ANCHORAGE, Alaska The state of Alaska filed notice on Friday that it will appeal a federal judge's ruling upholding the listing of polar bears as a threatened species.
The state, which maintains that U.S. Endangered Species Act protections are not warranted for polar bears, sued the federal government in 2008 to overturn the Bush administration's decision to list the animal as threatened.
That decision was based on what the U.S. Department of Interior said was the rapid warming of the Arctic climate and the melting of summer and fall sea ice that it considered crucial to polar bears' habitat.
Washington, D.C.-based U.S. District Judge Emmet Sullivan upheld the endangered listing in a June ruling.
Alaska Governor Sean Parnell, a Republican, said on Friday that the listing was flawed because polar bears have thrived through past climate changes.
The world population of polar bears has grown from a low of between 8,000 and 10,000 in the late 1960s to the current count of about 20,000 to 25,000, Parnell said.
"The Endangered Species Act was not intended for species that are healthy with populations that have more than doubled in the last 40 years," Parnell said in a statement.
Alaska's court challenge was consolidated with other lawsuits filed by organizations that oppose the listing, including the U.S. Chamber of Commerce, the American Petroleum Institute and hunting group Safari Club International.
The Safari Club and other plaintiffs filed their notices of intent to appeal in Judge Sullivan's court on Thursday, one day before Alaska did the same.
The state and oil companies have argued that Endangered Species Act protections for polar bears diminish opportunities for Alaska energy development.
Rebecca Noblin is an attorney for the Center for Biological Diversity, an environmental group that had sued to win the threatened listing.
"We don't think the appeal has any merit," Noblin said. "The science pretty clearly shows that polar bears are threatened with extinction and should be listed."
She acknowledged that polar bear populations have increased since the 1960s, but said that credit lies with the Marine Mammal Protection Act of 1972, which outlawed sport hunting of polar bears in the United States.
Now, melting sea ice poses new and dire dangers to polar bears, she said.
"Just because they rebounded from one threat doesn't mean they are not susceptible to another threat," she said.