"The nation's highest court has set the White House straight," says David Doniger, an attorney for the Natural Resources Defense Council who is involved in the case. "Carbon dioxide is an air pollutant, and the Clean Air Act gives EPA the power to start cutting the pollution from new vehicles that is wreaking havoc with our climate."

After a four-year court battle, the Supreme Court ruled this month 5-4 in Massachusetts vs. EPA that CO2 and other heat-trapping releases are "air pollutants" under the Clean Air Act, and that the U.S. government already has authority to start curbing them. By extension, Doniger says that if the EPA cannot block action at the federal level then it cannot do so at the state level either.

In 2004, California adopted the nation's first ever regulation to reduce global warming pollution from cars. It requires emissions of carbon dioxide and other pollutants to be reduced by 22 percent by the 2012 model year and 30 percent by the 2016 model year. Another bill enacted in 2002 requires the California Air Resources Board to adopt regulation aimed at cutting such emissions. Meantime, New York State is taking a tough position on all power plant emissions that also include CO2.

The Supreme Court's decision will embolden Congress as it considers legislation to cap and reduce global warming pollution from all major sources across the economy. At the same time, such companies as General Electric, DuPont and BP have come out in favor of curbs while others have argued that one uniform federal policy is better than having to obey a patchwork of state polices. The Natural Resources Defense Council insists that the ruling will "light a fire" under some industries that have been dragging their feet.

"EPA has offered no reasoned explanation for its refusal to decide whether greenhouse gases cause or contribute to climate change,'' Justice John Paul Stevens wrote for the majority in the decision. The agency "identifies nothing suggesting that Congress meant to curtail EPA's power to treat greenhouse gases as air pollutants.''

Details Must Follow

At a press conference, President Bush addressed the Supreme Court ruling along with several other issues. Now that the matter had been "settled," he said the administration would take a long look at its current policies.

Others were less conciliatory, however, saying that the Congress never intended CO2 to be among the pollutants regulated under the Clean Air Act. They also said the court ruling is a de-facto acceptance of the global warming treaty Kyoto Protocol, which the United States Senate refused to ratify in 1997.

The science is inconclusive as to whether manmade CO2 emissions contribute significantly to climate change, those critics say. They add that any future compliance with CO2 constraints would cause great economic harm, noting that new emissions control systems for CO2 are unproven and cost prohibitive. "The implications could be staggering," says Patrick Michaels, a senior fellow at the Cato Institute.

Despite the doomsday tone set by some, the decision does not address any of the peculiarities of how CO2 would be regulated. The court clearly directed the EPA to rethink its position. The Bush administration will therefore acclimate to the ruling. Still, Congress has given every indication that it will take matters into its own hands at some point in the near future and probably make any such action moot.

"Even though the State of Massachusetts has prevailed here, that fact does not bring Congress one step closer to resolving the details of a regulatory program for greenhouse gas emissions," says Christine Tezak and Whitney Stanco, regulatory analysts for Stanford Group Co. Just how any regulation reads "existed yesterday, exists today, and will exist tomorrow as an issue to be resolved."

Those facts remain. But, the ruling is still a major victory for green groups -- a decision that is also likely to rally "strange bedfellows." The outcome of the case is just the latest in a series of events that have drawn the world's attention to CO2 and global warming that include Democratic control of Congress beginning in 2006 and a recent report by the world's climate scientists saying that the phenomenon is "very likely" caused by man and one that necessitates an immediate fix.

Utilities, in turn, have accepted the eventuality of carbon constraints, with the Edison Electric Institute that represents investor-owned utilities saying legislation is coming sooner rather than later. Some of its members such as American Electric Power and Duke Energy are working on coal gasification plants that have the potential to drastically cut all emissions as well as capture carbon emissions.

While the High Court ruling involves tailpipe emissions in Massachusetts, it will boil over and have a profound effect on CO2 emissions from power plants. Addressing the subject will neither be easy nor inexpensive. But it's an issue that can no longer be ignored and one that all stakeholders must carefully consider.