Global Warming: More Than Hot Air

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Global Warming More Than Hot Air
D.S. ChapmanUniversity of Utah
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Measuring Temperature in the Earth
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1850
1928
1981
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• The Greenland Ice Sheet Dominates Land Ice in the
  Arctic
• From 1979 to 2005, the melt area on the
  Greenland Ice Sheet has increased by about 20.
• Recent satellite observations suggest that ice
  accumulation on the dome is less than losses due
  to melting around the edges.

Source Business Week Aug. 2004
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Some observed changes have been very rapid--much
more rapid than can be simulated by models
Larsen Ice Shelf--January 31, 2002
Larsen Ice Shelf--March 5, 2002
MODIS images courtesy of NASA's Terra satellite
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Shishmaref, Alaska 2005
About 40 m (125 ft) in one storm
The melting back of sea ice in spring and fall is
already increasing coastal erosion.
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Freeze and Thaw
Source Magnuson, et al. Science 2000
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Alaska Tundra Travel Days Decreased by Half Since
1970
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An increased rate of rise of sea level is likely
to inundate low-lying island nations
Maldive Islands
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Consequences of Global Warming
Ward Hunt Ice Shelf, 2002
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Radiative forcing 1750 to 2005
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What Dont We Know?
Public policy debates are constantly getting
stuck in the mire of perceptions about scientific
uncertainty and risk. Yet science is no
different to many other areas of human
experience, in that uncertainty and risk are
inevitably present. In a readable, entertaining
presentation, Henry Pollack removes some of the
mystery surrounding scientific uncertainty by
placing it alongside examples from everyday
life. Sir John Houghton, Co-chair of the
Intergovernmental Panel on Climate Change
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1 bulb/household 400,000 cars/year
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Thursday, 31 March, 2005, 1746 GMT 1846 UK
Dress down to save Japan, PM says
Japan's prime minister plans to dress down this
summer, and wants millions of Japanese office
workers to do the same.
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It's time to go on a low-carbon diet.
Natural Gas Hydrogen Solar
beyond petroleum
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Chevron Steps Taken Committing over 100 million
every year on renewable energies, alternative
fuels and improving efficiency
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U.S. Climate Action Partnership
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Five Western Governors Announce Regional
Greenhouse Gas Reduction Agreement
Monday February 26, 2007
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Q Why should we be concerned about the year 2100?
A This will be the world of our children,
grandchildren and great grandchildren.
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Global Warming More Than Hot Air

• Warming is real.
• Feedback system is complex.
• Consequences of warming are mixed losers
  outnumber winners.
• Greenhouse gas emissions are growing residence
  times are long. Time to act is NOW.
• Citizen groups have impact.
• Prudent path has benefits beyond reducing warming.

D.S. ChapmanUniversity of Utah
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Questions About Global Warming
Q Why should I be concerned by just a few
degrees of warming? Q How can global warming be
caused by greenhouse gases when temperatures
have sometimes decreased while greenhouse
gases were increasing? Q Wont taking steps to
reduce carbon emissions ruin our economy?
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Q Why should I be concerned about just a
few degrees of warming ?

• Shift in the global mean tells only part of the
  story.
• Regional warming may be much greater than the
  global mean warming.
• Focus on critical temperature.
• Distribution may broaden (more extreme climate).

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Q Wont taking steps to reduce our CO2
emissions to the atmosphere ruin our
economy?

• Studies are mixed
• Consider

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Global Warming More Than Hot Air

• Warming is real.
• Feedback system is complex.
• Consequences of warming are mixed losers
  outnumber winners.
• Greenhouse gas emissions are growing residence
  times are long. Time to act is NOW.
• Citizen groups have impact.
• Prudent path has benefits beyond reducing warming.

D.S. ChapmanUniversity of Utah
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The World at Night Gives an Indication of the
Extent of Human Influences
Fossil fuels (coal, oil, natural gas) provide
about 90 of the worlds energy