Climate change is forcing the U.S. to consider protecting the polar bear under its endangered species act.

The U.S. Fish and Wildlife Service is launching a review of the bear, to determine whether changes in climate and other threats are hurting its chances for survival.

It's estimated 60 per cent of the world's polar bears live in Canada.
It's estimated 60 per cent of the world's polar bears live in Canada.

A petition with "substantial scientific and commercial information indicating that listing the polar bear may be warranted" prompted the department to launch the review, it said Wednesday.

The review is expected to take a year, at which time the service will release its findings.

The wildlife agency received the petition in February 2005 to list the bear as threatened, which means it is likely to become endangered. The petition also called for habitat protection for the animals.

Scientists say climate change is reducing ice floes in the Arctic, disrupting the bear's feeding grounds and migration patterns.

Biologists estimate there about 22,000 to 25,000 polar bears in the world, with 60 per cent of that number in Canada. While their populations are thought to be currently stable, there are also disagreements about the health of the animals in certain regions.

Some scientists have speculated the bears could be extinct in about 100 years if climate change continues at its present pace.

American wildlife managers also announced last week they were reviewing changes to polar bear hunting quotas in Nunavut, after scientists opposed a 28 per cent increase in the number of permits issued by the territory.

The U.S. Fish and Wildlife Service is the principal federal agency responsible for conserving, protecting and enhancing fish, wildlife and plants and their habitats.