CHN-CH ₄ : a gridded (0.1 <i>°</i>  × 0.1 <i>°</i> ) 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 annually. 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 37.3 [28.1-46.4 Tg of methane annually, with the highest emission occurred in the last decade. But this decade also marked the beginning of a decreasing trend, from 45.0 [32.8–56.5] Tg in 2010 to 43.4 [31.6–53.4] 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. The dataset of methane emissions in China and its eight major sectors is publicly available at https://doi.org/10.5281/zenodo.15107383 (Guo et al., 2025).