The Supreme Court on Wednesday wrestled with the thorny issues surrounding global warming and the government's efforts to abate it. There was little indication of how the court will rule.
At issue in the case, Massachusetts vs. EPA, are two questions: Whether the Clean Air Act authorizes the Environmental Protection Agency to regulate air pollutants that may contribute to climate change; and, if so, if the EPA properly used its discretion when it chose not to regulate auto emissions.
Also at stake in the case is whether states have the right to sue to force EPA action on pollutants from cars and other sources.
The case is the high court's first foray into the argument over global warming, and its ruling could have far-reaching effects. If the justices determine the EPA is not responsible for regulating greenhouse gases, it would likely require congressional intervention to initiate government action on that front. If the justices decide states don't have standing to sue, that would undercut other pending suits seeking to regulate factory emissions.
Environmental groups and business interests have both called it the most significant environmental case in a generation.
The justices' questions appeared to follow familiar lines. Conservative Justices Antonin Scalia, Samuel Alito and Chief Justice John Roberts appeared skeptical both of the EPA's authority and of the states' rights to sue.
Justice Clarence Thomas is expected to join other conservatives in the case.
Liberal Justices John Paul Stevens, David Souter, Ruth Bader Ginsburg and Stephen Breyer seemed inclined the other way.
That would leave Justice Anthony Kennedy as the deciding fifth vote to decide both issues, a role he increasingly plays.
James Milkey, an assistant attorney general from Massachusetts, argued that the Clean Air Act says the agency must set emission standards for "any air pollutant" from vehicles that might even be anticipated to threaten public health.
Bush administration lawyers counter that Congress never intended for the Clean Air Act to regulate greenhouse gases.
Court debates national bank subsidiaries
The Supreme Court on Wednesday also grappled with a turf battle between Wachovia Corp. and Michigan banking regulators that may set new parameters for how states and the federal government set requirements for numerous industries.
At issue is whether federal rules for Wachovia and other national banks extend to their state-chartered subsidiaries, exempting them from state regulation.
The case has broad implications on how much power states have to oversee an array of other industries, including pharmaceuticals and autos.
Information from the Associated Press, McClatchy Newspapers and Bloomberg News was used in this report.