Study: Fracking Responsible for Rising Methane Levels in Atmosphere

by Sergio Chapa (Houston Chronicle) Rising levels of the potent greenhouse gas methane in the atmosphere have been linked to emissions produced by the shale oil and natural gas industry, a new study from Cornell University reveals. -- In a study published this morning (August 14, 2019) in the European Geosciences Union journal Biogeosciences, Cornell University Ecology Professor Robert Howarth reported that an analysis of the methane found in the Earth's atmosphere has chemical fingerprints that point to shale, an industry which uses horizontal drilling and hydraulic fracturing to unlock oil and natural gas in tight geological formations.

A single methane molecule is made from one carbon atom at the center and four hydrogen atoms in orbit. But the study reveals that a rapidly growing amount of methane in the atmosphere is made from the carbon-13 atom, a type of carbon found in natural gas extracted from shale formations.

With two-thirds of all new natural gas production over the last decade coming from shale formations in the United Sates and Canada, Howarth reported that atmospheric methane concentrations have been rising since the rise of horizontal drilling and hydraulic fracturing in 2008.

"This recent increase in methane is massive," Howarth said in a statement. "It's globally significant. It's contributed to some of the increase in global warming we've seen and shale gas is a major player.

Most of the natural gas extracted from shale formations is used for power plants, petrochemical plants and heating buildings but because it is a byproduct of drilling for oil, a large amount of it is burned off at drilling sites in an industry practice known as flaring. Some methane is released into the atmosphere from leaky oil field equipment and pipelines.

"Reducing methane now can provide an instant way to slow global warming and meet the United Nations' target of keeping the planet well below a 2-degree Celsius average rise," Howarth said.

But not everybody agrees with Howarth's research. Quentin Fisher, a petroleum engineering professor at the University of Leeds in the United Kingdom, told Newsweek he was skeptical.

"The results are extremely sensitive to highly questionable assumptions regarding the isotopic composition of methane found in shale," Fisher told Newsweek. "The arguments made by previous studies that increase in methane in the atmosphere is from biogenic sources, such as release from wetlands and agriculture or burning of biomass, seem far more convincing." READ MORE

Excerpt from Science Magazine: The new findings come courtesy of data gathered by aircraft over six U.S. cities: Washington, D.C.; Baltimore, Maryland; Philadelphia, Pennsylvania; New York City; Providence; and Boston. In 2018, researchers flew at altitudes between 300 and 800 meters and measured concentrations of methane, ethane, CO₂, and carbon monoxide, among other gases.

The ethane measurements were clues to likely sources of the methane leaks, says Eric Kort, an atmospheric scientist at the University of Michigan in Ann Arbor and co-author of the new study. There aren’t any large natural sources of ethane, but it does appear in small amounts in the natural gas supplied to homes and businesses. Kort and his colleagues could, therefore, use detected ethane levels to distinguish leaked methane from other sources.

The team’s analyses suggest the five biggest urban areas studied—which together include about 12% of the nation’s population—emit about 890,000 tons of methane each year, the researchers report this week in Geophysical Research Letters. The vast majority of that, at least 750,000 tons, comes from methane leaks from homes, businesses, and gas distribution infrastructure, rather than natural sources and other human-driven sources such as landfills. For comparison, the team notes, that’s well over triple the amount emitted by gas production in the Bakken shale formation in the U.S. Midwest. READ MORE