The Environmental Defense Fund has a clear message for the Biden Administration on the eve of an international climate summit marking the U.S.’s further re-entry into the Paris climate agreement: “We need to cut methane now.“  

So says the U.S.-based environmental advocacy organization in a 15-second ad released after a missive the nonprofit and other, leading environmental advocacy groups sent to the president earlier this month.

The letter calls for a 40 percent or more cut in methane emissions by 2030, including a 65 percent reduction from the oil and gas sector, as part of an ambitious U.S. recommitment to the Paris climate agreement. The commitment, or nationally determined contribution, is anticipated to be released by the administration any day as the U.S. prepares to host the online Leaders Summit on Climate on Thursday and Friday. 

Methane is “the biggest and really the only lever we have to slow temperature rise during the next two decades, the critical decades for preventing irreversible tipping points and shaving the peak warming to protect vulnerable communities,” said Sarah Smith, super pollutants program director with the Clean Air Task Force, an environmental organization that co-authored the letter.  

Methane, the largest component of natural gas, is sometimes called a “short-lived climate pollutant” because it remains in the atmosphere for far less time than carbon dioxide, which can remain in the atmosphere for hundreds of years.  But methane is also a climate “super-pollutant,” 86 times more potent than carbon dioxide at warming the atmosphere over a 20-year period.  

Sources of methane include wetlands, rice paddies, livestock, biomass burning, organic waste decomposition and fossil fuel drilling and transport. 

Methane’s potency and short atmospheric life make it a key greenhouse gas for policy makers to focus on as a way to combat global warming in the near term because the impact of those cuts will be felt almost immediately. 

“If we cut methane emissions substantially during the 2020s, the abundance or concentration in the atmosphere will also drop rapidly during the 2020s,”  said Drew Shindell, an earth science professor at Duke University. “If we cut CO2 emissions, it takes a long time for actual concentrations to drop, and then longer for the climate to adjust.”

When the international community convened in 2015 to hash out the Paris climate agreement, few countries included specific targets for methane as part of their efforts to limit global warming.

However, a 2018 report by the UN’s Intergovernmental Panel on Climate Change concluded that global warming could not be limited to 1.5 degrees Celsius without rapid reductions in emissions of methane and other short-lived climate pollutants.  

The report said that reductions in methane similar to, or perhaps slightly greater than, those now being called for by the environmental advocacy groups would be needed to limit warming to 1.5 degrees Celsius above pre-industrial levels by the end of this century, the goal of the Paris accord.

Now, as countries are asked to strengthen their initial Paris commitments and the U.S. seeks to solidify its re-entry after the Trump administration’s withdrawal,  there is a growing understanding of the need to focus on methane, the second largest driver of climate change after carbon dioxide.

“While the Paris Agreement favors absolute economy‐wide emission reduction targets, it would be important for countries to also start developing separate targets for all climate forcers, including methane, individually,” a paper published last week in the journal Review of European, Comparative, and International Environmental Law concluded.  

In a letter to President Biden on Monday, U.S. Sen. Ed Markey (D-Mass.) expressed an “urgent need to address methane pollution” and said the U.S. has an “opportunity to cement its position as a global leader through robust methane reduction targets and strategies.”

The Biden administration has shown signs that it will target methane, although it remains unclear if it will set specific emissions reduction goals in its Paris pledge.  In one of his first executive orders signed on Inauguration Day, Biden called for an immediate review of the Trump administration’s rollback of federal standards for methane emissions from the oil and gas sector.

Following a virtual meeting with Prime Minister Justin Trudeau of Canada earlier this year, the Biden administration pledged to develop long-term emissions reduction strategies “including attention to short-lived climate pollutants that must be addressed to keep 1.5 ºC within reach.”

A U.S.-China joint statement “addressing the climate crisis” released by the State Department on Saturday pledged to address emissions of methane and other non-CO2 greenhouse gases, including a phasedown of hydrofluorocarbons, a short-lived climate super-pollutant and chemical refrigerant used in air conditioning and refrigeration.    

Shindell, who was a coordinating lead author of the 2018 IPCC 1.5 ºC report, said the 40 percent emissions reduction target for methane by 2030 that environmental groups are calling for is “aggressive and quick.”  However,  Shindell added that even greater cuts, adopted by all countries, may be needed to limit warming to 1.5 degrees. 

“It would probably get us closer to 2 degrees than 1.5 degrees, but it is way better than our current trajectory,” Shindell said.