The United States and the European Union pledged on Friday to reduce methane emissions by at least 30 percent below 2020 levels by 2030, ushering in the start of what they hope will be a “global methane pledge” to quickly address warming, as the next round of international climate negotiations nears. 

“This will not only rapidly reduce the rate of global warming, but it will also produce a very valuable side benefit, like improving public health and agricultural output,” President Joe Biden said Friday morning at the Major Economies Forum on Energy and Climate, which he convened ahead of the Conference of the Parties (COP26), the United Nations-led climate negotiations scheduled for November in Glasgow.

The announcement follows a landmark report by the United Nations in May that underscored the need to rapidly rein in emissions of methane, the second leading driver of climate change.

The report noted that reducing methane emissions is “one of the most cost-effective strategies to rapidly reduce the rate of warming and contribute significantly to global efforts to limit temperature rise to 1.5 degrees Celsius.”  

The U.N. called for a 45 percent reduction in methane emissions below a 2030 business-as-usual baseline, an aggressive cut that would avoid nearly 0.3 degrees Celsius of global warming by the 2040s, while improving human health and agricultural yields through reduced ground level ozone.

Drew Shindell, the lead author of the UN report and an earth science professor at Duke University, said Friday’s announcement is “really ambitious.”

Using the same yardstick as the U.N. report, the U.S.-E.U. pledge represents a 35 percent cut in methane emissions below the 2030 business-as-usual baseline.

“It’s most of the way there,” Shindell said. “Compared with where we’ve been going—which is up, up, up really fast—going down at this rate is a great step forward if it actually comes to pass.”

In 2016 the U.S., Canada and Mexico pledged to collectively reduce methane emissions from the oil and gas sector, one of the leading sources of human caused methane emissions alongside emissions from agriculture and waste, by 45 percent by 2025. U.S. methane regulations were subsequently rolled back by the Trump administration and the international effort was scuttled. 

The U.S. Environmental Protection Agency is expected to propose new methane regulations, with emissions reductions that are more stringent than those previously introduced by the Obama administration, before the end of the month.  

Congressional Democrats are also considering imposing a fee on methane emissions from oil and gas operations, where methane leaks and venting can often be eliminated at little to no cost, as part of a broad $3.5 trillion budget bill they aim to pass this fall.

Targeting emissions of methane, a potent and short-lived climate pollutant, is gaining increasing attention as an effective way to quickly address climate change. Methane is 81 times more warming as a greenhouse gas than carbon dioxide over the near term and only remains in the atmosphere for 12 years. The gas’s combined potency and short atmospheric life means that cuts in emissions have an almost immediate benefit.

Carbon dioxide, which is emitted in much higher volumes, remains the primary driver of climate change. However, it takes several decades before the climate benefits of CO2 emission reductions are realized. This is due to the gas’s long atmospheric life and its close ties to sulfate aerosols that delay the climate benefits of carbon dioxide reductions.  

International efforts such as the Paris cimate agreement have historically focused on carbon dioxide reductions. But a report by the Intergovernmental Panel on Climate Change released in August noted “strong, rapid and sustained reductions” in methane emissions would limit warming. It included a chapter on methane and other short-lived climate pollutants for the first time in the reports three-decade history.

Environmental advocates praised Friday’s announcement.

“This is the first time heads of State have pledged specific action to cut super climate pollutants, which is the only strategy that can reduce warming over the critical next decade to 2030, and slow the self-reinforcing feedbacks that are pushing the planet towards a series of potentially catastrophic tipping points,” said Durwood Zaelke, president of the Institute for Governance and Sustainable Development in a written statement.

“World leaders behind this pledge are opening up a crucial new opportunity to protect our climate and millions of people whose well being depends on it,” Fred Krupp, president of the Environmental Defense Fund, said.

The joint U.S.-E.U. pledge comes just 44 days before international climate talks are scheduled to resume in Glasgow, where countries will be expected to account for what they have done since the 2015 Paris climate agreement and set even more ambitious goals.

Getting other large methane emitting countries like India, or oil and gas producing countries in the Middle East and former Soviet Union, or even China, the largest methane emitter, to sign on to the pledge will be key for having a significant global impact, Shindell said.  

“Without some of the big, developing country emitters, I think that this is going to be useful but not necessarily a game changer,” he said.  If “you’ve got a few countries like that on board as well as the U.S. and Europe, then I think it really starts to take on momentum.”

In an update released late Friday the White House said Argentina, Indonesia, Mexico and the United Kingdom have also declared their intention to join the Global Methane Pledge and that Ghana and Iraq have also signaled an intention to join. 

“These early supporters of the Pledge include six of the top 15 methane emitters globally and together account for over one-fifth of global methane emissions and nearly half of the global economy,” the White House said.