Interior Secretary Dirk Kempthorne gestures during a news conference at the Interior Department in Washington, Wednesday, May 14, 2008, to announce the Interior Department has declared the polar bear a threatened species, saying it must be protected because of the decline in Arctic sea ice from global warming. (AP Photo/Pablo Martinez Monsivais)

Environmental activist from the Alaska Wilderness League and Green Peace watch Interior Secretary Dirk Kempthorne's news conference at the Interior Department in Washington, Wednesday, May 14, 2008, where he announced the status of the polar bear. (AP Photo/Pablo Martinez Monsivais)

In this 2003 file photo provided by Subhankar Banerjee a polar bear walks in the Arctic National Wildlife Refuge. The Interior Department has declared the polar bear a threatened species, saying it must be protected because of the decline in Arctic sea ice from global warming. Interior Secretary Dirk Kempthorne on Wednesday cited dramatic declines in sea ice over the last three decades and projections of continued losses. (AP Photo/Subhankar Banerjee, File)

Environmental activist from the Alaska Wilderness League, dressed in polar bear costumes, watch Interior Secretary Dirk Kempthorne's news conference announcing the status of the polar bear, Wednesday, May 14, 2008, at the Interior Department in Washington. (AP Photo/Pablo Martinez Monsivais)

In this 2003 file photo provided by Subhankar Banerjee a polar bear walks in the Arctic National Wildlife Refuge. The Interior Department has declared the polar bear a threatened species, saying it must be protected because of the decline in Arctic sea ice from global warming. Interior Secretary Dirk Kempthorne on Wednesday cited dramatic declines in sea ice over the last three decades and projections of continued losses. (AP Photo/Subhankar Banerjee, File)

Interior Secretary Dirk Kempthorne gestures during a news conference at the Interior Department in Washington, Wednesday, May 14, 2008, to announce the Interior Department has declared the polar bear a threatened species, saying it must be protected because of the decline in Arctic sea ice from global warming. (AP Photo/Pablo Martinez Monsivais)

Environmental activist from the Alaska Wilderness League, dressed in polar bear costumes, watch Interior Secretary Dirk Kempthorne's news conference announcing the status of the polar bear, Wednesday, May 14, 2008, at the Interior Department in Washington. (AP Photo/Pablo Martinez Monsivais)