Petitions Urge EPA to Regulate Aircraft Emissions

On Dec. 5, a coalition of environmental groups, states and regional governments filed petitions with EPA calling on the federal agency to curb carbon dioxide and other greenhouse gases emitted from airplanes.

According to Earthjustice, the petitions are the first step in a process that requires EPA to evaluate the current impacts of aircraft emissions, seek public comment and develop rules to reduce aircraft emissions or explain why it will not act. Earthjustice filed the environmental groups' petition on behalf of Friends of the Earth, Oceana and the Center for Biological Diversity.

Also filing petitions are the states of California, Connecticut, New Jersey and New Mexico and the District of Columbia through their attorneys general, the state of Pennsylvania through its Department of Environmental Protection, New York City through its Corporation Counsel, and the South Coast Air Quality Management District through its District Counsel.

According to Earthjustice, aircraft emit huge amounts of carbon dioxide (CO2), accounting for 12 percent of CO2 emissions from U.S. transportation sources and three percent of the United States' total CO2 emissions.

Aircraft also emit nitrogen oxide (NOx), which contribute to the formation of ozone, another greenhouse gas, Earthjustice stated. Emissions of NOx at high altitudes result in greater concentrations of ozone than ground-level emissions. Aircraft also emit water vapor at high altitude that forms condensation trails or "contrails." Contrails are visible cloud lines that form in cold, humid atmospheres and contribute to the warming impacts of aircraft emissions. Moreover, the persistent formation of contrails is associated with increased cirrus cloud cover, which also warms the Earth's surface, Earthjustice stated.

In the petition to Stephen L. Johnson, administrator of EPA, the environmental groups said:

"[I]t is indisputable that greenhouse gas emissions, including those from aircraft engines, are air pollutants that are causing and contributing to global climate change, with severe environmental consequences for the planet and all of its inhabitants. EPA has broad discretion in promulgating regulations to limit greenhouse gases from aviation. Moreover, numerous measures are currently available that can reduce the global warming impacts of aircraft emissions, and new technologies and other procedures under development can be brought online to further reduce emissions within reasonable timeframes. Consequently, petitioners request that EPA undertake its mandatory duty to regulate greenhouse gas emissions from aircraft engines."

The groups' petition asks the EPA to respond within 180 days and initiate a formal process to limit and reduce greenhouse gas emissions from all U.S. certified aircraft and all foreign aircraft arriving in or departing from U.S. airports.

The petition filed by the environmental groups can be accessed in PDF format at