Federal Agency Actions Following the Supreme Court’s Climate Change Decision in Massachusetts v. EPA: A Chronology

Robert Meltz
Legislative Attorney

On April 2, 2007, the Supreme Court rendered one of its most important environmental decisions. In Massachusetts v. EPA, the Court held 5-4 that greenhouse gases (GHGs), widely viewed as contributing to climate change, constitute “air pollutants” as that phrase is used in the Clean Air Act (CAA). As a result, said the Court, the U.S. Environmental Protection Agency (EPA) had improperly denied a petition seeking CAA regulation of GHG emissions from new motor vehicles by saying the agency lacked authority over such emissions.

This report offers a chronology of major federal agency actions, mainly by EPA, that involve GHGs or climate change and that occurred in the wake of Massachusetts v. EPA. Most of the listed actions trace directly or indirectly back to the decision. Examples include EPA’s “endangerment finding” for GHG emissions from new motor vehicles; the agency’s standards for GHG emissions from new motor vehicles; its interpretation of “pollutants subject to regulation,” the CAA trigger for requiring best available control technology (BACT) for such pollutants in “prevention of significant deterioration” areas; its guidance for determining BACT for GHG emissions; the “tailoring rule” (limiting the stationary sources that initially will have to install BACT and obtain CAA Title V permits based on their GHG emissions); and settlements of litigation seeking to compel new source performance standards (NSPSs) for GHG emissions from electric power plants and petroleum refineries. A few agency actions were included solely because of their relevance to climate change and their post-Massachusetts occurrence—for example, EPA’s responses to California’s request for a waiver of CAA preemption allowing that state to set its own limits for GHG emissions from new motor vehicles, and EPA’s monitoring rule for GHG emissions.

More analytical treatment of the government actions in this report may be found in CRS Report RL32764, Climate Change Litigation: A Survey, by Robert Meltz; CRS Report R40984, Legal Consequences of EPA’s Endangerment Finding for New Motor Vehicle Greenhouse Gas Emissions, by Robert Meltz; CRS Report RS22665, The Supreme Court’s Climate Change Decision: Massachusetts v. EPA, by Robert Meltz; CRS Report R40585, Climate Change: Potential Regulation of Stationary Greenhouse Gas Sources Under the Clean Air Act, by Larry Parker and James E. McCarthy; CRS Report R40506, Cars, Trucks, and Climate: EPA Regulation of Greenhouse Gases from Mobile Sources, by James E. McCarthy; and CRS Report R40166, Automobile and Light Truck Fuel Economy: The CAFE Standards, by Brent D. Yacobucci.


Date of Report: August 16, 2011
Number of Pages: 13
Order Number: R41103
Price: $29.95

Follow us on TWITTER at http://www.twitter.com/alertsPHP or #CRSreports

Document available via e-mail as a pdf file or in paper form.
To order, e-mail Penny Hill Press or call us at 301-253-0881. Provide a Visa, MasterCard, American Express, or Discover card number, expiration date, and name on the card. Indicate whether you want e-mail or postal delivery. Phone orders are preferred and receive priority processing.