The Interior Department on Thursday announced a rule that has largely freed federal agencies from their obligation to consult independent wildlife biologists before they build dams or highways or permit construction of transmission towers, housing developments or other projects that might harm federally protected wildlife.
The rule, quickly challenged by environmental groups, lets the Army Corps of Engineers or the Federal Highway Administration in many cases rely on their own personnel in deciding what impact a project would have on a fish, bird, plant, animal or insect protected under the Endangered Species Act.
In announcing the rule, Interior Secretary Dirk Kempthorne said his main intention was to ensure that the 1972 law was not used as a "back door" means of regulating the emission of the gases that accelerate climate change. Without this rule, Mr. Kempthorne said, his decision last summer to list the polar bear as threatened because of the loss of sea ice caused by the warming of the climate could be used to block projects far from the bear's Arctic habitat.
"The Endangered Species Act was never intended to be a back door opportunity for climate change policy," he said.
Legal experts said the change seemed intended to ensure that the protection of species like the polar bear would not impede development of coal-fired power plants or other federal actions that increased emissions of heat-trapping gases. The Endangered Species Act, a complicated law with numerous procedural requirements, has long infuriated business interests and property rights advocates. But the law's broad sweep, and its impact on a range of issues like hydroelectric power and logging, has largely been supported by federal courts.
Conservatives and business interests believed that the listing of the polar bear as a threatened species raised the specter that the law's impact would be felt far afield. A federal decision to license a coal-fired power plant in Missouri, the reasoning went, could be blocked because the plant's emissions would indirectly contribute to a reduction of the bear's icy habitat.
But the change to the rule, one of a series of regulatory shifts by the Bush administration in its final months, goes well beyond the concerns about climate change, several legal scholars said.
"This goes to the heart of the most important provision of the Endangered Species Act," said Brian E. Gray, a professor at the Hastings College of the Law in San Francisco.
Professor Gray added that a core principle of the act was that independent wildlife and fisheries agencies had the major say in determining whether an action could be taken "without jeopardizing the continued existence of the species."
"And protecting the continued existence of the species," he added, "is the overriding purpose" of the law.
Environmental groups, including the Center for Biological Diversity, Greenpeace and Defenders of Wildlife, filed suit in federal court to block the rule. And legal scholars said that, given the imminent arrival of a Democratic administration, the change was vulnerable to quick reversal.
But the change was welcomed by property rights advocates. Citing the current recession, Rob Rivett, the president of the Pacific Legal Foundation, applauded the revision and said that "the Endangered Species Act has been the opposite of an economic stimulus." Senator James M. Inhofe of Oklahoma, the ranking Republican on the Environment and Public Works Committee, released a statement praising the rule change as a "common sense" revision. Mr. Inhofe added, "This process is a good first step" toward reform of the Endangered Species Act.
Pat Parenteau, a professor at the Vermont Law School, disagreed, saying, "For all federal agencies, if this isn't a carte blanche, it's certainly a broad license to decide for yourself that you don't need to consult."
The new rule would take effect in 30 days, or just before President-elect Barack Obama was inaugurated. Legal experts said that among the Obama administration's options were two quick ones: suspending the rule or settling lawsuits.
In his news conference, Mr. Kempthorne said federal agencies proposing or approving construction projects had already had some leeway to decide whether to consult biologists at the Fish and Wildlife Service or the National Marine Fisheries Service. And, he added, "Nothing in this regulation relieves a federal agency of its responsibility to ensure that a listed species is not harmed."
Questioned about the last-minute nature of the rule change, which put Fish and Wildlife officials on a forced march to sort through more than 200,000 comments about the proposal, he asked, rhetorically, if Eli Manning, the New York Giants quarterback, should be taken off the field in the last five minutes of a game.
"We have 39 days of work left," the secretary said, "and we owe it to the public to keep working."