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Global and Regional Climate Change: What on Earth are We Doing?!. Eugene S. Takle Agronomy Department Geological and Atmospheric Science Department Iowa State University Ames, Iowa 50011 gstakle@iastate.edu. Ames Golden K Kiwanis, 10 February 2005. Outline.
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Global and Regional Climate Change: What on Earth are We Doing?! Eugene S. Takle Agronomy Department Geological and Atmospheric Science Department Iowa State University Ames, Iowa 50011 gstakle@iastate.edu Ames Golden K Kiwanis, 10 February 2005
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?
2040 Carbon Dioxide and Temperature 2004
Carbon Dioxide and Temperature Stabilization at 550 ppm
Carbon Dioxide and Temperature “Business as Usual” (fossil intensive) 2100
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
Mann, M. E., R. S. Bailey, and M. K. Hughes, 1999: Geophysical Research Letters 26, 759.
Source: IPCC, 2001: Climate Change 2001: The Scientific Basis
Source: IPCC, 2001: Climate Change 2001: The Scientific Basis
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.
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)
El Chichon (1982) Agung, 1963 Mt. Pinatubo (1991) Hansen, Scientific American, March 2004
Source: Jerry Meehl, National Center for Atmospheric Research
The planet is committed to a warming over the next 50 years regardless of political decisions Source: National Center for Atmospheric Research
Source: Intergovernmental Panel on Climate Change, 2001 Report
40% Probability 5% Probability Source: Intergovernmental Panel on Climate Change, 2001 Report
Climate Change Projected for 2100 Rapid Economic Growth Slower Economic Growth
Source: Corell, R. W., 2004: Impacts of a warming Arctic. Arctic Climate Impact Assessment (www.acia.uaf.edu) Cambridge University Press (www.cambridge.org).
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).
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
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
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
Climate Surprises • Breakdown of the ocean thermohaline circulation (Greenland melt water) • Break-off of the West Antarctic Ice Sheet
Kennedy Space Center Areas subjected to Inundation with a 1 m (~3 ft) rise in sea level Miami
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.
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
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
El Chichon (1982) Agung, 1963 Mt. Pinatubo (1991) Hansen, Scientific American, March 2004
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)
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”
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/