Image courtesy of NASA/GSFC

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Global Environmental Change: Technology and the Future of Planet Earth Eugene S. Takle, PhD, CCM Professor of Atmospheric Science Department of Geological and Atmospheric Sciences Professor of Agricultural Meteorology Department of Agronomy Iowa State University Ames, Iowa Globalization Course Cedar Rapids Iowa 19 October 2007

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Outline  Changes in atmospheric carbon dioxide  Radiative forcing  Simulations of global climate and future climate change  Climate change and the scientific process  Four components for addressing climate change Except where noted as personal views or from the ISU Global Change course, all materials presented herein are from peer-reviewed scientific reports

CO 2, CH 4 and temperature records from Antarctic ice core data Source: Vimeux, F., K.M. Cuffey, and Jouzel, J., 2002, "New insights into Southern Hemisphere temperature changes from Vostok ice cores using deuterium excess correction", Earth and Planetary Science Letters, 203,

CO 2, CH 4 and temperature records from Antarctic ice core data Source: Vimeux, F., K.M. Cuffey, and Jouzel, J., 2002, "New insights into Southern Hemisphere temperature changes from Vostok ice cores using deuterium excess correction", Earth and Planetary Science Letters, 203, Natural cycles Pattern repeats about every 100,000 years

IPCC Third Assessment Report

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS ppm Carbon Dioxide and Temperature

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS ppm Carbon Dioxide and Temperature

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS “Business as Usual” 950 ppm Carbon Dioxide and Temperature

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS “Business as Usual” 950 ppm ? Carbon Dioxide and Temperature

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

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS

IPCC Fourth Assessment Report Summary for Policy Makers

Hansen, Scientific American, March 2004 Mt. Pinatubo (1991) El Chichon (1982) Agung, 1963 At present trends the imbalance = 1 Watt/m 2 in 2018

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.

Source: Corell, R. W., 2004: Impacts of a warming Arctic. Arctic Climate Impact Assessment ( Cambridge University Press (

Areas subjected to Inundation with a 1 m (~3 ft) rise in sea level Kennedy Space Center Miami Impact of a 1-m rise in sea level on low-lying areas Source: Corell, R. W., 2004: Impacts of a warming Arctic. Arctic Climate Impact Assessment ( Cambridge University Press ( Projected sea-level rise In 21st century: 0.5 to 1.0 m

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS

Hansen, Scientific American, March 2004

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS

Climate Cold Warm Ice Volume 0 Antarctica Greenland

Natural and anthropogenic contributions to global temperature change (Meehl et al., 2004). Observed values from Jones and Moberg Grey bands indicate 68% and 95% range derived from multiple simulations.

Natural cycles

Natural and anthropogenic contributions to global temperature change (Meehl et al., 2004). Observed values from Jones and Moberg Grey bands indicate 68% and 95% range derived from multiple simulations. Not Natural

Natural and anthropogenic contributions to global temperature change (Meehl et al., 2004). Observed values from Jones and Moberg Grey bands indicate 68% and 95% range derived from multiple simulations. Not Natural Highly Likely Not Natural

Source: Jerry Meehl, National Center for Atmospheric Research

IPCC Fourth Assessment Report Summary for Policy Makers

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS IPCC Fourth Assessment Report Summary for Policy Makers Reduced Consumption Energy intensive Energy conserving

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS IPCC Fourth Assessment Report Summary for Policy Makers The planet is committed to a warming over the next 50 years regardless of political decisions Energy intensive Energy conserving Reduced Consumption

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS IPCC Fourth Assessment Report Summary for Policy Makers Reduced Consumption Energy intensive Energy conserving Adaptation Necessary Mitigation Possible

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS IPCC Fourth Assessment Report Summary for Policy Makers

“Warming Hole”  T max (JJA) ˚C Pan, Z., R. W. Arritt, E. S. Takle, W. J. Gutowski, Jr., C. J. Anderson, and M. Segal, 2004: Altered hydrologic feedback in a warming climate introduces a “warming hole”. Geophys. Res. Lett.31, L17109, doi: /2004GL

Observed summer (June-July-August) daily mean temperature changes (K) between (Adapted from Folland et al. [2001]).

Precipitation minus Evaporation for Western US (25N-40N, 95W- 125 W) R. Seager, et al., Model Projections of an Imminent Transition to a More Arid Climate in Southwestern North America. Science, Vol no. 5828, pp

Precipitation minus Evaporation for Western US (25N-40N, 95W-125 W) R. Seager, et al.,2007. Model Projections of an Imminent Transition to a More Arid Climate in Southwestern North America. Science, Vol no. 5828, pp

Precipitation minus Evaporation for Western US (25N-40N, 95W-125 W) R. Seager, et al.,2007. Model Projections of an Imminent Transition to a More Arid Climate in Southwestern North America. Science, Vol no. 5828, pp Colorado River Compact established, 1922

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Four-Component Approach for Addressing Climate Change  Mitigation policies: –Example: reduction in GHG emissions  Adaptation (long-term): –Example: Developing Iowa’s competitive economic advantage  Adaptation (short-term): –Example: redefining climate “normals” when needed and scientifically justified EST personal view

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Projected Changes for the Climate of Iowa/Midwest (My tentative assessment)  Longer frost-free period (high)  Higher average winter temperatures (high)  Fewer extreme cold temperatures in winter (high)  More extreme high temperatures in summer (medium)  Higher nighttime temperatures both summer and winter (high)  More (~10%) precipitation (medium)  More variability of summer precipitation (high) –More intense rain events and hence more runoff (high) –Higher episodic streamflow (medium) –Longer periods without rain (medium)  Higher absolute humidity (high)  Stronger storm systems (medium)  Reduced annual mean wind speeds (medium) Follows trend of last 25 years and projected by models No current trend but model suggestion or current trend but models inconclusive

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Summary  Climate change of the past 35 years is not consistent with natural variations over the last 400,000 years  Evidence clearly shows that radiative forcing due to anthropogenic greenhouse gases has contributed over half of the warming of the last 35 years  Mitigation efforts, although urgently needed, will have little effect on global warming until the latter half of the 21st century  Adaptation strategies should be developed for the next 50 years  Recent trends and model projections should be used to develop adaptation strategies for the next 10 years EST personal view

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS For More Information  For peer-reviewed evidence supporting everything you have seen in this presentation, see my online Global Change course:  Contact me directly:  Current research on regional climate and climate change is being conducted at Iowa State Unversity under the Regional Climate Modeling Laboratory  North American Regional Climate Change Assessment Program  For this and other climate change presentations see my personal website: Or just Google Eugene Takle