Climate Change and Conservation

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Climate Change and Conservation

• 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

Iowa Water Conference Ames, Iowa  8-9 March 2010
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Outline

• Causes of climate change
• Global and regional changes in climate and
  projected future changes
• Past trends in Iowa and producer adjustments to
  climate change
• My speculation on future climate trends of
  importance to agriculture and conservation

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NASA
http//data.giss.nasa.gov/gistemp/graphs/
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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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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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Karl, T. R., J. M. Melillo, and T. C. Peterson,
(eds.), 2009 Global Climate Change Impacts in
the United States. Cambridge University Press,
2009.
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(No Transcript)
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Global Carbon Emissions (Gt)
Actual emissions are exceeding worst case
scenarios projected in 1990
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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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Source Jerry Meehl, National Center for
Atmospheric Research
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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
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IPCC 2007
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Low confidence in model projection of summer
precipitation
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.
20
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.
21
Low confidence
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.
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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.
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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
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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Warming Hole Simulations of changes in
daily maximum summertime temperatures between
1990s and 2040s
DTmax (JJA)
C
Pan, Z., R. W. Arritt, E. S. Takle, W. J.
Gutowski, Jr., C. J. Anderson, and M. Segal,2004
Altered hydrologic feedback in a warming climate
introduces a warming hole. Geophys. Res.
Lett.31, L17109, doi10.1029/2004GL020528.
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State-Wide Average Data
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State-Wide Average Data
Totals above 40
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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, more problems with
  fall crop dry-down, wider bean heads for faster
  harvest due to shorter harvest period during the
  daytime.

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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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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 and
  conservation interests will intensify toward
  mid-century
• Global and regional climate models have much to
  offer for understanding future Midwest
  agriculture-climate and conservation-climate
  interactions
• Agriculturists and conservationists needs future
  climate information at regional scales.

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For More Information

• 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