How much methane leaks out of the ground during the fracking process? There's a long-running debate over that question, and the answer could determine the role of natural gas in a climate-changed world. Natural gas burns more cleanly than coal and oil, but that benefit could be outweighed if fracking causes significant releases of methane, a greenhouse gas that is orders of magnitude more effective at trapping heat than carbon dioxide.
Last year, researchers from Cornell reported that fracked natural-gas wells leak 40 to 60 percent more methane than conventional natural-gas wells -- making fracking a more dangerous source of greenhouse gas emissions than coal.
But today, a team from MIT suggested the Cornell report may be incorrect -- that fracking doesn't result in much more methane emission than standard natural-gas drilling.
From E&E News:
[A]bout 216 gigagrams of methane [emitted] in 2010 ... was due to hydraulic fracturing, a technique in which drillers inject pressurized water, sand and chemicals to fracture shale rock and release trapped gas. Fracking accounted for 3.6 percent of the 6,002 gigagrams of methane emitted overall by natural gas operations in 2010.
The implication is that shale gas drilling operations leak most of their methane from much of the same points as conventional gas drilling operations: pipelines, compressor stations, valves and other point sources. These account for about 96.4 percent of the emissions from a gas production site, the study finds.