With urban agglomerations becoming the core areas of economic development and carbon dioxide (CO2) emissions in China, the impact of the spatial structure of urban agglomerations, including monocentric and polycentric structure and reflecting the distribution of elements and resources among cities on CO2 emissions should be investigated. This paper empirically analyzed the impact of spatial structure of urban agglomeration on CO2 emissions and the inherent mechanism. The nightlight data is utilized to firstly evaluate the long-term evolution of the spatial structure of 19 urban agglomerations in China in terms of morphology. Then, econometric model is constructed, combining panel data of urban agglomerations during 2000-2018 to explore the relationship between spatial structure and CO2 emissions. Whatâ€™s more, the mediation effect model is applied to trace the internal mechanism of industrial division. The results show that the polycentricity of the spatial structure of 19 urban agglomerations in China has increased since 2000, especially those on the coastal area. Whatâ€™s more, polycentric spatial structure of urban agglomerations can help reduce carbon intensity, which is partly realized by promoting industrial division. Besides, spatial structure poses greater CO2 emission impact on core cities rather than non-core cities. Therefore, this paper could provide new insight into the realization of low-carbon urban agglomerations from the perspective of urban spatial planning and city positioning.
Keywords spatial structure of urban agglomerations, polycentric development, nightlight data, carbon dioxide emissions, industrial division