The House Science Committee has notified the chief executives of 10 major oil companies that they must disclose more data about their emissions of methane, a powerful greenhouse gas, in one of America’s biggest oil and gas producing regions.

The lawmakers wrote late Thursday that the companies’ current approach to monitoring methane emissions in the Permian Basin is inadequate, and that they must to do more to curb a pollutant that more than 100 other countries have pledged to cut by 30 percent by the end of the decade. The commitment, launched by the United States and the European Union, marked one of the highlights of last month’s U.N. climate summit in Glasgow, Scotland.

“The United States cannot achieve its targeted reduction in methane emissions under the Global Methane Pledge without a swift and large-scale decline in oil and gas sector methane leaks,” Rep. Eddie Bernice Johnson (D-Texas), chair of the House Committee on Science, Space and Technology, wrote in a letter to the chief executives. “The existence of these leaks, as well as continued uncertainty regarding their size, duration, and frequency, threatens America’s ability to avoid the worst impacts of climate change.”

Johnson wrote to most of the biggest fossil fuel producers in the Permian Basin, which extends from west Texas to New Mexico. They included ExxonMobil, Occidental Petroleum, ConocoPhillips, Chevron and Pioneer Natural Resources, as well as lesser-known companies including Ameredev II LLC, Coterra, Devon Energy, Admiral Permian Resources, and Mewbourne Oil.

ExxonMobil spokesman Casey Norton said the company’s plans align with the global methane goal. It plans to cut its own methane emissions 40 to 50 percent by 2026 compared with a decade earlier, while “developing, testing and deploying new methane detection and mitigation technologies.”

Pioneer Natural Resources Vice President Tadd Owens said that the company shares Johnson’s "interest in better understanding and minimizing methane emissions from the Permian Basin” and was “proud of the progress” it has made in methane and flaring reduction. He said it would take some time to provide a detailed reply to Johnson’s letter.

Methane, the main component of natural gas, is the world’s second-largest contributor to climate change behind carbon dioxide. Although it dissipates more quickly, it is more than 80 times more powerful than CO2 for the first 20 years after it is first released into the atmosphere.

Clamping down on methane could help world leaders meet their target of containing planetary warming to no more than 1.5 degrees Celsius, or 2.7 degrees Fahrenheit, above levels at the beginning of the Industrial Revolution.

Eliminating methane leaks from existing oil and gas operations represents one of the easiest ways to cut U.S. greenhouse gas emissions, in part because companies often profit by capturing natural gas that would otherwise escape. This fall the International Energy Agency estimated that “more than 70 percent of current emissions from oil and gas operations are technically feasible to prevent" and around 45 percent could be plugged at no net cost.

IEA said it would be even more profitable to do so now, given the turmoil in European energy markets and record high natural gas prices. In some places, capturing methane would mean building new pipelines, processing centers and storage.

But estimating the cost of those investments requires accurate information.

Johnson said she was “concerned” that leak detection and repair, or LDAR, programs at the companies “may not be designed and equipped to comprehensively monitor and detect methane leaks, particularly the intermittent, ‘super-emitting’ leaks that are responsible for much of the sector’s leak emissions.”

The congressional request demands that the companies disclose information about their own intermittent, large emission leaks, and how they found them. It also asked operators how their methods for calculating emissions differed from those required by the Environmental Protection Agency’s greenhouse gas reporting program.

Recent advances in satellites, sensors, drones and computers capable of speedier data sifting have made it difficult for methane emitters to conceal their leaks. The House Science Committee said “innovative” LDAR techniques include aerial surveys, drone-based surveys and ground-based monitoring sensors.

The panel is looking into whether federal agencies monitoring greenhouse gases are collecting accurate information.

Separately, standards proposed by the EPA a month ago would establish standards for old wells, impose more frequent and stringent leak monitoring, and require the capture of natural gas that is found alongside oil and is often released into the atmosphere. The rules mark the first time the federal government has moved to comprehensively tackle the seepage of methane from U.S. oil and gas infrastructure.

ExxonMobil’s Norton said the company supports the EPA “directly regulating methane emissions for both new and existing sources of oil and gas production.”

Some oil industry veterans acknowledge federal regulators don’t have a good handle on the extent to which drilling sites release global warming pollutants.

“EPA methane data is meticulously curated but inaccurate,” said Robert Kleinberg, who spent 38 years at the oil services company Schlumberger and is now a fellow at Columbia University’s Center for Global Energy Policy. He said that nongovernmental groups that measured methane emissions found they were roughly twice as large as EPA estimates indicated.

Unlike carbon dioxide produced by burning coal or oil, methane emitted without combustion doesn’t help anyone, Kleinberg said in an email. "It is just lost or vented, and no one is careful about keeping track of it,” he said.

Some states have already moved beyond the federal government and have imposed stricter requirements on industry. In February, Colorado regulators unanimously adopted rules to plug methane leaks from pneumatic devices, which are powered and controlled by pressurized natural gas. The regulation, which got support from both industry and environmental groups, would require the use of cutting-edge, zero-emitting components at all new and most existing facilities statewide, according to the Environmental Defense Fund.

In New Mexico, state regulators have ordered oil and gas companies to capture at least 98 percent of all methane released starting in 2026.

“One thing that was recognized throughout the process was that we needed better data, more robust data,” said Adrienne Sandoval, director of the state’s Oil Conservation Division. Companies in New Mexico are supposed to disclose methane information about actual production for the fourth quarter of this year, and in mid-February will publish detailed reports, which will serve as baselines for the companies.

The rules apply to well heads, pipelines, compressors and storage tanks.

There have been relatively few protests from the oil and gas industry, Sandoval said, even though the state has roughly 60,000 active wells. While the state set a series of deadlines for appealing the rule, which went into effect in May, she said, “We have blown past all those timelines and there have been no appeals."

In Texas, which has been friendlier to the oil and gas industry, independent watchdog groups have uncovered a host of unreported methane emissions.

Sharon Wilson, senior field advocate and optical gas imaging thermographer for the advocacy group Earthworks, said that oil and gas operators usually report emissions based on their equipment’s ability to combust or capture methane. But that’s in the ideal world.

Wilson, who has used special imaging to track otherwise-invisible emissions, noted that companies get permits based on the manufacturer’s emissions estimate.

“All the calculations are done based on the very best case,” she said. “Man, I never find the best case when I go into the field. That’s not the reality on the ground. Nothing is measured. Nothing is metered to say this is how much we are really releasing.”