A dozen states, a number of cities and various environmental groups asked the court to take up the case after a divided lower court ruled against them.
They argue that the Environmental Protection Agency is obligated to limit carbon dioxide emissions from motor vehicles under the federal Clean Air Act because as the primary "greenhouse" gas causing a warming of the earth, carbon dioxide is a pollutant.
The administration maintains that carbon dioxide, unlike other chemicals that must be controlled to assure healthy air, is not a pollutant under the federal clean air law, and that even if it were the EPA has discretion over whether to regulate it.
A federal appeals court sided with the administration in a sharply divided ruling.
One judge said the EPA's refusal to regulate carbon dioxide was contrary to the clean air law; another said that even if the Clean Air Act gave the EPA authority over the heat-trapping chemical, the agency could choose not to use that authority; a third judge ruled against the suit because, he said, the plaintiffs had no standing because they hadn't proven harm.
"This is clearly going to be one of the most closely-watched cases for next term, a referendum really on the nation's environmental laws and whether they must be used to combat global warming," CBS News legal analyst Andrew Cohen says. "And in some ways it's a victory for environmentalists just to have the Justices hear the case, which wasn't going well for EPA allies down in the lower courts."
Carbon dioxide, which is release when burning fossil fuels such as coal or gasoline, is the leading so-called "greenhouse" gas because as it drifts into the atmosphere it traps the earth's heat, much like a greenhouse. Many scientists cite growing evidence that this pollution is warming the earth to a point of beginning to change global climate.
At the heart of the climate debate is whether carbon dioxide releases should be controlled by emission caps on power plants and requiring motor vehicles to become more fuel efficient, therefore burning less fuel and producing less carbon dioxide.
President Bush, when first running for president, expressed support for regulating carbon dioxide, but he reversed himself shortly after getting into office, saying he was convinced that voluntary plans to curtail carbon were a better way to go and mandatory regulation would be too expensive for business.
In 2003, the EPA's top lawyer concluded that the agency lacked the authority to regulate carbon dioxide under the Clean Air Act, reversing a legal opinion issued several years earlier by the Clinton administration and prompting the lawsuit.
"If ever there was a case that warranted Supreme Court review this is it," says Massachusetts Attorney General Tom Reilly, whose state is one of 12 involved in the lawsuit.
In their appeal, the states argued that the case "goes to the heart of the EPA's statutory responsibilities to deal with the most pressing environmental problem of our time," the threat of global warming.
The administration countered that the EPA should not be required to "embark on the extraordinarily complex and scientifically uncertain task of addressing the global issue of greenhouse gas emissions" when other, voluntary ways to address climate change are available.
In addition to Massachusetts, the states are California, Connecticut, Illinois, Maine, New Jersey, New Mexico, New York, Oregon, Rhode Island, Vermont and Washington. They were joined by a number of cities including Baltimore, New York City and Washington D.C., the Pacific island of America Samoa, the Union of Concerned Scientists, Greenpeace, and Friends of the Earth.
The case is Massachusetts v. Environmental Protection Agency, 05-1120
In other rulings handed out Monday, the Supreme Court ruled thaton contributions and spending in political campaigns are too low and improperly hinder the ability of candidates to raise money and speak to voters. And, new Supreme Court Justice Samuel Alito broke a tie in a ruling that affirmed a Kansas state death penalty law, which also revealed the court's deep divisions over capital punishment.