Despite the rants of some conservative politicians and fringe scientists, it's a fact that greenhouse gases produced by human activity contribute to global warming. Last week the Supreme Court considered one way that such emissions might be controlled: through a huge and unwieldy lawsuit brought by California and five other states against five power companies and the Tennessee Valley Authority. Several justices expressed skepticism about the suit, but if the court rejects it there will still be opportunities to abate greenhouse gases.
Though the justices and lawyers traded esoteric legal terms, the important arguments concerned whether the states had a right to sue and what the role of the courts should be in controlling emissions. One problem for the states is that they grounded their suit not in the Clean Air Act but in the common-law notion that the courts should step in to address the "public nuisance" created by the defendants' emissions. The lawyer for the power companies said — and the justices seemed to agree — that the court's authority in this case was displaced by that of the Environmental Protection Agency.
A related weakness of the case is that the lawsuit would make the courts the regulator of first resort. As Justice Ruth Bader Ginsburg put it, the states would "set up a district judge, who does not have the resources, the expertise, as a kind of super EPA."
This case is different from a 2007 decision in which the court ruled that the EPA had the authority from Congress to regulate carbon dioxide and other greenhouse gases. In that case, which concerned emissions from cars, the ruling was anchored to a statute and the court's role was to interpret the statute. The finding that the EPA could regulate greenhouse gases has had practical consequences: The Obama administration has begun the rule-making process for such regulation.
The regulatory process is not, however, immune to politics. Because the EPA ultimately derives its authority from an act of Congress, the Republican majority in the House of Representatives has tried to strip the agency of the authority to regulate greenhouse gases. The Senate should continue to resist that regressive effort.