Atmospheric methane levels increased at the fastest rate in five years between 2018 and 2019, according to preliminary data released last week by the U.S. National Oceanic and Atmospheric Administration (NOAA), and scientists aren’t entirely sure why.
“It is not entirely clear what factors are driving the surge. However, there is a firm consensus among scientists that the best response is deep and rapid reductions in methane emitted from the production and distribution of natural gas,” Climate Nexus reports. “If not mitigated, this new trend could, for example, wipe out the gains anticipated from the Paris climate agreement.”
Climate Nexus has a detailed explainer on methane sources and the best strategies for rapidly reducing emissions.
The increase of 11.54 parts per billion is the largest in a single year since 2014, when concentrations jumped by 12.72 ppb. Methane is 25 times more effective a greenhouse gas than carbon dioxide over a 100-year span, and more than 80 times more potent over the 20-year period that will be most crucial for efforts to bring climate change under control.
“If you do something about methane, you see benefits in the first decade of action,” Duke University Earth scientist Drew Shindell told The Hill. “What we had been really hoping, of course, was that emissions of all of the powerful greenhouse gases would be well on their way down by now, and instead to see record highs in their growth rate is very alarming.”
“Last year’s jump in methane is one of the biggest we’ve seen over the past 20 years,” added Stanford University Earth System Scientist Rob Jackson, chair of the Global Carbon Project. “It’s too early to say why, but increases from both agriculture and natural gas use are likely. Natural gas consumption surged more than 2% last year.”
NOAA’s data showed methane concentrations at 1,847.7 ppb last December, though the agency said that number is “likely to change significantly” before a final report is issued in the fall.