In its latest gift to oil and gas companies, the Trump administration is expected to announce plans today to weaken rules that guard against methane leaks.

Methane is a smog-forming pollutant and a powerful greenhouse gas that’s up to 80 times as potent as carbon dioxide on a 20-year horizon. It’s the primary component of what the fossil fuel industry calls “natural gas” that routinely leaks from oil and gas wells and pipelines.

The Environmental Protection Agency (EPA) is reversing course on its previous efforts to plug those leaks. As part of President Donald Trump’s deregulatory agenda, the EPA plans to undo Biden-era rules that were expected to cut methane emissions by 80 percent over 14 years.

The EPA teased the rule change earlier this month, saying in a press release that it was “days away” from making the proposal. EPA Administrator Lee Zeldin says the rollbacks will save oil and gas companies $45 billion, while the previous rules would have incurred $18 billion in regulatory costs.

“This proposal takes on many of the problems American [oil and gas] producers and operators have raised with us,” Zeldin said in the October 7th press release. “The Trump EPA is committed to fixing this so the U.S. can reach its full energy potential.”

The agency is expected to step back standards for so-called “marginal wells” — old wells that produce little fuel but create an outsize amount of methane pollution from leaks. These wells are responsible for half of the industry’s methane emissions despite only producing 6 percent of US oil and gas, ProPublica reports. The EPA is also expected to end the Super Emitter Program that notified oil and gas infrastructure operators of large releases of methane reaching 100 kilograms per hour or more.

Methane has caused about 30 percent of global warming so far. But unlike carbon dioxide, which can linger in the atmosphere for hundreds or thousands of years, methane dissipates in a little over a decade. That makes eliminating methane emissions, particularly from unintentional leaks, one of the fastest and most straightforward ways to stop global temperatures from rising.

The EPA’s rollbacks quickly triggered furor from health and environmental advocates. “Any proposed rollback to the federal methane rule is a slap in the face to families who are exposed to oil and gas pollution where they live, work, and play,” Celerah Hewes, a senior manager for state field campaigns at Moms Clean Air Force, said in an email ahead of the expected announcement. “For over a decade, [our group] has been fighting for methane protections for our families—and we were making progress. Today’s announcement from EPA is a massive blow to the efforts to safeguard our children’s health and our climate.”

The Biden-era methane rules were estimated to bring in up to $98 billion in benefits by reducing climate risks and health costs from air pollution, even after factoring in the costs of compliance. Plugging leaks was supposed to lead to up to $13 billion worth of recovered natural gas.