Constraint or catalyst? Unraveling the nonlinear relationship between industrial linkages and CO2 emissions.

Industrial linkages shape production efficiency, resource allocation, and technology diffusion, yet their environmental consequences remain underexplored. This paper investigates the relationship between industrial linkages and sectoral CO2 emissions. We construct weighted forward and backward linkage indicators based on input-output tables, covering 24 harmonized sectors across 30 Chinese provinces. Empirical findings reveal an inverted-U relationship between industrial linkages and CO2 emissions: stronger linkages are initially associated with higher emissions, but beyond a threshold they are linked to lower emissions. Mechanism analysis identifies three impact channels: output scale effect, technological innovation effect, and energy intensity effect. Furthermore, we construct a measure of regional industrial linkage structures to help identify key areas for emissions reduction. The results highlight regions such as Anhui, Henan, Liaoning, and Shaanxi as priority zones for targeted emissions mitigation. Our study provides empirical insights and policy implications for understanding the role of industrial linkages in reducing carbon emissions.