The spatiotemporal heterogenous impact of urban multidimensional compactness on household carbon emissions in China

Compact city is considered an important planning approach to alleviate carbon emissions (CE) and achieve "carbon neutrality". However, previous studies tended to intensively investigate the relationship between unidimensional urban compactness (urban form) and household carbon emissions (HCE). In fact, compact city is not only physical compactness but also economic, population, land use and infrastructure compactness. Therefore, the article constructed a multidimensional compactness index system to comprehensively investigate the influence of compact city on HCE in 286 cities in China, using DMSP-OLS/NPP-VIIRS nightlight data and socioeconomic data from 2000 to 2015. The Geographical and Temporal Weighted Regression (GTWR) model is employed in the study to examine the localized impact of different levels of compactness on HCE. The results found: (1) Economic compactness has a promoting effect on HCE in resource-endowed cities with well developed heavy industry and abundon fossil fuels, while economic compactness inhibits HCE in cities dominated by service and high-tech industry. (2) Cities with higher population carrying capacity are more easily to reduce HCE when cities become more compact. (3) For cities with large land carrying capacity and well-built road transportation facilities, the greater the compactness of land use, the more conducive to restraining an increase of HCE. (4) With the rational layout of infrastructure construction, the more compact the infrastructure, the more conducive to restraining the increase of HCE.