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Global Climate Change:
What on Earth are we Doing?!
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
Impacts of climate change
Social inequities and ethical issues surrounding
climate change
Summary
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Carbon Dioxide
and Temperature
Carbon Dioxide
and Temperature
2005
Carbon Dioxide
and Temperature
2040
2005
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
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Agung, 1963
El Chichon (1982)
Mt. Pinatubo (1991)
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
Source: Intergovernmental Panel on Climate Change, 2001 Report
40% Probability
5% Probability
Source: Intergovernmental Panel on Climate Change, 2001 Report
Climate Change
Projected for 2100
Rapid Economic
Growth
Slower Economic
Growth
Source: IPCC, 2001: Climate Change 2001: The Scientific Basis
Source: IPCC, 2001: Climate Change 2001: The Scientific Basis
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
 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
 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
Antarctica
Greenland
0
Cold
Warm
Climate
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Hansen,
Scientific American, March 2004
PROJECT TO INTERCOMPARE REGIONAL CLIMATE
SIMULATIONS
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
RegCM2 Simulation Domain
Red = global model grid point
Green/blue = regional model grid points
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
Relation of Runoff to Precipitation
for Various Climates
“Warming Hole”
˚C
DTmax (JJA)
Source: IPCC, 2001: Climate Change 2001: The Scientific Basis
Social Inequities due to Climate
Change
 Agricultural
production
 Freshwater availability
 Sea-water innundation
 Intergenerational equities
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Social Inequities due to Climate
Change
 Agricultural
production
 Freshwater availability
 Sea-water innundation
 Intergenerational equities
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Social Inequities due to Climate
Change
 Agricultural
production
 Freshwater availability
 Sea-water innundation
 Intergenerational equities
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
http://www.grida.no/climate/vital/37.htm
http://www.grida.no/climate/vital/38.htm
Social Inequities due to Climate
Change
 Agricultural
production
 Freshwater availability
 Sea-water innundation
 Intergenerational equities
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Sea-Water Innundation
Example: The Maldives
 Area:
115 square miles
 Population: 143,000
 Highest point: 20 ft above sea level
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Social Inequities due to Climate
Change
 Agricultural
production
 Freshwater availability
 Sea-water innundation
 Intergenerational inequities
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Intergenerational Inequities
Sustainable Development: “To meet the needs of
the present without compromising the ability of
future generations to meet their needs.”
 Energy sources?
 Non-renewable earth resources?
 Agricultural productivity?
 Fresh water supplies?
 Heavy metal contamination of soil
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and water?
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Summary
 Climate
change is real and we need to be
doing something about it
 The longer we wait, the fewer our options
 Regional patterns of warming will be
complicated
 Climate surprises can’t be
discounted
 Climate change carries ethical
implications
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]
http://www.meteor.iastate.edu/faculty/takle/
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS