Environmental groups sue EPA over airplane pollution

WASHINGTON — A coalition of environmental groups sued federal regulators Tuesday over long-sought pollution standards for airliners and cargo planes.

The Center for Biological Diversity and Friends of the Earth filed a lawsuit in U.S. District Court in Washington. The groups allege the Environmental Protection Agency has unreasonably delayed for years using the Clean Air Act to enforce limits on heat-trapping greenhouse gas emissions from aircraft.

A United Nations panel in February proposed an average 4 percent reduction in fuel consumption during the cruise phase of flight starting in 2028 when compared with planes delivered in 2015. However, planes burn the most fuel during takeoffs and landings, while cruising at high altitudes is already the most fuel-efficient phase of flight.

Environmentalists have criticized that proposed reduction as too modest to significantly curb climate change, and are pushing the EPA to enact more stringent standards for domestic aircraft. Jet engines have a disproportionate effect on global warming compared to other pollution sources because the harmful gasses are released at high altitude.

Aviation accounts for about 5 percent of global carbon emissions, with U.S.-owned airliners emitting about 30 percent of all aircraft pollution worldwide. While carbon emissions from land-based sources are largely in decline, pollution from airplanes is projected to triple by 2050 without stricter limits, the environmental groups say.

The groups first filed a legal petition in 2007 urging the EPA to reduce air pollution from aircraft. A federal judge later ruled that the EPA is required to address aircraft emissions under the Clean Air Act. EPA has set 2018 as the earliest possible date for it to issue its final regulations. Environmental groups say that’s too long.

The newest Boeing and Airbus designs already meet the proposed international efficiency standards.