Spatial correlation network structure and its influencing factors on municipal solid waste carbon emissions in three major urban agglomerations in China

As key drivers of urbanisation and economic growth in China, major urban agglomerations play a critical role in mitigating carbon emissions from municipal solid waste (MSW) treatment. This study investigated the spatial correlation network and its underlying drivers across 63 cities in urban agglomerations from 2006 to 2022, using social network analysis and quadratic assignment procedure regression. The results reveal that the total MSW carbon emissions peaked at 1.28 million tons in 2017 and dropped to − 27,200 tons by 2022, with 87.30 % of cities achieving net-negative emissions. The emissions network evolved into a core-periphery structure, with leading cities such as Beijing, Shanghai, and Guangzhou driving regional coordination. Intercity linkages increased from 708 in 2010 to 1246 in 2022, reflecting a shift from fragmented, unidirectional flows to a more integrated, bidirectional network. Further, divergences in population density, treatment capacity, and policy support consistently fostered stronger network connectivity, whereas mismatches in technology, industrial structure, and economic development posed persistent barriers to collaboration, varying notably across urban agglomerations. These findings underscore the need for region-specific governance models and differentiated policy strategies to strengthen spatial coordination for MSW carbon mitigation.