The Supreme Court on Monday placed limits on the sole Obama administration program already in place to deal with power plant and factory emissions of gases blamed for global warming.
The justices said that the Environmental Protection Agency lacks authority in some cases to force companies to evaluate ways to reduce carbon dioxide emissions. This rule applies when a company needs a permit to expand facilities or build new ones that would increase overall pollution. Carbon dioxide is the chief gas linked to global warming.
The decision does not affect EPA 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 by 2030, but won't take effect for at least another two years.
The outcome also preserves EPA's authority over facilities that already emit pollutants that the agency regulates other than greenhouse gases. EPA called the decision "a win for our efforts to reduce carbon pollution because it allows EPA, states and other permitting authorities to continue to require carbon pollution limits in permits for the largest pollution sources."
Justice Antonin Scalia, writing for the court, said "EPA is getting almost everything it wanted in this case." Scalia said the agency wanted to regulate 86 percent of all greenhouse gases emitted from plants nationwide. The agency will be able to regulate 83 percent of the emissions under the ruling, Scalia said. The court voted 7-2 in this portion of the decision, with Justices Samuel Alito and Clarence Thomas saying they would bar all regulation of greenhouse gases under the permitting program.
EPA said that, as of late March, 166 permits have been issued by state and federal regulators since 2011.
Permits have been issued to power plants, but also to plants that produce chemicals, cement, iron and steel, fertilizer, ceramics and ethanol. Oil refineries and municipal landfills also have obtained greenhouse gas permits since 2011, EPA said.
Under Monday's ruling, EPA can continue to require permits for greenhouse gas emissions for those facilities that already have to obtain permits because they emit other pollutants that EPA has long regulated.
But Scalia, writing for the court's conservatives in the part of the ruling in which the justices split 5-4, said EPA could not require a permit solely on the basis of greenhouse gas emissions.
The program at issue is the first piece of EPA's attempt to reduce carbon output from large sources of pollution.
The utility industry, the U.S. Chamber of Commerce and 13 states led by Texas asked the court to rule that the EPAoverstepped its authority by trying to regulate greenhouse gas emissions through the permitting program. The administration failed to get climate change legislation through Congress.
In 2012, a three-judge panel of the U.S. Court of Appeals for the District of Columbia Circuit concluded that the EPA was "unambiguously correct" in using existing federal law to address global warming.
The agency's authority came from the high court's 2007 ruling in Massachusetts v. EPA, which said the Clean Air Act givesEPA power to limit emissions of greenhouse gases from vehicles.
Two years later, with Obama in office, the EPA concluded that the release of carbon dioxide and other heat-trapping gases endangered human health and welfare. The administration used that finding to extend its regulatory reach beyond automobiles and develop national standards for large stationary sources. Of those, electric plants are the largest source of emissions.
When the Supreme Court considered the appeals in October, the justices declined requests to consider overruling the court's 2007 decision, review the EPA's conclusion about the health effects of greenhouse gas emissions or question limits on vehicle emissions.
This story has been updated.