How does green technology innovation affect urban carbon emissions? Evidence from Chinese cities

Green technology innovation is regarded as a key catalyst for sustainable urban development. This study mainly utilizes 278 Chinese cities data from the China Urban Statistical Yearbook, adopting ordinary least squares (OLS) and mediation effect model to investigate the dual impact and mechanism of green technology innovation on urban carbon emissions. Besides, spatial Durbin model (SDM) and threshold model are employed to examine spillover and non-linear impact. The results indicate that: (1) Green technology innovation can significantly mitigate carbon emission intensity, but cannot reduce carbon emissions. Thus, both carbon emission reduction effect and rebound effect coexist, and there is heterogeneity across different cities. (2) Green technology innovation has the potential to decrease carbon intensity through optimizing energy intensity, government participation and basic life cleanliness. (3) There is a spatial spillover effect concerning the emission reduction impact of green technology innovation. (4) The relationship between carbon emission intensity and green technology innovation exhibits a non-linear impact under varying levels of energy intensity, government participation, industrial structure rationalization, and environmental regulation. Building upon these findings, policy recommendations outlined in this study encompass the reinforcement of technological utilization, avoidance of excessive governmental intervention, and adoption of strategies for regional connectivity and differentiation.