Also filing petitions today are the States of California, Connecticut, New Jersey and New Mexico and the District of Columbia through their Attorneys General, the Commonwealth of Pennsylvania through its Department of Environmental Protection, the City of New York through its Corporation Counsel, and the South Coast Air Quality Management District through its District Counsel.
Aviation's Contribution to Global Warming
Aircraft emit huge amounts of carbon dioxide. In fact, they currently account for 12 percent of carbon dioxide emissions from U.S. transportation sources and three percent of the United States' total carbon dioxide emissions. The United States is responsible for nearly half of worldwide carbon dioxide emissions from aircraft.
Aircraft also emit nitrogen oxides, known as NOX, which contribute to the formation of ozone, another greenhouse gas. 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.
Together, these high altitude emissions have a greater global warming impact than if the emissions were released at ground-level. A recent report by the UK Royal Commission on Environmental Protection found that the net effects of ozone, contrail and aviation-induced cloud cover is likely to triple the warming effect of aircraft-emitted CO2 alone. The report concludes that if these estimates are correct and the anticipated growth in aviation realized, aviation may be responsible for between six and ten percent of the human impact on climate by the year 2050.
Aircraft Emissions Expected to Triple by Mid-Century
Greenhouse gas emissions from aircraft are anticipated to increase substantially in the coming decades due to the projected growth in air transport both domestically and globally. According to the Federal Aviation Administration, greenhouse gas emissions from U.S. domestic aircraft are expected to increase 60 percent by 2025. Globally, aircraft emissions are expected to more than triple by mid-century. While some countries have already begun to respond to these challenges, the United States has failed to address this enormous source of emissions.
The Petition
In the petition to Stephen L. Johnson, Administrator of the U.S. 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 petition filed today 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, which it could do by:
- Adopting operational measures to minimize fuel use and reduce emissions from aircraft;
- Requiring the use of lighter, more aerodynamic, and more energy efficient airplanes, as well as the development of even more efficient designs; and
- Adopting regulatory measures to create incentives for the use of cleaner jet fuels.
"With the April 2007 decision by the U.S. Supreme Court, EPA now has a mandate to regulate greenhouse gas emissions," said Alice Thomas, an attorney from Earthjustice who filed the petition on behalf of the environmental groups. "Today, we are asking the EPA to begin the process of reducing the global warming impact from one of the world's fastest growing sectors."
"Global warming pollution is taking a massive toll on marine life," said Dr. Michael Hirshfield, Oceana's chief scientist and senior vice president for North America. "To preserve these critical ecosystems, the U.S. must take the lead in regulating aircraft emissions, since aircraft are a major source of carbon dioxide," added Hirshfield.
"Halting and reversing global warming will require innovation across every sector of the global economy, including aviation," said Danielle Fugere of Friends of the Earth. "Regulating greenhouse gas pollution within, to and from the U.S. will speed international efforts to slow global warming."
"Global warming is the single greatest threat to the diversity of life on Earth," said Andrea Treece, staff attorney for the Center for Biological Diversity. "We still have a window of opportunity to save species like the polar bear but that window is rapidly closing. Limiting greenhouse gas pollution from aviation is an important part of the overall solution and the EPA should do so immediately."
Read the petition filed today by environmental groups
EPA Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990 – 2005, (2007)
Key Aviation and Global Warming Resources (cited in petition)