CHN-CH4: A Gridded (0.1°×0.1°) Anthropogenic Methane Emission Inventory of China from 1990 to 2020

Abstract. China is the largest emitter of global methane emissions, contributing about 10 % to anthropogenic climate change based on existing methane inventories. However, significant uncertainties in these statistics limit the accuracy at both national and sub-national scales. The lack of continuous gridded emissions inventories also constrains the inverse analysis of atmospheric observations. To address these, we present CHN-CH4, a spatially aggregated 0.1°×0.1° anthropogenic methane emission inventory for mainland China from 1990 to 2020. CHN-CH4 offers the country with new temporal coverage and details, by means of national statistical yearbooks and remote sensing products. Over the three decades, mainland China emitted 1156.689 [884.857–1413.315] Tg of methane, with the highest emission occurred in the last decade. But this decade also marked the beginning of a decreasing trend, from 45.017 [33.329–55.738] Tg in 2010 to 43.351 [32.089–52.679] Tg in 2020. As important priors, CHN-CH4 enables robust comparisons between estimated emissions and atmospheric observations, thereby improving the accuracy of inverse modelling, which is crucial for effective tracking of methane emissions. By providing a reliable and detailed emissions inventory, CHN-CH4 would be a valuable tool in accelerating the global effort to achieve equitable methane emission reduction goals, as well as supporting China’s climate policy.