The effects of urban expansion on carbon emissions: Based on the spatial interaction and transmission mechanism

Abstract

Timely and scientific investigation into the complex relationship between urban expansion and carbon emissions is imperative to support urban decarbonization efforts. However, the existing framework cannot fully consider spatial interaction or accurately explore the transmission mechanism. To narrow the knowledge gaps, this study provides both theoretical and empirical insights into the impacts of urban expansion on carbon emissions. Based on the panel data of 284 cities in China during 2007–2019, the spatial Durbin model and mediating effect model are primarily utilized to reveal the following results: (i) Urban expansion and carbon emissions show significant spatial heterogeneity, spatial autocorrelation, and spatial spillover. Urban expansion is shifting from a nationwide multi-point distribution to a localized regional distribution, while carbon emissions maintain stable spatial patterns. Urban expansion has U-shaped direct effects on local carbon emissions but inverted U-shaped spatial spillover effects on neighboring cities’ carbon emissions. (ii) Industrial structure upgrading and industrial agglomeration are pivotal mediating mechanisms in the relationship between urban expansion and carbon emissions. (iii) Urban expansion is recommended to be limited to a land expansion rate at about twice the population expansion rate. In essence, these findings underscore the need for reasonable urban expansion and spatial interaction strategies to promote collaborative low-carbon development.