Environmentalists have filed a federal lawsuit against U.S. EPA in an effort to prod the agency to regulate greenhouse gas emissions from aircraft, ships and the nonroad engines used in heavy industrial equipment.

Those three types of sources produce about a quarter of greenhouse gas emissions from mobile sources in the United States, but they were not addressed when EPA determined that tailpipe greenhouse gas emissions from automobiles pose a threat to public health and welfare. Saying that EPA has dragged its feet on a substantial source of emissions thought to be contributing to global warming, Earthjustice and the Western Environmental Law Center sued the agency Friday in the U.S. District Court for the District of Columbia.

The plaintiffs include Oceana, Friends of the Earth, the Center for Biological Diversity, the Center for Food Safety, and the International Center for Technology Assessment. Their lawsuit came one day after the Senate voted down a Republican-led resolution that would have overruled EPA's "endangerment" finding, preventing the agency from regulating greenhouse gas emissions from cars, trucks and stationary sources such as fossil fuel-fired power plants (E&ENews PM, June 10).

The groups petitioned EPA in 2007 and 2008 to assess boats, planes and nonroad vehicles in addition to the sources covered by last December's endangerment finding. Their requests followed the Supreme Court's 2007 ruling in Massachusetts v. EPA, which required the agency to decide whether greenhouse gases qualify as pollutants under the Clean Air Act.

"Having determined that greenhouse gases are air pollutants that endanger the public health and welfare, EPA must determine which sources 'cause and contribute' this pollution and issue regulations to control emissions from these sources," the lawsuit says, asking Judge Henry Kennedy to make the agency "determine whether aircraft, marine vessels and other nonroad sources cause and contribute to greenhouse gas pollution, and, if so, to promulgate regulations to reduce emissions from these sources."

The energy and climate bill passed last year by the House gave EPA the authority to regulate emissions from nonroad vehicles, as did legislation approved in November by the Senate Environment and Public Works Committee. Roger Martella, the agency's general counsel during the George W. Bush presidency, said upon the release of the endangerment finding for automobiles that he expects the agency to move forward with nonroad regulations once it finalizes the auto rule.

An EPA spokeswoman declined to comment on the lawsuit.

The final auto rule, issued jointly last month by EPA and the Department of Transportation, would set an average limit of 250 grams of carbon dioxide per mile per vehicle in 2016.

Groups have until July 6 to challenge the rule, which already has prompted industry-backed lawsuits from the Southeastern Legal Foundation and Coalition for Responsible Regulation Inc. Carmakers, environmentalists and a dozen states have filed petitions to intervene in support of the agency's rule (Greenwire, June 8).

Click here to read the nonroad vehicle emissions lawsuit.