WASHINGTON — The Supreme Court was divided Monday over whether the Obama administration's Environmental Protection Agency has gone too far in trying to regulate power plant and factory emissions of gases blamed for global warming.
Liberal justices seemed ready to defer to the agency's interpretation of how to protect the environment from greenhouse gases under a contested portion of the Clean Air Act. Conservative justices were skeptical of how the agency had to essentially rewrite some of the law's requirements to avoid "absurd" results.
But the justices also wondered whether it would make much difference in the long run. Both sides agreed that the EPA has the power to regulate greenhouse gases, but they differed on how the agency should go about it. Even if the government lost, some justices said, it would make only a small difference in the number of facilities that could be regulated.
The back-and-forth suggested the possibility of a narrow ruling that limits the EPA's regulation to those plants and factories already subject to regulation because of other pollutants.
Justice Anthony Kennedy — who cast the decisive vote in a 2007 ruling that said greenhouses gases met the definition of pollutants subject to EPA regulation — is also likely to have that role in this case.
On one hand, he seemed uninterested in revisiting the court's earlier decision, as some objecting states have asked. But he also questioned whether the EPA has gone too far in reinterpreting the part of the law it is using to regulate the facilities.
"I couldn't find a single precedent that strongly supports your position," Kennedy told Solicitor General Donald Verrilli, who is defending the EPA.
Verrilli acknowledged that the EPA might be moving quickly.
"This is an urgent environmental problem," Verrilli said. "The effects are cumulative and they're delayed, and so every year we wait we make the hole deeper and we create an even greater threat to future generations."