London, May 15 : Polar bears have been listed as threatened under the US Endangered Species Act (ESA), rather than endangered.
According to a report in Nature News, Dirk Kempthorne, the secretary of the interior, made the announcement, which stated that the listing would offer almost no new protections for the bears, which are threatened primarily by melting sea ice.
The decision was based primarily on a series of nine reports issued by the US Geological Survey (USGS) last September.
"Our reports, along with the rest of the body of research, suggested clearly that if sea ice continues to decline, the future of the polar bear was indeed threatened," says Steve Amstrup of the USGS in Anchorage, Alaska, who led the effort.
Those reports found that sea ice is vital to polar bear survival and has declined dramatically in recent years. Furthermore, multiple climate models - chosen for their accuracy in describing observed declines in Arctic ice - predict that ice will continue to recede.
Thin ice covering much of the Arctic Ocean is expected to melt entirely this summer, potentially leaving the North Pole free of ice, according to a projection by the National Snow and Ice Data Center.
Although Kempthorne acknowledged that global warming has caused the retreat of Arctic ice, and that human activities had "some impact" on climate change, no link could be made between any individual power plant or effort to drill for gas or oil and the fate of the bear.
"The loss of sea ice, not oil and gas exploration or subsistence activity, is the primary threat to the polar bear," he said.
"It should not open the door to use the ESA to regulate greenhouse gases. It is not the appropriate tool for addressing climate change," he added.
The long-awaited decision comes months after the first legal deadline for making it, in January, and one day before a new deadline imposed by a federal court in response to the environmental groups' suit.