Environmental Protection Agency
Press Releases
Supreme Court Decision Calls for EPA to Address Greenhouse Gas Emissions Standards for Motor Vehicles—04/02/07
On April 2, the U.S. Supreme Court ruled against the Environmental Protection Agency (EPA) in a case that challenged the agency’s lack of regulatory action in controlling greenhouse gas emissions from motor vehicles. The case, Massachusetts vs. Environmental Protection Agency, was brought by 12 states and multiple environmental groups in response to EPA’s denial of a 1999 petition under the Clean Air Act. That petition had asked EPA to regulate emissions from new motor vehicles on the basis of their impact on global warming; EPA refused in 2003, maintaining that it held no statutory authority over greenhouse gas emissions.
This case marks the first time that the Supreme Court has addressed the issue of global warming and the Clean Air Act’s authority to regulate suspected greenhouse gas emissions. Although EPA supports voluntary emissions-reduction programs, it has stated that the most recent Clean Air Act Amendments do not require or empower it to establish binding emissions limitations on greenhouse gases. The Court held that the agency does have the statutory authority to regulate greenhouse gases under the Clean Air Act. It also ruled that the EPA has not sufficiently supported its refusal to regulate greenhouse gases from motor vehicle emissions.
The future regulatory status of greenhouse gas emissions such as carbon dioxide from motor vehicles and other sources is still far from certain. The Court has ordered EPA to reconsider its position. It must develop a “reasoned justification” based on the statutory language and not policy statements if it decides not to regulate greenhouse gases from mobile sources. The impact of this ruling on stationary sources is not immediate. However, this ruling and several pending legislative efforts may soon compel EPA to consider standards for both mobile and stationary sources.
The full text of the Supreme Court’s final decision, including dissenting arguments, is available
online.
