Research by the U.S. National Aeronautics and Space Administration (NASA) has unmasked the production, collection, movement, and distribution of natural gas as the biggest contributor to a big, scary bump in methane emissions over the past decade.
“Methane (CH4) traps 86 times as much heat as CO2 over a 20-year period,” Think Progress notes. As a result, multiple studies have found that “even a very small leakage rate of methane from the natural gas supply chain (production to delivery to combustion) can have a large climate impact—enough to gut the entire benefit of switching from coal-fired power to gas for a long, long time.”
NASA’s research was aimed at resolving a dilemma for climate investigators. Rival scientific theories each suggested “viable” explanations for the 25 megatonne-per-year increase in annual methane emissions observed since about 2008. One suggested the methane came from the production and use of natural gas; another traced the increase to microbial action in warming wetlands and rice paddies.
Both could not be right, scientists believed. “In fact, each new estimate was large enough to explain the whole increase by itself,” the U.S. agency wrote in a release.
Reviewing data from NASA’s Moderate Resolution Imaging Spectrometer satellite instruments, agency investigators made a surprising tangential discovery: the area of Earth’s surface burned by fires each year “decreased about 12% between the early 2000s and the more recent period of 2007 to 2014.”
Once the associated drop in methane emissions was taken into account, NASA calculated that both rival theories for the methane emissions spike had merit. Wetland microbes are responsible for 12 of the annual 25-megatonne increase in emissions. The contribution from fires fell by four megatonnes over the period.
And more than two-thirds of the increase in the decade’s emissions—17 megatonnes per year—was due to supply chain emissions of methane from the natural gas industry, substantially more than previously estimated.
The findings, Think Progress notes, provide “one final nail in the coffin of the myth that natural gas is a climate solution, or a ‘bridge’ from the dirtiest fossil fuels to low-carbon fuels like solar and wind.”
“Equally important,” writes veteran climate hawk Joe Romm, “many studies find that natural gas plants don’t replace only high-carbon coal plants. They often replace very low-carbon power sources like solar, wind, nuclear, and even energy efficiency. And that means even a very low leakage rate wipes out the climate benefit of fracking.”
Moreover, “the new study suggests leakage rates aren’t very low, and that would mean fracking is truly part of the climate problem, and likely to become a bigger problem over time as natural gas competes more and more with renewable energy sources.”
Under pressure from fossil industries, Canada introduced a three-year delay for regulations to control methane releases from natural gas operations and transmission.