With small limits, Supreme Court backs EPA authority over carbon emissions

[Updated: 4:30 p.m. EDT] In a split decision, the Supreme Court today put limits on one way the Environmental Protection Agency regulates climate-harming emissions [PDF], but upheld the government agency’s right to control greenhouse gases overall.

In their 5-4 ruling, the court found that EPA rules on what are called “stationary” polluters — which includes big power plants, but could also include some midsized businesses and large commercial operations like megamalls — were written too broadly, and should be reworked to focus on the industries that produce the lion’s share of greenhouse gas emissions.

But, by a 7-2 margin in a concurring opinion, the court again found that the EPA was within its rights to regulate carbon dioxide and other emissions deemed harmful to the climate under the authority granted by the 1970 Clean Air Act. It was the third such affirmation by the Roberts Court, and the decision indicated the justices were not inclined to hear any more challenges to that basic premise.

“EPA is getting almost everything it wanted in this case,” wrote Justice Antonin Scalia in his opinion. “It sought to regulate sources it said were responsible for 86 percent of all the greenhouse gases emitted from stationary sources nationwide. Under our holdings, EPA will be able to regulate sources responsible for 83 percent of those emissions.”

And even that difference is not considered a big loss by environmental groups involved with the case. “It obviates the need for some very heavy administrative interpretation for just 3 percent more of greenhouse gas emissions,” said Sean Donahue of the Environmental Defense Fund, indicating the cost of regulating those smaller polluters would outweigh the benefit.

Most important to the Obama administration, the decision is seen as a go-ahead for new carbon emission standards proposed earlier this month. That plan would put in place a regulatory process where each of the 50 states would determine a customized regulatory target, with the goal of reducing carbon production 30 percent off a 2005 baseline nationwide by 2030.

Under today’s decision, the EPA was limited in its statutory authority to change emissions thresholds under the Clean Air Act, but the court made clear that industries that needed permits from the government for other pollutants could be subject to EPA oversight on greenhouse gasses. That finding covers the vast majority of current stationary sources of carbon dioxide.

“Today is a good day for all supporters of clean air and public health and those concerned with creating a better environment for future generations,” said an EPA statement, terming the court decision a “win.” The court’s ruling allows the agency, “states and other permitting authorities,” the statement said, “to continue to require carbon pollution limits in permits for the largest pollution sources.”

The case decided was Utility Air Regulatory Group v. Environmental Protection Agency, No. 12-1146.

Peter Moskowitz contributed to this report.