This Editorial originally appeared in the New York Times.
The Supreme Court’s decision on greenhouse gases on Monday is a disappointment to the states and environmental groups that had hoped to use federal common law to curb carbon dioxide pollution from power plants. It would also appear to be a setback in the fight against global warming. But it is, in fact, a clarifying and positive decision — vindicating the Clean Air Act, which is under siege in the House, and increasing pressure on the Environmental Protection Agency to carry out its authority to regulate greenhouse gases under that act.
The decision arose from a lawsuit brought by New York and other states against five of the country’s biggest polluters in 2004 — a time when the administration of George W. Bush was arguing that it had no authority under the Clean Air Act to regulate greenhouse gases. Seeking another avenue to reduce emissions, the plaintiffs sought to invoke a history of precedents upholding the right of states to seek relief in federal court against polluters in other states when pollution crosses state lines.
Their argument was rejected in district court, upheld on appeal and rebuffed again by the Supreme Court. Why? Because, the court argued in so many words, it was superfluous: a 2007 Supreme Court ruling had already authorized the federal government to regulate greenhouse gases under the Clean Air Act, and the Environmental Protection Agency had already taken steps to do so.
Writing for an 8-to-0 majority, Justice Ruth Bader Ginsburg said, “We hold that the Clean Air Act and the E.P.A. actions it authorizes displace any federal common-law right to seek abatement of carbon dioxide emissions from fossil-fuel-fired power plants.”
As she noted, the E.P.A. was already moving in the direction mandated by the 2007 ruling. In 2009, it set standards to reduce carbon pollution from new cars and light trucks by 30 percent over the next five years. And it plans to propose new rules to regulate emissions from new and existing power plants by next September.
With the failure of cap-and-trade legislation last year, the E.P.A.’s rules are among the last remaining regulatory weapons the government can use to combat global warming; a counterattack from some power companies and their Congressional allies can be anticipated. The court’s reasoned reaffirmation of the law and the government’s obligation to carry it out is thus timely and welcome.