Facts and Myths about Global Warming

1. Facts and Myths about Global Warming John R. Christy NWS Climate Services University of Alabama in Huntsville 20 June 2007

2. Consensus is not Science Michael Crichton

3. Consensus is not Science Michael Crichton All Science is numbers William Thompson (Lord Kelvin)

4. Some people will do anything to save the Earth ...except take a science course.

5. Some people will do anything to save the Earth ...except take a science course. Greenhouse “Affect”, Rolling Stone P.J. O’Rourke

6. Two Main observing systems for detecting Greenhouse Gas effects • Surface thermometers • Daily High Temperature • Daily Low Temperature • Daily Mean Temperature (popular) • Upper Air Temperatures • Balloon • Microwave emissions

7. Constructed from Mean Temperatures

8. Vertical Temperature Change due to Greenhouse Forcing in Models Model Simulations of Tropical Troposphere Warming: About 2X surface Lee et al. 2007

9. Is Mean Surface Temperature an Appropriate Index for the Greenhouse Effect? TMean = (TMax + TMin)/2

10. Day vs. Night Surface Temp Nighttime - disconnected shallow layer/inversion. Temperature affected by land-use changes, buildings, farming, etc. Daytime - deep layer mixing, connected with levels impacted by enhanced greenhouse effect

11. Night Surface Temp Warm air above inversion Warm air Cold air near surface Buildings, heat releasing surfaces, aerosols, greenhouse gases, etc. can disrupt the delicate inversion, mixing warm air downward - affecting TMin. Nighttime - disconnected shallow layer/inversion. But this situation can be sensitive to small changes such as roughness or heat sources.

12. The nighttime minimum is related to the delicate formation of the nocturnal boundary layer which can be easily disrupted, mixing warm air downward and sending temperatures up dramatically Walters et al. (in press)

13. No. Alabama Summer TMax Temperatures Christy 2002

14. Mean TemperatureSoutheast USA 1899-2003 Models Observation

15. Christy et al. 2006, J. Climate

16. MODIS 21 Jul 2002 Jacques Descloitres MODIS Land Rapid Response Team NASA GSFC

17. + Valley Stations • ° Mountain Stns • Christy et al. 2006, J. Climate

18. Manually digitized thousands of records

19. Valley affected by irrigation and urbanization Christy et al. 2006

20. Christy et al. 2006 Consistent with irrigation and urbanization Consistent with irrigation

21. Sierras warm faster than Valley in model simulations Snyder et al. 2002

22. East Africa (Kenya/Tanzania)

23. East Africa: 5°S-Eq, 35-40°E (Nairobi, Mt. Kilimanjaro, Mt. Kenya) Christy et al. (submitted) uses 10 times the amount of surface data Upper Air Daytime warming rate 20% of Mainline Datasets in E. Africa

24. Model vs. Observations TMin minus TMax Preliminary study

25. Is Mean Surface Temperature an Appropriate Index for the Greenhouse Effect? Evidence indicates TMaxis the better metric to serve as a proxy for monitoring deep atmospheric change Pielke et al. 2007, Walters et al. 2007, Christy et al. (submitted)

26. Upper Air Temperatures

27. Upper Air Temperatures • Recent claims suggest the upper air temperature record is in agreement with the surface and with climate models, so global warming theory must be right • IPCC more or less supports this view • UAH satellite data reportedly “flawed”

28. Vertical Temperature Change due to Greenhouse Forcing in Models Model Simulations of Tropical Troposphere Warming: About 2X surface Lee et al. 2007

29. Christy and Spencer 2005 Christy and Norris 2006 Christy et al. 2007

30. Christy and Norris 2006 Christy et al. 2007

31. Global Bulk Atmospheric Temperatures UAH Satellite Data Warming rate 60% of model projections

32. Greenhouse Effect

33. Total Greenhouse Effect • Water vapor and Clouds Dominate • Total Greenhouse Effect is variable • Climate models show strong water-vapor/cloud positive feedback with increased CO2

34. Greenhouse Effect

35. Greenhouse Effect ?

36. Tropical Temp. and Cloud Forcing (major part of total greenhouse effect) based on latest satellite sensorsNegative feedback on monthly time scalesSpencer et al. (submitted)

37. What about Cold Places?

39. North Polar RegionsHadCRUT3 Period of most polar ice observations

40. Greenland Summer Temperatures1780-2005 Period of most polar ice observations

41. Greenland Borehole TemperatureDahl-Jensen et al. 1998

42. Greenland Borehole TemperatureDahl-Jensen et al. 1998

43. AlaskaHadley CRU 3 (°C)Shift in 1977, but high natural variability

44. When Hemingway writes “Snows of Kilimanjaro”—half of the “snows” are already gone X Mass Gain in 2006 Molg and Kaser 2007

45. Regional Snowpack, Central Andes, 1951-2005 Masiokas et al. 2006

47. Ice Cores Antarctica Schneider et al. 2006 Doran et al. 2002 Thermometers

48. Antarctica snow accumulation trends cm/yr 1992-2003 Davis et al. 2005 See also: Monoghan et al 2006 Van de Berg et a. 2006

49. Evidence Thus Far • Global surface temperature is rising, but in a way inconsistent with model projections of GHG forcing • Overall decline in ice mass, with sea level rise of about 1” per decade • Severe weather not becoming more frequent

50. Main Point: I don’t see a disaster developing But, suppose you do ….