The impact of urbanization on carbon emissions: both from heterogeneity and mechanism test

It is of great significance to understand the relationship between urbanization and carbon emissions and the impact mechanism, which can help formulate climate policies and provide insights into how to achieve lower emissions with the urbanization development. Utilizing China’s provincial panel dataset during period 2003–2015, this study employed the “Threshold-STIRPAT” model to investigate the impact of urbanization on carbon emissions under different urbanization thresholds, with the intermediate effect model combined. Initially, the results show that, once the urbanization development rate is less than 47.04%, each 1% increase in urbanization rate will increase the carbon emission by 0.23%, and while once the urbanization rate is greater than 47.04%, each 1% increase in urbanization rate will increase carbon emissions by 0.78%. Moreover, the intermediary transmission mechanisms, from the aspect of the improvement in resident consumption level, technological progress, industrial restructuring and energy structure adjustment, account for 1.24%, 0.78%, 0.05% and 0.02%, respectively. Ultimately, the resident consumption improvement and technological progress play the main transmission role through the empirical study of the whole sample and heterogeneous urban samples. The research results are expected to give inspiration to low carbon policies making in different urbanization stages, and to guide the direction how to optimize resident consumption and technology progress.