerlies in eastern Anatolia. Influenced by rough topography at Lake Van, the expansion of temperate species (e.g. deciduous Quercus was stronger during interstadials DO 19, 17–16, 14, 12 and 8. However, Heinrich events (HE, characterized by highest concentrations of ice-rafted debris in marine sediments, are identified in eastern Anatolia by AP values not lower and high steppe components not more abundant than during DO stadials. In addition, this work is a first attempt to establish a continuous microscopic charcoal record over the last glacial in the Near East, which documents an initial immediate response to millennial-scale climate and environmental variability and enables the shed light on the history of fire activity during the last glacial.

  8. Creationism & Climate Change (Invited)

    Newton, S.

    2009-12-01

    Although creationists focus on the biological sciences, recently creationists have also expanded their attacks to include the earth sciences, especially on the topic of climate change. The creationist effort to deny climate change, in addition to evolution and radiometric dating, is part of a broader denial of the methodology and validity of science itself. Creationist misinformation can pose a serious problem for science educators, who are further hindered by the poor treatment of the earth sciences and climate change in state science standards. Recent changes to Texas’ science standards, for example, require that students learn “different views on the existence of global warming.” Because of Texas’ large influence on the national textbook market, textbooks presenting non-scientific “different views” about climate change—or simply omitting the subject entirely because of the alleged “controversy”—could become part of K-12 classrooms across the country.

  9. Climate change and compensation

    Jensen, Karsten Klint; Flanagan, Tine Bech

    2013-01-01

    This paper presents a case for compensation of actual harm from climate change in the poorest countries. First, it is shown that climate change threatens to reverse the fight to eradicate poverty. Secondly, it is shown how the problems raised in the literature for compensation to some extent...... are based on misconceptions and do not apply to compensation of present actual harm. Finally, two arguments are presented to the effect that, in so far as developed countries accept a major commitment to mitigate climate change, they should also accept a commitment to address or compensate actual harm from...... climate change. The first argument appeals to the principle that if it is an injustice to cause risk of incurring harm in the future, then it is also an injustice to cause a similar harm now. The second argument appeals to the principle that if there is moral reason to reduce the risk of specific harms...

  10. Population and Climate Change

    O'Neill, Brian C.; Landis MacKellar, F.; Lutz, Wolfgang

    2000-11-01

    Population and Climate Change provides the first systematic in-depth treatment of links between two major themes of the 21st century: population growth (and associated demographic trends such as aging) and climate change. It is written by a multidisciplinary team of authors from the International Institute for Applied Systems Analysis who integrate both natural science and social science perspectives in a way that is comprehensible to members of both communities. The book will be of primary interest to researchers in the fields of climate change, demography, and economics. It will also be useful to policy-makers and NGOs dealing with issues of population dynamics and climate change, and to teachers and students in courses such as environmental studies, demography, climatology, economics, earth systems science, and international relations.

  11. Criminality and climate change

    White, Rob

    2016-08-01

    The impacts of climate change imply a reconceptualization of environment-related criminality. Criminology can offer insight into the definitions and dynamics of this behaviour, and outline potential areas of redress.

  12. Evaluation of the capability of the Lombard test in detecting abrupt changes in variance

    Nayak, Munir A.; Villarini, Gabriele

    2016-03-01

    Hydrologic time series are often characterized by temporal changes that give rise to non-stationarity. When the distribution describing the data changes over time, it is important to detect these changes so that correct inferences can be drawn from the data. The Lombard test, a non-parametric rank-based test to detect change points in the moments of a time series, has been recently used in the hydrologic literature to detect change points in the mean and variance. Little is known, however, about the performance of this test in detecting changes in variance, despite the potentially large impacts that these changes (shifts) could have when dealing with extremes. Here we address this issue in a Monte Carlo simulation framework. We consider a number of different situations that can manifest themselves in hydrologic time series, including the dependence of the results on the magnitude of the shift, significance level, sample size and location of the change point within the series. Analyses are performed considering abrupt changes in variance occurring with and without shifts in the mean. The results show that the power of the test in detecting change points in variance is small when the changes are small. It is large when the change point occurs close to the middle of the time series, and it increases nonlinearly with increasing sample size. Moreover, the power of the test is greatly reduced by the presence of change points in mean. We propose removing the change in the mean before testing for change points in variance. Simulation results demonstrate that this strategy effectively increases the power of the test. Finally, the Lombard test is applied to annual peak discharge records from 3686 U.S. Geological Survey stream-gaging stations across the conterminous United States, and the results are discussed in light of the insights from the simulations' results.

  13. Climate change - the impacts

    This special dossier about the impacts of climate change is made of 6 contributions dealing with: the mitigation of climate effects and how to deal with them (Bertrand Reysset); how to dare and transmit (Laurent Billes-Garabedian); littoral risks, the Pas-de-Calais example (Julien Henique); extreme meteorological events and health impacts (Mathilde Pascal, Philippe Pirard, Yvon Motreff); Biodiversity and climate: the janus of global change (Robert Barbault, Jacques Weber); adapting agriculture to dryness and temperatures (Philippe Gate); Paris and the future heats of the year 2100 (Jean-Luc Salagnac, Julien Desplat, Raphaelle Kounkou-Arnaud)

  14. Climate change: Recent findings

    In the late eighties several reports have been published on climate change and sea level rise. In the meantime insights may have changed due to the availability of better and more observations and/or more advanced climate models. The aim of this report is to present the most recent findings with respect to climate change, in particular of sea level rise, storm surges and river peak flows. These climate factors are important for the safety of low-lying areas with respect to coastal erosion and flooding. In the first chapters a short review is presented of a few of the eighties reports. Furthermore, the predictions by state of the art climate models at that time are given. The reports from the eighties should be considered as 'old' information, whereas the IPCC supplement and work, for example, by Wigley should be considered as new information. To assess the latest findings two experts in this field were interviewed: dr J. Oerlemans and dr C.J.E. Schuurmans, a climate expert from the Royal Netherlands Meteorological Institute (KNMI). Their views are presented together with results published in recent papers on the subject. On the basis of this assessment, the report presents current knowledge regarding predictions of climate change (including sea-level rise) over the next century, together with an assessment of the uncertainties associated with these predictions. 14 figs., 11 tabs., 24 refs

  15. GREEN ECONOMY AND CLIMATE CHANGE PREVENTION CYCLE

    Andreea CONSTANTINESCU

    2014-12-01

    Full Text Available While experts in economics place transition to green economy on two directions - reducing ecological footprint and increasing human welfare - climate change specialists warn that effects of global warming will have a much greater impact in the future. It is natural to join scientific contributions in these two areas because both perspectives recognize the ravages made by industrialization, which triggered a serie of abrupt climate changes. For example, the average temperature in Europe has increased about 1oC. Based on these evidences, this article will show the usefulness of introducing a concept of full cycle to prevent climate change in the new paradigm that seeks to solve problems related to the fundamentals of sustainable development through transition to green economy. Using this method, this approach intends to be a new theoretical contribution which can act as support to efficiency of new clean technologies.

  16. Abrupt changes in neon discharge plasma detected via the optogalvanic effect

    Han, Xianming L., E-mail: xhan@butler.edu [Dept. of Physics and Astronomy, Butler University, Indianapolis, IN 46208 (United States); Blosser, Michael C. [Dept. of Physics and Astronomy, Butler University, Indianapolis, IN 46208 (United States); Misra, Prabhakar [Dept. of Physics and Astronomy, Howard University, Washington DC 20059 (United States); Chandran, Haridass [Dept. of Physical Science, Belfry School, Belfry, KY 41514 (United States)

    2012-10-30

    When a laser is tuned between two excited energy levels of a gas in a Direct Current discharge lamp, the discharge current will experience a temporary disturbance lasting tens or hundreds of microseconds known as the optogalvanic effect. We have carried out extensive studies of optogalvanic effects in neon discharge plasmas for transitions at 621.7 nm, 630.5 nm, 638.3 nm, 650.7 nm and 659.9 nm. A nonlinear least-squares Monte Carlo technique has been used to determine the relevant amplitude coefficients, decay rates and the instrumental time constant. We discovered an abrupt change in the neon discharge plasma at a discharge current of about 6 mA.

  17. Behavioral reactions of the bat Carollia perspicillata to abrupt changes in gravity.

    Fejtek, M; Delorme, M; Wassersug, R

    1995-06-01

    As part of an ongoing survey of the behavioral responses of vertebrates to abrupt changes in gravity, we report here on the reactions of bats (Carollia perspicillata) exposed to altered gravity during parabolic aircraft flight. In microgravity, mammals typically behave as if they were upside-down and exhibit repetitive righting reflexes, which often lead to long axis rolling. Since bats, however, normally rest upside-down, we hypothesized that they would not roll in microgravity. Only one of three specimens attempted to fly during microgravity. None rolled or performed any righting maneuvers. During periods of microgravity the bats partially extended their forearms but kept their wings folded and parallel to the body. Between parabolas and occasionally during microgravity the bats groomed themselves. Both the extended limbs and autogrooming may be stress responses to the novel stimulus of altered gravity. This is the first behavioral record of Chiroptera in microgravity. PMID:11541842

  18. Use of calcareous algae and monensin in Nellore cattle subjected to an abrupt change in diet

    Roberta Ferreira Carvalho

    2016-04-01

    Full Text Available ABSTRACT: Additives are used in high concentrate diets to prevent metabolic disorders in cattle. This study was designed to evaluate the effect of calcium sources and monensin on the control of ruminal acidosis in Nellore cattle that were abruptly shifted to a high (92.3% concentrate diet. Eight cannulated steers were randomly assigned to two contemporary 4x4 Latin square. Treatments involved the addition of a calcium source, either limestone (LI or a product derived from calcareous algae (CA, to the basic diet with or without the presence of monensin. Calcareous alga (Lithothamnium calcareum is a natural and renewable product and a source of calcium carbonate. The quantity of added limestone, calcareous algae and monensin was 7.1g kg-1, 7.4g kg-1 and 30mg kg-1 DM, respectively. There was no effect of calcium source (P=0.607 or monensin (P=0.294 on feed intake or on the concentration of short chain fatty acids. Treatments with calcareous algae resulted in a higher mean ruminal pH (P=0.039, a shorter amount of time with the ruminal pH under 5.2 (P<0.001 and a better control of blood pH (P=0.006. Treatments with monensin also resulted in a shorter amount of time with the ruminal pH below 5.2 (P=0.023. Calcareous algae were shown to be effective in controlling adverse changes in the rumen and in blood variables for Nellore cattle that were subjected to an abrupt change to a high concentrate diet.

  19. Climate change - global warming

    An explanation about climate, weather, climate changes. What is a greenhouse effect, i.e. global warming and reasons which contribute to this effect. Greenhouse gases (GHG) and GWP (Global Warming Potential) as a factor for estimating their influence on the greenhouse effect. Indicators of the climate changes in the previous period by known international institutions, higher concentrations of global average temperature. Projecting of likely scenarios for the future climate changes and consequences of them on the environment and human activities: industry, energy, agriculture, water resources. The main points of the Kyoto Protocol and problems in its realization. The need of preparing a country strategy concerning the acts of the Kyoto Protocol, suggestions which could contribute in the preparation of the strategy. A special attention is pointed to the energy, its resources, the structure of energy consumption and the energy efficiency. (Author)

  20. Abrupt state change of river water quality (turbidity): Effect of extreme rainfalls and typhoons.

    Lee, Chih-Sheng; Lee, Yi-Chao; Chiang, Hui-Min

    2016-07-01

    River turbidity is of dynamic nature, and its stable state is significantly changed during the period of heavy rainfall events. The frequent occurrence of typhoons in Taiwan has caused serious problems in drinking water treatment due to extremely high turbidity. The aim of the present study is to evaluate impact of typhoons on river turbidity. The statistical methods used included analyses of paired annual mean and standard deviation, frequency distribution, and moving standard deviation, skewness, and autocorrelation; all clearly indicating significant state changes of river turbidity. Typhoon Morakot of 2009 (recorded high rainfall over 2000mm in three days, responsible for significant disaster in southern Taiwan) is assumed as a major initiated event leading to critical state change. In addition, increasing rate of turbidity in rainfall events is highly and positively correlated with rainfall intensity both for pre- and post-Morakot periods. Daily turbidity is also well correlated with daily flow rate for all the eleven events evaluated. That implies potential prediction of river turbidity by river flow rate during rainfall and typhoon events. Based on analysis of stable state changes, more effective regulations for better basin management including soil-water conservation in watershed are necessary. Furthermore, municipal and industrial water treatment plants need to prepare and ensure the adequate operation of water treatment with high raw water turbidity (e.g., >2000NTU). Finally, methodology used in the present of this study can be applied to other environmental problems with abrupt state changes. PMID:26994797

  1. Managing Climate Change Refugia for Climate Adaptation

    Daly, Christopher; Dobrowski, Solomon Z.; Dulen, Deanna M.; Ebersole, Joseph L.; Jackson, Stephen T.; Lundquist, Jessica D.; Millar, Constance I.; Maher, Sean P.; Monahan, William B.; Nydick, Koren R.; Redmond, Kelly T.; Sawyer, Sarah C.; Stock, Sarah; Beissinger, Steven R.

    2016-01-01

    Refugia have long been studied from paleontological and biogeographical perspectives to understand how populations persisted during past periods of unfavorable climate. Recently, researchers have applied the idea to contemporary landscapes to identify climate change refugia, here defined as areas relatively buffered from contemporary climate change over time that enable persistence of valued physical, ecological, and socio-cultural resources. We differentiate historical and contemporary views, and characterize physical and ecological processes that create and maintain climate change refugia. We then delineate how refugia can fit into existing decision support frameworks for climate adaptation and describe seven steps for managing them. Finally, we identify challenges and opportunities for operationalizing the concept of climate change refugia. Managing climate change refugia can be an important option for conservation in the face of ongoing climate change. PMID:27509088

  2. Managing Climate Change Refugia for Climate Adaptation.

    Morelli, Toni Lyn; Daly, Christopher; Dobrowski, Solomon Z; Dulen, Deanna M; Ebersole, Joseph L; Jackson, Stephen T; Lundquist, Jessica D; Millar, Constance I; Maher, Sean P; Monahan, William B; Nydick, Koren R; Redmond, Kelly T; Sawyer, Sarah C; Stock, Sarah; Beissinger, Steven R

    2016-01-01

    Refugia have long been studied from paleontological and biogeographical perspectives to understand how populations persisted during past periods of unfavorable climate. Recently, researchers have applied the idea to contemporary landscapes to identify climate change refugia, here defined as areas relatively buffered from contemporary climate change over time that enable persistence of valued physical, ecological, and socio-cultural resources. We differentiate historical and contemporary views, and characterize physical and ecological processes that create and maintain climate change refugia. We then delineate how refugia can fit into existing decision support frameworks for climate adaptation and describe seven steps for managing them. Finally, we identify challenges and opportunities for operationalizing the concept of climate change refugia. Managing climate change refugia can be an important option for conservation in the face of ongoing climate change. PMID:27509088

  3. Current Climate Variability & Change

    Diem, J.; Criswell, B.; Elliott, W. C.

    2013-12-01

    Current Climate Variability & Change is the ninth among a suite of ten interconnected, sequential labs that address all 39 climate-literacy concepts in the U.S. Global Change Research Program's Climate Literacy: The Essential Principles of Climate Sciences. The labs are as follows: Solar Radiation & Seasons, Stratospheric Ozone, The Troposphere, The Carbon Cycle, Global Surface Temperature, Glacial-Interglacial Cycles, Temperature Changes over the Past Millennium, Climates & Ecosystems, Current Climate Variability & Change, and Future Climate Change. All are inquiry-based, on-line products designed in a way that enables students to construct their own knowledge of a topic. Questions representative of various levels of Webb's depth of knowledge are embedded in each lab. In addition to the embedded questions, each lab has three or four essential questions related to the driving questions for the lab suite. These essential questions are presented as statements at the beginning of the material to represent the lab objectives, and then are asked at the end as questions to function as a summative assessment. For example, the Current Climate Variability & Change is built around these essential questions: (1) What has happened to the global temperature at the Earth's surface, in the middle troposphere, and in the lower stratosphere over the past several decades?; (2) What is the most likely cause of the changes in global temperature over the past several decades and what evidence is there that this is the cause?; and (3) What have been some of the clearly defined effects of the change in global temperature on the atmosphere and other spheres of the Earth system? An introductory Prezi allows the instructor to assess students' prior knowledge in relation to these questions, while also providing 'hooks' to pique their interest related to the topic. The lab begins by presenting examples of and key differences between climate variability (e.g., Mt. Pinatubo eruption) and

  4. Climate Change and Roads

    Chinowsky, P.; Arndt, Channing

    2012-01-01

    Decision-makers who are responsible for determining when and where infrastructure should be developed and/or enhanced are facing a new challenge with the emerging topic of climate change. The paper introduces a stressor–response methodology where engineering-based models are used as a basis...... to estimate the impact of individual climate stressors on road infrastructure in Mozambique. Through these models, stressor–response functions are introduced that quantify the cost impact of a specific stressor based on the intensity of the stressor and the type of infrastructure it is affecting. Utilizing...... four climate projection scenarios, the paper details how climate change response decisions may cost the Mozambican government in terms of maintenance costs and long-term roadstock inventory reduction. Through this approach the paper details how a 14% reduction in inventory loss can be achieved through...

  5. The climatic change

    In order to take stock on the climatic change situation and initiatives at the beginning of 2006, the INES (National Institute on the Solar Energy) proposes this special document. It presents the Montreal conference of December 2005, realized to reinforced the actions of the international community against the greenhouse gases. The technical decisions decided at this conference are detailed. The document discusses also the causes and consequences of the climatic warming, the intervention sectors and the actions possibilities. (A.L.B.)

  6. Libertarianism and Climate Change

    Torpman, Olle

    2016-01-01

    In this dissertation, I investigate the implications of libertarian morality in relation to the problem of climate change. This problem is explicated in the first chapter, where preliminary clarifications are also made. In the second chapter, I briefly explain the characteristics of libertarianism relevant to the subsequent study, including the central non-aggression principle. In chapter three, I examine whether our individual emissions of greenhouse gases, which together give rise to climat...

  7. Ireland and climate change

    As the rise of sea level, the higher frequency of tempests, and the threat of water shortages in some parts of the country are the major stakes for Ireland in the struggle against climate change, this report gives an overview of greenhouse gas emissions in this country (globally and per sector) and of their evolution. It presents the Irish policy to struggle against climate change since 2000, its public actors (ministries, agencies), its different action plans (National Climate Change Strategy, energy sector planning, promotion of renewable energies, transport sector planning), and sector-based and tax measures implemented in Ireland. It discusses the limitations of the current policy (insufficient results, limited domestic measures, socioeconomic obstacles, complex political steering), describes the new European context and the present Irish context (economic crisis). Some new orientations are discussed

  8. AMS and climate change

    Kutschera, Walter, E-mail: walter.kutschera@univie.ac.a [Vienna Environmental Research Accelerator (VERA), Fakultaet fuer Physik - Isotopenforschung, Universitaet Wien, Waehringerstrasse 17, A-1090 Wien (Austria)

    2010-04-15

    This paper attempts to draw a connection between information that can be gained from measurements with accelerator mass spectrometry (AMS) and the study of climate change on earth. The power of AMS to help in this endeavor is demonstrated by many contributions to these proceedings. Just like in archaeology, we are entering a phase of an 'integrated approach' to understand the various components of climate change. Even though some basic understanding emerged, we are still largely in a situation of a phenomenological description of climate change. Collecting more data is therefore of paramount interest. Based on a recent suggestion of 'geo-engineering' to take out CO{sub 2} from the atmosphere, this radical step will also be briefly discussed.

  9. AMS and climate change

    Kutschera, Walter

    2010-04-01

    This paper attempts to draw a connection between information that can be gained from measurements with accelerator mass spectrometry (AMS) and the study of climate change on earth. The power of AMS to help in this endeavor is demonstrated by many contributions to these proceedings. Just like in archaeology, we are entering a phase of an 'integrated approach' to understand the various components of climate change. Even though some basic understanding emerged, we are still largely in a situation of a phenomenological description of climate change. Collecting more data is therefore of paramount interest. Based on a recent suggestion of 'geo-engineering' to take out CO 2 from the atmosphere, this radical step will also be briefly discussed.

  10. Climate change matters.

    Macpherson, Cheryl Cox

    2014-04-01

    One manifestation of climate change is the increasingly severe extreme weather that causes injury, illness and death through heat stress, air pollution, infectious disease and other means. Leading health organisations around the world are responding to the related water and food shortages and volatility of energy and agriculture prices that threaten health and health economics. Environmental and climate ethics highlight the associated challenges to human rights and distributive justice but rarely address health or encompass bioethical methods or analyses. Public health ethics and its broader umbrella, bioethics, remain relatively silent on climate change. Meanwhile global population growth creates more people who aspire to Western lifestyles and unrestrained socioeconomic growth. Fulfilling these aspirations generates more emissions; worsens climate change; and undermines virtues and values that engender appreciation of, and protections for, natural resources. Greater understanding of how virtues and values are evolving in different contexts, and the associated consequences, might nudge the individual and collective priorities that inform public policy toward embracing stewardship and responsibility for environmental resources necessary to health. Instead of neglecting climate change and related policy, public health ethics and bioethics should explore these issues; bring transparency to the tradeoffs that permit emissions to continue at current rates; and offer deeper understanding about what is at stake and what it means to live a good life in today's world. PMID:23665996

  11. Addressing Climate Change

    Peter S. Heller

    2007-01-01

    Global climate change has moved high on the agenda of key policy makers in many industrial countries. As a “global public good,†a coordinated global response in terms of efforts at mitigation will be critically necessary. Equally, many countries will face serious economic harm in the absence of adaptation efforts. As one of the key global institutions with responsibility for global economic stability and growth, this paper argues that climate change should be on the economic surveillance ...

  12. Climatic change and nuclear

    One of the main priorities of the WWF is to increase the implementing of solutions relative to the greenhouse effect fight. In this framework the foundation published a study on the nuclear facing the climatic change problem. The following chapters are detailed: the nuclear and the negotiations on the climatic change; the nuclear close; the unrealistic hypothesis of the nuclear forecast; the nuclear facing other energy supplying options; supplying efficiency for heating, electric power, gas and renewable energies; the consumption efficiency facing the nuclear; the economical aspects; the deregulation effect; the political aspects; the nuclear AND the greenhouse effect. (A.L.B.)

  13. Climatic change. What solutions?

    From 1990 to the present day, worldwide greenhouse gas emissions have increased by about 25%. Fighting climatic change has become an urgency: we only have 15 years in front of us to inflect the trajectory of worldwide emissions and to avoid a temperature rise of more than 2 deg. C during this century. Therefore, how is it possible to explain the shift between the need of an urgent action and the apparent inertia of some governing parties? How is it possible to implement a worldwide governance capable to answer the urgency of the fight against climatic change? These are the two questions that this pedagogical and concrete book tries to answer by analysing the different dimensions of climatic change and by making a first status of the building up of the international action, and in particular of the Kyoto protocol. For the post-2012 era, research and negotiations are in progress with the objective of reaching an agreement for the Copenhagen conference of December 2009. Several architectures are possible. This book shades light on the advantages and limitations of each of them with the possible compromises. It supplies a pluri-disciplinary approach of the international negotiations, often considered as complex by the general public. Content: 1 - understanding the climatic change stakes: climatic stakes, the main actors behind the figures, the technical-economical stakes; 2 - understanding the present day architecture of the fight against climatic change: strengths and weaknesses of the Kyoto protocol; encouraging research and technology spreading; the other action means in developing countries; 3 - what structure for a future international agreement?: the Bali negotiation process; the ideal vision: an improved Kyoto protocol; the pragmatic vision: individualized commitments; the negotiation space; preventing a planned fiasco. (J.S.)

  14. Macrosegregation in Al-7Si alloy caused by abrupt cross-section change during directional solidification

    Ghods, M.; Johnson, L.; Lauer, M.; Grugel, R. N.; Tewari, S. N.; Poirier, D. R.

    2016-09-01

    Hypoeutectic Al-7 wt .% Si alloys were directionally solidified vertically downward in cylindrical molds that incorporated an abrupt cross-section decrease (9.5 mm to 3.2 mm diameter) which, after 5 cm, reverted back to 9.5 mm diameter in a Bridgman furnace; two constant growth speeds and thermal gradients were investigated. Thermosolutal convection and cross-section-change-induced shrinkage flow effects on macrosegregation were investigated. Dendrite clustering and extensive radial macrosegregation was seen, particularly in the larger cross-sections, before contraction and after expansion, this more evident at the lower growth speed. This alloy shows positive longitudinal macrosegregation near cross-section decrease followed by negative macrosegregation right after it; the extent of macrosegregation, however, decreases with increasing growth speed. Primary dendrite steepling intensified as solidification proceeded into the narrower section and negative longitudinal macrosegregation was seen on the re-entrant shelves at expansion. A two-dimensional model accounting for both shrinkage and thermo-solutal convection was used to simulate solidification and the resulting mushy-zone steepling and macrosegregation. The experimentally observed longitudinal and radial macrosegregation associated with the cross-section changes during directional solidification of an Al-7Si alloy is well captured by the numerical simulations.

  15. Climate change and amphibians

    Corn, P. S.

    2005-01-01

    Full Text Available Amphibian life histories are exceedingly sensitive to temperature and precipitation, and there is good evidence that recent climate change has already resulted in a shift to breeding earlier in the year for some species. There are also suggestions that the recent increase in the occurrence of El Niño events has caused declines of anurans in Central America and is linked to elevated mortality of amphibian embryos in the northwestern United States. However, evidence linking amphibian declines in Central America to climate relies solely on correlations, and the mechanisms underlying the declines are not understood. Connections between embryo mortality and declines in abundance have not been demonstrated. Analyses of existing data have generally failed to find a link between climate and amphibian declines. It is likely, however, that future climate change will cause further declines of some amphibian species. Reduced soil moisture could reduce prey species and eliminate habitat. Reduced snowfall and increased summer evaporation could have dramatic effects on the duration or occurrence of seasonal wetlands, which are primary habitat for many species of amphibians. Climate change may be a relatively minor cause of current amphibian declines, but it may be the biggest future challenge to the persistence of many species

  16. Energy and Climate Change

    NONE

    2007-06-15

    Climate change, and more specifically the carbon emissions from energy production and use, is one of the more vexing problems facing society today. The Intergovernmental Panel on Climate Change (IPCC) has just completed its latest assessment on the state of the science of climate change, on the potential consequences related to this change, and on the mitigation steps that could be implemented beginning now, particularly in the energy sector. Few people now doubt that anthropogenic climate change is real or that steps must be taken to deal with it. The World Energy Council has long recognized this serious concern and that in its role as the world's leading international energy organization, it can address the concerns of how to provide adequate energy for human well-being while sustaining our overall quality of life. It has now performed and published 15 reports and working papers on this subject. This report examines what has worked and what is likely to work in the future in this regard and provides policymakers with a practical roadmap to a low-carbon future and the steps needed to achieve it.

  17. Climate Change Adaptation

    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. The research was carried out between January 2000 and March 2012. One of the biggest challenges that mankind has to face is the prospect of climate change resulting from emissions of greenhouse gases. These gases trap energy in the atmosphere and cause global surface temperatures to rise. This...

  18. Topologies of climate change

    Blok, Anders

    2010-01-01

    Climate change is quickly becoming a ubiquitous socionatural reality, mediating extremes of sociospatial scale from the bodily to the planetary. Although environmentalism invites us to ‘think globally and act locally', the meaning of these scalar designations remains ambiguous. This paper explores...... the topological presuppositions of social theory in the context of global climate change, asking how carbon emissions ‘translate' into various sociomaterial forms. Staging a meeting between Tim Ingold's phenomenology of globes and spheres and the social topologies of actor-network theory (ANT), the...... paper advances a ‘relational-scalar' analytics of spatial practices, technoscience, and power. As technoscience gradually constructs a networked global climate, this ‘grey box' comes to circulate within fluid social spaces, taking on new shades as it hybridizes knowledges, symbols, and practices. Global...

  19. Climate change velocity underestimates climate change exposure in mountainous regions

    Dobrowski, Solomon Z.; Parks, Sean A.

    2016-08-01

    Climate change velocity is a vector depiction of the rate of climate displacement used for assessing climate change impacts. Interpreting velocity requires an assumption that climate trajectory length is proportional to climate change exposure; longer paths suggest greater exposure. However, distance is an imperfect measure of exposure because it does not quantify the extent to which trajectories traverse areas of dissimilar climate. Here we calculate velocity and minimum cumulative exposure (MCE) in degrees Celsius along climate trajectories for North America. We find that velocity is weakly related to MCE; each metric identifies contrasting areas of vulnerability to climate change. Notably, velocity underestimates exposure in mountainous regions where climate trajectories traverse dissimilar climates, resulting in high MCE. In contrast, in flat regions velocity is high where MCE is low, as these areas have negligible climatic resistance to movement. Our results suggest that mountainous regions are more climatically isolated than previously reported.

  20. Corporate Climate Change

    2006-01-01

    The American Chamber of Commerce, the People's Republic of China (AmCham-China) and the American Chamber of Commerce in Shanghai recently released "American Corporate Experience in a Changing China: Insights From AmCham Business Climate Surveys, 1999-2005." Excerpts of the report follow:

  1. DTU Climate Change Technologies

    During 2008 and 2009, DTU held a workshop series focusing on assessment of and adaption to climate changes as well as on mitigation of green house gasses. In the workshops, a total of 1500 scientists, government officials and business leaders have outlined scenarios for technology development...

  2. Learning Progressions & Climate Change

    Parker, Joyce M.; de los Santos, Elizabeth X.; Anderson, Charles W.

    2015-01-01

    Our society is currently having serious debates about sources of energy and global climate change. But do students (and the public) have the requisite knowledge to engage these issues as informed citizenry? The learning-progression research summarized here indicates that only 10% of high school students typically have a level of understanding…

  3. Adaptation to climate change

    J. Carmin; K. Tierney; E. Chu; L.M. Hunter; J.T. Roberts; L. Shi

    2015-01-01

    Climate change adaptation involves major global and societal challenges such as finding adequate and equitable adaptation funding and integrating adaptation and development programs. Current funding is insufficient. Debates between the Global North and South center on how best to allocate the financ

  4. Comparison of performance between rescaled range analysis and rescaled variance analysis in detecting abrupt dynamic change

    何文平; 刘群群; 姜允迪; 卢莹

    2015-01-01

    In the present paper, a comparison of the performance between moving cutting data-rescaled range analysis (MC-R/S) and moving cutting data-rescaled variance analysis (MC-V/S) is made. The results clearly indicate that the operating efficiency of the MC-R/S algorithm is higher than that of the MC-V/S algorithm. In our numerical test, the computer time consumed by MC-V/S is approximately 25 times that by MC-R/S for an identical window size in artificial data. Except for the difference in operating efficiency, there are no significant differences in performance between MC-R/S and MC-V/S for the abrupt dynamic change detection. MC-R/S and MC-V/S both display some degree of anti-noise ability. However, it is important to consider the influences of strong noise on the detection results of MC-R/S and MC-V/S in practical application processes.

  5. Abrupt change in the dip of the subducting plate beneath north Chile

    Contreras-Reyes, E.; Jara, J.; Grevemeyer, I.; Ruiz, S.; Carrizo, D.

    2012-05-01

    No large tsunamigenic earthquake has occurred in north Chile since 1877 and the region has been largely recognized as a mature seismic gap. At the southern end of the seismic gap, the 2007 Mw7.7 Tocopilla earthquake ruptured the deeper seismogenic interface, whereas the coupled upper interface remained unbroken. Seismological studies onshore show a gently varying dip of 20° to 30° of the downgoing Nazca plate, which extends from the trench down to depths of 40-50km. Here, we study the lithospheric structure of the subduction zone of north Chile at about 22°S, using wide-angle seismic refraction and reflection data from land and sea, complemented by hypocentre data recorded during the 2007 Tocopilla aftershocks. Our data document an abrupt increase in the dip of the subducting plate, from less than 10° to about 22°, at a depth of approximately 20km. The distribution of the 2007 aftershocks indicates that the change in dip acted as a barrier for the propagation of the 2007 earthquake towards the trench, which, in turn, indicates that the subduction megathrust is not only segmented along the trench, but also in the direction of the dip. We propose that large-magnitude tsunamigenic earthquakes must cross the barrier and rupture the entire seismogenic zone.

  6. Yangtze Delta floods and droughts of the last millennium: Abrupt changes and long term memory

    Jiang, T.; Zhang, Q.; Blender, R.; Fraedrich, K.

    2005-09-01

    Climate variability and flood events in the Yangtze Delta, which is a low-lying terrain prone to flood hazards, storm tides and typhoons, are studied in terms of a trend and detrended fluctuation analysis of historical records. The data used in this paper were extracted from historical records such as local annuals and chronologies from 1000 1950 and supplemented by instrumental observations since 1950. The historical data includes frequencies of floods, droughts and maritime events on a decadal basis. Flood magnitudes increase during the transition from the medieval warm interval into the early Little Ice Age. Fluctuating climate changes of the Little Ice Age, which are characterised by arid climate events, are followed by wet and cold climate conditions with frequent flood hazards. For trend analysis, the Mann-Kendall test is applied to determine the changing trends of flood and drought frequency. Flood frequency during 1000 1950 shows a negative trend before 1600 A.D. and a positive trend thereafter; drought frequency increases after 1300. The detrended fluctuation analysis of the flood and drought frequencies reveals power law scaling up to centuries; this is related to long-term memory and is similar to the river Nile floods.

  7. Africa and climate change

    Toulmin, Camilla; Huq, Saleemul

    2006-10-15

    Remember the scenes from New Orleans of flooded streets and scavenging people? One year on and little progress is evident in achieving the step-change needed in controlling greenhouse gases. Hurricane Katrina showed only too vividly the massive power of natural forces combined with inadequate preparation. The flood waters washed away and exposed fully the lack of planning and low priority given to securing life and livelihoods, especially of the more vulnerable groups in the community. If this is what a whirlwind can bring in the southern USA, what might we reap in further storms and droughts tomorrow in poorer parts of the world? New research findings point to the likelihood of larger, faster and more substantial changes to our climate system. The African continent is particularly vulnerable to adverse changes in climate, the evidence for which is becoming more and more stark.

  8. Climate change and coasts

    The investigation of climatic processes and behaviour examines the effects of climatic changes on human beings and the surrounding environment. The authors discuss, in a wide-subject perspective, the regional impacts of the greenhouse effect, increase of the sea level, and changed conditions of both precipitation and wind using the North and Baltic Sea as examples. In this effort, questions dealing with changes of water level, motion and (disturbance) of the sea and morphodynamic in the coastal apron, in reference to requirements on a future protection of the shore, are handled. In addition, not only the aspects of ecosystem-orientated adaption in the strip of land between the continent northern islands 'Wattenmeer' and ground landscape (Bodenlandschaft) are taken into consideration, but also the impact of these on human beings and their interest to use the coastal regions. (orig.). 102 figs., 9 tabs

  9. Climate change and human health

    Warren, John A; Berner, James E; Curtis, Tine

    2005-01-01

    In northern regions, climate change can include changes in precipitation magnitude and frequency, reductions in sea ice extent and thickness, and climate warming and cooling. These changes can increase the frequency and severity of storms, flooding, or erosion; other changes may include drought o...... communities can begin to develop a response to climate change. With this information, planners, engineers, health care professionals and governments can begin to develop approaches to address the challenges related to climate change....

  10. Interdecadal Variations of Precipitation and Temperature in China Around the Abrupt Change of Atmospheric Circulation in 1976

    LI Chunhui; WAN Qilin; LIN Ailan; GU Dejun; ZHENG Bin

    2009-01-01

    The interdecadal characteristics of rainfall and temperature in China before and after the abrupt change of the general circulation in 1976 are analyzed using the global 2.5°×2.5° monthly mean reanalysis data from the National Centers for Environmental Prediction of US and the precipitation and temperature data at the 743 stations of China from the National Climate Center of China. The results show that after 1976, springtime precipitation and temperature were anomalously enhanced and reduced respectively in South China, while the reverse was true in the western Yangtze River basin. In summer, precipitation was anomalously less in South China, more in the Yangtze River basin, less again in North China and more again in Northeast China, showing a distribution pattern alternating with negative and positive anomalies ("-, +, -, +"). Meanwhile, temperature shows a distribution of warming in South China, cooling in the Yangtze and Huaihe River basins, and warming again in northern China. In autumn, precipitation tended to decrease and temperature tended to increase in most parts of the country. In winter, precipitation increased moderately in South China and warming was the trend across all parts of China. The interdecadal decline of mean temperature in spring and summer in China was mainly due to the daily maximum temperature variation, while the interdecadal increase was mainly the result of the minimum temperature change. The overall warming in autumn (winter) was mostly influenced by the minimum (maximum) temperature variation. These changes were closely related to the north-south shifts of the ascending and descending branches of the Hadley cell, the strengthening and north-south progression of the westerly jet stream, and the atmospheric stratification and water vapor transport conditions.

  11. Abrupt recent trend changes in atmospheric nitrogen dioxide over the Middle East

    Lelieveld, J.

    2015-08-21

    Nitrogen oxides, released from fossil fuel use and other combustion processes, affect air quality and climate. From the mid-1990s onward, nitrogen dioxide (NO2) has been monitored from space, and since 2004 with relatively high spatial resolution by the Ozone Monitoring Instrument. Strong upward NO2 trends have been observed over South and East Asia and the Middle East, in particular over major cities. We show, however, that a combination of air quality control and political factors, including economical crisis and armed conflict, has drastically altered the emission landscape of nitrogen oxides in the Middle East. Large changes, including trend reversals, have occurred since about 2010 that could not have been predicted and therefore are at odds with emission scenarios used in projections of air pollution and climate change in the early 21st century.

  12. The Nonlinear Response of the Equatorial Pacific Ocean-Atmosphere System to Periodic Variations in Insolation and its Association with the Abrupt Climate Transitions during the Quaternary.

    Lopes, P. G.

    2015-12-01

    The evidences of climate changes during the Quaternary are abundant but the physical mechanisms behind the climate transitions are controversial. The theory of Milankovitch takes into account the periodic orbital variations and the solar radiation received by the Earth as the main explanation for the glacial-interglacial cycles. However, some gaps in the theory still remain. In this study, we propose elucidating some of these gaps by approaching the Equatorial Pacific Ocean as a large oscillator, capable of triggering climate changes in different temporal scales. A mathematical model representing El Ninõ-like phenomena, based on Duffing equation and modulated by the astronomical cycle of 100 ka, was used to simulate the variability of the equatorial Pacific climate system over the last 2 Ma. The physical configuration of the Pacific Ocean, expressed in the equation, explains the temporal limit of the glacial-interglacial cycles. According to the simulation results, consistent with paleoclimate records, the amplification of the effects of the gradual variation of the Earth's orbit eccentricity - another unclear question - is due to the feedback mechanism of the Pacific ocean-atmosphere system, which responds non-linearly to small variations in insolation forcing and determines the ENSO-like phase (warm or cold) at different time scales and different intensities. The approach proposed here takes into account that the abrupt transitions between the ENSO-like phases, and the consequent changes in the sea surface temperature (SST) along the Equatorial Pacific Ocean, produce reactions that act as secondary causes of the temperature fluctuations that result in a glaciation (or deglaciation) - as the drastic change on the rate of evaporation/precipitation around the globe, and the increase (or decrease) of the atmospheric CO2 absorption by the phytoplankton. The transitional behavior between the warm and the cold phases, according to the presented model, is enhanced as

  13. Weather it's Climate Change?

    Bostrom, A.; Lashof, D.

    2004-12-01

    For almost two decades both national polls and in-depth studies of global warming perceptions have shown that people commonly conflate weather and global climate change. Not only are current weather events such as anecdotal heat waves, droughts or cold spells treated as evidence for or against global warming, but weather changes such as warmer weather and increased storm intensity and frequency are the consequences most likely to come to mind. Distinguishing weather from climate remains a challenge for many. This weather 'framing' of global warming may inhibit behavioral and policy change in several ways. Weather is understood as natural, on an immense scale that makes controlling it difficult to conceive. Further, these attributes contribute to perceptions that global warming, like weather, is uncontrollable. This talk presents an analysis of data from public opinion polls, focus groups, and cognitive studies regarding people's mental models of and 'frames' for global warming and climate change, and the role weather plays in these. This research suggests that priming people with a model of global warming as being caused by a "thickening blanket of carbon dioxide" that "traps heat" in the atmosphere solves some of these communications problems and makes it more likely that people will support policies to address global warming.

  14. Global climate change

    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 ( CO2, CH4, N2O, HFCs, PFCs and SF6) amounted to 79.2 million tonnes of CO2 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 CO2. Figs. 2, Tables 1. (nevyjel)

  15. Outchasing climate change

    Showstack, Randy

    Pygmy possums, monarch butterflies, spoon-billed sandpipers, and a number of trees and other plants could be among the species unable to migrate fast enough to new habitat in the face of potential global climate changes, according to an August 30 report by the Switzerland-based World Wide Fund for Nature (WWF) and the U.S. based Clean-Air-Cool Planet (CACP), two conservation organizations.

  16. Confronting Climate Change

    Mintzer, Irving M.

    1992-06-01

    This book, which was published in time for the Earth Summit in Brazil in June 1992, is likely to make a huge impact on the political and economic agendas of international policy makers. It summarizes the scientific findings of Working Group I of the IPCC in the first part of the book. While acknowledging the uncertainties in subsequent chapters, it challenges and expands upon the existing views on how we should tackle the problems of climate change.

  17. Climate change and forest

    Studies of the earth's present forms of vegetation show that the climate change to be expected from double the current greenhouse gas concentrations would have a fundamental impact on forest structures. This problem can be confronted in two ways: Either by adusting long-term silvicultural planning according to predictions derived from vegetation model calculations; or by managing forests in the manner of a flexible response strategy until changes actually occur. An evaluation of representative surveys of forests in Bavaria has shown that contrary to widerspread regions of Bavaria. This suggests that in the event of a warning by 1 to 2 C, assuming all other climate parameters to remain roughly constant, the beech could play a major role in the forest structure in large parts of Bavaria. The data material also shows that in defiance of all pessimistic forecasts the growth of beech has markedly improved over the past decade. To date the only explanations offered for this phenomenon are growth-stimulating changes in the chemical composition of the atmosphere, specifically the rise in carbon dioxide; and the enhanced nitrogen deposition in the soil. This example shows that the immense number of unpredictable influences prohibit long-term forecasts on forest development. Now if the forest is made up of a large number of tree species whose most favoured climatic ranges are known, then it is possible to meet climate changes with early silvicultural interventions and so preclude forest destruction. Scientifically founded silviculature can thus become an important support for the stability of our forests. (orig.)

  18. Managing Climate Change Risks

    Jones, R. [CSIRO Atmospheric Research, PMB1 Aspendale, Victoria 3195 (Australia)

    2003-07-01

    Issues of uncertainty, scale and delay between action and response mean that 'dangerous' climate change is best managed within a risk assessment framework that evolves as new information is gathered. Risk can be broadly defined as the combination of likelihood and consequence; the latter measured as vulnerability to greenhouse-induced climate change. The most robust way to assess climate change damages in a probabilistic framework is as the likelihood of critical threshold exceedance. Because vulnerability is dominated by local factors, global vulnerability is the aggregation of many local impacts being forced beyond their coping ranges. Several case studies, generic sea level rise and temperature, coral bleaching on the Great Barrier Reef and water supply in an Australian catchment, are used to show how local risk assessments can be assessed then expressed as a function of global warming. Impacts treated thus can be aggregated to assess global risks consistent with Article 2 of the UNFCCC. A 'proof of concept' example is then used to show how the stabilisation of greenhouse gases can constrain the likelihood of exceeding critical thresholds at both the both local and global scale. This analysis suggests that even if the costs of reducing greenhouse gas emissions and the benefits of avoiding climate damages can be estimated, the likelihood of being able to meet a cost-benefit target is limited by both physical and socio-economic uncertainties. In terms of managing climate change risks, adaptation will be most effective at reducing vulnerability likely to occur at low levels of warming. Successive efforts to mitigate greenhouse gases will reduce the likelihood of reaching levels of global warming from the top down, with the highest potential temperatures being avoided first, irrespective of contributing scientific uncertainties. This implies that the first cuts in emissions will always produce the largest economic benefits in terms of avoided

  19. Stop the climate change

    This book tries to answer today's main environmental questions relative to the climatic change: how our massive petroleum and coal consumption has led to a greenhouse effect? What will happen tomorrow when Chinese and Indian people will reach the same energy consumption levels as people of western countries? Is it too late to reverse the trend? If solar energy is the long-term solution, what can we do in the meantime? The author presents the conditions we must fulfill to keep the Earth in a good environmental condition: 1 - a brief story of energy; 2 - the climatic changes and their secrets; 3 - the greenhouse effect: necessary for life but worrying for the future; 4 - the energy demand and the stakes; 2 - fossil fuels: abundance or shortage? 6 - can we fight against greenhouse gases? 7 - the nuclear energy (reactors and wastes management); 8 - the renewable energies: a necessary contribution at the century scale and the unique answer at the millennium scale; 9 - the time of main choices is not so far; 10 - two questions (energy demand and climatic change) and a unique answer (sustainable development). (J.S.)

  20. Designing Global Climate Change

    Griffith, P. C.; ORyan, C.

    2012-12-01

    In a time when sensationalism rules the online world, it is best to keep things short. The people of the online world are not passing back and forth lengthy articles, but rather brief glimpses of complex information. This is the target audience we attempt to educate. Our challenge is then to attack not only ignorance, but also apathy toward global climate change, while conforming to popular modes of learning. When communicating our scientific material, it was difficult to determine what level of information was appropriate for our audience, especially with complex subject matter. Our unconventional approach for communicating the carbon crisis as it applies to global climate change caters to these 'recreational learners'. Using story-telling devices acquired from Carolyne's biomedical art background coupled with Peter's extensive knowledge of carbon cycle and ecosystems science, we developed a dynamic series of illustrations that capture the attention of a callous audience. Adapting complex carbon cycle and climate science into comic-book-style animations creates a channel between artist, scientist, and the general public. Brief scenes of information accompanied by text provide a perfect platform for visual learners, as well as fresh portrayals of stale material for the jaded. In this way art transcends the barriers of the cerebral and the abstract, paving the road to understanding.;

  1. Climate Change and Forests

    The causes for climatic change in the period between 3000 and 1250 BC was different from what present scenario portends. After industrialization, temperatures has arisen by 0.5 degrees centigrade every 100 years since factories started to spew out smoke. Over the last two centuries, the concentration of Carbon Dioxide in the atmosphere has increased by more than 25% from about 275ppm in the 18th Century to more than 350ppm at the present time while the current level is expected to double by the year 2050. The increase in Carbon Dioxide and together with other greenhouse gases in the atmosphere will trap the sun's radiation causing the mean global temperatures to rise by between 1 degree and 5 degrees centigrade by 2050. The climatic change affects forestry in many ways for instance, temperatures determines the rate at which enzymes catalyze biochemical reactions while solar radiation provide the energy which drive light reactions in photosynthesis. On the other hand, water which is a component of climate is a universal solvent which enables plants to transport nutrients through the transpirational stream, and similarly transport photosynthates from the leave to all parts of the plants. It is a raw material for photosynthesis and important for maintaining turgidity, which is important for growth

  2. Lay rationalities of climate change

    Alves, Fátima; Caeiro, Sandra; Azeiteiro, Ulisses

    2014-01-01

    In this special issue we were also interested in revealing the level of concepts and the level of social action, trying to contribute to the answer of questions like: How local populations explain, interpret and deal with climate change? What are the individual and collective actions in response to climate change? How do populations deal with Climate Change mitigation (risk perception and risk-mitigating)? What is the available traditional knowledge about Climate Change? How does the cu...

  3. Strategy for Climate Change Adaptation

    Rasmussen, Torben Valdbjørn

    The absence of a global agreement on the reduction of greenhouse gas emissions calls for adaptation to climate change. The associated paper explains the need for climate change adaptation of the building stock and suggests a pattern for a strategic approach to how to reach the climate change...... adaptation needed. Issues that must be addressed in case a strategic approach is not developed, as the building sector is continuously investing in measures to adapt to climate change as impacts emerge are described....

  4. Economic impacts of climate change

    Tol, Richard S.J.

    2015-01-01

    Climate change will probably have a limited impact on the economy and human welfare in the 21st century. The initial impacts of climate change may well be positive. In the long run, the negative impacts dominate the positive ones. Negative impacts will be substantially greater in poorer, hotter, and lower-lying countries. Poverty reduction complements greenhouse gas emissions reduction as a means to reduce climate change impacts. Climate change may affect the growth rate of the economy and ma...

  5. Agenda to address climate change

    This document looks at addressing climate change in the 21st century. Topics covered are: Responding to climate change; exploring new avenues in energy efficiency; energy efficiency and alternative energy; residential sector; commercial sector; industrial sector; transportation sector; communities; renewable energy; understanding forests to mitigate and adapt to climate change; the Forest Carbon budget; mitigation and adaptation

  6. Climate change, agriculture and poverty

    Hertel, Thomas W.; Rosch, Stephanie D

    2010-01-01

    Although much has been written about climate change and poverty as distinct and complex problems, the link between them has received little attention. Understanding this link is vital for the formulation of effective policy responses to climate change. This paper focuses on agriculture as a primary means by which the impacts of climate change are transmitted to the poor, and as a sector at...

  7. Agriculture and climate change

    How will increases in levels of CO2 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 CO2 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 CO2 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 CO2 by growth and utilization of biomass. Large areas are already available that could be devoted to energy crops

  8. Climatic change and impacts: a general introduction

    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

  9. Abrupt summer warming and changes in temperature extremes over Northeast Asia since the mid-1990s: Drivers and physical processes

    Dong, Buwen; Sutton, Rowan T.; Chen, Wei; Liu, Xiaodong; Lu, Riyu; Sun, Ying

    2016-09-01

    This study investigated the drivers and physical processes for the abrupt decadal summer surface warming and increases in hot temperature extremes that occurred over Northeast Asia in the mid-1990s. Observations indicate an abrupt increase in summer mean surface air temperature (SAT) over Northeast Asia since the mid-1990s. Accompanying this abrupt surface warming, significant changes in some temperature extremes, characterized by increases in summer mean daily maximum temperature (Tmax), daily minimum temperature (Tmin), annual hottest day temperature (TXx), and annual warmest night temperature (TNx) were observed. There were also increases in the frequency of summer days (SU) and tropical nights (TR). Atmospheric general circulation model experiments forced by changes in sea surface temperature (SST)/sea ice extent (SIE), anthropogenic greenhouse gas (GHG) concentrations, and anthropogenic aerosol (AA) forcing, relative to the period 1964-93, reproduced the general patterns of observed summer mean SAT changes and associated changes in temperature extremes, although the abrupt decrease in precipitation since the mid-1990s was not simulated. Additional model experiments with different forcings indicated that changes in SST/SIE explained 76% of the area-averaged summer mean surface warming signal over Northeast Asia, while the direct impact of changes in GHG and AA explained the remaining 24% of the surface warming signal. Analysis of physical processes indicated that the direct impact of the changes in AA (through aerosol-radiation and aerosol-cloud interactions), mainly related to the reduction of AA precursor emissions over Europe, played a dominant role in the increase in TXx and a similarly important role as SST/SIE changes in the increase in the frequency of SU over Northeast Asia via AA-induced coupled atmosphere-land surface and cloud feedbacks, rather than through a direct impact of AA changes on cloud condensation nuclei. The modelling results also imply

  10. Scenarios of climate change

    This article provides an overview of current and prospected climate changes, their causes and implied threats, and of a possible route to keep the changes within a tolerable level. The global mean temperature has up to 2005 risen by almost 0.8 C deg., and the change expected by 2100 is as large as glacial-interglacial changes in the past, which were commonly spread out over 10 000 years. As is well known, the principle actor is man-made CO2, which, together with other anthropogenic gases, enhances the atmosphere's greenhouse effect. The only man-made cooling agent appears to be atmospheric aerosols. Atmospheric CO2 has now reached levels unprecedented during the past several million years. Principal threats are a greatly reduced biodiversity (species extinction), changes in the atmospheric precipitation pattern, more frequent weather extremes, and not the least, sea level rise. The expected precipitation pattern will enhance water scarcity in and around regions that suffer from water shortage already, affecting many countries. Sea level rise will act on a longer time scale. It is expected to amount to more than 50 cm by 2100, and over the coming centuries the potential rise is of the order of 10 m. A global-mean temperature increase of 2 C deg. is often quoted as a safe limit, beyond which irreversible effects must be expected. To achieve that limit, a major, rapid, and coordinated international effort will be needed. Up to the year 2050, the man-made CO2 releases must be reduced by at least 50%. This must be accompanied by a complete overhaul of the global energy supply toward depending increasingly on the Sun's supply of energy, both directly and in converted form, such as wind energy. Much of the information and insight available today has been generated by the Intergovernmental Panel on Climate Change (IPCC), in particular its Fourth Assessment Report of 2007, which greatly advanced both public attention and political action. (author)

  11. The climatic change

    This paper has been developed to show how the future of the climate of our planet could become. The factors that takes places in this possible change are also carefully explained. The human action over the environment is probably disturbing the atmospheric system. The processes that involves this perturbations are shown: pollution, fires in hugh regions such as Amazonia Central Australia, Central and East Africa and some others. Factors like these seems are destroying the ozone shell. We also explain the problems to be sure that the expectatives for the future are reliable. Finally, we propose some solutions for this situation. Special situations like nuclear winter or the desertization are also included. (Author)

  12. Assessing Climate Change Impacts: Agriculture

    Bosello, Francesco; Zhang, Jian

    2005-01-01

    The economy-wide implications of climate change on agricultural sectors in 2050 are estimated using a static computable general equilibrium model. Peculiar to this exercise is the coupling of the economic model with a climatic model forecasting temperature increase in the relevant year and with a crop-growth model estimating climate change impact on cereal productivity. The main results of the study point out on the one hand the limited influence of climate change on world food supply and wel...

  13. Strategy for Climate Change Adaptation

    Rasmussen, Torben Valdbjørn

    2014-01-01

    . This absence of an agreement calls for adaptation to climate change. Emphasis should be put on buildings, as they play a vital economic and social role in society and are vulnerable to climate change. Therefore, the building stock deserves its own policy and implementation plans as well as tools that...... enable adequate and cost-efficient adaptation to climate change. This paper explains the need for climate change adaptation of the building stock and suggests a pattern for a strategic approach to how to reach the climate change adaptation needed. The suggested and presented need of a strategic approach...... is based on three main initiatives consisting of the need to examine the potential impacts of climate change on the building stock, the need to assess and develop a roadmap of current and future adaptation measures that can withstand the effects of climate change, and the need to engage relevant...

  14. Strategy for Climate Change Adaptation

    Rasmussen, Torben Valdbjørn

    2013-01-01

    . This absence of an agreement calls for adaptation to climate change. Emphasis should be put on buildings, as they play a vital economic and social role in society and are vulnerable to climate change. Therefore, the building stock deserves its own policy and implementation plans as well as tools that...... enable adequate and cost-efficient adaptation to climate change. This paper explains the need for climate change adaptation of the building stock and suggests a pattern for a strategic approach to how to reach the climate change adaptation needed. The suggested and presented need of a strategic approach...... is based on three main initiatives consisting of the need to examine the potential impacts of climate change on the building stock, the need to assess and develop a roadmap of current and future adaptation measures that can withstand the effects of climate change, and the need to engage relevant...

  15. Financing for climate change

    This paper argues that the 2009 pledge of $100 billion in 2020 by rich countries for mitigation and adaptation should not be used for mitigation by commercial firms in developing countries, since that would artificially create competitive advantage for such firms and provoke protectionist reactions in the rich countries where firms must bear the costs of mitigation, thereby undermining the world trading system. The costs of heating the earth's surface should be borne by all emitters, just as the price of copper and other scarce resources is paid by all users, rich or poor. That will still leave scope for rich country help in adaptation to climate change and in bringing to fruition new technologies to reduce emissions. - Highlights: ► Slowing climate change significantly cannot occur without the participation of the largest emitters among developing countries. ► The cost of GHG mitigation must be the same for all competing firms, wherever they are located. ► The world trading system is seriously at risk in the face of a poorly designed system for global mitigation of greenhouse gases. ► No significantly emitting firm, anywhere, public or private, should be protected from the incentive to reduce its emissions. ► Higher prices for fossil fuels need not reduce national growth rates in consuming countries.

  16. certainty and Climate Change Policy

    Quiggin, John

    2008-01-01

    The paper consists of a summary of the main sources of uncertainty about climate change, and a discussion of the major implications for economic analysis and the formulation of climate policy. Uncertainty typically implies that the optimal policy is more risk-averse than otherwise, and therefore enhances the case for action to mitigate climate change.

  17. Mapping Vulnerability to Climate Change

    Heltberg, Rasmus; Bonch-Osmolovskiy, Misha

    2011-01-01

    This paper develops a methodology for regional disaggregated estimation and mapping of the areas that are ex-ante the most vulnerable to the impacts of climate change and variability and applies it to Tajikistan, a mountainous country highly vulnerable to the impacts of climate change. The authors construct the vulnerability index as a function of exposure to climate variability and natura...

  18. NPOESS, Essential Climates Variables and Climate Change

    Forsythe-Newell, S. P.; Bates, J. J.; Barkstrom, B. R.; Privette, J. L.; Kearns, E. J.

    2008-12-01

    Advancement in understanding, predicting and mitigating against climate change implies collaboration, close monitoring of Essential Climate Variable (ECV)s through development of Climate Data Record (CDR)s and effective action with specific thematic focus on human and environmental impacts. Towards this end, NCDC's Scientific Data Stewardship (SDS) Program Office developed Climate Long-term Information and Observation system (CLIO) for satellite data identification, characterization and use interrogation. This "proof-of-concept" online tool provides the ability to visualize global CDR information gaps and overlaps with options to temporally zoom-in from satellite instruments to climate products, data sets, data set versions and files. CLIO provides an intuitive one-stop web site that displays past, current and planned launches of environmental satellites in conjunction with associated imagery and detailed information. This tool is also capable of accepting and displaying Web-based input from Subject Matter Expert (SME)s providing a global to sub-regional scale perspective of all ECV's and their impacts upon climate studies. SME's can access and interact with temporal data from the past and present, or for future planning of products, datasets/dataset versions, instruments, platforms and networks. CLIO offers quantifiable prioritization of ECV/CDR impacts that effectively deal with climate change issues, their associated impacts upon climate, and this offers an intuitively objective collaboration and consensus building tool. NCDC's latest tool empowers decision makers and the scientific community to rapidly identify weaknesses and strengths in climate change monitoring strategies and significantly enhances climate change collaboration and awareness.

  19. Changing heathlands in a changing climate

    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...

  20. Adaptation : climate change briefing paper

    Acclimatise

    2009-01-01

    Climate change adaptation means recognising what is happening to our climate on a global and local scale, and developing strategies to manage the risks that this presents is crucial to the growth, development and continuing success of any organisation.

  1. Climate Change and Poverty Reduction

    Anderson, Simon

    2011-08-15

    Climate change will make it increasingly difficult to achieve and sustain development goals. This is largely because climate effects on poverty remain poorly understood, and poverty reduction strategies do not adequately support climate resilience. Ensuring effective development in the face of climate change requires action on six fronts: investing in a stronger climate and poverty evidence base; applying the learning about development effectiveness to how we address adaptation needs; supporting nationally derived, integrated policies and programmes; including the climate-vulnerable poor in developing strategies; and identifying how mitigation strategies can also reduce poverty and enable adaptation.

  2. Climate changes and biodiversity

    As some people forecast an average temperature increase between 1 and 3.5 degrees by the end of the century, with higher increases under high latitudes (it could reach 8 degrees in some regions of Canada), other changes will occur: precipitations, sea level rise, reductions in polar ice, extreme climatic events, glacier melting, and so on. The author discusses how these changes will impact biodiversity as they will threat habitat and living conditions of many species. Some studies assess a loss of 15 to 37 per cent of biodiversity by 2050. Moreover, physiology is influenced by temperature: for some species, higher temperatures favour the development of female embryos, or the increase of their population, or may result in an evolution of their reproduction strategy. Life rhythm will also change, for plants as well as for animals. Species will keep on changing their distribution area, but some others will not be able to and are therefore threatened. Finally, as the evolutions concern their vectors, some diseases will spread in new regions

  3. Climate change, wine, and conservation

    Hannah, L.; Roehrdanz, PR; Ikegami, M; Shepard, AV; Shaw; Tabor, G; Zhi, L; Marquet, PA; Hijmans, RJ

    2013-01-01

    Climate change is expected to impact ecosystems directly, such as through shifting climatic controls on species ranges, and indirectly, for example through changes in human land use that may result in habitat loss. Shifting patterns of agricultural production in response to climate change have received little attention as a potential impact pathway for ecosystems. Wine grape production provides a good test case for measuring indirect impacts mediated by changes in agriculture, because viticul...

  4. Climate change and catchment hydrology

    Murphy, Conor

    2013-01-01

    Climate change is expected to alter catchment hydrology through changes in extremes of flooding and drought. River catchments are complex, dynamic systems and it is important to develop our understanding of how these systems are likely to respond to changes in climate. Work is ongoing in using EC-Earth simulations to further our understanding of how climate change will affect catchment hydrology and flood risk. In Ireland, the importance of this task is emphasised ...

  5. Climate change convention

    Principles that guide Canada's Green Plan with respect to global warming are outlined. These include respect for nature, meeting environmental goals in an economically beneficial manner, efficient use of resources, shared responsibilities, federal leadership, and informed decision making. The policy side of the international Framework Convention on Climate Change is then discussed and related to the Green Plan. The Convention has been signed by 154 nations and has the long-term objective of stabilizing anthropogenic greenhouse gas concentrations in the atmosphere at levels that prevent dangerous interference with the climate system. Some of the Convention's commitments toward achieving that objective are only applicable to the developed countries. Five general areas of commitment are emissions reductions, assistance to developing countries, reporting requirements, scientific and socioeconomic research, and education. The most controversial area is that of limiting emissions. The Convention has strong measures for public accountability and is open to future revisions. Canada's Green Plan represents one country's response to the Convention commitments, including a national goal to stabilize greenhouse gas emissions at the 1990 level by the year 2000

  6. Potential global climate change

    Global economic integration and growth contribute much to the construction of energy plants, vehicles and other industrial products that produces carbon emission and in effect cause the destruction of the environment. A coordinated policy and response worldwide to curb emissions and to effect global climate change must be introduced. Improvement in scientific understanding is required to monitor how much emission reduction is necessary. In the near term, especially in the next seven years, sustained research and development for low carbon or carbon-free energy is necessary. Other measures must also be introduced, such as limiting the use of vehicles, closing down inefficient power plants, etc. In the long term, the use of the electric car, use solar energy, etc. is required. Reforestation must also be considered to absorb large amounts of carbon in the atmosphere

  7. Competitiveness and climate change

    The author addresses the relationship between competitiveness and climate policy beyond the issue of emission quota trading, and with taking into account links between different activities. For some sectors, demand may depend on measures undertaken to reduce emissions in the transport and building sectors. According to the author, these interactions could transform the industry on a middle term, more than the required technical changes aimed at the reduction of emissions. After a detailed analysis on these issues, this paper discusses the results of several studies dealing with the relationship between environmental regulation and competitiveness, and with global assessments of carbon leakages. Then, the author discusses the European directive which introduces the Emission Trading Scheme (ETS)

  8. Indications of climatic change

    The earth's annual mean global temperature increased by around 0,6 C during the 20 century, with wide regional differences. Even if solar activity has played some part in the mean temperature rise and some greenhouse gases are present naturally in the atmosphere, enhancing of the greenhouse effect due to the human activities is responsible for a large and increasing part of the observed warming. The work of the Intergovernmental Panel on Climate Change confirms the future increase under all scenarios. Depending on the efforts made by mankind to limit greenhouse gases emissions, the global mean temperature in 2100 could be between 1,4 and 5,8 C higher than in 2000. (A.L.B.)

  9. Geopolitics of climate change

    Climate change has become an international policy topic. Its stakes go beyond the simple ecological question to encompass the overall global equilibrium, and in particular the North-South relations. This book, with solid references and illustrated with a tenth of color maps, examines the geopolitical dimension of global warming. Who are the countries responsible or considered to be so? Who are those who will be the most impacted? What population migrations have already started or have to be foreseen? What are the international security risks? The author presents also the different international cooperation mechanisms already implemented and takes stock of the present day situation of negotiations. We are entering into the critical phase, and probably into the potentially dramatic phase as well. This book allows to understand its key aspects and driving forces

  10. Economic analysis of climate change

    Vojtíšek, Petr

    2012-01-01

    The bachelor thesis themed “Economic Analysis of Climate Change” focuses on the climate change from an economical point of view. The theoretical part sums up the basic facts about climate change, go through the most important social, environmental and economic impacts, main opinions about the climate change and also the main ideas of the mitigation and adaptation processes. The analyses tries to give the climate a monetary value with a use of non-market method to find out how much would be st...