(CN) - The Ninth Circuit on Monday restored a critical habitat that the U.S. government designated to protect the polar bear from the threat of climate change.
Regulators listed the polar bear as an endangered species in 2008 because of declining Arctic sea ice. Two years later, the U.S. Fish and Wildlife Service designated 187,000 square miles of sea ice, terrestrial denning and barrier islands in Alaska's Chuckchi Sea as critical polar bear habitat.
Three entities including the Alaska Oil & Gas Association, the state of Alaska and a coalition of Alaska native interests challenged the designation with federal complaints, accusing the agency of making numerous substantive and procedural errors under the Endangered Species Act and the Administrative Procedure Act.
A federal judge rejected most of the plaintiffs' claims except those having to do with the terrestrial denning and barrier island habitats, which the Ninth Circuit opinion says comprise 4.1 percent of the total habitat at issue.
Still, the judge vacated the agency's designation in its entirety, finding that the record did not support its designation of that portion of the habitat and that the agency failed to follow Endangered Species Act procedure.
But the Ninth Circuit reversed the court's ruling Monday, finding that the judge should have favored the government.
Writing for the three-judge panel in Anchorage, Judge Mary Schroeder said that the district court held federal regulators to a standard of specificity that the Endangered Species Act does not require.
"The Act is concerned with protecting the future of the species, not merely the preservation of existing bears," Schroeder said. "And it requires use of the best available technology, not perfection."
By requiring proof of "existing polar bear activity," the court "impermissibly shifted the focus" of the critical habitat designation away from the population's "primary constituent elements," according to the 43-page opinion.
Schroeder rejected the court's criticizing the designation as an attempt to designate "potential" habitat on the same basis, pointing out that the agency "must look beyond evidence of actual presence to where the species is likely to be found."
Finding that the agency provided a rational explanation for using the mapping technology that it did, the court also struck down assertions that "future climate change is not an appropriate consideration" under the Endangered Species Act.
"The record belies these contentions, as the D.C. Circuit has recognized," Schroeder wrote.
"That court reviewed the bases for listing the polar bear [as an endangered species] and found that in collecting data on climate change and sea ice, FWS relied on numerous published studies and reports describing the effects of climate change," she added.
Schroeder also cited the "unassailable fact that bears need room to roam" in support of the agency's habitat designation.
Accordingly, the agency's designation of critical denning habitat was not arbitrary and capricious, she said, and nor was its designation of the barrier islands, which she said polar bears use both as denning habitat and as migration corridors.
"FWS drew rational conclusions from the best available scientific data, which is what the statute requires," Schroeder said.
The circuit remanded the case to the lower court for judgment in favor of the government.
A representative of the U.S. Department of Justice said in an email that the government was pleased with the court's decision.
The plaintiffs' attorneys did not immediately respond to an email requesting comment.
Read the Top 8
Sign up for the Top 8, a roundup of the day's top stories delivered directly to your inbox Monday through Friday.