The Interior Department could play an unprecedented role in shaping the new administration's attempts to regulate greenhouse gas emissions.

Some environmentalists say President-elect Barack Obama's transition team is eyeing the Endangered Species Act, a 1973 law largely overseen by the Interior Department, as a backdoor vehicle to help jump-start the regulation of global warming emissions.

Green groups have prodded the Bush administration to recognize the connection between the decline of the polar bear's Arctic habitat and climate change, which prompted the bear's designation as a threatened species.

Interior's Fish and Wildlife Service listed the polar bear earlier this year as "threatened," but the administration simultaneously noted that the bear's decline due to carbon emissions would not result in requiring emissions to be reduced to help protect the bear.

If Obama officially recognizes the connection and pushes for action, it would draw a definitive link between industrial emissions and the threat to a declining species, likely necessitating new emission regulations and pressuring Congress to move ahead with cap-and-trade legislation.

The quandary is drawing attention to two key appointments: those of the secretary of the interior and the director of the U.S. Fish and Wildlife Service, who'll play an integral role in how aggressively the policy is applied.

If Obama clarifies the global warming link, environmentalists say he would be jump-starting a process that should have happened years ago.

"We live in a changing world, and that's going to necessitate that we adapt our laws accordingly," said Carroll Muffett, political director at Greenpeace. "We need someone willing to use the Endangered Species Act to the full extent of the law."

One Bush rule aims to stymie the connection by relieving federal agencies of the duty of consulting with the Fish and Wildlife Service to determine whether a new policy would contribute to global warming. Instead, agencies would conduct their own reviews.

While Obama has signaled he would overturn such a move, the rule could be finalized before he takes office and could take months or years to undo.

"This department is at the heart of a lot of eleventh-hour Bush regulatory changes that Bush is striving to jam through," said Andrew Wetzler, director of the endangered species project at the Natural Resources Defense Council.

The business community is already expressing serious concerns about strengthening the link between threatened species and emissions, which they say is an overextension of the law. The movement would require the formation of a cumbersome carbon regulation process, business lobbyists warn, and that could grind the economy to a halt and tie up the legal system.

Instead, business trade groups argue that Obama should formulate new climate regulation policy.

"This avenue is neither appropriate nor adequate," said Karen Harbert, vice president of the U.S. Chamber of Commerce's Institute for 21st Century Energy. "We need new policy led by the president rather than trying to use the Endangered Species Act, which was only intended to protect endangered species. It should not be manipulated to try and overreach its intent."

Lobby groups on both sides of the issue are prepared to offer their opinions as candidates surface for the positions of interior secretary and wildlife service director.

Both appointments require Senate confirmation, but it could be weeks before either position is filled. The president-elect's first appointments are expected to be key White House officials and members of his economic and national security teams.

But Obama may be under some pressure to fill the interior slots more quickly.

The next interior secretary is expected to play an important role on global warming issues similar to that of Obama's secretary of energy and administrator of the Environmental Protection Agency.

In past administrations, the director of the Fish and Wildlife Service has played an influential role in expanding the Endangered Species Act.

Jamie Clark, who was the service's director under President Bill Clinton, was able to work with then-Interior Secretary Bruce Babbitt to extend the act to protect species on private land.

Much of her time was spent working hand in hand with the president's Council on Environmental Quality to hammer out key policy moves and implementing the day-to-day details of the law.

A career biologist with the agency, Clark predicts the next director will likely come up through the agency, too, but will be held to higher standards.

"The next director could be part of the federal voice, which the last administration lacked," Clark said. "In that case, the administration won't want any of these agencies to go without leadership for very long."

Clark is believed to be on Obama's shortlist for director.

"The success will largely depend on how much the political appointees will respect the work and expertise of the career staff below them," said Muffett of Greenpeace. "We will be paying close attention to these appointments to make sure they signal a move in the right direction."

Environmentalists say Obama's appointees will also need to make several key changes to ensure success.

Conservationists say the endangered species laws have atrophied under the Bush administration, which put little pressure on the Fish and Wildlife Service to designate threatened and endangered species.

Even though federal funds allocated for listing species has increased from $6.2 million in 2000 to $18 million in 2008, the agency listed only 61 species, compared with the 521 listed during the Clinton administration, according to the Center for Biological Diversity, which tracks the issue.

There's a backlog of 281 species proposed for protection, and some species have already become extinct since being put on the list.

The Fish and Wildlife Service "could play a much more robust role in international conservation of species and habitat if it had the right leadership," said Jason Patlis, vice president of government relations at the World Wildlife Fund. "A good director can work with the secretary of the interior to get more funding and tackle more global issues."