Impact of urban density on carbon emissions in China

Based on the panel data of 108 prefecture-level cities in China from 2003 to 2018, the carbon emission effect of urban density was studied by establishing a dynamic panel model. We found that there was a significant negative correlation between urban density and carbon emissions, and the increase in urban density reduced carbon dioxide emissions. The nonlinear estimation results of urban density and carbon emission show that urban density has different impacts on carbon emission at different urban population levels. With the increase in population size, the carbon emission reduction effect brought by urban density growth decreases. In medium-sized cities, increased urban density leads to the greatest reduction in carbon emissions, followed by large cities with populations of less than 5 million. In megacities with a population size of more than 5 million, the carbon emission reduction effect of urban density is not significant. Our conclusion supports the proposition of building compact cities and provides decision support for the ideal of 'beautiful China' in the process of urbanization in China.