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Surprisingly large amounts of methane are leaking from wells and pipelines in New Mexico, suggesting that the oil and gas industry may be contributing more to climate change than previously known, according to a new analysis of weather data.

The study, by researchers at Stanford University, estimates that oil and gas operations in New Mexico’s Permian Basin released 194 metric tons/hour of methane, a planet-warming gas much stronger than carbon dioxide. That’s six times more than the Environmental Protection Agency’s most recent estimate.

This number came as a surprise to the study’s lead authors, Yuanlei Chen and Evan Sherwin. Published Wednesday in the journal Environmental Science and Technology.

A postdoctoral research fellow in energy resources engineering at Stanford, Dr. “We’ve spent the past two years thinking we might be wrong and talking to other experts in the methane community,” Sherwin said. “And at the end of that process, we realized that this was our best estimate of methane emissions in this region and this time, and we had to publish it.”

He and Ms. Chen received a Ph.D. The energy resources engineering student said they believe their results demonstrate the need for multiple field studies to accurately measure the environmental impact of oil and gas production.

The previous largest assessment of methane emissions from oil and gas in the United States, Released in 2018reviewed studies covering nearly 1,000 well sites, a small fraction of the more than one million active wells in the country. The new study, by contrast, used weather data to survey nearly 27,000 sites from above: more than 90 percent of all wells in the New Mexico portion of the Permian Basin that also extends into Texas.

The researchers also took measurements at each site multiple times to account for the fact that operations, and therefore emissions, change over time. Methane can be released from wells both in a process known as aeration and through unintentional leaks from aging or faulty equipment.

“Extensive point source studies find higher-end emission events driving overall emissions,” said Ms. Chen, finding that a small number of wells and pipelines account for “the vast majority” of methane leaks.

Robert Howarth, a professor of ecology and environmental biology at Cornell University who was not involved in the study, described it as “very carefully done.” Dr. Howarth has long argued that the EPA has greatly underestimated the methane problem. The new study calculated methane emissions at 9.4 percent of gross gas production, dwarfing the Environmental Protection Agency’s 1.4 percent estimate.

Because natural gas accounts for about a third of American energy consumption and is less costly than coal in terms of carbon dioxide emissions, many policymakers have promoted it as a “bridge” that could do less damage to the climate while working on society. long-term transition to renewable energy. But compared to coal, natural gas causes much higher emissions of methane, a greenhouse gas more powerful than carbon dioxide, but doesn’t last long in the atmosphere.

About a decade ago, Ramón Alvarez, an atmospheric chemist at the Environmental Defense Fund, estimated the breakeven point—the point above which natural gas would do more damage to the climate than coal—was a 3.1 percent methane seepage rate. Based on more recent data from the Intergovernmental Panel on Climate Change, Dr. Howarth estimates the threshold is closer to 2.8 or 2.9 percent.

The leak rate of 9.4 percent in the new study is extremely worrying, although experts stress that the rate in the Permian Basin may not be comparable to rates elsewhere.

“If this result is similar in other basins — which we don’t know if it does — it would eliminate the greenhouse gas emissions savings of switching from coal to gas,” said Amy Townsend-Small, associate professor of environmental science. at the University of Cincinnati.

If there was any good news in the study, it was that few oil and gas fields contributed disproportionately to emissions – suggesting that it’s possible for the industry to run cleaner if the worst offenders change their practices.

A rule finalized last year by the New Mexico Petroleum Conservation Commission prohibits regular venting and gas burning, referring to the practice of releasing or burning natural gas rather than controlling it. Another regulation considered by the state’s Environmental Improvement Board will require more frequent inspections and repairs of oil and gas infrastructure. (This measure is designed to reduce emissions of volatile organic compounds, a group of chemicals that can have adverse health effects, but oil and gas fields that leak VOCs also tend to leak methane.)

The Stanford researchers stressed that the same methodology they used to measure methane emissions could be used to identify problem areas and target regulations accordingly.

“Air technology has found high methane emissions, but it can also help fix them in a cost-effective way,” Ms. Chen said.