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Global Change and Antarctica

This article discusses the evidence for global climate change, future carbon dioxide concentrations, simulations of global climate change, and the role of Antarctica. It highlights the associated climate changes and emphasizes the need for action.

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Global Change and Antarctica

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  1. Global Change and Antarctica Eugene S. Takle Agronomy Department Geological and Atmospheric Science Department Iowa State University Ames, Iowa 50011 gstakle@iastate.edu ISU Biology Travel Class, 22 September 2004

  2. Outline • Evidence for global climate change • Future atmospheric carbon dioxide concentrations • Simulations of global climate and future climate change • Role of Antartica in climate change • Summary

  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

  8. 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

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

  10. Hansen, Scientific American, March 2004

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

  12. Source: National Center for Atmospheric Research

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

  14. 40% Probability 5% Probability Source: Intergovernmental Panel on Climate Change, 2001 Report

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

  16. 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

  17. 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

  18. Climate Surprises • Breakdown of the ocean thermohaline circulation (Greenland melt water) • Breakoff of the West Antarctic Ice Sheet

  19. 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

  20. Sub-Basins of the Upper Mississippi River Basin 119 sub-basins Outflow measured at Grafton, IL Approximately one observing station per sub-basin Approximately one model grid point per sub-basin

  21. “Warming Hole” ˚C DTmax (JJA)

  22. Global warming is at least as important an issue as gay marriage or the rising cost of Social Security. And if it is not seriously debated in the general election, it will measure the irresponsibility of the entire political class. This is an issue that cannot, and must not, be ignored any longer.

  23. Global warming is at least as important an issue as gay marriage or the rising cost of Social Security. And if it is not seriously debated in the general election, it will measure the irresponsibility of the entire political class. This is an issue that cannot, and must not, be ignored any longer. Walter Cronkite 12 March 2004 http://www.philly.com/mld/dailytimes/news/opinion/8159334.htm

  24. 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)

  25. Calving of an Iceberg 9 Jan 1995 12 Feb 1995 The ice shelf which formerly occupied Prince Gustav Channel and connected James Ross Island to the Antarctic Peninsula Disintegrated making James Ross Island circumnavigable for the first time in recorded history. The new iceberg calved from the Larsen Ice Shelf and measured 78 km x 37 km x 200 m thick.

  26. Summary • Climate change is real and should be considered something other than “tomorrow’s problem” • We are committed to a warming over the next 40 years regardless of what policy path we choose • Policy decisions today will affect global warming and associated environmental changes in the latter half of the 21st century and beyond • Consider adopting a simpler lifestyle • Ice is very important to the climate system and needs to be protected

  27. For More Information • See my online Global Change course: http://www.meteor.iastate.edu/gccourse • Contact me directly: gstakle@iastate.edu

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