In the latest case before the court, Utility Air Regulatory Group v. EPA, industry and its allies are challenging the authority of the Environmental Protection Agency to regulate the carbon emissions of "major stationary source polluters," or factories and power plants.
In the 2007 Massachusetts v. the United States ruling, the Supreme Court concluded that the EPA had the authority to regulate greenhouse gases like carbon dioxide under the Clean Air Act. While the 2007 decision dealt specifically with non-stationary polluters (car and truck emissions), that EPA has since interpreted the decision as empowering broader authority -- like regulating power plant emissions.
The latest challenge by regulatory-antagonists focuses on the EPA's requirement that power plants apply for emissions permits before expanding operations or building new polluting facilities. The Supreme Court agreed to hear the complaint in 2011.
Environmental advocates have repeatedly implored the courts to dismiss this complaint from major polluters.
“Industry continues year after year not only to emit huge amounts of carbon pollution, but also to resist common-sense solutions,” said Howard Fox of Earthjustice, co-counsel for Environmental Defense Fund, in a brief filed with the Supreme Court. “Using available technology cuts carbon pollution, and saves money by also reducing energy costs.”
"This is a very narrow case," Jeffrey Holmstead, the industry attorney, told NPR. "I think the outcome won't have much of an impact one way or another on EPA's ability to regulate carbon."
Others say the case could have larger implications: a rejection of EPA behavior by the Supreme Court could be seen as a repudiation of Obama's efforts to curb emissions via the powers of the executive branch.
In addition to environmental groups, a number of states, including New York, California, Illinois and others, have pledged their support of the administration and EPA's efforts to combat climate change.
A decision on the matter is expected from the high court sometime before June.