1. Global Climate Change

2. 150 Authors 1,000 Contributing Authors 5 Years Work 130 Countries 1,000 Expert Reviewers The Famous “IPCC Report”

3. Vostok Ice Core Looking Back in Time

4. Temperature From 650,000 Years Ago N20N20 CH 4 CO 2 T Thousands years before 1950

5. Temperature From 1,300 Years Ago Year Little Ice Age Medieval Warm Period Temperature Change (°C)

6. Temperature From 150 Years Ago Year ~1°C Temperature Change (°C)

7. SurfaceAbove Where is This Happening?

8. An Explosion of New Data Oceans are warming Glaciers are retreating Ice sheets are melting Sea level is rising Sea-ice is melting

9. Oceans are Warming Year Heat Content Change

10. Photos: US Geological Service, via National Snow and Ice Data Centre 1909 Toboggan Glacier, Alaska 2000 Glaciers are Retreating Year Length Change (m)

11. Ice Sheets are Melting Elevation Change (cm/year)

12. Reconstructed sea level fields Tide gauges Satellites Sea Level is Rising ~20 cm Year Sea Level Change (mm)

13. Sea-ice is Melting Year Millions of square km

14. Why is This Happening? Climate models used to understand and predict climate change Based on physical principles, and subject to extensive validation

15. Observations Climate Models

16. Observations Climate Models

17. What About the Next 20 Years? 0.5°C

18. What About the Next 90 Years? 1-4°C

19. And the Next 300 Years?

20. Expect Sea Level Rise ~ 0.5 m Sea Level Change Anomalies

21. Expect Large Warming Over Land Temperature Change (°C)

22. Expect Regional Precipitation Change Precipitation Change

23. Heavier Precipitation Longer Growing Season More Heat Waves More Drought

24. Winners and Losers

25. Key Messages The climate has warmed, will continue to warm, and humans are the cause Mitigation will not substantially affect the climate over the next few decades But, choices made now will have a big impact on the late 21 st century climate

26. Global Climate Change