Global Climate Change: Science and Consequences

1. Global Climate Change:Science and Consequences Eugene S. Takle Agronomy Department Geological and Atmospheric Science Department Iowa State University Ames, Iowa 50011 gstakle@iastate.edu Energy Awareness Group Ames Public Library, 7 September 2005

2. Outline • Evidence for global climate change • Future atmospheric carbon dioxide concentrations • Simulations of global climate and future climate change • Impact on global food production and fresh-water availability • Implications for the Midwest • “Dangerous anthropogenic inter- ference with the climate system”? • What can I do? • Hurricane Katrina

3. Carbon Dioxide and Temperature

4. Carbon Dioxide and Temperature 2004

5. 2040 Carbon Dioxide and Temperature 2004

6. Carbon Dioxide and Temperature Stabilization at 550 ppm

7. Carbon Dioxide and Temperature “Business as Usual” (fossil intensive) 2100

9. Associated Climate Changes • Global sea-level has increased 1-2 mm/yr • Duration of ice cover of rivers and lakes decreased by 2 weeks in N. Hemisphere • Arctic ice has thinned substantially, decreased in extent by 10-15% • Reduced permafrost in polar, sub-polar, mountainous regions • Growing season lengthened by 1-4 days in N. Hemisphere • Retreat of continental glaciers on all continents • Poleward shift of animal and plant ranges • Snow cover decreased by 10% • Earlier flowering dates • Coral reef bleaching Source: Intergovernmental Panel on Climate Change, 2001 Report

10. Mann, M. E., R. S. Bailey, and M. K. Hughes, 1999: Geophysical Research Letters 26, 759.

11. Source: IPCC, 2001: Climate Change 2001: The Scientific Basis

12. Source: IPCC, 2001: Climate Change 2001: The Scientific Basis

13. NASA photographs show the minimm Arctic sea ice concentration in 1979 at left and in 2003.Satellite passive microwave data since 1970s indicate a 3% decrease per decade in arctic sea ice extent.

14. Since 1979, the size of the summer polar ice cap has shrunk more than 20 percent. (Illustration from NASA) (http://www.nrdc.org/globalWarming/qthinice.asp)

17. http://www.earth-policy.org/Indicators/CO2/2004.htm

19. El Chichon (1982) Agung, 1963 Mt. Pinatubo (1991) Hansen, Scientific American, March 2004

20. Source: Jerry Meehl, National Center for Atmospheric Research

21. Source: National Center for Atmospheric Research

22. The planet is committed to a warming over the next 50 years regardless of political decisions Source: National Center for Atmospheric Research

23. Source: Intergovernmental Panel on Climate Change, 2001 Report

24. 40% Probability 5% Probability Source: Intergovernmental Panel on Climate Change, 2001 Report

25. Climate Change Projected for 2100 Rapid Economic Growth Slower Economic Growth

26. Source: Corell, R. W., 2004: Impacts of a warming Arctic. Arctic Climate Impact Assessment (www.acia.uaf.edu) Cambridge University Press (www.cambridge.org).

27. Kennedy Space Center Impact of a 1-m rise in sea level on low-lying areas Areas subjected to Inundation with a 1 m (~3 ft) rise in sea level Miami Source: Corell, R. W., 2004: Impacts of a warming Arctic. Arctic Climate Impact Assessment (www.acia.uaf.edu) Cambridge University Press (www.cambridge.org).

28. IPCC Summary for Policy Makers • An increasing body of observations gives a collective picture of a warming world and other changes in the climate system • Emissions of greenhouse gases and aerosols due to human activities continue to alter the atmosphere in ways that are expected to affect the climate

29. IPCC Summary for Policy Makers, cont’d • There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities • Anthropogenic climate change will persist for many centuries

32. http://www.grida.no/climate/vital/37.htm

33. For the Midwest • Warming will be greater for winter than summer • Warming will be greater at night than during the day • A 3oF rise in summer daytime temperature triples the probability of a heat wave • Growing season will be longer (8-9 days longer now than in 1950) • More precipitation • Likely more soil moisture in summer • More rain will come in intense rainfall events • Higher stream flow, more flooding

34. Climate Surprises • Breakdown of the ocean thermohaline circulation (Greenland melt water) • Break-off of the West Antarctic Ice Sheet

37. Kennedy Space Center Areas subjected to Inundation with a 1 m (~3 ft) rise in sea level Miami

39. What Consitutes “Dangerous Anthropogenic Interference with the Climate System”? James Hansen, Director of the NASA Goddard Institute for Space Studies: * Radiative forcing limit: 1 Watt/ m2 * 1 oC additional rise in global mean temperature

40. El Chichon (1982) Agung, 1963 Mt. Pinatubo (1991) Hansen, Scientific American, March 2004

42. Tropical Weather Weather Underground: http://www.wunderground.com/tropical/

43. Saffir/Simpson Hurricane Scale CAT Winds & Effects Surge 1 74-95 mph  4-5 ft No real damage to building structures. Damage primarily to unanchored mobile homes, shrubbery, and trees. Also, some coastal flooding and minor pier damage. 2 96-110 mph 6-8 ft Some roofing material, door, and window damage. Considerable damage to vegetation, mobile homes, etc. Flooding damages piers and small craft may break their moorings. 3 111-130 mph 9-12 ft Some structural damage to small residences and utility buildings, with a minor amount of curtainwall failures. Mobile homes are destroyed. Flooding near the coast destroys smaller structures, with larger structures damaged by floating debris. Terrain flooding inland. 4 131-155 mph 13-18 ft More extensive curtainwall failures with some complete roof structure failure on small residences. Major erosion of beach areas. Terrain may be flooded well inland. 5 155 mph+ 18 ft + Complete roof failure on many residences and industrial buildings. Some complete building failures with small utility buildings blown over or away. Flooding causes major damage to lower floors of all structures near the shoreline. Massive evacuation of residential areas may be required.

44. US Army Corps of Engineers Category 5 Winds greater than 155 mph Shrubs and trees down; considerable damage to roofing; all signs down. Severe and extensive damage to windows and doors Complete roof collapse Destruction of glass in windows and doors Some complete building failures Small buildings overturned or blown away Complete destruction of mobile homes Storm surge higher than 18 feet above normal Major damage to lower floors of all structures less than 15 feet above sea level within 500 yards of shore Low lying escape routes inland cut off by rising water three to five hours before hurricane center arrives Massive evacuation of residential areas on low ground within five to 10 miles of shore possibly required Catastrophic Hurricanes: Category 3 or larger Katrina: Category 5, Winds > 175 mph, Storm surge > 25 ft http://www.sas.usace.army.mil/em/emhurcatinfo.htm

45. What Can I Do? • Conserve energy • Adopt a simpler lifestyle: • “Elegant simplicity” • “Sophisticated modesty” • “Affluence lite” Sustainable Development: To meet the needs of the present without compromising the ability of future generations to meet their needs Brundtland Commission (World Commission on Environment and Development)

46. Summary • Climate change is real and we need to be doing something about it • The longer we wait, the fewer our options • Regional patterns of warming will be complicated • Climate surprises can’t be discounted • We need dialog on what constitutes “dangerous anthropogenic interference with the climate system” • More intense hurricanes can be expected in the future due to global warming

47. For More Information • For peer-reviewed evidence supporting everything you have seen in this presentation, see my online Global Change course: http://www.meteor.iastate.edu/gccourse • Contact me directly: gstakle@iastate.edu • For a copy of this presentation: http://www.meteor.iastate.edu/faculty/takle/