Global Change and Antarctica

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Global Change and Antarctica

• Eugene S. Takle
• Agronomy Department
• Geological and Atmospheric Science Department
• Iowa State University
• Ames, Iowa 50011
• gstakle_at_iastate.edu

ISU Biology Travel Class, 22 September 2004
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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
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Carbon Dioxide and Temperature
2004
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Carbon Dioxide and Temperature
2040
2004
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Carbon Dioxide and Temperature
Stabilization at 550 ppm
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Carbon Dioxide and Temperature
Business as Usual (fossil intensive) 2100
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Associated Climate Changes

• 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
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Source Jerry Meehl, National Center for
Atmospheric Research
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Source National Center for Atmospheric Research
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Source Intergovernmental Panel on Climate
Change, 2001 Report
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40 Probability
5 Probability
Source Intergovernmental Panel on Climate
Change, 2001 Report
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Climate Change Projected for 2100
Rapid Economic Growth
Slower Economic Growth
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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

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IPCC Summary for Policy Makers, contd

• 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

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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
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Warming Hole
C
DTmax (JJA)
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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.

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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.
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Summary

• Climate change is real and should be considered
  something other than tomorrows 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

• See my online Global Change course
• http//www.meteor.iastate.edu/gccourse
• Contact me directly
• gstakle_at_iastate.edu