Climate Change an Introduction ecbi Workshops 2007 Claire

Climate Change: an Introduction ecbi Workshops 2007 Claire N Parker Environmental Policy Consultant for sustained capacity building in support of international climate change negotiations pour un renforcement durable des capacités en appui aux négociations internationales sur les changements climatiques european capacity building initiative ecbi european capacity building initiative européenne de renforcement des ecbi

The greenhouse effect in the atmosphere european capacity building initiative ecbi

Natural and man-made carbon cycles 1. 7 1. 9 60 ATMOSPHERE 3. 3 5. 4 1. 9 90 OCEAN LAND european capacity building initiative ecbi Annual transfers, natural and human-made (Gt. C) Source: IPCC

CO 2 is major contributor to global warming Current emissions, effect over next 100 years Nitrous oxide 10% Others 3% Carbon dioxide 63% european capacity building initiative ecbi Methane 24%

european capacity building initiative ecbi Sources of Greenhouse Gases • CO 2 from fossil fuel use (mainly power generation, transport) and land use change (e. g. deforestation) • CH 4 (methane) and NO 2 (nitrous oxide) primarily from agriculture

Stages in predicting climate change CONCENTRATIONS Carbon cycle and chemistry models ‘Climate Forcing’. CLIMATE CHANGE feedbacks CO 2, methane, etc. HEATING EFFECT Gas properties Temp, rain, sea level, etc. Coupled climate models IMPACTS Impacts models Flooding, food supply, etc. european capacity building initiative ecbi Scenarios from population, energy, economics models EMISSIONS

The climate system european capacity building initiative ecbi

Strong global warming observed since 1975 european capacity building initiative ecbi

european capacity building initiative ecbi IPCC’s AR 4 2007 Warming is unequivocal… now clearly evident in many aspects of the climate system

• Earth surface has warmed by 0. 74 C over last century • Sea levels rose 20 cm last century • Glaciers, snow cover and sea ice all declining • More heat-waves, droughts and extreme rainfalls • More intense cyclones european capacity building initiative ecbi Signs of climate change

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european capacity building initiative ecbi Carbon dioxide in the atmosphere: rapid rise due to human activities

CO 2 from fossil-fuel burning: rapid rise since 1950 european capacity building initiative ecbi Source: CDIAC, ORNL

Similar patterns are observed for methane (CH 4) and nitrous oxide (NO 2) european capacity building initiative ecbi Other Greenhouse gases

Anthropogenic is > 10 times that of solar since 1750 european capacity building initiative ecbi AR 4: high confidence in radiative forcing data

european capacity building initiative ecbi AR 4: models are getting better • Models are used to simulate the warming of the last 150 years • Their results correlate with anthropogenic + natural warming • Natural causes can’t explain what has happened.

european capacity building initiative ecbi AR 4: observed vs. modelled global climate change

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european capacity building initiative ecbi What do models predict? • AR 4: There is now higher confidence in projected patterns of warming, and other regional-scale features, including changes in wind patterns, precipitation and some aspects of extreme events and changes in ice cover

european capacity building initiative ecbi This century global temperature likely to be between 1. 8 and 4 C above today’s

• Scale of warming depends on emissions: Low scenario 1. 1 – 2. 9 C High scenario 2. 4 – 6. 4 C european capacity building initiative ecbi • A further warming of about 0. 6 C likely from past emissions alone

Warming expected to be greatest over land at high northern latitudes european capacity building initiative ecbi Geographical patterns of warming

• Sea levels will rise by 18 to 59 cm by 2100. Additional 10 -20 cm or more may come from Greenland Antarctic ice sheets • Snow cover, glaciers and sea ice will continue to decline • Rainfall and wind patterns will change • Extreme events (rainfall and droughts) more frequent • Tropical cyclones more intense • Meridional Overturning Circulation in N Atlantic likely to slow down by 25% european capacity building initiative ecbi Other changes in climate will continue

The Atlantic Ocean’s Circulation System european capacity building initiative ecbi

european capacity building initiative ecbi Changes will continue for centuries, even if GHG concentrations were to be stabilised by 2100

Emissions to 2000, and IPCC projections to 2100 european capacity building initiative ecbi

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european capacity building initiative ecbi Past and projected CO 2 emissions from fuel burning IEA World Energy Outlook fossil 2004

References & Acknowledgements • IPCC, Climate Change 2001 Synthesis Report of the Third Assessment Report • IPCC, AR 4, 2007 • DEFRA, UK (Department for Environment, Food and Rural Affairs) european capacity building initiative ecbi • Climate Change and The Greenhouse Effect, A briefing from the Hadley Centre, Dec 2005 enquiries@metoffice. gov. uk

Claire N Parker claire. n. parker@btopenworld. com +44 1763 209 066 +44 7769 66 47 01 european capacity building initiative ecbi Thank You