Climate_Change_introduction and basic concepts.ppt
- 1. Climate Change: an Introduction ecbi Workshops 2007 Claire N Parker Environmental Policy Consultant european capacity building initiative initiative européenne de renforcement des capacités ecbi 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
- 2. The greenhouse effect in the atmosphere
- 3. Natural and man-made carbon cycles OCEAN LAND ATMOSPHERE 90 60 5.4 1.7 1.9 1.9 Annual transfers,natural and human-made (GtC) 3.3 Source: IPCC
- 4. CO2 is major contributor to global warming Current emissions, effect over next 100 years Methane 24% Carbon dioxide 63% Nitrous oxide 10% Others 3%
- 5. Sources of Greenhouse Gases • CO2 from fossil fuel use (mainly power generation, transport) and land use change (e.g. deforestation) • CH4 (methane) and NO2 (nitrous oxide) primarily from agriculture
- 6. Stages in predicting climate change CONCENTRATIONS CO2, methane, etc. HEATING EFFECT ‘Climate Forcing’. IMPACTS Flooding, food supply, etc. Scenarios from population, energy, economics models Carbon cycle and chemistry models Gas properties Coupled climate models Impacts models CLIMATE CHANGE Temp, rain, sea level, etc. EMISSIONS feedbacks
- 8. Strong global warming observed since 1975
- 9. IPCC’s AR4 2007 Warming is unequivocal… now clearly evident in many aspects of the climate system
- 10. Signs of climate change • Earth surface has warmed by 0.74C over last century • Sea levels rose 20cm last century • Glaciers, snow cover and sea ice all declining • More heat-waves, droughts and extreme rainfalls • More intense cyclones
- 11. Carbon dioxide in the atmosphere: rapid rise due to human activities
- 12. CO2 from fossil-fuel burning: rapid rise since 1950 Source: CDIAC, ORNL
- 13. Other Greenhouse gases Similar patterns are observed for methane (CH4) and nitrous oxide (NO2)
- 14. AR4: high confidence in radiative forcing data Anthropogeni c is > 10 times that of solar since 1750
- 15. AR4: 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.
- 16. AR4: observed vs. modelled global climate change
- 18. What do models predict? • AR4: 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
- 19. This century global temperature likely to be between 1.8 and 4 C above today’s
- 20. • A further warming of about 0.6C likely from past emissions alone • Scale of warming depends on emissions: Low scenario 1.1 – 2.9 C High scenario 2.4 – 6.4 C
- 21. Geographical patterns of warming Warming expected to be greatest over land and at high northern latitudes
- 22. •Sea levels will rise by 18 to 59 cm by 2100. Additional 10-20 cm or more may come from Greenland and 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% Other changes in climate will continue
- 23. The Atlantic Ocean’s Circulation System
- 24. Changes will continue for centuries, even if GHG concentrations were to be stabilised by 2100
- 25. Emissions to 2000, and IPCC projections to 2100
- 27. Past and projected CO2 emissions from fossil fuel burning IEA World Energy Outlook 2004
- 28. References & Acknowledgements • Climate Change and The Greenhouse Effect, A briefing from the Hadley Centre, Dec 2005- enquiries@metoffice.gov.uk • IPCC, Climate Change 2001 Synthesis Report of the Third Assessment Report • IPCC, AR4, 2007 • DEFRA, UK (Department for Environment, Food and Rural Affairs)
- 29. Thank You Claire N Parker claire.n.parker@btopenworld.com +44 1763 209 066 +44 7769 66 47 01