Under President Clinton the U.S. EPA took the position that it had the authority to regulate greenhouse gases (GHGs) from motor vehicles under the Clean Air Act as written, but the Clinton administration did not take affirmative steps to actually employ that authority. When President Bush took office, the General Counsel of EPA took the opposite position, stating that it would need special authorizing legislation in order to architect that regulation. A petition was filed with the EPA by the International Council for Technology Assessment and other organizations asking EPA to impose such regulations. EPA denied the petition. This led to Massachusetts v. EPA , in which 12 states along with many municipalities and non-government organizations joined together and challenged the EPA determination. On April 1, 2007 the Supreme Court issued a 5-to-4 ruling that EPA does indeed have the authority to regulate GHGs. The decision from the Supreme Court indicated that the next step would be for EPA to decide whether or not greenhouse gases posed an endangerment to public health or welfare, which is the test under the Clean Air Act for regulation of a particular air pollutant.
Environmental Law | Law
Sabin Center for Climate Change Law
Michael B. Gerrard,
The Obama Administration's First Environmental Policy Changes,
Metropolitan Corp. Couns.
Available at: https://scholarship.law.columbia.edu/faculty_scholarship/3129