Justices to weigh greenhouse-gas regulation

WASHINGTON — The polar ice caps are melting, summers are growing hotter and hurricanes are becoming more powerful, but the Bush administration has insisted it cannot regulate the gases that many believe are responsible.

On Wednesday, a coalition of 12 states, led by California and Massachusetts and including Washington state, will go before the Supreme Court seeking to show that the nation's environmental regulators have the legal authority and responsibility to control greenhouse-gas emissions linked to global warming, which many scientists describe as the biggest environmental threat to the planet.

The administration says it is studying the problem and "seeking a cooperative international approach to addressing global climate change," Solicitor General Paul Clement wrote in his brief to the court.

Putting new limits on emissions from motor vehicles and power plants is out of the question, at least for now, he added, saying, "the Environmental Protection Authority lacks authority under the Clean Air Act ... to regulate greenhouse-gas emissions."

The case before the Supreme Court tests that conclusion. It begins with a simple question: Is carbon dioxide an "air pollutant" under the terms of the Clean Air Act? The answer may determine whether federal regulators must tackle global warming and whether California and other states may do so on their own.

Four years ago, California adopted stricter rules to reduce greenhouse-gas emissions from motor vehicles. These standards for new cars and trucks are to take effect in 2009.

Because of California's notorious smog problem, Congress permitted the state to adopt stricter exhaust standards for cars and trucks under a special provision in federal air-pollution laws. Other states are allowed under those laws to follow California's lead.

The legality of California's new vehicle-emission standards remains in doubt. They must be approved by the Environmental Protection Agency (EPA). But the agency has yet to do so, mostly because of its view that carbon dioxide and other greenhouse gases are not "air pollutants" under the Clean Air Act.

The automakers have moved to block California's rules from taking effect in a separate lawsuit, citing the EPA's stand.

Bush administration lawyers do not discount the importance of global warming, but they argue it is not covered by the Clear Air Act. That measure, they say, targets pollutants, such as ozone, that are dangerous to breathe, not ones that occur in nature and are essentially harmless to breathe, such as carbon dioxide.

Disagreeing, the state's lawyers point to the language of the law. It says an air pollutant is "any physical, chemical [or] biological ... substance or matter which is emitted ... into the ambient air."

In their brief to the court, they point out, "Motor vehicles emit the physical and chemical matter carbon dioxide, methane, nitrous oxide and hydro-fluorocarbons into the ambient air." Motor vehicles are the source of about 25 percent of the nation's greenhouse-gas emissions.

Another provision says the EPA "shall" regulate any pollutant from cars or trucks "which may reasonably be anticipated to endanger public health or welfare."

The law defines the public's welfare to include effects on "climate" and "weather." The state lawyers argue that because it is apparent that greenhouse gases are endangering the public welfare, the EPA must regulate them.

Lawyers for the administration and automakers say the high court should dismiss the lawsuit brought by the 12 states. They argue the nation's policy on global warming is a political issue to be decided by Congress and the president, not a legal issue to be decided in court.

This argument may appeal to Chief Justice John Roberts, who has said the court should adopt a more modest role and allow politicians to set policies.

But environmental activists and the state lawyers were pleasantly surprised in June when the Supreme Court voted to take up the case, Massachusetts v. EPA, despite the objections of the Bush administration.

If the court rules on the question of whether the Clean Air Act regulates greenhouse gases, the stakes will be high for environmentalists, regulators and the auto industry.

"If we win, it will free California and other states from a legal threat," said David Bookbinder, a Sierra Club lawyer. "But if the Supreme Court says the Clean Air Act does not cover climate change, it would be hard for California to say it has the authority to regulate greenhouse gases."

If the court rejects the Bush administration's stand, the automakers will be under pressure to produce vehicles that get better gas mileage.

The court could also issue a split decision. It could rule that carbon dioxide is an air pollutant under the Clean Air Act, but that the EPA's administrator is free to decide whether to issue new emissions standards for these greenhouse gases. In the past, the court has been very reluctant to require an agency to issue new regulations.

Such a split decision would not force the federal agency to regulate greenhouse gases, but it could clear the way for states to do so on their own.