Trends in greenhouse gas emissions from China's municipal solid waste sector at urban and county levels: key drivers and mitigation strategies.

Significant changes have occurred in China's municipal solid waste (MSW) management methods over the last two decades, yet comprehensive assessments of greenhouse gas (GHG) emission patterns and their driving factors remain limited. In this study, GHG emissions from the urban and county-level MSW disposal sector in China during 2006-2023 were quantified using the IPCC methodology, and the Logarithmic Mean Divisia Index (LMDI) was applied to identify key drivers. Urban and county-level emissions followed different temporal trajectories, with the transition in county-level MSW management occurring later than in urban areas. Total emissions peaked at 134.06 Mt CO2-eq in 2019 and remained relatively stable thereafter, while the national average emission intensity declined over the study period. The dominant emission source gradually shifted from landfill to incineration, and this transition occurred earlier in urban areas. Multi-scale spatial heterogeneity was evident, with emission hotspots progressively shifting from eastern and southern coastal regions toward inland areas. Compared with urban areas, county-level waste disposal showed greater mitigation potential due to less developed treatment infrastructure. LMDI results showed that waste generation intensity and treatment structure contributed negatively to emission changes, whereas economic development and population contributed positively to emission changes. These findings support differentiated mitigation strategies for urban and county MSW disposal in China, emphasizing source reduction, system-level optimization, energy efficiency improvement, and regional coordination.