Can Urban–Rural Industrial Synergy Accelerate Low-Carbon Transition? The Mediating Role of Industrial Structure Upgrading and Green Technology Diffusion

In the context of global carbon reduction and rural revitalization, identifying effective drivers for the low-carbon transition has become crucial. As a key pathway linking urban and rural economies, it remains unclear whether urban–rural industrial synergy can effectively accelerate this transition. This study integrates carbon emission efficiency into its analytical framework and uses panel data from 282 Chinese cities from 2008 to 2022 to examine the relationship between urban–rural industrial synergy and the low-carbon transition through a province and year fixed-effects model. Additionally, a mediation model is employed to explore the roles of industrial structure upgrading and green technology diffusion in facilitating this transition. The findings indicate a significant positive relationship between urban–rural industrial synergy and carbon emission efficiency in the baseline specification. Both industrial structure upgrading and the patent-based proxy for green technology diffusion display partial mediation patterns in the original specification, although the evidence for industrial structure upgrading is weaker and the mechanism interpretation is subject to measurement overlap and specification sensitivity. This research contributes to low-carbon transition studies and provides empirical insights for policy formulation. Specifically, it informs efforts to promote urban–rural integration and align carbon reduction with agricultural modernization and sustainable rural development in China.