IPY/NSTA Web Seminar: Arctic and Antarctic Living Systems LIVE INTERACTIVE YOUR DESKTOP Thursday, December 20, 2007

POLAR AMPLIFICATION Earth = 4,500,000,000 years ~3,500,000,000 yrs – atmosphere changing

Green plants evolved from bacteria Plants put O 2 into atmosphere

↑ CO 2 > 380 ppm ↑ CH 3 ↑ H 2 O

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

Summarizing What changed in earth’s atmosphere 3.5 billion years ago? What organisms were responsible? What changed in earth’s atmosphere years ago? What organisms were responsible? 2. 1.

Let’s Pause for Two Questions

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

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

1980 GREENLAND ALASKA SIBERIA March Annual maximal ice extent ~ 15,000,000 km 2

1980 GREENLAND ALASKA SIBERIA Sept. Annual minimal ice extent ~ 7,000,000 km 2

2005 GREENLAND ALASKA SIBERIA Sept. -27% of 1979 – 1990 average

2007 GREENLAND ALASKA SIBERIA Sept. -23% of 2005 minimum!

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.

Let’s Pause for Two Questions

Krill?, amphipods? amphipod copepod arctic cod black guillemot

harp seal ribbon seal bearded seal walrus spotted seal ringed seal hooded seal

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

NASA logo Thanks to our presenter, Dr. Brendan Kelly, and to NSF, NASA, & NOAA

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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 YOUR DESKTOP NSTA Web Seminars Flavio Mendez, Director Danielle Troiano, Project Coordinator Jeff Layman, Technical Coordinator