WASHINGTON — Drilling and fracking for natural gas don’t seem to spew immense amounts of the greenhouse gas methane into the air, as has been feared, a new study says.
The findings bolster a big selling point for natural gas, that it isn’t as bad for global warming as coal. And they undercut a major environmental argument against fracking, a process that breaks apart deep rock to recover more gas. The study, mostly funded by energy interests, doesn’t address other fracking concerns about potential air and water pollution.
The results, which generally agree with earlier Environmental Protection Agency estimates, were published Monday by the Proceedings of the National Academy of Sciences.
About 90 percent of the study funding came from nine energy companies that drill for natural gas with the rest coming from an environmental group. But study authors said they controlled how the research was done and how the wells were chosen for study. And even Robert Howarth of Cornell University, one of the scientists who first raised the methane leak alarm, calls the results ‘‘good news.’’
Howarth, who didn’t participate in the new work, did caution that the results may represent a ‘‘best-case scenario.’’ It might be, he said, that industry can produce gas with very low emissions, ‘‘but they very often do not do so. They do better when they know they are being carefully watched.’’
He and the study authors say more research is needed to explain why some studies have found high rates of leaking methane and others have not.
The University of Texas study wasn’t a comprehensive study of all the places natural gas can leak. But Steve Hamburg, chief scientist at the market-oriented Environmental Defense Fund, which helped fund the study, noted that it presents ‘‘direct measures of things that everyone’s been hand-waving about before. These are hard numbers using the best scientific approach that we can.’’
The study found that during the process of extracting natural gas from the ground, total leakage at the sites was 0.42 percent of all produced gas.