Transcript PPT file - Department of Geological & Atmospheric

Global Climate Change
and Regional Impacts:
Are We Building the Right Kind of Drainage
Structures to Handle Climate Change?
Eugene S. Takle
Agronomy Department
Geological and Atmospheric Science
Department
Iowa State University
Ames, Iowa 50011
[email protected]
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Outline
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Evidence for global climate change
Future atmospheric carbon dioxide concentrations
Simulations of global climate and future climate
change
Implications for stream flow and
nutrient loss
Summary
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Carbon Dioxide
and Temperature
Carbon Dioxide
and Temperature
2004
Carbon Dioxide
and Temperature
2040
2004
Carbon Dioxide
and Temperature
Stabilization at 550 ppm
Carbon Dioxide
and Temperature
“Business as Usual”
(fossil intensive)
2100
?
Associated Climate Changes
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Global sea-level has increased 1-2 mm/yr
Duration of ice cover of rivers and lakes decreased by 2 weeks in N.
Hemisphere
Arctic ice has thinned substantially, decreased in extent by 10-15%
Reduced permafrost in polar, sub-polar, mountainous regions
Growing season lengthened by 1-4 days in N. Hemisphere
Retreat of continental glaciers on all continents
Poleward shift of animal and plant ranges
Snow cover decreased by 10%
Earlier flowering dates
Coral reef bleaching
Source: Intergovernmental Panel on Climate Change, 2001 Report
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Mann, M. E., R. S. Bailey, and M. K. Hughes, 1999: Geophysical Research Letters 26, 759.
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Source: IPCC, 2001: Climate Change 2001: The Scientific Basis
Source: IPCC, 2001: Climate Change 2001: The Scientific Basis
Observed summer (June-July-August) daily mean temperature
changes (K) between 1976-2000 (Adapted from Folland et al. [2001]).
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Hansen, Scientific American, March 2004
Source: Jerry Meehl, National Center for Atmospheric Research
Source: National Center for Atmospheric Research
The planet is committed to
a warming over the next
50 years regardless of
political decisions
Source: National Center for Atmospheric Research
Amount of warming is
in question, but all models
project a warming
Source: Intergovernmental Panel on Climate Change, 2001 Report
Climate Change
Projected for 2100
Rapid Economic
Growth
Slower Economic
Growth
IPCC Summary for
Policy Makers
 An
increasing body of observations gives a
collective picture of a warming world and
other changes in the climate system
 Emissions of greenhouse gases and aerosols
due to human activities continue to
alter the atmosphere in ways that
are expected to affect the climate
IPCC Summary for
Policy Makers, cont’d
 Confidence
in the ability of models to
project future climate has increased
 There is new and stronger evidence that
most of the warming observed over
the last 50 years is attributable
to human activities
IPCC Summary for
Policy Makers, cont’d
 Anthropogenic
climate change will persist
for many centuries
 Further action is required to address
remaining gaps in information and
understanding
Climate Surprises
 Breakdown
of the ocean thermohaline
circulation (Greenland melt water)
 Breakoff of the West Antarctic Ice Sheet
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Regional Climate Change
for the US Midwest
 Observed
and projected changes in
climate
 Impact on water quantity and water
quality
 Policy implications
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Changes in Daily Maximum Temperature
Projected for 2040 by a Regional Climate Model
Changes in Daily Minimum Temperature
Projected for 2040 by a Regional Climate Model
“Warming Hole”
˚C
DTmax (JJA)
For the Midwest
Warming will be greater for winter than summer
 Warming will be greater at night than during the
day
 A 3oF rise in summer daytime temperature triples
the probability of a heat wave
 Growing season will be longer (8-9 days longer
now than in 1950)
 More precipitation
 Likely more soil moisture in summer
 More rain will come in intense rainfall events
 Higher stream flow, more flooding
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Sub-Basins of the
Upper Mississippi
River Basin
119 sub-basins
Outflow measured
at Grafton, IL
Approximately one
observing station
per sub-basin
Approximately one
model grid point
per sub-basin
Soil Water Assessment Tool
(SWAT)
Long-term, continuous watershed simulation model
(Arnold et al,1998)
 Assesses impacts of climate and management on
yields of water, sediment, and agricultural chemicals
 Physically based, including hydrology, soil
temperature, plant growth, nutrients,
pesticides and land management
 Daily time steps
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PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Validation of SWAT:
Annual Stream Flow at Grafton, IL
Validation of SWAT:
Monthly Stream Flow at Grafton, IL
Ten-Year Mean Precipitation Generated by the RegCM2
Regional Climate Model Driven with HadCM2
Global Model Results for the Contemporary and
Future Scenario (2040s) Climate
Ten-Year Mean Monthly Stream Flow Generated by the
RegCM2 Regional Climate Model Driven
with HadCM2 Global Model Results for the
Contemporary and Future Scenario (2040s) Climate
Comparison of Simulated Stream Flow under
Climate Change with Various Model Biases
Relation of Runoff to Precipitation
for Various Climates
Regional Climate Modeling for
Informing Policy on Water Quality
 How
does the combination of climate
change and land use impact water quality?
 Use nitrates and sediment as indicators
 What alternative land management
strategies will improve water quality?
 What policies need to be
implemented to achieve this water
quality improvement?
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Maquoketa Watershed
Scenario 1: all Agriculture
Scenario 2: all Forest
Scenario 3: N. half Agric.
and S. half Forest.
Scenario 4: S. half Agric.
and N. half Forest.
Scenario 5: Upper half Agric.
and lower half Forest.
Scenario 6: Lower half Agric.
and upper half Forest.
Scenario 7: Main channel
basins - Agric.
Scenario 8: Main channel
basins - Forest.
Improving Regional Climate Models
 Project
to Intercompare Regional Climate
Simulations
 Transferability Working Group of GEWEX
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Summary
Regional climate models demonstrate
sufficient skill to be useful for driving
some climate impacts assessment
models for the purpose of informing
policy makers and decision-makers of
vulnerabilities and opportunities
associated with future climate change
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
For More Information
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See my online Global Change course:
http://www.meteor.iastate.edu/gccourse
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Contact me directly:
[email protected]
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS