That ruling, which the U.S. Supreme Court issued exactly one year ago today, required EPA to make a decision on whether to regulate greenhouse gas emissions from motor vehicles under the federal Clean Air Act.  A year later, EPA has not issued a decision.  Today’s court filing, known as a Petition for Mandamus, requests an order requiring EPA to act within 60 days.

 “The Bush administration has ignored science, it has ignored policy makers, and now it is ignoring the Supreme Court of the United States.  It is sad that the states must once again petition a court to force the EPA to deal with global warming.” Said Maine Attorney General Steve Rowe.

In Massachusetts v. EPA, the Supreme Court ruled that – contrary to the agency’s claim – the EPA has authority to regulate greenhouse gases under the Clean Air Act.  The Court also declared that the agency could not refuse to exercise that authority based on the agency’s policy preferences.  Instead, the EPA would have to decide, based on scientific information, whether it believed that greenhouse gas emissions were posing dangers to public health or welfare.

According to the petition, after last year’s ruling, EPA publicly made clear its belief that greenhouse gases were in fact endangering public health or welfare. Once EPA comes to that judgment, it must regulate greenhouse gases under the Clean Air Act. On multiple occasions, the agency promised that it would respond to the Supreme Court’s opinion by issuing an endangerment determination and draft motor vehicle emission standards by the end of last year.

When it recently decided whether California could set its own standards for greenhouse gas emissions from motor vehicles, the EPA issued detailed findings about the widespread harms that greenhouse gases are causing.  For example, the Administrator specifically found that “[s]evere heat waves are projected to intensify in magnitude and duration over portions of the U.S. where these events already occur, with likely increases in mortality and morbidity, especially among the elderly, young, and frail.” The EPA then denied California’s request only on the grounds that the many severe harms that California faced would also afflict other states across the country.

The petition further asserts that the EPA has already prepared an endangerment determination. A Congressional investigation conducted by Congressman Henry Waxman confirmed that the EPA in fact sent its draft endangerment determination and proposed regulations to the Office of Management & Budget in December 2007. According to the petition, an investigation conducted by the House Committee on Oversight and Government Reform established that consistent with its announced schedule, the EPA implemented its internal process of drafting an affirmative endangerment determination during the Fall of 2007.

The EPA has now declined to issue that proposed endangerment determination, and it last week said that it would delay responding to the Supreme Court’s opinion until after it conducts a lengthy public comment period later this year to examine policy issues raised by regulating greenhouse gases under the Clean Air Act.

Joining Maine in the Petition for Mandamus are: the states of Arizona, California, Connecticut, Delaware, Illinois, Iowa, Maryland, Massachusetts, Minnesota, New Jersey, New Mexico, New York, Oregon, Rhode Island, Vermont, and Washington, the City of New York, and the Mayor and City Council for Baltimore, the District of Columbia, Center for Biological Diversity, Center for Food Safety, Conservation Law Foundation, Environmental Advocates, Environmental Defense Fund, Friends of the Earth, Greenpeace, International Center for Technological Assessment, Natural Resources Defense Council, Sierra Club, and U.S. Public Interest Research Group.  All of these parties were either petitioners in Massachusetts v. EPA, or joined amicus briefs in support of the petitioners.