At least half of a Delaware-sized cloud of methane hovering over the Four Corners region is coming from natural gas operations, and most of that is coming from two dozen individual sources, according to a new NASA-led study.
The report, published Monday in the Proceedings of the National Academy of Sciences, said about 250 individual sources — including gas wells, storage tanks, pipelines, and processing plants — appear to account for about half of all methane emissions in the area. Of that, about 50 percent is coming from just 25 individual sources, meaning two dozen points of emission are responsible for about one-fourth of all the methane spewing into the atmosphere in the Four Corners.
The report showed broad variation in methane leakage rates from identified sources, with emissions ranging from just a few pounds to 11,000 pounds per hour.
NASA’s Jet Propulsion Laboratory led the study, which aimed to identify the source of a 2,500-square-mile cloud of methane that had showed up in satellite images in 2014. Researchers from the California Institute of Technology, the National Oceanic and Atmospheric Administration and the University of Michigan also participated.
Scientists took measurements with infrared spectrometers aboard aircraft that flew in April 2015 over some 1,200 square miles. Ground crews also compiled measurements.
The results did show some methane emissions coming from venting at the San Juan Coal Mine. But in general, the report shows the lion’s share is from the oil and gas industry, said Thomas Singer, senior policy adviser with the Western Environmental Law Center.
“It shows the hotspot is from natural gas production, with some emissions also from coal mining,” Singer said. “It refutes industry claims that other sources like landfills or natural seeps are responsible.”
But industry representatives said more research is needed, since the study only focused on about half of the region’s methane emissions.
“It addressed a limited set of methane sources,” said New Mexico Oil and Gas Association president Steve Henke in a prepared statement. “It has been known by the states and tribes in the Four Corners that natural methane seeps occur throughout the area from the Fruitland Formation outcrop. Also the topography of the area traps air and causes methane to build up over time, whether from human or natural sources.”
The study comes amid debate over new Environmental Protection Agency rules released in May, plus forthcoming Bureau of Land Management regulations, that require industry operators to cease venting natural gas into the air, repair leaky infrastructure and monitor their assets for methane emissions. Those policies aim to slow global warming, since methane is about 80 times more powerful as a greenhouse gas over the first 20 years after entering the atmosphere than carbon dioxide.
“Methane is a huge climate pollutant, and it needs to be kept in the pipeline,” Singer said.
Industry leaders, however said new regulations should await the results of more research now underway.
“We believe a whole lot of additional studies are needed before we can say massive policy changes are called for in the San Juan Basin,” said NMOGA vice president Wally Drangmeister.