WASHINGTON — The Obama administration took a major step Monday toward imposing the first federal limits on climate-changing pollution from cars, power plants and factories, declaring there was compelling scientific evidence that global warming from man-made greenhouse gases endangers Americans' health.
The announcement by the Environmental Protection Agency was clearly timed to build momentum toward an agreement at the international conference on climate change that opened Monday in Copenhagen, Denmark. It signaled the administration was prepared to push ahead for significant controls in the U.S. if Congress doesn't act first on its own.
The price could be steep for both industry and consumers. The EPA finding clears the way for rules that eventually could force the sale of more fuel-efficient vehicles and require plants to install costly new equipment — at a cost of billions or even many tens of billions of dollars — or shift to other forms of energy.
No analysis has been conducted by the EPA on costs of such broad regulations, although the agency put the price tag of its proposed climate-related car rules at $60 billion, with an estimated benefit of $250 billion.
Energy prices for many Americans probably would rise, too — though Monday's finding will have no immediate impact since regulations have yet to be written.
Environmentalists hailed the EPA announcement as a clear indication the United States will take steps to attack climate change even if Congress fails to act. And they welcomed the timing of the declaration, saying it will help the Obama administration convince delegates at the international climate talks that the U.S. is serious about addressing the problem. Obama addresses the conference next week.
But business groups said regulating carbon emissions through the EPA under existing clean air law would put new economic burdens on manufacturers, cost jobs and drive up energy prices.
The EPA signaled last April that it was inclined to view heat-trapping pollution as a threat to public health and welfare and began to take public comments for formal rulemaking. That marked a reversal from the Bush administration, which had refused to issue the finding, despite a conclusion by EPA scientists that it was warranted.
EPA Administrator Lisa Jackson said Monday, "There are no more excuses for delaying." After the official finding, she said the agency is now "obligated to make reasonable efforts to reduce greenhouse pollutants under the Clean Air Act."
The EPA said scientific evidence clearly shows that greenhouse gases "threaten the public health and welfare of the American people" and that the pollutants — mainly carbon dioxide from burning fossil fuels — should be reduced, if not by Congress then by the agency responsible for enforcing air pollution.
"These long-overdue findings cement 2009's place in history as the year when the United States government began addressing the challenge of greenhouse-gas pollution," said Jackson.
She rejected claims by climate skeptics that the science of global warming remains in doubt, an argument given additional attention in recent weeks with the disclosure through intercepted e-mails that a British scientist had privately discussed ways to shield certain climate data from public scrutiny.
"The vast body of evidence not only remains unassailable, it has grown even stronger," said Jackson.