1. GLOBAL WARMING What impact will it have on the world? And what impact will it have on me?

2. Future Climate Change What are the likely climate changes during this century? -global temperature increase -change in precipitation distribution -sea level rise -glacier/sea ice melting - ocean acidification What factors will likely control the magnitude of climate change? -population and economic growth -CO 2, CH 4 and SO 2 (aerosol) emissions and response of clouds -success of mitigation efforts

3. The Real Announcement of THE END OF THE WORLD IT WON’T LOOK LIKE THIS IT WILL LOOK A LOT LIKE THIS

4. Is Global Warming real? YES - GLOBAL TEMPERATURES HAVE SHOWN AN AVERAGE INCREASE OF ABOUT 1.5°F (0.76°C) OVER THE PAST 100 YEARS.

5. Why are a few degrees °C a big deal? The temperature varies more than that between night and day; summer and winter! Because we are talking about global temperature averages, NOT weather.

6. For comparison; some global temperature differences: Last glacial maximum: - 4°C [20,000 years BP] Western Washington Cretaceous Hot House (palm trees and alligators in the Arctic Ocean) + 10°C [100 million years BP] Barrow Alaska

7. WHY IS THE GLOBAL CLIMATE WARMING? Global temperatures are controlled by the amount of GREENHOUSE GASES in the atmosphere. These gases are the ‘THERMOSTAT’ of the earth.

8. The main greenhouse gases are… WATER CO 2 METHANE NITROUS OXIDE CFCs (freon) What are “GREENHOUSE GASES”? And where do they come from? And these have both natural and man-made sources

9. If there were NO Greenhouse gases in the atmosphere, the global temperature would be -15°C, instead of the present +15°C. And this has happened in the past (+ 1 billion years ago). It is called ‘SnowBall Earth’ – and the oceans froze solid.

10. How have greenhouse gases changed recently? CO 2 concentrations over the last 10,000 years NOW

11. Are humans responsible for Global Warming? There ARE natural variations in climate. For example, there have been about 20 ‘switches’ between GLACIAL AND INTERGLACIAL PERIODS in the late 2 million years. Like a CLOCK.

12. NOW

13. But we know what causes these natural swings between glacial and inter-glacial periods. They are caused by variations in the earth’s orbit around the sun and changes in the tilt angle of the earth. And, being astronomical, they change regularly, Like a clock - COLD for 100,000 years, then WARM for 4000 or 5000 years.

14. By this astronomical ‘clock’ (known as Milankovitch cycle), we should be in another ICE AGE! But – we aren’t. sun

15. Global Sea Level has increased in the recent past – by about 10 cm (i.e., 4 inches)

16. Estimated Sea Level Rise from Total Loss of Ice Sheets - (with no sea water temperature change) Sea Level Rise projection for 2000 to 2100 = 0.1 to 0.88 meters E + W Antarctic Ice Sheet = 70 meters West Antarctic Ice Sheet = 5 meters Greenland Ice Sheet = 7 meters

17. But – don’t become too complacent with the old (i.e., 2006) models: New data indicates that the ice discharge from many major Greenland ice streams has accelerated markedly.

18. During the Eemian Period (the last warm inter-glacial period, 125,000 years ago), global temperatures were +3°C higher and sea level was +5 meters higher. NOW warmer colder

20. Sea Level Rise of 3 meters in NE U.S. – red areas are underwater.

21. What is going on in the Arctic and Antarctic? Why does everyone get excited about a little ice melting there? BECAUSE, THE WAY THE GLOBAL CLIMATE WORKS, THE CHANGES IN THE POLAR REGIONS ARE ABOUT 2x LARGER (and therefore quicker) THAN FOR THE REST OF THE WORLD.

22. In the geological past, when climate has ‘changed’, the major change is in the Arctic/Antarctic, with much less change occurring at equatorial latitudes. That is what the models predict, and that is what we are seeing now.

23. Change in Arctic Ice Cap, from 1979 to 2005. Models predict that all arctic ice will be gone during the summer in less than 100 years.

24. Summer Arctic sea ice is shrinking at a rate of 9% per decade. Last summer (2007), arctic sea ice cover was 43% of historical normal.

25. Clear signs of melting permafrost are already common in the Arctic.

26. However, just warming-up globally is not our only worry. Rainfall distribution will change. Bottom line: areas that are wet – will get wetter. Areas that are dry – will get (a lot) dryer.

27. Below is what you and I (in the U.S.) are emitting right now. U.S. CO 2 emissions by ‘product’ total coal gas oil Global use of coal is dramatically increasing; China is putting 2 new major coal-fired power plants on-line each week; and is scheduled to put 200 more on-line in next 10 years. We however (the U.S.), are only planning for 1 new coal fired power plant coming on-line, each week.

28. The average person in the world today releases about 25 pounds (10 kg) of CO 2 into the atmosphere – each day. Beijing, 15 years ago 25 x 365 days = 9125 lbs = 4.5 tons/year Beijing, last August

29. 120 x 365 days = 43,800 lbs = 21.9 tons/yr. About 5 times the global average. The average American emits about 120 pounds of CO 2 per day.

30. The scariest plot that I show in this class We are here. You will be here.

31. AMOUNT OF SPACE REQUIRED TO TRANSPORT THE SAME NUMBER OF PASSENGERS - BY CAR, BUS, OR BICYCLE.

32. PREDICTIONS OF REDUCED AGRICULTURE PRODUCTION DUE TO GLOBAL WARMING DROUGHT CONDITIONS BY 2080. EQUATORIAL AFRICA -50% INDIA-40% REMAINING AFRICA -30% SOUTH AMERICA -20% Think about what that means….

33. SHOULD WE PANIC? While that can be exciting, there are more effective things to do. What we decide to do in the next decade (transportation, housing, industry) will determine whether the equilibrium temperature in 100 years is either +2.5°C or +8.0°C But neither of these worlds will be particularly nice to live in and it will certainly be a different sort of world.

34. We actually get to choose which path we are on. Business-as-Usual Zero carbon footprint, starting tomorrow. But the time to choose won’t last long.

35. Can’t we just “wait it out?” How long can this ‘warming’ last? About 75% of CO 2 emissions will have an average perturbation lifetime of 1800 years and 25% have lifetimes greater than 5000 years.

36. We get to decide the type of world – for our kids and grandkids; but we have to decide pretty soon. Is our current lifestyle the highest priority?

37. Or our kids?

38. End of the slides But maybe not of the world.

39. Global temperatures, °C Global Climate has been unusually stable – over the past 6000 years.

40. Nearly every glacier in the Cascades and Olympics has retreated during the past 50-150 years Photos courtesy of Dr. Ed Josberger, USGS Glacier Group, Tacoma, WA South Cascade Glacier, 1928 (top) and 2000 (right)

41. Spring snow pack is projected to decline as more winter precipitation falls as rain rather than snow, especially in warmer mid-elevation basins Snow pack will melt earlier with warmer spring temperatures Lower Spring Snow pack +4°F, +4.5% winter precip April 1 Snowpack

42. 3 My ago, global temperatures were +3°C higher than present – and sea level was 25 to 35 meters higher than present. [SO, if you raise the temperature +3°C, SL should rise about that much] So our projected (minimum) increase in global temperature of 3.5°C should eventually produce about the same amount: +20 to +35 meters of sea level rise. But not right away…. Have these dramatic rises in Sea Level happened in the PAST?