Environmental campaigners drew solace from a supreme court hearing on greenhouse gas controls on Monday that left justices appearing to support the US government’s broad role in setting emissions limits for power stations.

The case, brought by power companies and 13 states including Texas, argued that the Environmental Protection Agency was overstepping its powers by using air quality rules to tackle climate change.

But a majority of court justices who spoke during Monday’s 90 minute oral arguments did not appear willing to re-open a 2007 Massachusetts case upholding the broad power of the EPA, according to experts following the case.



David Doniger, the Climate and Clean Air director at the Natural Resources Defense Council, said: “Chief Justice Roberts made that clear early on, saying that even though he was a dissenter in 2007, the court isn’t going to reconsider Massachusetts, or the follow-on decision in American Electric Power v Connecticut, which establish EPA’s authority to set Clean Air Act standards for both vehicles and factories that emit carbon pollution that drives dangerous climate change.”

Doniger added: “Now more than ever, it’s clear that EPA’s authority to set standards for carbon pollution – the basis of Obama’s Climate Action Plan – is firmly settled on solid ground.”

The results of the latest and narrower challenge to EPA powers may not be known for several months and industry lawyers argued the agency should not be able to use permits to tackle climate change.

“Greenhouse gases are not included within the (permitting) program at all,” said Peter Keisler, representing the American Chemistry Council, which is among two dozen manufacturing and industry groups that want the court to throw out the rule.

But solicitor general Donald Verrilli, arguing for the administration, urged the court to leave the permitting program in place. “This is an urgent problem. Every year that passes, the problem gets worse and the problem for future generations gets worse,” Verrilli said.

The supreme court justices also appeared unwilling to hear challenges to basic science of linking carbon pollution and climate change.

“None of the petitioners tried to pick a fight there,” said Doniger. “Justice Antonin Scalia asked sarcastically if sea level rise was occurring anywhere but in Massachusetts, but no one seriously challenged EPA on scientific issues this time.”

Supreme court experts expect a decision in the case, called Utility Air Regulatory Group v Environmental Protection Agency, may narrowly come down in favour of the EPA based on Monday’s arguments.

“As is so often the case when the Court is closely divided, the vote of Justice Anthony M Kennedy loomed as the critical one, and that vote seemed inclined toward the EPA,” said Lyle Denniston of the legal website Scotusblog.