FINAL Abstract Book 1

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This abstract book is ordered by conference,session and presentation order. Session 1 Opening talks and scene setting 3, Session 2 3 Agriculture food and water security 10. Session 4 Ecosystems and ecosystem services 72,Session 5 6 Vulnerable people and places 97. Session 8 Adaptation 143,Session 9 10 Avoiding large climatic changes 160. Conference Agenda 197,Opening session,Terra quasi incognita beyond the 2 C line.
Professor John Schellnhuber, Potsdam Institute for Climate Impact Research Potsdam Germany. The G8 countries as well as the most important developing countries have formally. acknowledged the emerging scientific consensus that global warming should be confined to. maximally 2 C My presentation will first summarize salient general arguments why that. guardrail should be observed and then sketch the scope of the challenges involved in. holding the line The latter analysis will be based upon recent insights on the relationship. between planetary mean temperature and cumulative CO2 emissions According to the new. report of the German Advisory Council on Global Change WBGU a full fair and feasible. solution of the climate problem can be derived from that budget approach yet its adoption. by the multilateral political system is rather unlikely Therefore a world warming up by 3 4. or even more degrees needs to be faced or at least imagined The lecture will proceed by. reviewing the state of the art concerning the highly nonlinear impacts on the Earth System. that can be expected as a consequence of unlimited climate change or cannot be safely. excluded to arise beyond the 2 C line The focus will be on tipping elements in the. planetary machinery and their possible interactions The talk will conclude by touching upon. the tantalizing question whether there is such a thing on Earth as a run away greenhouse. 4 degrees of global warming regional patterns and timing. Richard Betts1 Michael Sanderson1 Deborah Hemming1 Ben Booth1 Jason Lowe1 Chris. Jones1 Mark New2, Met Office Hadley Centre Exeter United Kingdom 2Tyndall Centre University of Oxford. Oxford United Kingdom, If global mean temperatures reach 4 C above pre industrial which seems likely if greenhouse. gas emissions continue at current rates for much of the coming century we can expect a very. wide variation in regional climate responses across the globe This presentation examines a. large number of climate simulations to assess such potential changes and the ranges of. uncertainty in these While most of the ocean surface is expected to warm at less than the. global mean rate the Arctic ocean surface is projected to warm faster than the global mean. due to positive feedbacks from melting sea ice Figure 1 At 4 C global warming regional. warming of 10 C or more is plausible in the Arctic High levels of warming such as 7 C are. also projected for many land regions Precipitation patterns are also projected to change but. models disagree strongly on the regional details On average across model ensembles. precipitation decreases of approximately 20 are projected in some regions such as the. Mediterranean central America and southern Africa although some individual models give. much larger decreases in some regions Figure 2, Of key interest is the timing of when 4 C could occur This depends on both the emissions. scenario and on the strength of feedbacks between climate change and the carbon cycle. There is an emerging consensus that the airborne fraction of CO2 emissions is expected to. increase in response to climate change accelerating the CO2 rise and hence accelerating. global warming Clearly this would bring forward the time at which global warming would. surpass 4 C for a given emissions scenario However uncertainties in the strength of carbon. cycle feedbacks are large This presentation assesses the current range of model projections. for this timing and identifies key uncertainties to be addressed. Figure 1 Ensemble mean patterns of temperature change C relative to 1961 1990 average. for high end climate change projected by the subset of the IPCC AR4 climate models that. exceed 4 C by 2100 relative to pre industrial when driven by the A2 emissions scenario. neglecting the effect of climate carbon cycle feedbacks High end climate change is. defined as exceeding 4 C relative to pre industrial. Figure 2 Ensemble mean patterns of precipitation change of 1961 1990 average for. high end climate change projected by the subset of the IPCC AR4 climate models that. exceed 4 C by 2100 when driven by the A2 emissions scenario neglecting the effect of. climate carbon cycle feedbacks High end climate change is defined as exceeding 4 C. relative to pre industrial,Beyond 4oC impacts across the global scale.
Nigel Arnell1 Tim Osborn2 Robert Nicholls3 Tim Wheeler1 Terry Dawson3 Pete Smith4. Richard Harding5 Evan Fraser6 Richard Betts9 Graham Pilling7 Richard Taylor8. University of Reading Reading United Kingdom 2University of East Anglia Norwich. United Kingdom 3University of Southampton Southampton United Kingdom 4University of. Aberdeen Aberdeen United Kingdom 5CEH Wallingford Oxfordshire United Kingdom. University of Leeds Leeds United Kingdom 7CEFAS Suffolk United Kingdom 8UCL. London United Kingdom 9Met Office Hadley Centre Exeter United Kingdom. Most studies of the potential impact of climate change focus on impacts at the local and. regional scales there are few consistent projections of impacts across the global domain The. QUEST GSI project takes a global perspective using a suite of linked spatially explicit. impacts models with a range of socio economic and climate scenarios This presentation. focuses on initial assessments of impacts by the end of the 21st century under large increases. in global mean temperature more than 4oC higher than pre industrial and compares these. impacts with those under lower rates of change, The QUEST GSI project includes impact indicators representing water resources flooding. food crops fisheries and food security health and the environment terrestrial ecosystem. productivity biome types and soil carbon The models mostly operate at the fine resolution. gridded scale or by coastal unit with results aggregated to country and regional levels. Climate scenarios are derived from the climate model simulations presented in the IPCC s. Fourth Assessment Report the CMIP3 data set and are scaled to represent the regional and. seasonal changes in temperature rainfall and other climate variables corresponding to a set of. defined changes in global mean temperature ranging from 0 5oC to 6oC above the 1961 1990. mean For most of the climate models estimates of climate change for increases in global. mean temperature above 4oC are an extrapolation beyond the climate model results and at. such high increases in temperature the assumption that regional and seasonal climate changes. scale linearly with global mean temperature becomes increasingly unrealistic estimated. impacts at such high global temperature changes are therefore more uncertain than estimates. at lower temperature changes, The modelled biophysical impacts of these climate scenarios are then combined with socio. economic scenarios to express impacts in a range of socio economic indicators. A number of preliminary conclusions can be drawn from the analyses A given change in. global mean temperature corresponds to different changes in temperature in different places. and at different times of the year with different climate models producing quantitively. different patterns of change Regional temperature changes tend to be above the global mean. in high latitudes and close to or below the global mean in low latitudes and below the global. mean across most of the oceans overall the increase in temperature across land is greater. than the global mean Temperature changes vary through the year For example a 4oC. change in global mean temperature change corresponds to an increase in December February. temperature in southern Asia under one model of 6oC but an incease in June August of only. 3oC Whilst there is a broad degree of consistency in the qualitative patterns of change in. climate between models with notable exceptions in south Asia and parts of Africa. different climate models produce quantitatively different estimates of the regional. consequences associated with a given change in global mean temperature The estimated. impacts associated with that change in global mean temperature are therefore quantitatively. uncertain particularly at the local and regional scale and depend on which climate models. are considered, In many impact sectors the response between rate of climate forcing and impact is non linear. so that for example impacts under a 4oC global change are not necessarily twice the impacts. under a 2oC change In biophysical systems this can occur because of phase state changes. e g the switch from snowfall to rain produces a regime shift in hydrological regimes or. because the relative effects of different drivers of change such as temperature and. precipitation vary as these drivers change For example in some locations wheat yields. increase for relatively low temperature and rainfall changes but decrease for larger changes. as the damaging effect of high temperatures begin to dominate It is not therefore possible to. infer directly impacts at one global temperature change from impacts estimated at another. The shape of the relationship between magnitude of climate change and impact and hence on. the relative impacts with low and high climate change varies between regions Figure 1. shows the proportion of regional population exposed to an increase in water resources stress. under one climate model different models produce different shape relationships In some. regions a relatively low climate change 1oC is sufficient to trigger large adverse impacts. whilst in others major step changes in impact occur only at higher temperatures. The actual impact in socio economic terms of a given biophysical change depends on the. socio economic conditions pertaining at the time For example a 4oC increase in global mean. temperature in 2080 would under one climate model mean that approximately 1 billion. people would be exposed to increased water resources stress under one population scenario. but under another more populous scenario the figure would be closer to 2 billion people a. slightly larger proportion of a much larger population. The estimated impacts of high rates of climate change are therefore dependent on the. climate models used to project the regional and seasonal changes in climate associated with a. given global temperature change and assumed future socio economic conditions including. adaptive capacity impacts at one temperature change also cannot be inferred directly from. impacts at another Nevertheless the presentation concludes with a initial qualitative multi. sectoral assessment of impacts across the global domain at 4oC change above 1961 1990. based on multiple climate model runs and a range of socio economic futures. 2080 HadCM3 A1b,of regional population,0 1 2 3 4 5 6. Global temperature change C above 1961 1990, Figure 1 Regional impact of rising global temperature on the proportion of regional.
Agriculture Food, Four degrees plus What might this mean for agriculture in sub Saharan Africa. Philip K Thornton1 Peter G Jones2, International Livestock Research Institute ILRI Nairobi Kenya 2Waen Associates. Dolgellau Wales United Kingdom, Potential impacts of climate change on agricultural production in sub Saharan Africa SSA. have been assessed in numerous studies recently Ranges for major crops depend on the. methods and models used and the emission scenarios simulated but for maize there is some. consensus that yields may be reduced overall by 10 30 to the middle of the century. Challinor et al 2007 Lobell et al 2008 Despite the uncertainty African agricultural. productivity will be severely affected in the coming decades by climate change The losses. estimated in the literature are generally incomplete however First they are often aggregated. hiding great heterogeneity For example there will be areas in East Africa particularly in the. lowlands where crop yield reductions of 40 or more may occur for the staples maize and. beans largely as a result of increasing temperatures Thornton et al 2009 Second it is not. clear how the impacts of carbon fertilisation on crop yields in an African context might best. be addressed There is ongoing debate about the size of the effects on the physiology of. crops Ainsworth et al 2008 there are also knowledge gaps concerning the impacts of. changing ozone concentrations on crop growth and how these may interact with CO2 effects. and with other biotic and abiotic stresses Challinor et al 2009 and the carbon fertilisation. impacts on the low input subsistence production systems that prevail in SSA will generally. be smaller than those seen in controlled high input environments Third agricultural. production will be affected by climate change not only over the long term but also over the. short the impacts of changing extremes and increasing weather variability on agricultural. production are largely unknown pending the generation of robust estimates of future. variability associated with specific greenhouse gas emission scenarios. The multi model means of surface warming relative to 1980 1999 for SRES scenarios A2. A1B and B1 from the IPCC s Fourth Assessment show increases of about 1 2 C to the 2050s. This abstract book is ordered by conference United Kingdom 7CEFAS Suffolk United Kingdom 8UCL London United Kingdom 9Met Office Hadley Centre Exeter United Kingdom Most studies of the potential impact of climate change focus on impacts at the local and regional scales there are few consistent projections of impacts across the global domain The QUEST GSI project takes a global

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