WASHINGTON — The Supreme Court entered the debate over global warming Monday, agreeing at the urging of environmentalists to rule on whether emissions from new cars, trucks and power plants must be further regulated to slow climate change.
The court's action gave a surprising, if tentative, boost to 12 states, including California, and a coalition of environmentalists who say the federal government must restrict the exhaust fumes that contribute to global warming. Their appeal accused the Environmental Protection Agency of having "squandered nearly a decade" by failing to act.
The high court voted to take up the issue over the objection of the Bush administration. Its lawyers questioned whether the government could and should "embark on the extraordinarily complex and scientifically uncertain task of addressing the global issue of greenhouse gas emissions" by regulating motor vehicles sold in the United States.
The case, to be heard in the fall, could be one of the most important environmental disputes to come before the court. Environmental advocates said automakers could be forced to produce a fleet of vehicles that pollute less.
The outcome also could determine the fate of California's effort to adopt its own rules designed to limit greenhouse gases from cars and trucks. Those rules, set to go into effect in 2009, require EPA approval.
"Everything now hinges on what the Supreme Court does," said David Bookbinder, a lawyer for the Sierra Club, one of the environmental groups that pressed the issue.
Until now, the threat of global warming has prompted little government action.
The legal dispute turns on standards set during the 1970s when Congress passed the Clear Air Act. One provision requires the government to regulate "any air pollutant" from motor vehicles or power plants that may well "endanger public health or welfare" -- including by affecting the "weather" or "climate."
In 1999, a group of environmental scientists pointed to this legal standard and petitioned the EPA to set new regulations to confront the problem of global warming. They said the evidence showed that pollutants from cars, trucks and power plants were endangering the public welfare by changing the climate.
They called upon the EPA to restrict emissions of carbon dioxide, methane, nitrous oxide and hydrofluorocarbons.
