Agriculture and fossil fuels are driving record-high methane emissions
Methane levels in the atmosphere are at an all-time high. But curbing emissions of that potent greenhouse gas requires knowing where methane is being released, and why. Now, a global inventory of methane sources reveals the major culprits behind rising methane pollution in the 21st century. Agriculture, landfill waste and fossil fuel use were the primary reasons that Earth’s atmosphere absorbed about 40 million metric tons more methane from human activities in 2017 than it did per year in the early 2000s. Expanding agriculture dominated methane release in places like Africa, South Asia and Oceania, while increasing fossil fuel use heightened emissions in China and the United States, researchers report online July 14 in Environmental Research Letters. Methane “is one of the most important greenhouse gases — arguably the second most important after CO2,” says Alexander Turner, an atmospheric scientist who will join the University of Washington in Seattle in 2021. Although there...