WASHINGTON — The states of California and Pennsylvania intend to join other governments and environmental groups Wednesday in filing legal petitions demanding that the Environmental Protection Agency order a reduction of greenhouse gas emissions from aircraft.
Aircraft account for 3 percent of U.S. emissions of carbon dioxide, the main gas responsible for the Earth's warming, the EPA reported in April. Some scientists predict that unless steps are taken, carbon emissions from aircraft will triple globally by 2050. The U.S. airline industry accounts for nearly half of carbon emissions from aircraft worldwide.
Aircraft emissions have a greater impact on climate change than their carbon output alone. Aircraft also spew nitrogen oxides, gases that have more impact on global warming at the altitudes of air travel than they would if emitted at ground level. Aircraft also emit water vapor, which can be seen as contrail lines across the sky. Contrails are thought to add to high cloud cover, another element that contributes to rising temperatures.
A study by the Royal Commission on Environmental Protection in Britain found that pollution from planes could amount to 10 percent of the pollution that's causing climate change by midcentury.
The EPA has issued standards on some types of aircraft pollution but hasn't regulated greenhouse gas emissions. The petition calls on the agency to make a finding that greenhouse gas emissions from aircraft endanger public health and welfare under the Clean Air Act.
Earthjustice, a nonprofit public-interest law firm, planned to file the petition on behalf of the environmental groups Friends of the Earth, Oceana and the Center for Biological Diversity. Similar petitions were to be filed at the same time by the attorneys general of California, Connecticut and New Mexico, Southern California's South Coast Air Quality Management District, the Pennsylvania Department of Environmental Protection and the cities of New York and Washington.
President Bush opposes mandatory caps on greenhouse gas emissions. EPA spokeswoman Roxanne Smith said she couldn't comment on the petition before the agency had had time to review it, but noted that the EPA relied on voluntary programs such as Energy Star, a consumer-advice program on energy-efficient appliances.
The petition argues that voluntary measures won't do enough to reduce aircraft pollution.
Officials from around the world are meeting this month in Bali, Indonesia, at a U.N. climate conference to work out a road map leading to a new global system of reducing emissions, protecting forests and promoting clean technology.
A Nobel Prize-winning U.N. scientific panel's report in November called climate warming an "unequivocal" fact and warned that failure to curb it could be devastating for life on Earth.
Another report, a summary of the U.N.'s 2007-2008 Human Development Report, warned on Nov. 27: "Our generation may not live to see the consequences. But our children and their grandchildren will have no alternative but to live with them. Aversion to poverty and inequality today, and to catastrophic risk in the future, provides a strong rationale for urgent action."
The petition on aircraft emissions argues that the EPA could adopt new operations rules for aircraft that minimize fuel use, require more energy-efficient airplanes and create incentives for using cleaner jet fuels.