Recent Slowdown of Anthropogenic Methane Emissions in China Driven by Stabilized Coal Production

Anthropogenic methane emissions in China increased by 40% in the 2000s, contributing 16% of global anthropogenic emissions. The trend after 2010, however, remains under debate. An improved understanding of major sources and their trends, informed by timely and accurate data, is required to monitor efforts toward climate mitigation goals. Here we update a detailed bottom-up inventory to evaluate recent changes in China's anthropogenic CH4 emissions. Combining our and other bottom-up inventories and seven global CH4 inversions, we show a slowdown of emission increase after 2010 [0.2 (-0.3 to 0.7) Tg of CH4 year(-2)] compared to the 2000s [1.2 (0.6-1.8) Tg of CH4 year(-2)], with a downward trend detected after 2014. Although there are considerable uncertainties, this slowdown is statistically significant (p < 0.001). The slowdown is mainly attributed to stabilized coal production in the 2010s, along with a regional shift of production toward mining areas with low emission factors and increased utilization of coal mine methane. Our results suggest that China's recent energy policies have helped control coal mine emissions, and further work is needed to narrow down the uncertainty in both bottom-up inventories and top-down inversions.