PITTSBURGH — The Environmental Protection Agency has dramatically lowered its estimate of how much of a potent heat-trapping gas leaks during natural gas production, in a shift with major implications for a debate that has divided environmentalists: Does the recent boom in fracking help or hurt the fight against climate change?
Oil and gas drilling companies had pushed for the change, but there have been differing scientific estimates of the amount of methane that leaks from wells, pipelines and other facilities during production and delivery. Methane is the main component of natural gas.
"This is great news for anybody concerned about the climate and strong proof that existing technologies can be deployed to reduce methane leaks," said Michael Shellenberger, the president of the Breakthrough Institute, an environmental group based in Oakland, Calif.
The scope of the EPA's revision was vast. In a mid-April report on greenhouse emissions, the agency now says that tighter pollution controls instituted by the industry resulted in an average annual decrease of 41.6 million metric tons of methane emissions from 1990 through 2010, or more than 850 million metric tons overall. That's about a 20 percent reduction from previous estimates.