Atmospheric methane experienced an unprecedented increase in the early 2020s, with its growth rate peaking at 16.2 ppb per year in 2020 before declining to 8.6 ppb per year in 2023.[2][1] The main cause was the decrease of hydroxide radicals (OH), which form the main atmospheric sink of methane, which explains approximately 80-85% of the interannual changes in its concentration.[1][2][3] The decrease in OH radicals in 2020-2021 was due to a decrease in nitrogen oxide (NOₓ) emissions during the COVID-19-related lockdowns.[1][3] The remainder of the increase was caused by increased emissions from microbial sources, particularly from wetlands, rivers, lakes, and agricultural land, enhanced by wet conditions during the extended La Niña of 2020-2023 in tropical Africa, Southeast Asia, and Arctic regions.[1][2][3] Emissions from fossil fuels and forest fires played only a minor role, as confirmed by isotopic evidence.[1][3] The study integrated satellite data, ground-based measurements and atmospheric inversions to update the global methane budget to 2023.[2][3] Future trends in methane will depend on both emission controls and climate-driven changes in natural and economic resources.[1]