Gov. Sarah Palin and other state officials fear a listing will cripple offshore oil and gas development in the Chukchi and Beaufort seas in Alaska's northern waters, which provide prime habitat for the only polar bears under U.S. jurisdiction.
"We believe that the Service's decision to list the polar bear was not based on the best scientific and commercial data available," Palin said in announcing the lawsuit.
Kassie Siegel of the Center for Biological Diversity, the lead author of the petition that led to the listing, said U.S. Fish and Wildlife Service scientists addressed skeptics' objections during the listing process. She called the lawsuit "completely ridiculous and a waste of the court's time."
"This lawsuit and her head-in-the-sand approach to global warming only helps oil companies, certainly not Alaska or the polar bear," Siegel said. "Gov. Palin should be working for sustainable, clean energy development in Alaska instead of extinction for the polar bear."
Kempthorne announced the listing May 14. The process started with the filing of the petition in 2005, a yearlong initial review, another year of public comment and additional studies, and court action to force a final decision.
Kempthorne concluded that sea ice was vital to polar bear survival, that sea ice had dramatically melted in recent decades and that computer models suggest sea ice likely will further recede in the future.
Summer sea ice last year shrank to a record low, about 1.65 million square miles, nearly 40 percent less than the long-term average between 1979 and 2000.
The lawsuit, filed in Washington, D.C., claims the federal analysis did not adequately consider polar bear survival through earlier warming periods centuries ago.
Alaska objects to the conclusion that polar bears could be endangered within the "foreseeable future," a timeline the Fish and Wildlife Service put at 45 years, or three generations of polar bears. The state called that number arbitrary.
The state contends there are no real differences between the bears in the 19 subpopulations identified in Kempthorne's decision, and that the population as a whole is healthy. That would undermine the argument that ice loss off Alaska would affect world polar bear population.
The lawsuit contends federal officials did not consider the best scientific evidence demonstrating bears' ability to survive and adapt to changing climate conditions.
That view is rejected by most polar bear experts, who say the animals need ice to hunt seals and will not win a territory fight with grizzly bears that already inhabit northern Alaska.
