The Environmental Protection Agency on Thursday took a step toward crafting regulations for greenhouse gas emissions from aircrafts.
The agency released a timeline to propose and finalize an endangerment finding on emissions from airlines. It submitted the plan to the United Nation's International Civil Aviation Organization Thursday, which is working to finalize global standards for airlines by early 2016.
Environmentalists say aviation produces about 11 percent of global warming-causing carbon emissions in the U.S. Those emissions are expected to quadruple by 2050 if regulations are not proposed, they said.
Under the plan, the agency expects to propose its endangerment finding by April 2015 and finalize it by spring of 2016. Any proposed regulation would come after the endangerment finding, leaving it to the next administration to finalize.
In 2010, the D.C. District Court ruled that the EPA must publish an endangerment finding but has yet to do so. Green groups said in August that they planned to sue the agency for failing to take action after the 2010 ruling.
In its timeline, the EPA cited pressure from stakeholders and court proceedings.