Interior Secretary Dirk Kempthorne said late Monday the changes were needed to ensure that the Endangered Species Act would not be used as a "back door" to regulate the gases blamed for global warming. In May, the polar bear became the first species declared as threatened because of climate change. Warming temperatures are expected to melt the sea ice the bear depends on for survival.

The draft rules would bar federal agencies from assessing the emissions from projects that contribute to global warming and its effect on species and habitats.

"We need to focus our efforts where they will do the most good," Kempthorne said in a news conference organized quickly after AP reported details of the proposal. "It is important to use our time and resources to protect the most vulnerable species. It is not possible to draw a link between greenhouse gas emissions and distant observations of impacts on species."

If approved, the changes would represent the biggest overhaul of endangered species regulations since 1986. They would accomplish through rules what conservative Republicans have been unable to achieve in Congress: ending some environmental reviews that developers and other federal agencies blame for delays and cost increases on many projects.

The chairman of the House Natural Resources Committee, which oversees the Interior Department, said he was "deeply troubled" by the changes.

"This proposed rule ... gives federal agencies an unacceptable degree of discretion to decide whether or not to comply with the Endangered Species Act," said Rep. Nick Rahall, D-W.Va. "Eleventh-hour rulemakings rarely if ever lead to good government."

The new regulations follow a pattern by the Bush administration not to seek input from its scientists. The regulations were drafted by attorneys at both the Interior and Commerce Departments. Scientists with both agencies were first briefed on the proposal last week during a conference call, according to an official who asked not to be identified.

Last month, in similar fashion, the Environmental Protection Agency surprised its scientific experts when it decided it did not want to regulate greenhouse gases under the Clean Air Act.

The rule changes unveiled Monday would apply to any project a federal agency would fund, build or authorize that the agency itself determines is unlikely to harm endangered wildlife and their habitat. Government wildlife experts now participate in tens of thousands of such reviews each year.

The revisions also would limit which effects can be considered harmful and set a 60-day deadline for wildlife experts to evaluate a project when they are asked to become involved. If no decision is made within 60 days, the project can move ahead.

"If adopted, these changes would seriously weaken the safety net of habitat protections that we have relied upon to protect and recover endangered fish, wildlife and plants for the past 35 years," said John Kostyack, executive director of the National Wildlife Federation's Wildlife Conservation and Global Warming initiative.

Under current law, federal agencies must consult with experts at the Fish and Wildlife Service or the National Marine Fisheries Service to determine whether a project is likely to jeopardize any endangered species or to damage habitat, even if no harm seems likely. This initial review usually results in accommodations that better protect the 1,353 animals and plants in the U.S. listed as threatened or endangered and determines whether a more formal analysis is warranted.

The Interior Department said such consultations are no longer necessary because federal agencies have developed expertise to review their own construction and development projects, according to the 30-page draft obtained by the AP.

"We believe federal action agencies will err on the side of caution in making these determinations," the proposal said.

The director of the Fish and Wildlife Service, Dale Hall, said the changes would help focus expertise on "where we know we don't have a negative effect on the species but where the agency is vulnerable if we don't complete a consultation."

Responding to questions about the process, Hall said, "We will not do anything that leaves the public out of this process."

A couple of environmentalists from the Las Vegas Valley said they fear that the proposed rule changes, if put in place, will erode protections for many birds, fishes, frogs, plants, invertebrates and the Mojave Desert tortoise, a threatened reptile.

Despite Hall's comment that major projects will still be subject to the same consultation and review process that has been followed for three decades, John Hiatt, conservation chairman for the Red Rock Audubon Society, questioned what that means

"My perception is that it is all about the details, and the big detail here, which is unanswered, is what's the definition of a major project and who will determine that?" Hiatt asked Monday.

Concerning the desert tortoise, Hiatt said he foresees critical habitat could be affected by road widening projects or decisions not to close certain roads that are made in the absence of consultation with U.S. Fish and Wildlife Service biologists.

Consultation for a project to build a water pipeline to Southern Nevada would still be required. But for smaller development projects, the rule changes would remove "the Fish and Wildlife Service from the table a good share of the time," he said.

Hall said environmental review for construction of a culvert along the Lower Colorado River system, for example, would be left to the affected agency without consultation with Fish and Wildlife Service biologists on species issues if no protected species would be killed or displaced during the project.

Henderson zoologist James Deacon, founder of the Environmental Studies Program at the University of Nevada, Las Vegas, described the proposal as "a terrible move" that's "part of the general attempt by the Bush administration to reverse the Endangered Species Act."

If put in place, Deacon foresees the rule changes could be short-lived and reversed under a new administration.

"That's the only hope I could offer for what would be an environmental disaster," he said.

The new rules were expected to be formally proposed immediately, officials said. They would be subject to a 30-day public comment period before being finalized by the Interior Department. That would give the administration enough time to impose the rules before November's presidential election. A new administration could freeze any pending regulations or reverse them, a process that could take months. Congress could also overturn the rules through legislation, but that could take even longer.

The proposal was drafted largely by attorneys in the general counsel's offices of the Commerce Department's National Oceanic and Atmospheric Administration and the Interior Department, according to an official with the National Marine Fisheries Service, who spoke on condition of anonymity because the plan hadn't yet been circulated publicly. The two agencies' experts were not consulted until last week, the official said.

Between 1998 and 2002, the Fish and Wildlife Service conducted 300,000 consultations. The National Marine Fisheries Service, which evaluates projects affecting marine species, conducts about 1,300 reviews each year.

The reviews have helped safeguard protected species such as bald eagles, Florida panthers and whooping cranes. A federal government handbook from 1998 described the consultations as "some of the most valuable and powerful tools to conserve listed species."

In recent years, however, some federal agencies and private developers have complained that the process results in delays and increased construction costs.

"We have always had concerns with respect to the need for streamlining and making it a more efficient process," said Joe Nelson, a lawyer for the National Endangered Species Act Reform Coalition, a trade group for home builders and the paper and farming industry.

Sen. Barbara Boxer, D-Calif., chairwoman of the Environment and Public Works Committee, called the proposed changes illegal.

"This proposed regulation is another in a continuing stream of proposals to repeal our landmark environmental laws through the back door," she said. "If this proposed regulation had been in place, it would have undermined our ability to protect the bald eagle, the grizzly bear and the gray whale."

The Bush administration and Congress have attempted with mixed success to change the law.

In 2003, the administration imposed similar rules that would have allowed agencies to approve new pesticides and projects to reduce wildfire risks without asking the opinion of government scientists about whether threatened or endangered species and habitats might be affected. The pesticide rule was later overturned in court. The Interior Department, along with the Forest Service, is currently being sued over the rule governing wildfire prevention.

In 2005, the House passed a bill that would have made similar changes to the Endangered Species Act, but the bill died in the Senate.

The sponsor of that bill, then-House Natural Resources chairman Richard Pombo, R-Calif., told the AP Monday that allowing agencies to judge for themselves the effects of a project will not harm species or habitat.

Review-Journal writer Keith Rogers contributed to this report.