Spatial-temporal characteristics of methane emission in shandong, China, based on an updated comprehensive methane emission inventory in 2020

Abstract

As methane (CH4) is a powerful greenhouse gas (GHG) responsible for global warming, a refined CH4 emission inventory is crucial for formulating targeted mitigation policies and achieving carbon neutrality. However, provincial comprehensive CH4 emission inventories are rare due to data deficiency and fail to reflect the spatial and temporal characteristics of CH4 emission. Owing to its large population and rapid economic growth, Shandong Province has become the largest GHG emitter in China. Combining bottom-up and top-down methods, a high-spatial-resolution (0.03° × 0.03°) natural and anthropogenic CH4 emission inventory across Shandong Province in 2020 was established based on detailed activity data and updated source-specific emission factors. The total CH4 emission of Shandong was 1711.31 Gg in 2020, of which anthropogenic sources were responsible for 89.96% emission. The top three contributors, namely energy activities, agricultural activities, and waste treatment accounted for 52.86%, 21.25% and 12.70% emission, respectively, followed by vegetation (5.40%), wetland (4.64%), biomass burning (3.14%). Owing to the emission structure, spatial distribution of CH4 emission varied significantly. Jining was the largest contributor (488.92 Gg; 28.57% provincial CH4 emission) owing to the high coal production, followed by Heze (149.17 Gg; 8.72% provincial CH4 emission) and Dongying (138.28 Gg; 8.08% provincial CH4 emission) owing to coal and oil production. The monthly variation of CH4 emission from different sources are different, and the maximum emissions occurred in August. This study reports a set of methods for creating a CH4 emission inventory in China and provides detailed data for air quality simulations and various emission control policies.