PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Climate Change: Understanding the Science and Developing Strategies for Action 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 Environmental Protection Committee, Iowa House of Representatives 26 February 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 for Iowa and the Midwest  Four components for addressing climate change Except where noted as personal views or from the ISU Global Change course or the Iowa Environmental Mesonet, 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

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

Source: Jerry Meehl, National Center for Atmospheric Research

Emanual, Kerry, 2005: Increasing destructiveness of tropical cyclones over the past 30 years. Nature, 436, Sea-surface temperature VV Tropical Atlantic Ocean Hurricane Power Dissipation Index (PDI) V

Emanual, Kerry, 2005: Increasing destructiveness of tropical cyclones over the past 30 years. Nature, 436, Sea-surface temperature VV Tropical Atlantic Ocean Hurricane Power Dissipation Index (PDI) V

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Also…  Precipitation in the central US has increased since 1970  Fraction of high-precipitation events has increased since 1970  Extended ice-free periods of lakes has increased  Milder winters Groisman et al (2001) Diffenbaugh et al (2005)

IPCC Fourth Assessment Report Summary for Policy Makers

Source: 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 The planet is committed to a warming over the next 50 years regardless of political decisions Adaptation Necessary Mitigation Possible

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

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

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 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  Scenario planning for Iowa’s “Katrina”: –Example: Multi-year drought, recurrent floods, combination of both; drought and wildfire EST personal view

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS If a meteorological variable began departing from its long-term background near or after 1970 it may be related to the radiation imbalance and thereby has a better chance than not of continuing its new trend over the next 5-10 years. Climate Adaptation(Short-Term) EST personal view

D. Herzmann, Iowa Environmental Mesonet

North America Regional Climate Change Assessment Program  Raymond Arritt, William Gutowski, Gene Takle, Iowa State University  Erasmo Buono, Richard Jones, Hadley Centre, UK  Daniel Caya, OURANOS, Canada  Phil Duffy, Lawrence Livermore National Laboratories, USA  Filippo Giorgi, Jeremy Pal, Abdus Salam ICTP, Italy  Isaac Held, Ron Stouffer, NOAA Geophysical Fluid Dynamics Laboratory, USA  René Laprise, Univ. de Québec à Montréal, Canada  Ruby Leung, Pacific Northwest National Laboratories, USA  Linda O. Mearns, Doug Nychka, Phil Rasch, Tom Wigley, National Center for Atmospheric Research, USA  Ana Nunes, John Roads, Scripps Institution of Oceanography, USA  Steve Sain, Univ. of Colorado at Denver, USA  Lisa Sloan, Mark Snyder, Univ. of California at Santa Cruz, USA Linda O. Mearns, National Center for Atmospheric Research Principal Investigator

NARCCAP Plan A2 Emissions Scenario GFDLCCSM HADAM3 link to EU programs CGCM current future Provide boundary conditions MM5 Iowa State/ PNNL RegCM3 UC Santa Cruz ICTP CRCM Quebec, Ouranos HADRM3 Hadley Centre RSM Scripps WRF NCAR/ PNNL Reanalyzed climate,

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: