PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Climate Change: How did we get here and what do we do now? Eugene S. Takle, PhD, CCM Professor of

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS

Climate Change: How did we get here and what do we

do now?Eugene S. Takle, PhD, CCM

Professor of Atmospheric Science

Department of Geological and Atmospheric Sciences

Professor of Agricultural Meteorology

Department of Agronomy

Director, Climate Science Initiative

Iowa State University

Ames, Iowa 50011

[email protected]

Noon Rotary Club, Ames, IA 28, July 2008

Image courtesy of NASA/GSFC


Outline

Comparison of natural variability of climate and human induced climate change

Projections of future climate change Impact of climate change on “regions suitable for

rain-fed agriculture”, including the US Midwest Climate change for Iowa and the Midwest:

adaptation strategy

Except where noted as personal views or from the Iowa Environmental Mesonet, all materials presented herein are from peer-reviewed scientific reports

CO2, CH4 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, 829-843.

CO2, CH4 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, 829-843.

Natural cycles

Pattern repeats about every 100,000 years

IPCC Third Assessment Report


2007

380 ppm

Carbon Dioxide and Temperature


2050

550 ppm



“Business as Usual”

950 ppm



“Business as Usual”

950 ppm

?


http://www.ncdc.noaa.gov/img/climate/research/2006/ann/glob_jan-dec-error-bar_pg.gif

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

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


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


PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONSHansen, Scientific American, March 2004

http://www.ncdc.noaa.gov/img/climate/research/2006/ann/glob_jan-dec-error-bar_pg.gif

Natural and anthropogenic contributions to global temperature change (Meehl et al., 2004). Observed values from Jones and Moberg 2001. Grey bands indicate 68% and 95% range derived from multiple simulations.


Natural cycles


Not Natural


Not Natural

Highly Likely Not Natural

Source: Jerry Meehl, National Center for Atmospheric Research


Reduced ConsumptionEnergy intensive

Energy conserving


The planet is committed to a warming over the next 50 years regardless of political decisions

Energy intensive

Energy conservingReduced Consumption


Reduced ConsumptionEnergy intensive

Energy conserving

AdaptationNecessary

MitigationPossible




Suitability Index for Rainfed Agriculture

IPCC 2007


Suitability Index for Rainfed Agriculture

IPCC 2007


Projected changes in precipitation between 1980-1999 and 2080-2099 for an energy-conserving scenario of greenhouse gas emissions

IPCC 2007


Projected Changes* for the Climate of the Midwest

Temperature Longer frost-free period (high) Higher average winter temperatures (high) Fewer extreme cold temperatures in winter (high) Fewer extreme high temperatures in summer in short

term but more in long term (medium) Higher nighttime temperatures both summer and winter

(high) More freeze-thaw cycles (high) Increased temperature variability (high)

Follows trend of last 25 years and projected by models No current trend but model suggestion or current trend but models inconclusive

*Estimated from IPCC reports


More (~10%) precipitation annually (medium) Change in “seasonality”: Most of the increase will come in the first half of the

year (wetter springs, drier summers) (high) More water-logging of soils (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) Snowfall increases (late winter) in short term but decreases in long run

(medium) More winter soil moisture recharge



Precipitation

*Estimated from IPCC reports


Reduced wind speeds (high) Reduced solar radiation (medium) Increased tropospheric ozone (high) Accelerated loss of soil carbon (high) Phenological states are shortened high) Weeds grow more rapidly under elevated atmospheric CO2

(high) Weeds migrate northward and are less sensitive to herbicides

(high) Plants have increased water used efficiency (high)



Other

*Estimated from IPCC and CCSP reports

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONSD. Herzmann, Iowa Environmental Mesonet

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONSD. Herzmann, Iowa Environmental Mesonet


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:[email protected]

Current research on regional climate and climate change is being conducted at Iowa State Unversity under the Regional Climate Modeling Laboratory

http://rcmlab.agron.iastate.edu/

North American Regional Climate Change Assessment Program

http://www.narccap.ucar.edu/

For this and other climate change presentations see my personal website:

http://www.meteor.iastate.edu/faculty/takle/

Or just Google Eugene Takle

http://www.meteor.iastate.edu/gccourse

mailto:[email protected]

http://rcmlab.agron.iastate.edu/

http://www.narccap.ucar.edu/

http://www.meteor.iastate.edu/faculty/takle/

Documents

PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS Climate Change: How did we get here and what do we do now? Eugene S. Takle, PhD, CCM Professor of