1. Global Warming Thinking it Through Together James L. Powell, PhD jpowell@usc.edu www.jamespowell.org.org

2. Charles David Keeling, 1928-2005

3. Actual ice sheets were ~5 times taller than shown

4. Charles David Keeling, 1928-2005

5. Mauna Loa Research Station

7. CO2 today=394.45 ppm

8. French scientist with Antarctic ice core. The cores go back for 800,000 years

9. Rise=41%

13. Astronomical cycles start temperature rise, CO2 and feedbacks follow ~ 1000 years later

15. Total=347 billion tons

17. compared to 1951-1980 average

22. What is in that glass?

23. Floyd Landis and Global Warming 1. testosterone is mostly carbon 2. natural human testosterone comes from our overall environment 3. but synthetic testosterone is made entirely from plants 4. plant carbon has a different isotope ratio-- think of it as different DNA--than the carbon in our environment 5. Landis’s testosterone had the plant ratio, proving that he had doped.

24. As carbon emissions in the atmosphere rose (black), carbon isotopes (red) shifted toward plant carbon Plant Carbon

26. Without human disturbance, proportion of C14 in the atmosphere is constant

27. Adding ancient, C14-free carbon lowers proportion of C14 in atmosphere

28. After nuclear tests stopped in 1960s, proportion of C14 began to decline again.

29. Conclusions from carbon isotope data 1. Some process has been adding plant carbon to the atmosphere. (Has plant carbon isotope DNA.) 2. The plant carbon is coming from sources millions of years old. (No C14) 3. Carbon from ancient plants=carbon from fossil fuels. 4. Because of the greenhouse effect, the extra carbon must cause extra warming 5. Conclusion: humans are causing global warming.

31. Global Warming: The Evidence

32. Record high temperatures now twice record lows

35. High records demolish cold records

37. Since the 1970s, warm nights have been increasing more than warm days

38. Number of days w/o frost (growing season) increasing

39. Western snowfields melting up to 20 days earlier

40. Temperature (red) and wildfires (black) growing in Canadian forests

41. Glaciers losing ice worldwide

42. Arctic sea ice extent (area) declining

43. Arctic sea ice gone by 2085--maybe a lot sooner

44. Greenland is losing ice

45. Antarctica is losing land ice

46. Sea level is rising at fastest rate in history

47. Plants and animals migrating upslope and toward poles

48. Spring events coming earlier for plants and animals

49. U.S. plant zones shifting

50. Species are migrating, but they can only go so far From Nature Magazine, 2004 “We predict [that by] 2050, 15-37% of species will be ‘committed to extinction’.” One million species, countless individuals

53. What is to be done?

54. What Can You Do? Recognize that it is not too late. We have perhaps 15 years in which we to act to reduce carbon emissions. It is not a question of science, but of will. Each year we wait further endangers our grandchildren. Reduce your carbon footprint. This is the least you can do and will make you feel better, though it will not be nearly enough. Talk and write to your elected leaders. Do not vote for any politician who rejects the best scientific advice.

55. What Can Nations Do? Put a price on carbon that reflects its true cost, including global warming, fealty to Middle Eastern despots, mining accidents, health problems, landscape destruction, social fabric in Appalachia, etc. Move to 100% carbon-free electricity in no more than 20 years. Their leaders must recognize that global warming is the greatest problem humanity has ever faced and that history will judge them almost entirely by what they do or don’t do about it.