Countries must make “strong, rapid and sustained” methane pollution reductions to slow global warming and stave off the most dire impacts of climate change, the IPCC warned in its landmark report Monday. The focus on methane by the UN’s consensus-setting Intergovernmental Panel on Climate Change is new, as past reports have focused mainly on CO2, and highlights a major opportunity to slow rising temperatures.

Methane is a much more potent heat-trapping gas than CO2, and it also breaks down in the atmosphere much quicker, so methane pollution cuts could have significant and more short-term effects on temperatures. Atmospheric methane levels are higher than at any point in the last 800,000 years, the report says, and the growth in methane pollution since 2007 is “largely driven by emissions from the fossil fuels and agriculture” sectors.

Following the release of the IPCC report, Rick Duke, a White House liaison for U.S. climate envoy John Kerry, told reporters “imminently, we will see a comprehensive approach on methane from this administration that will span what is required in terms of fossil methane reductions.”

“If there’s one simple takeaway [from this report], it’s urgency,” Ilissa Ocko, a climate scientist at EDF, told reporters Monday. “Drastic cuts in CO2 … will be critical to limiting the extent of future warming. But cutting methane emissions is the single fastest, most effective way there is to slow the rate of warming right now.” (Earther, Reuters, E&E $, Clean Technica, S&P Global, Politico Pro $, KPVI, Bloomberg Law, The Verge, Vox; White House action: E&E $; Commentary: New York Times, Rep. Kathy Castor op-ed $, The Hill, Durwood Zaelke and Gabrielle Dreyfus op-ed)