U.S. Supreme Court Weighs EPA’s Power to Regulate Greenhouse Gases From Smokestacks

By SEMA Washington, D.C., Staff

The United States Supreme Court heard arguments in a case that pits one dozen states and a number of industrial groups against the U.S. Environmental Protection Agency (EPA) on whether the agency has the authority to regulate greenhouse gases from stationary sources. 

The Court ruled in 2007 that carbon dioxide, the primary greenhouse gas element, was a pollutant under the Clean Air Act and that the EPA had a duty to regulate the gas. The EPA subsequently issued new tailpipe emission standards to reduce carbon emissions by establishing greenhouse gas levels tied to increases in the CAFE standards. The EPA then moved to regulate emissions from the very largest stationary source emitters, such as refineries, steel mills, chemical and cement plants, by requiring these “smokestack” industries to obtain permits and pursue best available reduction technology if their emissions exceeded between 75,000 and 100,000 tons per year. 

However, the Clean Air Act’s permit program is set at 100 to 250 tons for all other regulated pollutants (ozone, particulate matter, nitrogen oxides, etc.). If applied to greenhouse gases, the lower limit would require thousands of small source emitters to register with the EPA. A primary question before the Supreme Court is whether the EPA has the flexibility to set the higher greenhouse gas limit in the absence of congressional action to change the law. 

For more information, contact Stuart Gosswein at