A federal judge today vacated the George W. Bush administration rule that barred the use of the Endangered Species Act to regulate greenhouse gases.

At issue was the so-called 4(d) rule that accompanied the 2008 decision to list the polar bear as a "threatened" species.

U.S. District Judge Emmet Sullivan of the District of Columbia ordered the Fish and Wildlife Service to carry out an environmental review to meet the requirements of the National Environmental Policy Act (NEPA).

But, importantly, he upheld FWS's decision that the Endangered Species Act was not the appropriate vehicle to regulate greenhouse gases.

In June, Sullivan upheld the Bush administration's underlying determination that the bear is a threatened species under the Endangered Species Act (Greenwire, June 30).

On NEPA, Sullivan wrote that the service had failed to take into account the potential environmental impacts of the special rule, which addressed, among other things, the direct impact on polar bear habitat from oil and gas exploration.

At the time, the service did not carry out any NEPA analysis.

Sullivan wrote that his decision does not mean the agency is required to carry out a full environmental impact statement, but it must convince him of the need not to do so.

While the NEPA analysis is carried out, a May 2008 interim rule that is essentially the same as the final rule, remains in place.

On the question of whether the species law can be used to regulate greenhouse gases, Sullivan said the government's conclusion that the statute was not the appropriate vehicle to regulate greenhouse gases was not a violation of the Administrative Procedure Act.

"Although the court is sensitive to plaintiffs' arguments for a strong mechanism to combat the effects of global climate change, the court finds that the agency's conclusion was not arbitrary, capricious or contrary to law," Sullivan wrote.

In a separate decision also issued today, Sullivan held that the government did not violate the law in ruling that sports-hunted polar bear trophies can no longer be imported into the United States under the Marine Mammal Protection Act.