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Climate Change:
Globally and In Iowa
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
[email protected]
PEO
Ames, Iowa
22 June 2010
Observations: global mean temperature and
carbon dioxide are rising together since 1860
Base period 1961-90
Global average sea level is rising from expansion
of water due to warming and melting glaciers
Since 1992 sea
level has risen 55mm
(2.2 inches)
www.aviso.oceanobs.com/en/news/ocean-indicators/mean-sea-level/
Models: Natural processes do not account for
observed 20th century warming after 1965
Observed Trends
in Iowa Precipitation
State-Wide Average Data
State-Wide Average Data
37.5”
31.5”
19% increase
State-Wide Average Data
Totals above 40”
2 years
8 years
State-Wide Average Data
Cedar Rapids Data
28.0”
32% increase
37.0”
Cedar Rapids Data
7.8”
51% increase
11.8”
Cedar Rapids Data
20.2”
34% increase
26.8”
“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.
Cedar Rapids Data
4.2 days
57% increase
6.6 days
Cedar Rapids Data
Years having more
than 8 days
11
2
4.2 days
57% increase
6.6 days
Great Flood of 1993 in the US Midwest:
A New “Great Lake”
Historical Data indicate this should
happen about once every 500 years
Lakshmi, V., and K. Schaaf, 2001: Analysis of the 1993 Midwestern flood using satellite and ground data. IEEE Trans. Geosci & Remote Sens.,
39, 1736-1743.
Projected Future Trends
in Iowa Precipitation
“The future isn’t what it used
to be”
Yogi Berra
Global Carbon Emissions (Gt)
Actual emissions are exceeding worst
case scenarios projected in 1990
Source: Jerry Meehl, National Center for Atmospheric Research
Energy intensive
Balanced fuel sources
More environmentally friendly
Limit to avoid “dangerous anthropogenic
Interference” with the climate system
2oC limit
IPCC Fourth Assessment Report Summary for Policy Makers
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.
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.
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.
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.
Relationship of Streamflow
to Precipitation in Current
and Future Climates
Relationship of Streamflow
to Precipitation in Current
and Future Climates
SWAT (RegCM2):
21 % increase in precip
-> 50% increase in
streamflow
DrainMod (RegCM2):
24 % increase in precip
-> 35% increase in tile
drainage
DrainMod (HIRHAM):
32 % increase in precip
-> 80% increase in tile
drainage
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.
 Drier autumns: delay harvest to take advantage of natural drydown conditions
HIGHER YIELDS!!
Is it genetics or climate? Likely
some of each.
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: [email protected]