Impact of urban compactness on carbon emission in Chinese cities: From moderating effects of industrial diversity and job-housing imbalances

In the context of sustainable urban space utilization and carbon neutrality, this study systematically explores the relationship between urban form and carbon emissions in China from 2005 to 2020. Utilized night-light and Open-source Data Inventory for Anthropogenic CO2 data from 260 cities to measure urban form and carbon emissions, the threshold effect of urban form on carbon emissions was identified, and the moderating effects of industrial diversity and job-housing imbalances were explored. The results of the study show that, firstly, as urban form becomes compact, carbon emissions within built-up areas and cities both show a trend of decreasing and then increasing. In small and medium-sized cities, urban compactness tends to reduce carbon emissions, while in large and mega-cities, a more compact urban form increases carbon emissions. In addition, in cities with high industrial diversity and low job-housing imbalances, a more compact urban form helps to reduce carbon emissions. To optimize the carbon reduction benefits of urban compactness, our study offers urban planners' insights for comprehensive planning that integrates urban form with both production and residential considerations.