Swift action to cut methane emissions could slow the Earth’s warming by 30 percent, study finds

“People talk about net zero in 2050 but what the temperature will be in 2050 will be determined by what we do now,” says one author

By Brady Dennis and Steven Mufson April 27, 2021 washingtonpost.com

Moving quickly to cut emissions of methane, a potent greenhouse gas produced by everything from livestock farming to fossil fuel extraction, could slow the rate of the Earth’s warming as much as 30 percent, new research has found.

The study, published in the journal Environmental Research Letters, calculated that a full-scale push using existing technologies could reduce methane emissions in half by 2030. Such reductions could have a crucial impact in the global effort to limit warming below 2 degrees Celsius (3.6 Fahrenheit) compared to preindustrial levels — a central aim of the Paris climate accord.

In human terms, that could translate into fending off the most severe sea level rise, preventing more profound damage to animal habitats and ecosystems, and delaying other extreme climate impacts.

“If we really scale up methane reductions, we could have tangible benefits during our lifetime,” said Ilissa Ocko, senior climate scientist at the Environmental Defense Fund and a lead author of the study. “If you were to take these actions and cut as much methane as you could, you would see a clear benefit in the amount of warming we would avoid.”

Ocko and her co-authors note that pledges to tackle climate change often focus on cutting emissions of carbon dioxide — the most prevalent greenhouse gas — and doing so on a pace to reach net-zero emissions by 2050.

Carbon dioxide is far more abundant in the Earth’s atmosphere and can linger for hundreds of years, while methane typically breaks down after about a decade. But in the short term, methane is far more effective at trapping heat — roughly 80 times more potent than carbon dioxide.

That means cutting back on methane pollution in the near term could provide a relatively quick and compelling way to curb the Earth’s warming.

“People talk about net zero in 2050, but what the temperature will be in 2050 will be determined by what we do now,” Ocko said.

So far, the trajectory is not encouraging. Concentrations of methane in the atmosphere have been rising, and fast. Earlier this month, the National Oceanic and Atmospheric Administration reported that levels of methane showed a “significant jump” in 2020, marking “the largest annual increase recorded since systematic measurements began in 1983.”

David Victor, a professor of international law at the University of California at San Diego, said that “the politics of doing something about these problems are easier to manage; it is easier to build a coalition around demonstrable success.” But he warned that methane is “really, really potent” and “right now global warming is accelerating.”

Jason Bordoff, founder and director of Columbia University’s global energy institute, said that “we need companies to take this seriously both to be responsive to regulation and to maintain their social license.” Bordoff, who served in three posts in the Obama administration, said that consumers would start looking not only at the cost of a barrel of oil, but at the greenhouse intensity of an energy product. Oil and gas companies would “have to show you’re best in class on the methane issue.”

“It is a short-lived gas, but it has a powerful warming impact,” he said, adding that the technology for capturing methane is no secret. “We know how to do it,” he said.

The findings come at a moment when uncertainty remains about how — and how aggressively — world leaders will work to rein in methane emissions as they scramble to meet their pledges under the Paris agreement and try to avoid the worst consequences of climate change.

In vowing last week to cut U.S. emissions by at least 50 percent by the end of the decade, the Biden administration singled out methane as one key focus.

“The United States will update standards and invest in plugging leaks from wells and mines and across the natural gas distribution infrastructure,” the government said in a submission to the United Nations. “In addition, it will offer programs and incentives to improve agricultural productivity through practices and technologies that also reduce agricultural methane and [nitrous oxide] emissions, such as improved manure management and improved cropland nutrient management.”

In remarks opening a two-day White House climate summit last week, Biden said of his climate plans, “I see workers capping hundreds of thousands of abandoned oil and gas wells that need to be cleaned up, and abandoned coal mines that need to be reclaimed, putting a stop to the methane leaks and protecting the health of our communities.”

The Senate this week is also expected to hold a vote to use the Congressional Review Act, which allows Congress to overturn rules completed in the waning days of an outgoing administration, to scrap Trump-era efforts to weaken the Environmental Protection Agency’s ability to restrict methane emissions from the oil and gas sector.

Ocko said an all-out push to cut methane emissions would take different forms. It would include clamping down on oil- and gas-related leaks, cleaning up abandoned coal mines, expanding the use of feed supplements for cattle that could reduce methane from their belches and more broadly deploying technologies to capture emissions from landfills.

Such an approach, the authors found, has the potential to prevent nearly a half-degree Fahrenheit of warming by mid-century — an amount that sounds small but that could help avoid serious climate fallout.

At the same time, a slower approach could mean an increased rate of warming and more severe climate change by 2050, the authors found.

“While it is essential to minimize warming over the coming decades in addition to the long-term, we are currently on a path that supports either slow or delayed action on methane despite numerous readily available and affordable mitigation measures,” they wrote. “It is therefore possible that we are situated to miss an unmatched opportunity to slow down the rate of warming.”