A new study finds that shale oil and gas is behind the global rise in methane pollution over the past decade, a major source of greenhouse gas emissions.
The study, published in Biogeosciences, was able to separate methane emissions from conventional versus unconventional drilling, as well as methane from other “biogenic” sources, such as agriculture or wetlands. “This recent increase in methane is massive,” Robert W. Howarth of Cornell University, the author of the study, 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.”
Methane emissions rose in the late 20th century, and then leveled off in the early 2000s. “Since 2008, however, methane concentrations have again been rising rapidly,” Howarth wrote.
Howarth said that “chemical fingerprints” in the atmosphere point to shale oil and gas, as the methane from unconventional drilling has less carbon-13 relative to carbon-12, which distinguishes it from methane coming from conventional sources, including from gas and coal. Because two-thirds of all new natural gas production over the last decade has come from shale, and because the chemical composition of methane in the atmosphere has changed, Howarth concluded that shale gas is a key driver in the increase of methane.
Prior research did not explicitly focus on the fossil fuel industry, and instead put blame on other sources of methane emissions, such as agriculture and wetlands.
“Previous studies erroneously concluded that biological sources are the cause of the rising methane,” Howarth said. He was able to separate out the source of the increase. The conclusion was clear: “The commercialization of shale gas and oil in the 21st century has dramatically increased global methane emissions.”
Methane is a dramatically more powerful greenhouse gas than carbon dioxide, although it is much more short-lived. That makes it a dangerous greenhouse gas pollutant – but also low-hanging fruit for climate action. “If we can stop pouring methane into the atmosphere, it will dissipate,” he said. “It goes away pretty quickly, compared to carbon dioxide. It’s the low-hanging fruit to slow global warming.”
Methane can leak at multiple points in the supply chain – from wells, from pipelines, compressor stations, and also when companies deliberately vent gas into the air, although a more common practice is to flare the gas, which releases more CO2 and cuts down on methane.
It should be noted, however, that flaring is a major source of pollution as well, and flaring in the Permian is “running rampant.” In the first quarter of 2019, flaring surged to an all-time high of 661 million cubic feet per day (MMcfd) in the Permian, according to Rystad Energy, a figure that is likely outdated at this point.
Methane emissions are coming under greater scrutiny as the climate crisis worsens. According to the Wall Street Journal, methane leaks from U.S. oil and gas operations has reached the equivalent greenhouse gas impact of 69 million cars. Precise estimates vary, depending on the study, but as the WSJ notes, a 2018 study found that methane emissions from oil and gas operations were 60 percent higher than what the U.S. EPA estimates.
This is a problem that will likely come back to bite the industry. As it stands, the Trump administration has been working to roll back regulations on methane. But it wants to go further than simple deregulation. The EPA is working on a rule to essentially end its own ability to regulate methane on existing oil and gas wells, presumably to head off future limits. The White House is reviewing the proposal, according to Bloomberg.
Notably, the EPA proposal goes further than the industry wants. Oil and gas companies do not want such an aggressive deregulatory campaign, recognizing that it risks blowback. “Industry gets it,” David Hayes, a former Interior Department official who leads the State Energy and Environmental Impact Center at New York University School of Law, told Bloomberg. “They recognize that this is a tremendous liability.”
Ben Ratner of Environmental Defense Fund put it more bluntly. “Stakeholder confidence in natural gas is hanging by the thread, and the EPA is pulling out the scissors with this methane rollback,” he told Bloomberg.