Three environmental groups filed a lawsuit against the Environmental Protection Agency on Tuesday to press for faster action in setting limits on greenhouse gas emissions from the U.S. aviation industry.
Earthjustice, the Center for Biological Diversity and Friends of the Earth, filed the lawsuit to force the agency to complete its so-called "endangerment finding," a step in the EPA rule making process that would allow the agency to regulate carbon dioxide emissions from U.S. aircraft.
Any "unreasonable delay" in setting emission standards for airlines violates the law and the EPA's duty under the Clean Air Act, according to the lawsuit filed in federal court.
The EPA was expected to finalize a proposal for an endangerment finding in mid-2014. But last June it issued only a preliminary scientific finding on the emissions.
The environmental groups want the agency to publish its final finding, opening it up to a public comment period, before President Barack Obama leaves office.
"We have to push them to issue a final (endangerment finding) and CO2 standard so we can have a conversation about what the standard should be," said Marcie Keever, legal director for Friends of the Earth.