Climate Change and Impact on Corn and Grain Quality

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Climate Change and Impact on Corn and Grain
Quality 

• Eugene S. Takle
• Professor of Agricultural Meteorology, Department
  of Agronomy
• Professor of Atmospheric Science, Department of
  Geological and Atmospheric Sciences
• Director, Climate Science Initiative
• Iowa State University
• gstakle_at_iastate.edu

49th Annual Corn Dry Milling Conference, 29-30
May 2008, Peoria, IL
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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
• What does this mean for agriculture and corn
  production in the US Midwest?

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Pattern repeats about every 100,000 years
Natural cycles
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IPCC Third Assessment Report
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Carbon Dioxide and Temperature
2008 384 ppm
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Carbon Dioxide and Temperature
2050 550 ppm
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Carbon Dioxide and Temperature
Business as Usual 950 ppm
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Carbon Dioxide and Temperature
Business as Usual 950 ppm
?
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http//www.ncdc.noaa.gov/img/climate/research/2007
/ann/global-jan-dec-error-bar-pg.gif
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Source IPCC, 2001 Climate Change 2001 The
Scientific Basis
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Source IPCC, 2001 Climate Change 2001 The
Scientific Basis
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IPCC Fourth Assessment Report Summary for Policy
Makers
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http//www.ncdc.noaa.gov/img/climate/research/2007
/ann/glob-jan-dec-error-bar-pg.gif
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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.
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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
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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.
Not Natural
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Source Jerry Meehl, National Center for
Atmospheric Research
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Energy intensive
Reduced Consumption
Energy conserving
IPCC Fourth Assessment Report Summary for Policy
Makers
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Energy intensive
Reduced Consumption
Energy conserving
The planet is committed to a warming over the
next 50 years regardless of political decisions
IPCC Fourth Assessment Report Summary for Policy
Makers
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Energy intensive
Reduced Consumption
Energy conserving
Mitigation Possible
Adaptation Necessary
IPCC Fourth Assessment Report Summary for Policy
Makers
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Suitability Index for Rainfed Agriculture
IPCC 2007
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Suitability Index for Rainfed Agriculture
IPCC 2007
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Projected changes in precipitation between
1980-1999 and 2080-2099 for an energy-conserving
scenario of greenhouse gas emissions
IPCC 2007
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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
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Projected Changes for the Climate of the
Midwest Precipitation

• More (10) precipitation annually (medium)
• 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

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
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Projected Changes for the Climate of the
Midwest Other

• 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)

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
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2007 April Freeze Event
Gu, et al, 2008 The 2007 eastern US spring
freeze Increased cold damage in a warming
world? Bioscience 58 (3), 261-270.
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2007 April Freeze Event
Gu, et al, 2008 The 2007 eastern US spring
freeze Increased cold damage in a warming
world? Bioscience 58 (3), 261-270.
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2007 April Freeze Event
Gu, et al, 2008 The 2007 eastern US spring
freeze Increased cold damage in a warming
world? Bioscience 58 (3), 261-270.
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2007 April Freeze Event
Gu, et al, 2008 The 2007 eastern US spring
freeze Increased cold damage in a warming
world? Bioscience 58 (3), 261-270.
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2007 April Freeze Event
Gu, et al, 2008 The 2007 eastern US spring
freeze Increased cold damage in a warming
world? Bioscience 58 (3), 261-270.
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Summary

• Climate change since the 1970s cannot be
  explained on the basis of natural variation alone
  (consensus)
• Greenhouse gases emitted from burning fossil
  fuels account for more than half of the current
  warming (consensus)
• The warming already introduced will persist for
  more than a century (consensus)
• Corn production will encounter some benefits and
  numerous challenges (my assessment based on
  consensus)
• The US Midwest likely will suffer less adverse
  effects of climate change than many other major
  rain-fed agricultural areas (my assessment based
  on consensus)