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Climate Change in Earth’s Polar Regions. Ben Holt Oceans-Ice Group Jet Propulsion Laboratory. Arctic Ocean, 1982. Global Temperature Change Enhanced at Poles. Average 2001-2007 Surface Temperature Change, Relative to the 1951-1980 Average ( ◦ C). Sunlight Reflectivity on Ice and Ocean.
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Climate Change in Earth’s Polar Regions Ben Holt Oceans-Ice Group Jet Propulsion Laboratory Arctic Ocean, 1982
Global Temperature Change Enhanced at Poles Average 2001-2007 Surface Temperature Change, Relative to the 1951-1980 Average (◦C)
Sunlight Reflectivity on Ice and Ocean Sunlight 100 % Sunlight 100 % Reflected 85% Reflected 7% Ice / Snow Absorbs 15% Water Absorbs 93% •Increased warming => less ice => more open water => warmer water =>more ice melt and so on
Arctic and Antarctic Ice as key indicator of climate change Barrow, Alaska +30°F South Pole -80°F !! / Sea Ice (colored) and Land Ice (white)
Arctic Sea Ice – Reduced Extent September 19, 2010 Satellite Record 11.5 % Reduction Per Decade since 1979
Arctic Sea Ice Thickness Submarine and Satellite Record 1958-2007 •Sea ice thickness shows decadal thinning – over 40 % Reference: Kwok & Rothrock, Geophysical Research Letters, 2009
Land Ice Glaciers, Greenland, Antarctica ~Water stored above sea level
Greenland Ice Mass Loss 2002-2009 Derived From NASA GRACE Gravity Mission Greenland Change in Ice Mass Loss Gigatons Velicogna, Geophysical Research Letters, 2009 •Contributes to sea level rise J. Wahr, U. Colorado
2009 NOAA Arctic Report Card “Warming of the Arctic continues to be widespread, and in some cases, dramatic. Linkages between air, land, sea, and biology are evident.”
Evidence and Impact of Arctic Warming •Sea ice – thinning (>40%) and shrinking (11.5% / decade) •Permafrost melting – also releases methane •Land ice melting – sea level change •Loss of sea ice – impacts habitat of polar bears, walruses •Ecosystem shifts – from Arctic to subarctic communities •Increase human activities – shipping and oil production
Sources, References http://arctic.atmos.uiuc.edu/cryosphere/ http:www.giss.nasa.gov/research/news http://nsidc.org http://www.arctic.noaa.gov/reportcard/