Federal regulators want to limit emissions from some aircraft, saying the greenhouse gases contribute to global warming and endanger human health.
The announcement enables the Environmental Protection Agency, under the Clean Air Act, to propose rules to restrict greenhouse gas (GHG) emissions from airplanes. The 1970 Clean Air Act requires the federal government to regulate pollutants that are found to pose a health risk.
In the United States, aircraft account for 3% of total GHG emissions, including about 11% of emissions in the transportation sector, according to government statistics. Worldwide, U.S. planes account for nearly one-third of all aircraft emissions.
“Aircraft remain the single largest GHG-emitting transportation source not yet subject to GHG standards” in the United States, the Environmental Protection Agency (EPA) announced in June 2015.
The EPA said it will work with the International Civil Aviation Organization (ICAO), a branch of the United Nations, to craft an international set of standards for aircraft emissions. The U.S. rules would apply primarily to engines used in commercial aircraft, including larger jet and turboprop aircraft, while excluding smaller aircraft, helicopters and military planes.
The ICAO is expected to release its proposed emission standards by February 2016, with U.S. regulations to follow by 2018.
The National Business Aviation Association, an industry group for firms that rely on general aviation (GA) aircraft, noted that aviation emissions “account for a mere 2% of all transportation emissions globally,” with GA aircraft accounting for just a fraction of that total.
“The aviation community has long been committed to pursuing effective and workable efforts to lower the industry’s carbon footprint,” including through improved fuel efficiency, association President Ed Bolen said in a June statement.
The EPA move is the latest government initiative to tackle global warming. Significant regulations on cars and trucks have forced automakers to speed development of electric, hybrid and other fuel-efficient vehicles. Emissions limits on power plants have shifted the focus from fossil fuels to renewable sources, such as wind and solar.
The EPA’s efforts coincide with work by the Federal Aviation Administration (FAA) to reduce aircraft emissions through its Continuous Lower Energy, Emissions and Noise program.
While reducing airplane emissions can have positive environmental impacts, boosting sustainability initiatives at airports will also help, according to Ismael Cremer, an assistant professor at Florida Institute of Technology’s College of Aeronautics.
Cremer, who has conducted research into airport emissions and teaches a course on aviation sustainability, has said that airports can do several things to reduce their environmental footprint, from tapping renewable energy sources to using less water and initiating recycling programs.
Additionally, commercial airline companies continue experimenting with renewable jet fuel, including biofuels derived from sugar cane and used cooking oil. The FAA wants U.S. airlines to use 1 billion gallons of sustainable alternative jet fuels a year by 2018.
In 2014, U.S. carriers consumed 16.2 billion gallons of fuel at a total cost of $46.2 billion, federal statistics show.