Natural gas’ reputation as a climate-friendly alternative to coal has been tarnished recently by concerns that methane—a potent greenhouse gas—is leaking in copious quantities as the fuel makes its way from the ground to the consumer. A study released Monday provides the first on-the-ground measurements of methane leaks at hydraulically fractured natural gas well sites, and they're not as bad as some had feared.
University of Texas engineering professor David Allen says his team found that emissions are lower during construction, higher during production and about the same overall as previous estimates by the federal government. That runs counter to the results of several smaller studies, and Allen says it gives companies and regulators a better idea of where to focus their attention.
“The first step in trying to understand what to do about methane emissions is to make sure that you really know what the methane emissions are,” he says.
Drew Nelson works for the Environmental Defense Fund, one of the groups sponsoring the study. He says the results show new federal emissions policies are working, but he adds there’s still a long way to go.
“The leak rate that the study found is still, while it’s lower than some other studies, it’s still relatively high, and it’s very clear that there are opportunities to bring emissions down further,” Nelson says.
Regional variability in some of the emissions measurements might give companies and regulators clues about where to start. The study team found that during routine production, natural gas wells in the Rocky Mountain region emit significantly less methane than wells in other regions. They’re doing a follow-up this fall to figure out why that might be.
This is the first of sixteen studies scheduled to be released over the coming year about methane leaks. Future studies will deal with other parts of the natural gas supply chain, like storage and transportation.
The work is being funded through a partnership between the Environmental Defense Fund, industry and universities.