Climate Change Science

1. Climate Change Science David Stevenson Institute of Atmospheric and Environmental Sciences University of Edinburgh

2. Joint Statement from the world’s science academies for the 2005 G8 • Climate change is real – the evidence is overwhelming • We can reduce the causes of climate change – no single solution, but needs major changes in human behaviour • Future climate change (in the next few decades) is inevitable – we need to start preparing now

3. Global surface temperature 1855-2005 World has warmed 0.7°C in last century

4. Recent warming is unprecedented

5. The warming is happening almost everywhere

6. Nearly all the worlds glaciers are in retreat… 2004 1875

7. Sea levels are rising – 10-15 cm in last 100 years…

8. Sea-level from satellites: 4 cm rise in last 10 years

9. Thames Barrier Usage 1982-2003

10. Spring is getting earlier!

12. What is driving climate change? • Increases in greenhouse gases, in particular CO2 • Main sources are burning fossil fuels; also deforestation and agriculture • Minor influences on climate from natural processes (solar variations, volcanoes)

13. Including natural and anthropogenic forcings makes the model producethe best simulation of20th century climate

14. Q: Why worry about climate change ?

15. Q: Why worry about climate change ?

16. ‘Danger’ level Global temperature projections What are our future options? CO2 emissions scenarios • Warming of ~2°C is almost inevitable – even with very optimistic emissions; • 2°C is considered to be the ‘dangerous’ level of climate change…

17. Q: Why worry about climate change ?

18. Q: Why worry about climate change ?

19. Joint Statement from the world’s science academies for the 2005 G8 • Climate change is real – the evidence is overwhelming • We can reduce the causes of climate change – no single solution, but needs major changes in human behaviour • Future climate change (in the next few decades) is inevitable – we need to start preparing now