* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Climate change - cause and consequences
Climatic Research Unit email controversy wikipedia , lookup
Mitigation of global warming in Australia wikipedia , lookup
Soon and Baliunas controversy wikipedia , lookup
Heaven and Earth (book) wikipedia , lookup
German Climate Action Plan 2050 wikipedia , lookup
Michael E. Mann wikipedia , lookup
Climate resilience wikipedia , lookup
ExxonMobil climate change controversy wikipedia , lookup
Economics of climate change mitigation wikipedia , lookup
Climate change denial wikipedia , lookup
Global warming hiatus wikipedia , lookup
Fred Singer wikipedia , lookup
Global warming controversy wikipedia , lookup
2009 United Nations Climate Change Conference wikipedia , lookup
Instrumental temperature record wikipedia , lookup
Effects of global warming on human health wikipedia , lookup
Climate engineering wikipedia , lookup
Intergovernmental Panel on Climate Change wikipedia , lookup
Citizens' Climate Lobby wikipedia , lookup
Climate governance wikipedia , lookup
Climatic Research Unit documents wikipedia , lookup
Global warming wikipedia , lookup
Climate change in Saskatchewan wikipedia , lookup
Politics of global warming wikipedia , lookup
Climate change in Canada wikipedia , lookup
United Nations Framework Convention on Climate Change wikipedia , lookup
Climate change in Tuvalu wikipedia , lookup
Climate change adaptation wikipedia , lookup
Economics of global warming wikipedia , lookup
General circulation model wikipedia , lookup
Media coverage of global warming wikipedia , lookup
Climate sensitivity wikipedia , lookup
Criticism of the IPCC Fourth Assessment Report wikipedia , lookup
Solar radiation management wikipedia , lookup
Effects of global warming wikipedia , lookup
Climate change feedback wikipedia , lookup
Climate change and agriculture wikipedia , lookup
Public opinion on global warming wikipedia , lookup
Attribution of recent climate change wikipedia , lookup
Carbon Pollution Reduction Scheme wikipedia , lookup
Scientific opinion on climate change wikipedia , lookup
Surveys of scientists' views on climate change wikipedia , lookup
Climate change and poverty wikipedia , lookup
Climate change, industry and society wikipedia , lookup
Climate change causes and consequences Professor Nigel Arnell Walker Institute for Climate System Research Commonwealth War Graves Commission Climate change conference London, February 11 2008 Recent “unusual” weather… Summer 2007 Summer 2003 Met Office Global average temperature Global average temperature Temperature anomaly from 1961-1990 average (oC) 1 All of the 10 warmest years since 1850 have occurred since 1995 0.8 0.6 0.4 0.2 0 1840 1860 1880 1900 1920 1940 1960 1980 2000 -0.2 -0.4 -0.6 -0.8 Crutem3gl, Climatic Research Unit, University of East Anglia 2020 Outline • What is driving this change in climate? • What could happen in the future? • How will weather change? • What can we say about the next 20 years? • What will be the effects of climate policy? What is driving the change in climate? Possible explanations: - natural variability - variation in solar output - increasing concentration of greenhouse gases “Greenhouse” gases alter the radiative balance of the surface of the earth by trapping outgoing longwave radiation Carbon dioxide (CO2) Methane Nitrous oxides Water vapour Changing concentrations CO2 Methane Nitrous oxide IPCC AR4 WG1 2007 Changing emissions IPCC AR4 WG3 2007 Forcing the climate IPCC AR4 WG1 2007 Attributing change IPCC AR4 WG1 2007 Attributing change IPCC AR4 WG1 2007 What could happen in the future? Future climate changes will depend on: (i) rate of future emissions of greenhouse gases (ii) rate at which these are absorbed by land and oceans (iii) how the climate responds to the changing atmospheric composition Use climate models to simulate response Future global temperature change Different emissions Different climate models IPCC AR4 WG1 2007 Variations over space Change in average annual temperature by the end of the 21st century A1b IPCC AR4 WG1 2007 Variations over space December-February June-August IPCC AR4 WG1 2007 Changes in Europe 2-5oC by the end of the century 1-2.5oC by the 2020s IPCC AR4 WG1 2007 Changes in Europe IPCC AR4 WG1 2007 Changes in Asia 2-4oC by the end of the century 0.75-2oC by the 2020s IPCC AR4 WG1 2007 Change in Asia IPCC AR4 WG1 2007 How will weather change? A change in “climate” will impact via a change in local weather Change in the weather Widespread: Increase in the frequency of hot extremes Decrease in the frequency of cold extremes In many areas Increase in the frequency of high-intensity rainfall Increase in the frequency of “drought” events Change in key weather patterns Monsoons: - monsoon rainfall will probably increase, but this is uncertain El Nino: - uncertainty over how this will change Tropical cyclones - will probably increase in intensity, but not necessarily in frequency Significant uncertainty over changes in extremes: we know that they will change, but not how they will change High resolution weather simulation What will happen over the next 20 years? • Climate change is superimposed on natural variability; in the medium term this variability is relatively large – year to year variability – multi-year rhythms Our models don’t necessarily simulate this very well yet… The next 20 years • Model predictions depend on where the model starts from… Smith et al. (2007) Science What effects would climate policy have? Article 2: …stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system… • Kyoto target: - Annex 1 countries reduce emissions by 5% by 2008-12, compared to 1990 levels • EU target - Reduce emissions by 20% by 2020 Effects of policy on climate No climate policy commitment With policy targets Van Vuuren (2007) Adaptation We need to adapt to a changing climate Coping with uncertainty Develop risk-based methods with multiple scenarios Develop flexible adaptation measures which do not rely on precise forecasts Some conclusions • Climate change is happening, and is due to human activity • By the end of the century, temperatures will be 1.8-4oC higher – and possibly more • Effects on weather vary locally • General tendency towards an increasing frequency of extremes • Climate policy will not stop impacts over the next couple of decades Thank you www.walker-institute.ac.uk