Scientists with the National Snow and Ice Data Center in Boulder, Colorado, reported that in September 2005 the sea ice had shrunk to its lowest level on record.
If the melting trend continues, the Arctic could see ice-free summers by 2040, according to a Canadian climate model. Other models suggest open Arctic waters by the end of the century. (See "Arctic Ice Levels at Record Low, May Keep Melting, Study Warns.")
Bears in some areas spend the summer months on land. They fast until the ice forms in the fall, when they can use the ice as a vast platform from which to hunt the seas.
Studies of the polar bear populations around the western coast of Canada's Hudson Bay (map) show that this wait, and the bears' period of fasting, has increased by three weeks since the 1970s.
The population there is noticeably skinnier now, scientists say, and has declined by 15 percent in the last decade.
In northern Alaska the U.S. Minerals Management Service has concluded that some polar bears are drowning as they try to swim increasingly long distances between the ice and land.
The federal agency documented four drowned bears that had tried to swim a record 160-mile (257-kilometer) gap in September 2004.
The worldwide polar bear population is between 20,000 and 25,000, scientists estimate.
"We are not going to lose the polar bears," said Terry Root, an ecologist at Stanford University in Palo Alto, California.
"We will always have individuals around in zoos and places like that, but we are going to lose the natural behavior of polar bears," she said.
"We are so strongly affecting their habitat, their way of life, that they are going to have to basically become very similar to raccoons [which rely heavily on humans for survival], in the sense they are not going to be able to feed the way they have fed before, on seals and off the ice."
Today encounters between humans and polar bears are increasing on land, because the bears are stranded by the retreating ice, explained Meehan, the Fish and Wildlife Service biologist.
To combat the problem, the Fish and Wildlife Service is working with oil and gas companies and villagers to develop "strategies for people to be safe in bear country," Meehan said.
Some companies employ specially trained bear watchers to shoo the animals away.
Environmental groups often criticize the Bush Administration for ignoring scientific evidence of global climate change. Now many evangelical Christians, who are often considered administration allies, are joining the critics.
The day before the White House announced it would study whether polar bears warrant protection, more than 85 evangelical Christian leaders urged the federal government to clamp down on greenhouse gas emissions.
The statement, released by the Evangelical Climate Initiative reads, "Many of us have required considerable convincing before becoming persuaded that climate change is a real problem and that it ought to matter to us as Christians. But now we have seen and heard enough. "
Among the signers were Rick Warren, the author of the best-selling The Purpose Driven Life, and W. Todd Bassett, the U.S. national commander of the Salvation Army.
Siegel, the Center for Biological Diversity attorney, said the decision to conduct a status review of polar bears forces the Bush Administration to examine the very science on climate change it has "questioned, denied, and downplayed."
If the polar bears are given protection, federal agencies will be required to consider how their decisions affect polar bears. For example the listing of polar bears could impact a coal plant seeking federal permission to emit heat-trapping gases or an automaker seeking to sell a gas-guzzling car.
For Meehan, the biologist, the process is about the polar bears, not the politics.
"I care about polar bears. That's why I'm a wildlife biologist," Meehan said. "It's important to me personally and professionally to do the best we can for the polar bears."
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