It also challenges the notion that the federal government has the authority to regulate methane without first making a detailed determination that it qualifies as a pollutant under the Clean Air Act.

If successful, that change could hamper the ability of future administrations to enact tougher restrictions on methane. Already, the Trump administration has taken several steps to limit the government’s ability to regulate other greenhouse gases in the future, including in a recently finalized rule curbing carbon dioxide emissions from power plants.

“EPA’s proposal delivers on President Trump’s executive order and removes unnecessary and duplicative regulatory burdens from the oil and gas industry,” EPA Administrator Andrew Wheeler said in a statement. “The Trump administration recognizes that methane is valuable, and the industry has an incentive to minimize leaks and maximize its use.”

Methane is a significant contributor to the world’s greenhouse gas emissions, though it is shorter-lived than carbon dioxide and is not emitted in amounts as large. It often is leaked as companies drill for gas and transport it across the country, and methane emissions are more than 80 times as potent as carbon dioxide emissions over the short term.

Scientists have projected that the world needs to cut its overall greenhouse gas emissions nearly in half by mid-century to avert catastrophic effects from global warming.

According to the EPA, methane accounted for more than 10 percent of all U.S. greenhouse gas emissions from human activities as recently as 2017. Nearly a third of those emissions were generated by the natural gas and petroleum industry.

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“What they’re tackling is whether methane can lawfully be a regulatory pollutant,” Erik Milito, vice president of upstream and industry operations for the American Petroleum Institute, said in an interview. “We have a strong consensus that federal agencies need to follow the letter of the law. They did not do that, and they are going back and correcting that.”

Anne Idsal, assistant administrator​ of the EPA’s Office of Air and Radiation, said the administration is confident that methane emissions from oil and gas companies will continue to decline over time, even without the current regulations.

“Methane is a valuable resource,” Idsal told reporters in a call Thursday. “There’s every incentive for industry to minimize any type of fugitive methane emissions, capture it, use it and sell it down the road.”

The agency estimates that the proposed changes, which will be subject to public comment for 60 days after they are published, would save the oil and natural gas industry $17 million to $19 million a year.

But several of the world’s biggest fossil fuel companies, including Exxon, Shell and BP, have opposed the rollback and urged the Trump administration to keep the current standards in place. Collectively, these firms account for 11 percent of America’s natural gas output.

In a statement Thursday, Shell U.S. President Gretchen Watkins reiterated the company’s support for national limits on methane, noting that Shell has pledged to reduce its methane leaks from its global operations to less than 0.2 percent by 2025.

“We believe sound environmental policies are foundational to the vital role natural gas can play in the energy transition and have made clear our support of 2016 law to regulate methane from new and modified onshore sources,” she said. “Despite the administration’s proposal to no longer regulate methane, Shell’s U.S. assets will continue to contribute to that global target.”

The Wall Street Journal first reported news of the rollback.

Idsal said the agency will continue regulating volatile organic compounds, which are also released during oil and gas operations, rather than methane directly. Such limits could cut down on the amount of methane released in the process. Milito noted that by 2023, 90 percent of oil and gas facilities will have to install technology curbing volatile organic compounds.

In September, the Interior Department eased requirements that oil and gas firms operating on federal and tribal land capture the release of methane.

Environmentalists threatened to fight the Trump administration’s move in court.

Kassie Siegel, director of the Climate Law Institute at the Center for Biological Diversity, an advocacy group, called the proposal reckless, saying it shows “complete contempt for our climate.” She said that even the Obama administration’s efforts to limit methane emissions were modest, given the significant amount that escapes into the atmosphere each year.

“The Obama rule was like a Band-Aid on a gaping wound,” Siegel said. “The Trump administration is so fanatical that they couldn’t even live with the Band-Aid. They had to rip off the Band-Aid.”

The Obama administration’s push to impose the first limits on methane emissions from the oil and gas industry in 2016 came shortly after the EPA found that emissions were on an upswing at a time when booming U.S. shale oil and gas drilling had dramatically driven down the prices of domestic natural gas and global oil alike.

Ben Ratner, a senior director at the advocacy group Environmental Defense Fund, said in an interview that rolling back the regulations could reward bad actors in the industry. Given that many major players had embraced limits on methane, Ratner said, it made little sense for Trump officials to ease such restrictions.

“It’s more of an ideological reaction to regulation of any climate pollutant by the federal government,” he said.

Steven Mufson contributed to this report.