The U.S. Department of the Interior Wednesday listed the polar bear as a threatened species under the Endangered Species Act (ESA) of 1973 based on evidence that the animal's sea ice habitat is shrinking and is likely to continue to do so over the next several decades. Interior Secretary Dirk Kempthorne, however, made clear several times during a press conference announcing the department's decision that, despite his acknowledgement that the polar bear's sea ice habitat is melting due to global warming, the ESA will not be used as a tool for trying to regulate the greenhouse gas emissions blamed for creating climate change.

The decision was based on evidence that sea ice is vital for polar bear survival, that this sea ice habitat has been reduced, and that this process is likely to continue; if something is not done to change this situation, the polar bear will be extinct within 45 years, Kempthorne said. He pointed to computer models he and his colleagues studied that project a 30 percent decline in sea ice by 2050.

Listing the polar bear as "threatened" means the animal is at risk of becoming an "endangered" species--in danger of extinction--in the foreseeable future if its habitat continues to be destroyed or adversely changed. The listing does not protect the polar bear from being hunted by natives for food and other resources.

Cato Institute environmental studies senior fellow Patrick Michaels disputes the department's science, however. In a statement issued Wednesday, he noted: "This marks the first instance of a species being listed based upon a computer model of future climate from the United Nations Intergovernmental Panel on Climate Change. There has been no net warming in the last decade, and scientists recently discovered that it is likely there will be little if any for the next decade." He concludes that the department's listing is based on "obsolete science," making this more of a political than a scientific decision.

Kempthorne noted that decision to list the polar bear as a threatened species was particularly difficult. "The polar bear poses a unique conservation challenge," he said. "With most [species], we can identify a localized threat, but the threat to the polar bear comes from global influences on sea ice."

Interior's decision is intended to afford the polar bear protections without interfering with industry located in the Arctic. "I've accepted that the loss of sea ice, not subsistence [hunting of the animal] or the oil and gas industries, is the reason for the threat to the polar bears," which are already protected by the more stringent Marine Mammal Protection Act of 1972, Kempthorne said. Still, he acknowledged, "this decision will not stop global climate change or prevent sea ice from melting."

Although the polar bear's listing does recognize the impact of changing global conditions, the department is quick to point out that it does not assign blame for these conditions on anyone in particular. The ESA "can't make connections between greenhouse gas emissions and the polar bear's status as an endangered species," Dale Hall, director of the U.S. Fish & Wildlife Service, said at the press conference.

U.S. District Court Judge Claudia Wilken in Oakland, Calif., on April 29 ordered the Bush administration to stop dragging its feet on the fate of polar bears and decide by May 15 whether declining sea ice in the Arctic threatens their existence. That ruling was a small victory for a coalition of environmentalists—the Center for Biological Diversity, Greenpeace International and the Natural Resources Defense Council (NRDC)--which sued to force the Interior Department to decide whether to protect these Arctic predators under the ESA, which it had committed to do by January 9.

Wilken rejected Interior's request to postpone its decision on polar bears until June 30, saying that to do so violates "congressional intent that time is of the essence in listing threatened species," and ruled further that the agency had failed to prove that waiting "will not pose a threat to the polar bear."

The decision took as long as it did, Kempthorne said, because of the large amount of data that he and his colleagues had to study and debate before making a ruling. "You simply have to look at the best available science on this particular species," Kempthorne said, adding that he worked with the Fish & Wildlife Service and the U.S. Geological Survey to make his decision.

Others accused Interior of delaying its listing of the polar bear as an endangered species until after business deals had been done in Alaska. "The Minerals Management Service was set to finalize the sales of leases for exploratory oil and gas drilling off the coast of Alaska," says Andrew Wetzler, director of the NRDC's Endangered Species Project. This would have subjected those lease sales, such as the sale of oil and gas leases covering nearly 46,000 square miles (120, 000 square kilometers) in the Chukchi Sea off the northwest coast of Alaska, to additional regulatory oversight, he added.

Kempthorne flatly denied at the press conference that he waited until after the drilling jobs were handed out before making his decision. "No, we did not hold off on the polar bear decision until the leases had been awarded, he said.

According to the World Wildlife Fund, some polar bears are already starving as a result of changing conditions in the Arctic. And the U.S. Geological Survey recently reported that polar bear populations could drop precipitously in coming decades as the sea ice they rely on to hunt recedes as the globe warms. This past September the National Snow and Ice Data Center in Boulder, Colo., which collects polar and ice information for the government, announced that there was less sea ice covering the Arctic Ocean than at any time since satellite measurements began in 1979.

Critics of designating the animals as endangered charge that such a move is merely a smoke screen for efforts to stem global warming, such as curbs on greenhouse gas emissions. "What has become clear through this heavily litigated process is that listing the polar bear as a threatened species is not about protecting the polar bear but rather advancing a particular political agenda," Sen. James Inhofe (R–Okla.) said in a statement. Inhofe has previously called global warming "the greatest hoax ever perpetrated on the American people."

Rep. Edward J. Markey (D–Mass.), chairman of the House Select Committee on Energy Independence and Global Warming, accused the Bush administration of not going far enough to protect the polar bear, noting that the Interior Department included exemptions to the decision that do not address the reason the sea ice is melting and allowing oil drilling to continue in a major polar bear habitat. The administration "simultaneously announced a rule aimed at allowing oil and gas drilling in the Arctic to continue unchecked even in the face of the polar bear's threatened extinction," he said in a statement issued Wednesday. "Essentially, the administration is giving a gift to Big Oil, and short shrift to the polar bear."