Scientifiques parlant du changement climatique
 
PLANETE TERRE: NOTRE FOYER AIMANT Elle disparaît sous nos yeux : l’état grave de la glace arctique   
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HOST: Concerned viewers, welcome to this week’s edition of Planet Earth: Our Loving Home, featuring our program on the state of Arctic sea ice and glaciers. The Arctic is the polar crown of our planet, yet the ice and snow in this precious area are disappearing at an unprecedented rate due to climate change, which is driven by the production and consumption of animal products.

These destructive practices are the main source for the human-generated greenhouse gases rapidly heating the globe.

Today we’ll examine how the beautiful but fragile northern polar region is vital to life on our Earth and how it affects weather and climate. One way in which the Arctic plays a key role in regulating global temperatures is through the ice-albedo effect, by which the area’s ancient layer of snow and sea ice reflects 85 to 90% of the Sun’s energy back into space, keeping our planet cool.

Hence, the more ice and snow that are present in the region, the cooler our Earth becomes.  
However when this cover disappears, the opposite effect occurs, as the dark, Arctic Ocean and exposed Arctic land absorb the Sun’s energy and cause planetary warming, which in turn drives more melting and more exposure of these non-reflective surfaces.

Oceanographer Dr. James Overland of the US National Oceanic and Atmospheric Administration’s Pacific Marine Environmental Laboratory directs research on this phenomenon and will now provide more details.

James(m): Without ice there to reflect the summer sunlight from the white ice, we absorb a whole lot more heat from the Sun that the Earth normally used to not get, and that heat is returned to the atmosphere in the fall, and that helps set up these highly variable climate patterns.


For more details on the scientists featured in today’s program, please visit the following respective websites:
Dr. David Barber
www.UManitoba.ca
Dr. James Hansen
www.GISS.NASA.gov
Professor Anders Levermann
www.PIK-Potsdam.de
Dr. James Overland


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