1. Image courtesy of NASA/GSFC

2. Weather, Water, and Agriculture in the North Central US: The Future Isn’t What It Used To Be!
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
Faith, Reason, and World Affairs Symposium
Concordia College
16-17 September 2008

3. 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,
Pattern repeats about every 100,000 years
Natural cycles

4. IPCC Third Assessment Report

5. Carbon Dioxide and Temperature
2008
384 ppm

6. Carbon Dioxide and Temperature
“Business as Usual”
950 ppm ?

8. 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.

9. Highly Likely 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.
Highly Likely Not Natural
Not Natural

10. Source: Jerry Meehl, National Center for Atmospheric Research
From Jerry Meehl
This slide shows the time evolution of globally averaged surface air
temperature from multiple ensemble simulations of 20th century climate
from the NCAR Parallel Climate Model (PCM) compared to observations.
The simulations start in the late 19th century, and continue to the year
The temperature scale at left is in degrees Centigrade, and
temperature anomalies are calculated relative to a reference period
averaged from 1890 to The black line shows the observed data, or
the actual, recorded
globally averaged surface air temperatures from the past century. The
blue and red lines are the average of four simulations each from the
computer model. The pink and light blue shaded areas depict the range
of the four simulations for each experiment, giving an idea of the
uncertainty of a given realization of 20th century climate from the
climate model. The blue line shows the average from the four member
ensemble of the simulated time evolution of globally average surface air
temperature when only "natural" influences (solar variability and
volcanic eruptions) are included in the model. Therefore, the blue
line represents what the model says global average temperatures would
have been if there had been no human influences. The red line shows the
average of the four member ensemble experiment when natural forcings AND
anthropogenic influences (greenhouse gases including carbon dioxide,
sulfate aerosols from air pollution, and ozone changes) are included in
the model. Note that this model can reproduce the actual, observed data
very well only if the combined effects of natural and anthropogenic
factors are included. The conclusion that can be drawn is that
naturally occuring influences on climate contributed to most of the
warming that occurred before WWII, but that the large observed
temperature increases since the 1970s can only be simulated in the model
if anthropogenic factors are included.
This confirms the conclusion of the IPCC Third Assessment Report that
most of the warming we have observed in the latter part of the 20th
century has been due to human influences.
Source: Jerry Meehl, National Center for Atmospheric Research

11. Energy intensive Energy conserving Reduced Consumption
IPCC Fourth Assessment Report Summary for Policy Makers

12. Energy intensive Energy conserving Reduced Consumption
The planet is committed to a warming over the next 50 years regardless of political decisions
IPCC Fourth Assessment Report Summary for Policy Makers

13. Energy intensive Energy conserving Mitigation Possible Adaptation
Reduced Consumption
Energy conserving
Possible
Mitigation
Necessary
Adaptation
IPCC Fourth Assessment Report Summary for Policy Makers

15. Suitability Index for Rainfed Agriculture
IPCC 2007

16. Suitability Index for Rainfed Agriculture
IPCC 2007

17. Projected changes in precipitation between and for an energy-conserving scenario of greenhouse gas emissions
IPCC 2007

18. Grain and oilseed consumption
has exceeded production 7 of last 8 years
Tostle, Ronald, 2008: Global Agricultural Supply and Demand: Factors Contributing to the Recent
Increase in Food Commodity Prices WRS-0801 May USDA/ERS

23. Projected changes in precipitation between and for an energy-conserving scenario of greenhouse gas emissions
IPCC 2007

24. 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

25. Average Annual Precipitation

26. Projected Changes* for the Climate of the North Central US Temperature
Longer frost-free period (high)
Higher average winter temperatures (high)
Fewer extreme cold temperatures in winter (high)
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

27. Projected Changes* for the Climate of the North Central US Precipitation
More (~15%) 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 variability of summer precipitation (high)
More intense rain events and hence more runoff (high)
Higher episodic streamflow (medium)
Longer periods without rain (medium)
Stronger storm systems (medium)
Snowfall increases (late winter) in short term but decreases in long run (medium)
More winter soil moisture recharge
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

28. Projected Changes* for the Climate of the North Central US Other
Reduced wind speeds (high)
Reduced solar radiation (medium)
Accelerated loss of soil carbon (high)
Phenological stages 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)
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 and CCSP reports

29. A Few Areas Impacted by Climate Change
Crop & horticulture production
Soil erosion
Conservation practices
Water supplies
Stream flow
Water quality
Beef and pork daily gains
Livestock breeding success
Milk and egg production
Crop and livestock pests and pathogens
Biofuel production projection
Power demand for heating & cooling
Planning for droughts & floods
Agricultural tile drainage systems
Natural ecosystem species distributions
Human health (heat waves, influenza)
Building designs
Recreation opportunities
River navigation
Pavement performance (roads)
Corrosion rates (bridges)
Carbon sequestration/loss by soil
Forest productivity
Shipping limitations (Great Lakes)
Wind power resources
Winter maintenance costs (roads & bridges

30. Summary
Natural variability alone cannot explain the observed changes in global mean temperature
Regions now suitable for rain-fed agriculture may not be so in the future due to projected changes in precipitation
Recent trends in global grain and oilseed stocks and market volatilities underscore the fragility of global food production
Some climate changes projected for the North Central US are detrimental to agriculture but many are favorable

31. For More Information Or just Google Eugene Takle
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