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The Obama administration proposed Wednesday to regulate aircraft emissions in much the same way as power plants, saying they are a threat to human health because they contain pollutants that help cause global warming.
Using its authority under The Clean Air Act, the Environmental Protection Agency's preliminary finding of endangerment to human health clears the way for possible US adoption of international emissions standards.
The International Civil Aviation Organization, or ICAO, a UN agency, has been working for five years on developing global aircraft emissions standards for the first time. Final agreement on those standards is expected in February of next year.
But a final US decision on adoption of international standards is likely to be left to the next presidential administration. EPA officials said the earliest the agency is likely to propose adoption of ICAO standards would be in 2017.
US regulations would also apply only to engines used in large planes like airliners and cargo jets, turboprop planes and some business jets, and not to smaller jet aircraft, piston-engine planes, helicopters or military aircraft.
While ICAO negotiations on the standards are still underway, the standards ultimately aren't expected to go into effect until 2020 or afterward, and possibly as late as 2025, say environmentalists following the matter.
The international standards are also not expected to apply to airliners in service today or those that might be purchased before the effective date, said Vera Pardee, an attorney with the Center for Biological Diversity.
The Center is one of several environmental groups that sued the EPA to force the agency to issue its finding that emissions endanger public health.
Airlines typically fly planes for 20 years or more before replacing them. That means it's likely to be decades before planes that meet the anticipated global standards are in widespread use.
Airline emissions account for about 2% of total annual global greenhouse gas emissions.
That sounds small, but it's nearly as much as the emissions produced by Germany, the sixth-greatest greenhouse gas producing country, according to a study released last year by The International Council on Clean Transportation, an environmental group with offices in the US and Germany.
Aircraft manufacturers have already made significant strides in increasing fuel efficiency. Since the early years of the jet age in the 1960s, the fuel efficiency of airliners has increased 70%, according to Boeing.
