A sow polar bear rests with her cubs on the pack ice in the Beaufort Sea in northern Alaska. (U.S. Fish and Wild Life Service, Steve Amstrup/AP)

The massive fracture that ripped the Beaufort sea ice from the west coast of Banks last year could not have been better timed if nature had planned it.

The dramatic event was "absolutely" the result of climate change, according to David Barber of the Circumpolar Flaw Lead System Study.

And the threat of climate change to polar bear habitat is the reason politicians in both the U.S. and Canada must soon decide whether the bears should be listed under endangered species legislation.

A summer place

The thick, hard, old ice packed around Banks Island is the summer refuge for polar bears from both the South and North Beaufort Sea populations. Every year as the thinner annual ice melts in the warmth of summer, the bears head north to the multiyear ice.

The bears are as faithful to the territory they know as humans are to a family cottage. They live there. It's their home.

Last summer, as startled researchers recorded yet another record-breaking loss of Arctic sea ice, the bears' familiar patterns were thrown out of kilter. Canadian bears ended up in Russia. Manitoba bears ended up in Ontario. Some never got home.

Andrew Derocher knows this, because he was tracking the bears with radio collars. "The way the ice broke up this year was that different — they just couldn't maintain contact with where they needed to be," the University of Alberta biologist said.

So some of the bears walked 500 kilometres. Others 1,000 km. Without food. Derocher says it's as if the bears are on a treadmill, and we've turned up the speed.

"You're asking them to go farther and do it on less," he said.

Energy used to move about is energy not available for reproduction, growth and survival.

And now they face another challenge: the giant split in the ice off Banks Island.

"If all of a sudden the refuge isn't there when you're trying to get there, you are stuck a long ways away from shore and perhaps a long ways away from any ice, which means you are very vulnerable to drowning," said Derocher. "Or you starve to death."

The political battle

Environmental groups have seized on the polar bear to be the champion of all the ice-dependent creatures. The bear is carrying the colours of the walrus, Peary Caribou and ringed seal into the battle against climate change, rallying support to protect the species it endangers.

On the other side — other interest groups: oil and gas interests in Alaska, governments in Juneau and Iqaluit, Inuit hunters.

Few polar bear biologists doubt what the decision should be.

Last September, the US Geological Survey said that if the Arctic sea ice keeps melting, 2/3 of the world's polar bear population of between 20,000 and 25,000 animals will be gone by the middle of this century.

And 40 members of the World Conservation Union's polar bear specialist group decided, unanimously, to list the polar bear as vulnerable when they met 18 months ago.

Derocher, who heads the group, put it simply: "If there is no ice, there are no bears."

The decision by the U.S. Interior Secretary on whether to list the polar bear under the Endangered Species Act was due by Jan. 9th, but has been delayed due to the "taxing and challenging" nature of the issue.

And it's true — this is a tricky one, and not just because this is the first animal that might be listed as endangered specifically due to climate change. At the moment, there are lots of bears. For those monitoring many of the world's 19 populations of polar bears, climate change is a perceived threat, not yet a current one.

But in Canada, biologists believe five of the country's 13 populations are in trouble.

Government slow to react

I spent three days on Cape Churchill in Western Hudson Bay with scientists Ian Stirling and Nick Lunn in September of 1999. I can still feel beneath my hands the ribs and pelvis of a skinny little sedated cub; can still hear Stirling telling me she probably wouldn't make it.

Biologists have recorded the decline of these bears, famous for their hungry forays into the town of Churchill, for 35 years. As the spring melt advances and the fall freeze up retreats, the bears can't get on the ice to hunt.

Famished bears and their cubs don't do well. Between 1987 and 2004, the population dropped by 22 per cent.

There are other threats to polar bears: toxic chemicals accumulating in the animals' tissues, over-hunting, resource development.

COSEWIC, the committee with the unwieldy name that gives expert advice on the status of endangered wildlife in Canada, has several times declared the bears to be a species of "special concern." That's not as serious as saying they are threatened or endangered. It does mean their future looks shaky, rather like the sea ice they depend on.

But until SARA, the Species at Risk Act of 2002, governments were not required to take action based on assessments by COSEWIC. And when the Committee again assessed the polar bear as a species of special concern in 2004, the federal Minister of the Environment sent it back to COSEWIC for reassessment.

In April of 2008, the Committee reaffirmed its assessment: polar bears are of special concern, a decision that will be communicated to the Minister in August. Should the cabinet eventually decide to accept the listing, the federal government would be required to draw up a management plan to protect the species.

The results in the past have not encouraged Derocher, who said so far the reports just disappeared into "the vast black hole which is the bureaucracy of conservation in Ottawa."

What's more, a 2007 study in the journal Conservation Biology titled "Bias in Legal Listing under Canadian Endangered Species Legislation" found no northern species found in Nunavut has made it onto the list.

One of the co-authors, Marco Festa-Bianchet of the University of Sherbrooke, told CBC News that Nunavut has, "systematically opposed the listing of polar bears, grizzly bear, Peary caribou, populations of beluga, wolverine. Everything that was considered in Nunavut territory was not put on the list." It is all, he said, "essentially driven by politics."

Decision pending?

Which throws the bear's status back into the political arena. And that arena grows more complicated by the day.

The news release Inuit Tapiriit of Canada has denounced American environmental groups which have been pressuring the U.S. government to list the polar bear as endangered. Such a listing would mean American hunters would no longer be able to employ Inuit guides to shoot trophy bears.

But now it seems even some Nunavut hunters agree that they are seeing skinny bears.

This week, territorial government biologists told a hearing the bears in the Baffin Bay area are skinny because there isn't enough food, and the number of bears that hunters can kill should be reduced. The hunters argue the bears are skinny because there are so many competing for food.

The Inuit have contributed virtually nothing to atmospheric greenhouse gases, yet their culture and lifestyle is likely to be among the most affected in the world. Many Inuit believe that what's happening in the Arctic is a natural cycle, and that because they are seeing lots of bears, centuries of traditional knowledge and wisdom are being ignored by scientists.

But science says what is happening in the arctic is not a natural process, and traditional wisdom does not see with the satellite's eye. The interests of the Inuit, scientists, the public, and the bears should coincide, for the survival of the species is in everyone's interests.

Perhaps they eventually will. Politicians on both sides of the border have, so far, sided with politics. This summer will test their commitment to science.