WASHINGTON -- A lawyer arguing for the state of Alaska that polar bears are not a threatened species ran into skeptical appeals court judges Friday.

Alaska, along with hunting groups and others, is appealing the 2011 decision by a federal judge that the government correctly listed polar bears under the federal Endangered Species Act. It’s a case with major implications because polar bears are the first, and so far only, species listed solely on the basis of threats from global warming.

Polar bears are not today on the brink. But the U.S. Fish and Wildlife Service says sea ice melting means two-thirds of the world’s polar bears could be gone by 2050.

Murray Feldman, a private attorney from Boise, Idaho, who is representing Alaska and the other appellants, argued Friday that polar bears are doing fine and don’t need the protection of the threatened status.

“Polar bears occupy the entirety of their historic range, with population at an all-time high,” Feldman argued in front of the U.S. Court of Appeals in the District of Columbia.

The three-judge panel did not immediately rule. But at least two of them were clearly skeptical of some of Feldman’s arguments.

Judge Harry Edwards sounded unimpressed with Feldman’s claims that the Fish and Wildlife Service used flawed population forecasting models. The judge said those models simply confirmed other findings and were not a key part of the decision to list the bears.

“It’s beating up on something that appears not critical,” Edwards said.

He and Judge Merrick Garland also questioned Feldman’s repeated use of U.S. Geological Survey statements to argue against the listing. Edwards said that argument ignored the agency’s conclusion that the bears should have been listed as not only threatened, but endangered.

Arctic sea ice melted to a record low this summer, according to the National Snow and Ice Data Center, which said the seasonal melting is more rapid than expected. Polar bears spend much of their lives hunting seals from sea ice. Biologists say the melting makes it harder to find the seals and forces the bears to swim tremendous distances between ice, putting them at risk for drowning.

The Obama administration has blunted the impact of the polar bear listing with a proposed rule that the Endangered Species Act would not be used to control greenhouse gas emissions outside of the bears’ territory. That means a new coal-fired power plant in the Lower 48 couldn’t be stopped with the argument that it contributes to melting ice, driving Alaska’s polar bears toward extinction.

The Fish and Wildlife Service has designated 187,000 square miles in Alaska as critical habitat for polar bears, requiring federal officials to consider whether proposed development would hurt bears. Feldman, arguing for Alaska, told the judges that Fish and Wildlife used uncertain predictions and failed to connect the dots between habitat loss and the huge predicted drop in bears.

But Katherine Hazard, an attorney for the Fish and Wildlife Service, said the listing was based on decades of research and an extensive look at sea ice melting.

“They identified no science the agency should have considered and didn’t,” Hazard told the judges of the appellants’ argument.