On June 23, the U.S. Supreme Court issued a decision upholding the U.S. Environmental Protection Agency’s (EPA) ability to require large industrial sources to reduce greenhouse gases that contribute to global warming. The 7-2 decision represents a major victory for EPA’s efforts to combat climate change.

Specifically, the Court found that EPA can continue to require large industrial sources of greenhouse gas pollution, such as power plants, oil and gas-related plants, chemical plants, and cement plants, to use the best available pollution control technology when building or rebuilding plants. Since 2011, more than 160 new and modified large industrial sources have incorporated the best available technologies for limiting greenhouse gases. A 5-4 majority also determined that such "pre-construction permits" would not be required for the many smaller sources that EPA had concluded should not be included in the permit program. 

The Court also ruled that EPA could not require greenhouse gas emission permits from facilities that were not already required to obtain permits for other air pollutants. However, the effect of this ruling will only reduce the scope of potentially affected industrial sources by three percent, from 86 percent to 83 percent.

The Court also refused to consider challenges to two prior decisions from the U.S. Court of Appeals for the D.C. Circuit that provide the foundation for EPA’s authority to regulate carbon pollution. The first decision upheld EPA’s scientific finding that carbon pollution endangers public health and welfare, while the second decision affirmed EPA’s greenhouse gas emissions limits for cars and trucks.

EPA believes that the Supreme Court’s decision provides the legal foundation for regulating greenhouse gases, including standards recently proposed for existing power plants. Those rules, as well as proposed greenhouse gas emission limits for new power plants, will likely be challenged by industry when finalized. However, a recent poll released by the American Sustainable Business Council (ASBC) found that almost two-thirds of small business owners support govern­ment standards to reduce carbon emissions from power plants.