U.S. wildlife managers released on Thursday a draft plan for stemming the decline of polar bears threatened by melting Arctic sea ice linked to global warming, but the proposal hinges on reductions in greenhouse gas emissions that are far from assured.
Under a plan to be officially submitted on Monday for public comment, the U.S. Fish and Wildlife Service is urging cutbacks in carbon dioxide and other atmospheric pollutants generated by the burning of fossil fuels.
The draft proposal does not quantify the extent of greenhouse gas reductions that the agency deems necessary to save polar bears from extinction.
But the report says decreased carbon emissions constitute "the single most important action for the recovery of polar bears." An estimated 20,000 to 25,000 of the snow-white bruins are believed to remain in the Arctic, including parts of Alaska, Canada, Russia, Norway and Greenland.
Polar bears were listed as threatened under the U.S. Endangered Species Act in 2008 due to disappearing sea ice, becoming the first animals granted such protection because of conditions tied to global climate change.
Polar bears, which can stand as high as 11 feet tall and weigh as much as 1,400 pounds, use floating sea ice as platforms for hunting, mating and traveling vast distances.
Accelerated melting of polar ice has also led to a severe decline in populations of ringed seals that are the bears' preferred prey, forcing the bruins to swim longer distances and more quickly exhausting their crucial winter fat reserves, according to the Fish and Wildlife Service.
The draft recovery plan for polar bears sets such goals as limiting man-made air pollution, minimizing conflicts with humans that have become more frequent as the bears spend more time ashore in a search for food, and lessening the bears' exposure to contamination associated with oil spills.
A U.S. Geological Survey study released on Wednesday concluded polar bears face dramatic further declines in the next several decades even if reductions in greenhouse emissions could be realized and if global warming was stabilized.
Other factors, such as oil and gas exploration and hunting by indigenous peoples, had little impact on polar bears compared with the loss of sea ice, researchers found.
(Reporting by Laura Zuckerman in Salmon, Idaho; Editing by Steve Gorman)