A new NASA study is 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.
NASA found that most of the huge rise in global methane emissions in the past decade is in fact from the fossil fuel industry–and that this rise is “substantially larger” than previously thought. And that means natural gas is, as many earlier studies have found, not a climate solution.
Natural gas is mostly methane, a potent greenhouse gas. And methane emissions are responsible for about a quarter of the human-caused global warming we’re suffering today.
So scientists have been scrambling to figure out why methane emissions have been soaring in recent years after leveling off around the year 2000. The total methane in the air has been rising by 25 teragrams (27.5 million U.S. tons) a year, which NASA helpfully explains is the weight of some 5 million elephants.
Many studies have estimated that leaks from oil and gas production, particularly fracking, are a major driver of rising methane emissions. “A review of more than 200 earlier studies confirms that U.S. emissions of methane are considerably higher than official estimates,” as one 2014 Stanford University analysis explained. “Leaks from the nation’s natural gas system are an important part of the problem.”
But, NASA notes, other research groups have estimated that the rise in methane emissions was due to a rise in “microbial production in wet tropical environments like marshes and rice paddies.” The problem was that this estimate was almost “large enough to explain the whole increase by itself” — and so was the estimate of increased methane emissions from oil and gas production.
The two explanations both seemed right, yet could not both actually be right. Or could they?
After a very deep dive into multiple ground and satellite datasets, NASA determined that a third source of methane emissions — global fires — had been declining much more rapidly than previously realized (see animation below).
With wildfire emissions way down, it was now possible for both fossil fuel emissions and wetland emissions to be up. Indeed, the researchers found that some 17 teragrams of the 25 teragram annual increase is from fossil fuel production, 12 is from wetlands or rice farming, while fires are decreasing emissions by 4 teragrams (17 + 12 – 4 = 25).
Significantly, the authors point out that the huge rise in fossil fuel methane emissions “found here is substantially larger than in previous literature.” In short, the recent jump in methane emissions from oil and gas production appears to be a whole lot bigger than we previously thought.
And that is a bombshell finding.
After all, methane (CH4) traps 86 times as much heat as CO2 over a 20-year period. That’s why countless studies find 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.
Back in November, we reported on yet another a shocking study that found the methane emissions escaping from just New Mexico’s gas and oil industry are “equivalent to the climate impact of approximately 12 coal-fired power plants.”
Equally important, 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.
But 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.