Methane emissions decreased in fossil fuel exploitation and sustainably increased in microbial source sectors during 1990–2020

Abstract Setting and tracking mitigation goals for methane (CH 4 ) emissions to limit warming to 1.5°C can be supported by analyzing atmospheric CH 4 and its isotopic composition (δ 13 C, δD). This study, based on reconstructions of the temporal trends, latitudinal, and vertical gradient of CH4 and δ 13 C from 1985 to 2020 using an atmospheric chemistry transport model, suggests that (1) a reduction in emissions from oil and gas exploitation (ONG) since the 1990s stabilized the atmospheric CH4 growth rate in the late 1990s and early 2000s, and (2) emissions from farmed animals, waste management, and coal mining contributed to the increase in atmospheric CH4 since 2006. Our findings support neither the increasing ONG emissions reported by the EDGARv6 inventory during 1990-2020 nor the large unconventional emissions increase reported by the GAINSv4 inventory since 2006. Total fossil fuel emissions remained stable from 2000 to 2020, as the decrease in ONG emissions in some regions offset the increase in coal mining emissions in China.