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IPY/NSTA Web Seminar: Arctic and Antarctic Living Systems LIVE INTERACTIVE LEARNING @ YOUR DESKTOP Thursday, December 20, 2007
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POLAR AMPLIFICATION Earth = 4,500,000,000 years ~3,500,000,000 yrs – atmosphere changing
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Green plants evolved from bacteria Plants put O 2 into atmosphere
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↑ CO 2 > 380 ppm ↑ CH 3 ↑ H 2 O
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Scales in space and time: Weather = local and day-to-day Climate = regional to global - long term Human history = 0.1% of earth’s history
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Summarizing What changed in earth’s atmosphere 3.5 billion years ago? What organisms were responsible? What changed in earth’s atmosphere 100 - 150 years ago? What organisms were responsible? 2. 1.
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Let’s Pause for Two Questions
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Climate models predict further warming in this century – but, how much? Take a guess…before I tell you As much as 5 degrees C As much as 10 degrees C As much as 12 degrees C As much as 3 degrees C
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Albedo = reflectivity of a surface. Snow on sea ice reflects 80 – 90% of the sun’s energy. Sea water reflects only 10%. Atmospheric warming melts ice decreases albedo warms ocean melts more ice further decreases albedo
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1980 GREENLAND ALASKA SIBERIA March Annual maximal ice extent ~ 15,000,000 km 2
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1980 GREENLAND ALASKA SIBERIA Sept. Annual minimal ice extent ~ 7,000,000 km 2
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2005 GREENLAND ALASKA SIBERIA Sept. -27% of 1979 – 1990 average
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2007 GREENLAND ALASKA SIBERIA Sept. -23% of 2005 minimum!
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Why do I refer to decreasing albedo as ice melts as positive feedback? Where else on earth might we see much the same process and effects? 1. 2.
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Let’s Pause for Two Questions
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Krill?, amphipods? amphipod copepod arctic cod black guillemot
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harp seal ribbon seal bearded seal walrus spotted seal ringed seal hooded seal
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Plants changed climate by adding O 2 Absent GHG’s, earth frozen Humans warming climate by adding CO 2, CH 3, H 2 O Melting snow & ice decreases albedo = positive feedback to warming Loss of summer ice this century will radically change sea ice ecosystem Rapid environmental changes in the past lead to many extinctions
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NASA logo Thanks to our presenter, Dr. Brendan Kelly, and to NSF, NASA, & NOAA
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http://www.elluminate.com Elluminate logo
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http://learningcenter.nsta.org NLC screenshot
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National Science Teachers Association Gerry Wheeler, Executive Director Frank Owens, Associate Executive Director Conferences and Programs Al Byers, Assistant Executive Director e-Learning LIVE INTERACTIVE LEARNING @ YOUR DESKTOP NSTA Web Seminars Flavio Mendez, Director Danielle Troiano, Project Coordinator Jeff Layman, Technical Coordinator
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