Aboard the Louis S. St-Laurent - STANDING on the deck of this floating laboratory for Arctic science, which is part of Canada’s Coast Guard fleet and one of the world’s most powerful icebreakers, I can see vivid evidence of climate change. Channels through the Canadian Arctic archipelago that were choked with ice at this time of year two decades ago are now expanses of open water or vast patchworks of tiny islands of melting ice.
In 1994, the “Louie,” as the crew calls the ship, and a United States Coast Guard icebreaker, the Polar Sea, smashed their way to the North Pole through thousands of miles of pack ice six- to nine-feet thick. “The sea conditions in the Arctic Ocean were rarely an issue for us in those days, because the thick continuous ice kept waves from forming,” Marc Rothwell, the Louie’s captain, told me. “Now, there’s so much open water that we have to account for heavy swells that undulate through the sea ice. It’s almost like a dream: the swells move in slow motion, like nothing I’ve seen elsewhere.”
The Arctic is warming twice as fast as the rest of the planet, and this summer its sea ice is melting at a near-record pace. The sun is heating the newly open water, so it will take longer to refreeze this winter, and the resulting thinner ice will melt more easily next summer.
At the same time, warm Pacific Ocean water is pulsing through the Bering Strait into the Arctic basin, helping melt a large area of sea ice between Alaska and eastern Siberia. Scientists are just beginning to learn how this exposed water has changed the movement of heat energy and major air currents across the Arctic basin, in turn producing winds that push remaining sea ice down the coasts of Greenland into the Atlantic.
http://www.nytimes.com/2010/08/23/opinion/23homer-dixon.html?th&emc=th
Printer-friendly format
Email this thread to a friend
Bookmark this thread
(1000+ posts)
Send PM |
Profile |
Ignore
