The loss of arctic sea ice is bad for walrus populations, which means the walrus may soon be listed under the Endangered Species Act (ESA).

Though drops in walrus population haven't been documented, scientists and Natives are afraid the ripple effects of climate change could thin walrus numbers.

Walrus need to rest on sea ice no more than 400 feet above the ocean floor so they can dive down to eat shellfish and plants. But sea ice is retreating so far north that the waters are too deep for walrus to feed. This forces them to squeeze onto land, and last summer about 4,000 young walruses were trampled to death by males in the crowded conditions.

"On land, they are really vulnerable to predators and to being trampled by big males; when a human or polar bear shows up, they panic and stampede," said Shaye Wolf, a staff biologist for the Center for Biological Diversity, which is petitioning for an Endangered Species Act listing for the walrus.

The Center for Biological diversity is the same group that successfully petitioned the Fish & Wildlife Service to list the polar bear as a threatened species under the ESA.

My New Atlantis article on the FWS decision to list the polar as a "threatened species" under the Endangered Species Act is now available online. Here's my conclusion:

the polar bear's ESA listing will do little to preserve bear populations in the wild. It could complicate other conservation efforts. It will have no effect on the projected loss of sea ice over the next few decades. And it will have no effect on global warming. Getting a handle on anthropogenic climate change will require broad international efforts; jury-rigging a decades-old species-conservation statute just won't cut it. The polar bear may be an "animal to save the world," but the Endangered Species Act will do little to save the bear.

The National Association of Manufacturers, American Iron and Steel Institute, U.S. Chamber of Commerce and American Petroleum Institute have filed another challenge to the Fish & Wildlife Service's decision to list polar bears as "threatened" under the Endangered Species Act. Interestingly, one aspect of the listing they are challenging is the federal government's differential treatment of energy projects in Alaska.

They object to what they call the "Alaska Gap" in relation to the special rule the federal government issued in May in conjunction with the polar bear's protected status. The rule, meant to prevent the polar bear's status from being used as a tool for imposing greenhouse gas limits, exempts projects in all states except Alaska from undergoing review in relation to emissions.

NAM Vice President Keith McCoy said the group sees the rule as unfairly subjecting Alaskan industry to greenhouse gas controls and also opening a back door for greenhouse gas regulation nationwide.

"This could significantly curtail oil and gas exploration," especially on Alaska's North Slope, he said. "It's discrimination against the state of Alaska. During a time when gas prices are high and we need to look at all options, to issue something that shuts off a viable resource" is ill-advised, he said.

The lawsuit, filed in U.S. District Court for the D.C. Circuit, notes that greenhouse gas emissions worldwide contribute to global warming. It says projects in Alaska should not be subject to special scrutiny because of the polar bear's status.

Not having read the briefs (yet), this seems to me like a more fruitful avenue of attack than a frontal challenge to the listing itself. Overturning a listing decision is quite difficult, and I don't expect any of the lawsuits to be successful on that front.