Transcript PPT file - Regional Climate Modeling Laboratory

Global Change and Antarctica
Eugene S. Takle
Agronomy Department
Geological and Atmospheric Science
Department
Iowa State University
Ames, Iowa 50011
[email protected]
ISU Biology Travel Class, 22 September 2004
PROJECT TO INTERCOMPARE REGIONAL CLIMATE SIMULATIONS
Outline
Evidence for global climate change
 Future atmospheric carbon dioxide
concentrations
 Simulations of global climate and future
climate change
 Role of Antartica in climate change
 Summary
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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
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Mann, M. E., R. S. Bailey, and M. K. Hughes, 1999: Geophysical Research Letters 26, 759.
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Hansen, Scientific American, March 2004
Source: Jerry Meehl, National Center for Atmospheric Research
Source: National Center for Atmospheric Research
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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
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
 There
is new and stronger evidence that
most of the warming observed over
the last 50 years is attributable
to human activities
 Anthropogenic climate change will persist
for many centuries
Climate Surprises
 Breakdown
of the ocean thermohaline
circulation (Greenland melt water)
 Breakoff of the West Antarctic Ice Sheet
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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
“Warming Hole”
˚C
DTmax (JJA)
Global warming is at least as important
an issue as gay marriage or the rising cost
of Social Security.
And if it is not seriously debated in the
general election, it will measure the
irresponsibility of the entire political class.
This is an issue that cannot,
and must not, be ignored any
longer.
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Global warming is at least as important
an issue as gay marriage or the rising cost
of Social Security.
And if it is not seriously debated in the
general election, it will measure the
irresponsibility of the entire political class.
This is an issue that cannot,
and must not, be ignored any
longer.
Walter Cronkite
12 March 2004
http://www.philly.com/mld/dailytimes/news/opinion/8159334.htm
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What Can I Do?
 Conserve
energy
 Adopt a simpler lifestyle:
– “Elegant simplicity”
– “Sophisticated modesty”
– “Affluence lite”
Sustainable Development:
To meet the needs of the present without
compromising the ability of future
generations to meet their needs
Brundtland Commission (World Commission on Environment and Development)
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Calving of an Iceberg
9 Jan 1995
12 Feb 1995
The ice shelf which formerly occupied Prince Gustav Channel and connected James Ross Island to the Antarctic Peninsula
Disintegrated making James Ross Island circumnavigable for the first time in recorded history. The new iceberg calved from
the Larsen Ice Shelf and measured 78 km x 37 km x 200 m thick.
Summary
Climate change is real and should be considered
something other than “tomorrow’s problem”
 We are committed to a warming over the next 40
years regardless of what policy path we choose
 Policy decisions today will affect global warming
and associated environmental changes in
the latter half of the 21st century and
beyond
 Consider adopting a simpler lifestyle
 Ice is very important to the climate
system and needs to be protected
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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]
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