When discussing planet-warming emissions, we often talk about carbon dioxide. In the U.S., it accounts for about 80% of our greenhouse gas output. But a new study shows we’d do well to focus more on another greenhouse gas: methane.
Methane is an extremely potent greenhouse gas that is mostly produced by livestock and fossil fuel extraction. It only lasts for about a decade in the atmosphere — carbon dioxide, on the other hand, can stay up there for centuries — but in the short term, it’s got 80 times carbon dioxide’s heating potential.
That means efforts to curb methane pollution can come with huge rewards. The new research, published in the journal Environmental Research Letters on Tuesday, reveals that if world leaders put their all into reducing methane pollution, it could slow the planet’s rate of warming by up to 30% in the near term. It was also released just days after a United Nations report warned that the world needs to start drawing down methane emissions far more rapidly to avert critical levels of warming.
The authors found that the world has the technology to cut methane emissions in half within the next 10 years. That could allow us to avert around 0.25 degrees Celsius of warming by 2050 and put us on track to avoid twice that much by 2100.
To achieve those reductions, governments could focus on a few key sectors driving methane emissions, including energy, agriculture, and waste. An all-hands-on-deck approach would include stopping leaks in oil and gas infrastructure, as well as cleaning up abandoned coal mines so their pollution comes to a halt. For animal agriculture, it would require farmers working to lower methane emissions tied to the burps of cows and other ruminants. Among possible solutions are supplementing feed with seaweed, though it’s not a silver bullet alone. The world would also have to take on pollution from landfills, which produce some 12% of the world’s methane by capturing it at the source.
The most inexpensive solutions, the authors found, would come from the oil and gas industry limiting its pollution. Of course, that would be much easier to do if the industry stopped expanding its operations.
For this to work, the world needs to start implementing these changes now. Waiting until 2030 to take these steps to curb methane pollution, the study finds, “may result in an additional tenth of a degree of global-mean warming by midcentury” rather than a reduction. That would increase the rate of warming by 5% relative to acting quickly. The longer the world waits, the worse the situation will be. If the world lollygags until 2050, it would double the warming projected. The UN report released this week notes that if the world continues to expand the use of natural gas, the climate goals laid out in the Paris Climate Agreement will be out of reach, barring the development and deployment of yet-unproven carbon capture technologies.
Unfortunately, the world seems to be moving in the wrong direction. A study earlier this month found that methane in the atmosphere is rising more rapidly than ever. That’s despite 2020’s record drop in fuel demand and the widespread covid-19 lockdowns. There’s also growing evidence that scientists have been vastly undercounting global methane emissions for years.
The report comes four days after California Gov. Gavin Newsom pledged to quit issuing new fracking permits by 2024, and ban all oil extraction by 2045. That’s a pretty remarkable commitment — it’s the first time a U.S. state has ever committed to phasing out fossil fuel extraction for energy. But the authors show that for best results, California and other states should really begin even sooner.