Recent Observed and Projected Future Climate Trends for the Midwest: Agricultural Impacts

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Recent Observed and Projected Future Climate
Trends for the MidwestAgricultural Impacts

• Eugene S. Takle
• Director, Climate Science Initiative
• Professor of Atmospheric Science
• Department of Geological and Atmospheric Sciences
• Professor of Agricultural Meteorology
• Department of Agronomy
• Iowa State University
• Ames, Iowa 50011
• gstakle_at_iastate.edu

Climate Change and Its Impacts on Food Production
and Biofuels Ames, Iowa  2 March 2010
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I hear so many conflicting views on climate
change, I dont know what or who to believe
Soybean producer from NE Iowa
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US National Academy of Sciences

• Established on 3 March 1863 by Abraham Lincoln
• Act of Incorporation to "investigate, examine,
  experiment, and report upon any subject of
  science or art" whenever called upon to do so by
  any department of the government
• June 2001 National Academy of Sciences
  Committee on the Science of Climate Change
  concludes that human-induced global warming is a
  serious issue http//www.nasonline.org/site/DocS
  erver/speech2002.pdf?docID121

http//www.nasonline.org/
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US National Academy of Sciences

• "Human activities ... are modifying the
  concentration of atmospheric constituents ...
  that absorb or scatter radiant energy. ... Most
  of the observed warming over the last 50 years is
  likely to have been due to the increase in
  greenhouse gas concentrations (NAS, 2001 p.
  21)
• "The IPCC's conclusion that most of the observed
  warming of the last 50 years is likely to have
  been due to the increase in greenhouse gas
  concentrations accurately reflects the current
  thinking of the scientific community on this
  issue (NAS, 2001 p. 3)

National Academy of Sciences Committee on the
Science of Climate Change, 2001 Climate Change
Science An Analysis of Some Key Questions.
National Academy Press, Washington, DC.
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A critical examination of climate modeling as a
basis for assessing climate change

• Morning session
• The scientific basis underpinning climate change
  projections for the 21st century
• Recent trends in Midwest climate relating to
  agriculture and farmer adaptations
• Afternoon sessions
• Limitations of climate models (Arritt)
• Recent mild summers Whats going on?
  (Anderson)
• Emerging climate forecasting techniques
  (applications maybe you hadnt thought
  about)(Gutowski)

Presenters collectively have over 50 years of
global and regional climate modeling research
experience
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In science, the prevailing theory is the one that
explains the balance of evidence
What is the evidence?
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Global Mean Surface Temperature
http//www.ncdc.noaa.gov/img/climate/research/2008
/ann/global-jan-dec-error-bar-pg.gif
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Global Mean Surface Temperature
http//www.ncdc.noaa.gov/img/climate/research/2008
/ann/global-jan-dec-error-bar-pg.gif
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Global Mean Surface Temperature
http//www.ncdc.noaa.gov/img/climate/research/2008
/ann/global-jan-dec-error-bar-pg.gif
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NASA
http//data.giss.nasa.gov/gistemp/graphs/
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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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Temperature Trends in Upper and Lower Atmosphere
Upper Atmosphere (Stratosphere)
Lower Atmosphere (Troposphere)
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One of the clearest trends in the United States
observational record is an increasing frequency
and intensity of heavy precipitation events Over
the last century there was a 50 increase in the
frequency of days with precipitation over 101.6
mm (four inches) in the upper midwestern U.S.
this trend is statistically significant
Karl, T. R., J. M. Melillo, and T. C. Peterson,
(eds.), 2009 Global Climate Change Impacts in
the United States. Cambridge University Press,
2009, 196pp.
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Arctic Sea-Ice Decline
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Decline in Greenland Ice Mass
Equivalent to about 5 ft of ice over the state of
Iowa each year
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Tropical Atlantic Ocean
Hurricane Power Dissipation Index (PDI)
Sea-surface temperature
V
V
V
Emanual, Kerry, 2005 Increasing destructiveness
of tropical cyclones over the past 30 years.
Nature, 436, 686-688.
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Ocean Heat Content
1oC rise in top 3 m of global ocean is equivalent
to a 1oC rise in entire atmosphere
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Where is this extra heat coming from?

• Possible mechanisms
• More solar radiation
• Less reflection from clouds
• Less reflection from Earths surface
• More energy trapped and recycled by ozone and
  greenhouse gases

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Earths Energy Balance Incoming solar
outgoing infrared radiation But rapid changes in
atmosphere and ocean temperatures and loss of
land and sea ice indicate an imbalance
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?
Earths Energy Balance Incoming solar
outgoing infrared radiation But rapid changes in
atmosphere and ocean temperatures and loss of
land and sea ice indicate an imbalance
?
?
?
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0.1
Other solar cycles have periods of 22,000,
41,000, and 100,000 years with 0.1 variation.
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Forcing Factors in the Global Climate
More trapped (recycled) heat
See Arritt for details this afternoon
More cloud land reflection
Karl, T. R., J. M. Melillo, and T. C. Peterson,
(eds.), 2009 Global Climate Change Impacts in
the United States. Cambridge University Press,
2009, 196pp.
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Increased Greenhouse Gases gt Global Heating
Increasing greenhouse gases increases heating of
the Earth
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Karl, T. R., J. M. Melillo, and T. C. Peterson,
(eds.), 2009 Global Climate Change Impacts in
the United States. Cambridge University Press,
2009.
26
(No Transcript)
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Global Carbon Emissions (Gt)
Actual emissions are exceeding worst case
scenarios projected in 1990
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Warming of the Lower and Upper Atmosphere
Produced by Natural and Human Causes
Karl, T. R., J. M. Melillo, and T. C. Peterson,
(eds.), 2009 Global Climate Change Impacts in
the United States. Cambridge University Press,
2009, 196pp.
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Warming of the Lower and Upper Atmosphere
Produced by Natural and Human Causes
Note that greenhouse gases have a unique
temperature signature, with strong warming in the
upper troposphere, cooling in the lower
stratosphere and strong warming over the North
Pole. No other warming factors have this
signature.
Karl, T. R., J. M. Melillo, and T. C. Peterson,
(eds.), 2009 Global Climate Change Impacts in
the United States. Cambridge University Press,
2009, 196pp.
30
Global Mean Surface Temperature
http//www.ncdc.noaa.gov/img/climate/research/2008
/ann/global-jan-dec-error-bar-pg.gif
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Attribution studies See Anderson this afternoon
for applications to the Midwest
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Source Jerry Meehl, National Center for
Atmospheric Research
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The balance of evidence for the magnitude and
distribution of warming is explained by increases
in atmospheric greenhouse gases
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Energy intensive
Balanced fuel sources
More environmentally friendly
If current emission trends continue, global
temperature rise will exceed worst case scenarios
projected in 2007
Consider A1B
FI fossil intensive
IPCC Fourth Assessment Report Summary for Policy
Makers
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IPCC 2007
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December-January-February Temperature Change
7.2oF
6.3oF
A1B Emission Scenario 2080-2099 minus1980-1999
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IPCC 2007
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June-July-August Temperature Change
4.5oF
A1B Emission Scenario 2080-2099 minus1980-1999
5.4oF
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June-July-August Temperature Change
4.5oF
A1B Emission Scenario 2080-2099 minus1980-1999
5.4oF
Not the direction of current trends (see Anderson
this afternoon)
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IPCC 2007
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Low confidence in model projection of summer
precipitation. See Arritt presentation this
afternoon
IPCC 2007
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IPCC 2007
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Karl, T. R., J. M. Melillo, and T. C. Peterson,
(eds.), 2009 Global Climate Change Impacts in
the United States. Cambridge University Press,
2009, 196pp.
44
Karl, T. R., J. M. Melillo, and T. C. Peterson,
(eds.), 2009 Global Climate Change Impacts in
the United States. Cambridge University Press,
2009, 196pp.
45
Low confidence See Arritt this afternoon
Emerging techniques for improvement See
Gutowski this afternoon
Karl, T. R., J. M. Melillo, and T. C. Peterson,
(eds.), 2009 Global Climate Change Impacts in
the United States. Cambridge University Press,
2009, 196pp.
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Trend of increase in occurrence of heavy
precipitation over the 20th C is consistent with
increasing GHG concentrations. Frequency of
intense precipitation events is likely to
increase in the future.
Karl, T. R., J. M. Melillo, and T. C. Peterson,
(eds.), 2009 Global Climate Change Impacts in
the United States. Cambridge University Press,
2009, 196pp.
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The planet is committed to a warming over the
next 50 years regardless of political decisions
Adaptation Necessary
Adaptation Necessary
Mitigation Possible
Karl, T. R., J. M. Melillo, and T. C. Peterson,
(eds.), 2009 Global Climate Change Impacts in
the United States. Cambridge University Press,
2009, 196pp.
48
The planet is committed to a warming over the
next 50 years regardless of political decisions
Adaptation Necessary
Farmers install more drainage tile
Adaptation Necessary
Mitigation Possible
Karl, T. R., J. M. Melillo, and T. C. Peterson,
(eds.), 2009 Global Climate Change Impacts in
the United States. Cambridge University Press,
2009, 196pp.
49
The planet is committed to a warming over the
next 50 years regardless of political decisions
Adaptation Necessary
Adaptation Necessary
Mitigation Possible
Karl, T. R., J. M. Melillo, and T. C. Peterson,
(eds.), 2009 Global Climate Change Impacts in
the United States. Cambridge University Press,
2009, 196pp.
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The planet is committed to a warming over the
next 50 years regardless of political decisions
Adaptation Necessary
Farmers plant earlier, choose longer season
hybrids
Adaptation Necessary
Mitigation Possible
Karl, T. R., J. M. Melillo, and T. C. Peterson,
(eds.), 2009 Global Climate Change Impacts in
the United States. Cambridge University Press,
2009, 196pp.
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Observed Summer (JJA) Daily Maximum Temperature
Changes (K), 1976-2000
Adapted from Folland et al. 2001
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Observed Summer (JJA) Daily Maximum Temperature
Changes (K), 1976-2000
See Anderson presentation this afternoon
Adapted from Folland et al. 2001
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Des Moines Airport Data
1983 13
1988 10
2009 0
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Des Moines Airport Data
1983 13
1988 10
6 days 100oF in the last 20 years
2009 0
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State-Wide Average Data
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State-Wide Average Data
Totals above 40
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(No Transcript)
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Cedar Rapids Data
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Cedar Rapids Data
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Relationship of Streamflow to Precipitation in
Current and Future Climates
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D. Herzmann, Iowa Environmental Mesonet
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State-Wide Average Data
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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 model inconclusive
Estimated from IPCC reports
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Projected Changes for the Climate of the
Midwest Precipitation

• 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)
• More winter soil moisture recharge (medium)
• Snowfall increases (late winter) in short term
  but decreases in the
  long run (medium)

Follows trend of last 25 years and projected by
models No current trend but model suggestion or
current trend but model 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 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 model inconclusive
Estimated from IPCC and CCSP reports
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Iowa Agricultural Producers Adaptations to
Climate Change

• Longer growing season plant earlier, plant
  longer season hybrids, harvest later
• Wetter springs larger machinery enables
  planting in smaller weather windows
• More summer precipitation higher planting
  densities for higher yields
• Wetter springs and summers more subsurface
  drainage tile is being installed, closer spacing,
  sloped surfaces
• Fewer extreme heat events higher planting
  densities, fewer pollination failures
• Higher humidity more spraying for pathogens
  favored by moist conditions
• Drier autumns delay harvest to take advantage
  of natural dry-down conditions

Is it genetics or climate? See Anderson this
afternoon
HIGHER YIELDS!!
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Will These Agriculturally Favorable Midwest
Climate Trends Continue?
Caution These are my speculations!!

• In the short-term (next 5-10 years) climatic
  conditions will be dominated by natural
  variability from base conditions of the past 20
  years (not long-term averages)
• If we continue to have high spring and summer
  rainfall and soil moisture, we likely will
  continue to have lower chances of extended
  periods of extreme heat
• If we continue to have high spring and summer
  rainfall and soil moisture, we likely will
  continue to have pathogens favored by high
  humidities
• In the longer term (gt50 years), hot summers,
  milder winters, and higher variability of
  precipitation will become more dominant
• Failure to limit global carbon emissions will
  accelerate trends toward less favorable
  agricultural climate for Iowa

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Suitability Index for Rainfed Agriculture
IPCC 2007
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Summary

• There is no scientifically defensible explanation
  for atmospheric warming, increase in ocean heat
  content, and loss of ocean and land ice over the
  last 40 year other than increase of anthropogenic
  greenhouse gases
• Some recent climate trends in the Midwest that
  have been favorable to agriculture likely will
  continue in the next few years
• Climate challenges to agriculture will intensify
  toward mid-century
• Global and regional climate models have much to
  offer for understanding future Midwest and global
  agricultural production Agriculture needs
  future climate information at regional scales.
• The afternoon climate model session will be led
  by world experts in seasonal climate forecast
  models, future climate extremes, and attribution
  studies.

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For More Information

• National academies of science joint statement
  (May 2009) G85 Academies joint statement
  Climate change and the transformation of energy
  technologies for a low carbon future.
  http//www.nationalacademies.org/includes/G85ene
  rgy-climate09.pdf
• North American Regional Climate Change Assessment
  Program http//www.narccap.ucar.edu/
• For current activities on the ISU campus,
  regionally and nationally relating to climate
  change see the Climate Science Initiative
  website http//climate.agron.iastate.edu/
• Contact me directly gstakle_at_iastate.edu