A preliminary estimate from the US National Oceanic and Atmospheric Administration (NOAA) finds that levels of atmospheric methane, a potent heat-trapping gas, have hit an all-time high.
Methane is roughly 80 times more powerful than carbon dioxide, and, while it stays in the atmosphere for only around a decade as opposed to centuries like CO2, its continued rise poses a major challenge to international climate goals.
“Here we are. It’s 2020, and it’s not only not dropping. It’s not level. In fact, it’s one of the fastest growth rates we’ve seen in the last 20 years,” said Drew Shindell, a climate scientist at Duke University.
To gauge methane levels, scientists regularly gathered samples of air from dozens of sites around the world and analyzed them at NOAA’s Global Monitoring Laboratory in Boulder, Colorado. By comparing measurements, they were able to determine the global average. In 2019, the concentration of atmospheric methane reached nearly 1,875 parts per billion, the highest level since record-keeping began in 1983.
Even more troubling, 2019 saw the second-largest single-year leap in 2 decades. However, this figure may change because preliminary estimates have trended high, said Ed Dlugokencky, a research chemist at NOAA. The final numbers will likely be unveiled in November after a more-detailed analysis.
“We’re still waiting to see what the final number is going to be, and it’s going to be many months before we know that,” Dlugokencky said. “But the fact that methane is increasing means it’s further contributing to climate change.”
Methane emissions primarily come from natural sources such as wetlands and manmade sources such as farms and oil and gas wells. In wetlands, microbes excrete methane, an issue that humans can do little about. On farms, cows and sheep belch methane—a problem that people can address by raising fewer livestock.
“Eat less beef and less dairy. That’s the most straightforward thing,” Shindell said. “For the sake of our own health, we should be doing that anyway.”