Polar bears are facing threats from global warming and environmental contamination and need federal protection under the Endangered Species Act, Washington is expected to propose Wednesday.

Interior Secretary Dirk Kempthorne plans to announce that polar bears should be listed as a "threatened" species on the government list of imperiled species, a department official told The Associated Press.

The "endangered" category is reserved for species more likely to become extinct.

"The sea ice in the Arctic is changing very quickly. We're losing about 10 per cent of the ice each decade, and for polar bears, this is the habitat that they rely on for making their ends meet," Andrew Derocher, chair of the Polar Bear Specialist Group, told CTV Newsnet.

Two decades ago there were about 1,500 polar bears near Churchill, Man. The number has since fallen to about 900.

"Polar bears are coming off of the ice earlier," said Manitoba Premier Gary Doer.

"They're hunting for less periods of time because the ice is melting."

On Tuesday, an Interior Department official described the proposal as the first time the administration of U.S. President George Bush has identified climate change as the possible driving force behind the potential demise of a species, the Washington Post reported.

"We've reviewed all the available data that leads us to believe the sea ice the polar bear depends on has been receding," the Interior official, on condition of anonymity, told the paper.

"Obviously, the sea ice is melting because the temperatures are warmer."

The paper further quoted the official as saying Fish and Wildlife Service officials have concluded that polar bears could be endangered within 45 years.

Once a species is listed as threatened, the government is barred from doing anything to jeopardize the animal's existence or its habitat.

In the case of the polar bear, environmentalists hope to force the government to curb emissions of greenhouse gases such as carbon dioxide that can contribute to global warming.

Lawsuit

Responding to a lawsuit filed Dec. 15, 2005 by three environmental groups, the Interior Department's Fish and Wildlife Service announced in February that it was launching a review of polar bears and that designating the animals as "threatened" may be warranted.

The Post reported on its website Tuesday night that by submitting the proposal Wednesday, the government would be meeting a deadline under a legal settlement with the three groups that sued: the Center for Biological Diversity, the Natural Resources Defense Council and Greenpeace.

Their suit last year argued that the government, which has been examining the status of polar bears for more than two years, was moving too slowly.

Polar Bears are estimated to number between 22,000 and 25,000 worldwide with populations existing in Canada, Alaska, Greenland, Norway and Russia.

While their numbers have been stable in recent years, environmentalists say the bears face threats from global warming, environmental contamination and potential overhunting.

The Polar Bear Specialist Group of the World Conservation Union, based in Gland, Switzerland, lists the polar bear among more than 16,000 species threatened for survival worldwide. The group projects a 30 percent decline in their numbers over the next 45 years.

In Alaska, only Indians, Aleuts, and Eskimos who live in coastal areas are permitted to hunt the bears, which they can use for meat and in making native handicrafts.

In the past, the Bush administration has consistently rejected scientific thesis that human activity contributes to global warming and has resisted capping greenhouse gas emissions as bad for business and U.S. workers.

Greenhouse gases like carbon dioxide (CO2), produced by burning fossil fuels, trap heat in the atmosphere. Scientists say rising temperatures could raise sea levels and cause more droughts, floods and heat waves, and contribute to the melting of Arctic ice. Thinner sea ice reduces the amount of food polar bears can find, including ice seals that are their main prey.

With a report by CTV Winnipeg's Rachel Lagace and files from The Associated Press