SocraticGadfly: Multi-year Arctic ice gone? BAD news for polar bears

October 31, 2009

Multi-year Arctic ice gone? BAD news for polar bears

If this is the case, and I don’t doubt that it is, it’s a very direct refutation of global-warming denialists.

The assertion was made by David Barber, Canada’s Research Chair in Arctic System Science at the University of Manitoba:
“We are almost out of multiyear sea ice in the northern hemisphere,” he said in a presentation in Parliament.

Barber spoke shortly after returning from an expedition that sought — and largely failed to find — a huge multiyear ice pack that should have been in the Beaufort Sea off the Canadian coastal town of Tuktoyaktuk. Instead, his ice breaker found hundreds of miles of what he called “rotten ice” — 50-cm (20-inch) thin layers of fresh ice covering small chunks of older ice.

This is additional bad news for polar bears on two counts.

Not only does it mean they have little ice on which to hunt seals, the rush will now be on to “exploit the possibilities” of shipping not only across Canada’s fabled Northwest Passage, but, across the North Pole, to do the same with Russia’s Northeast Passage.

Canadian scientists are already familiar with how too much human presence can stress out isolated populations of grizzlies. I would guess shipping traffic would have similar effects on polar bears.

Of course, some will move south, and become year-round land animals — if they can hold off grizzlies moving north, and adapt their diets. A few of them, as we now know is possible, will interbreed, hastening the demise of polar bears as a separate species, while raising biological questions.

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