The Bush administration has single-mindedly worked for years to undo this country's landmark environmental conservation measures. So a rule change to emasculate the 35-year-old Endangered Species Act probably was to be expected. After all, efforts by conservative members of Congress have been thwarted for years by thoughtful senators and representatives with more concern for the environment than for developers, private contractors and the oil industry.

As his presidency grinds to a close, Bush and his appointees are working overtime on roadblocks to prevent the United States from taking any steps to reduce the use of fossil fuels that might shrink Big Oil's bottom line. The changes they're proposing would block regulation of the greenhouse-gas emissions that are endangering plant and animal species by eliminating science as a consideration.

Under the new rules, for example, the Bureau of Reclamation could decide for itself whether a new dam posed a threat to fish, and the Transportation Department alone could determine whether a major highway threatened wildlife habitat. No longer would those agencies have to consult with scientists at the Fish and Wildlife Service or the National Marine Fisheries Service who have expertise in this complex area of biology.

Bush has never let science get in the way of cronyism. On the critical issues of global warming, in particular, Bush's cohorts have soft-pedaled, ignored or simply edited out scientists' conclusions.

When the polar bear became the first species threatened by the effects of human-caused climate change, Interior Secretary Dirk Kempthorne took the unprecedented step of declaring the bear threatened, but also forbidding any requirements to reduce greenhouse-gas emissions, the primary cause of climate change, in order to protect the animal.

Besides eliminating all basic scientific recommendations, the rule change would extend the polar bear ruling to all species, barring federal agencies from even considering how CO2 emissions and their contribution to global warming impact species and habitat.

These execrable rule changes threaten the ESA, but they don't have to make it extinct. If the changes are approved by the agencies before Bush leaves office, a new president and Congress should act immediately to reverse them.