WASHINGTON — The Supreme Court largely left intact Monday the Obama administration's only existing program to limit power plant and factory emissions of the gases blamed for global warming. But a divided court also rebuked environmental regulators for taking too much authority into their own hands without congressional approval.
The justices said in a 5-4 vote along ideological lines that the Environmental Protection Agency cannot apply a permitting provision of the Clean Air Act to new and expanded power plants, refineries and factories solely because they emit greenhouse gases.
The decision underscores the limits of using the Clean Air Act to deal with greenhouse gases and the administration's inability to get climate change legislation through Congress.
"The Supreme Court put EPA on a leash but not in a noose," said Michael Gerrard, director of Columbia University's Center for Climate Change Law.
"It reaffirmed that EPA can regulate greenhouse gases, but it can only go so far in reinterpreting the statute," Gerrard said. "The court invalidated a small corner of a secondary program. The main event — EPA's proposed rules on existing power plants — remains to be fought another day."
The EPA and many environmental advocates said the ruling would not affect the agency's proposals for first-time national standards for new and existing power plants. The most recent proposal aims at a 30 percent reduction in greenhouse gas emissions from existing power plants by 2030, but won't take effect for at least another two years.
The justices warned that the regulation of greenhouse gases is not automatic under every program of the Clean Air Act as the administration had assumed it was. Similar logic is driving the EPA's other actions on global-warming pollution.
Justice Antonin Scalia, writing for his conservative colleagues, said EPA could not "just rewrite the statute" to bring greenhouse gases under a provision dealing with expanded and new facilities that would increase the overall amount of air pollution. Under the program, companies must evaluate ways to reduce carbon dioxide emissions in order to get a permit to build. Carbon dioxide is the chief gas linked to global warming.