The Nonlinear Impact of Economic Growth on Carbon Emissions in China’s Yellow River Basin Using Difference-in-Differences Models

The present empirical investigation sets out to systematically unpack the multifaceted effects of aggregate economic expansion on anthropogenic carbon discharge across China’s vast Yellow River Basin, with targeted analytical emphasis placed on unpacking the non-monotonic, curved associations between advancing economic activity levels and greenhouse gas output, as well as the underlying causal pathways that generate these complex interplays. Considering that most of the existing studies focus on the direct economic-carbon emission relationship, this paper adopts a double-difference model to analyse the mediating effect of economic growth through factors such as industrial structure, urbanisation level and regional innovation capacity. The empirical results show that there is an inverted U-shaped nonlinear relationship between economic growth and carbon emissions, with carbon emissions rising in the early stage of economic development, but gradually declining as the economy matures and the industrial structure transforms. In addition, the optimisation of industrial structure, the acceleration of urbanisation and the enhancement of regional innovation capacity play an important mediating role between economic growth and carbon emissions. The theoretical significance of this study is that it enriches the research framework of the nonlinear relationship between economic growth and environmental pollution, and the practical significance is that it provides empirical support for the formulation of differentiated carbon emission policies. The results of the study provide an important policy basis for promoting the transition to a low-carbon economy and the sustainable development of the region.