WASHINGTON - Today, the U.S. Supreme Court hears oral argument about whether carbon pollution limits will continue, under a Clean Air Act safeguard requiring major stationary source polluters to use available control technology.

In 2007, the Supreme Court ruled that carbon dioxide and other greenhouse gases are pollutants under the Clean Air Act. The EPA officially determined in 2009 that carbon pollution endangers public health and welfare, contributing (among other impacts) to heat waves that worsen smog, and sea-level rise that threatens coastal communities. In 2010 the EPA issued the first-ever federal carbon pollution standards for cars and trucks. As a result of these actions, the Clean Air Act requires that new and modified major stationary polluters such as power plants and factories apply available technologies to control their carbon pollution.

Industry and its allies filed lawsuits seeking to derail these safeguards, but in 2012 the U.S. Court of Appeals for the D.C. Circuit rejected the suits. Industry appealed to the Supreme Court, which refused to hear industry’s challenge to the EPA’s endangerment determination and its motor vehicle standards.

The Supreme Court did, however, agree to hear a narrow part of industry’s challenge, addressing the Clean Air Act requirement that industry obtain permits before constructing or modifying major polluting facilities. In a brief filed in January, environmental groups have asked (as have briefs filed by the EPA and by several states) that the Court reject industry’s challenge and leave in place existing safeguards—in effect since 2011—which require polluters to use available pollution controls as a condition for obtaining a permit.

“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 the litigation. “Using available technology cuts carbon pollution, and saves money by also reducing energy costs.”

Following today's oral argument, the Supreme Court is expected to issue a decision by June.

In addition to the program at issue in this case, the EPA is working to develop additional safeguards—most importantly, “new source performance standards” for power plants. Such standards would be set as a minimum across-the-board floor for power plants, and will thus offer an important supplement to the permitting program at issue here, which involves making case-by-case determinations for individual facilities one by one. The EPA’s authority to set new source performance standards was confirmed by the Supreme Court in 2011, in American Electric Power v. Connecticut, and is not at issue in the present case. Thus, the EPA is free to move forward with those much-needed standards, and environmental groups are among many stakeholders urging the agency to do so promptly.

Read the environmental group's Supreme Court brief.