Intrinsic mechanisms and spatial effects of multidimensional urbanization and carbon emissions.

Existing studies on urbanization and carbon emissions are mostly based on a single pathway and lack the support of a theoretical framework. This study innovatively integrates Grossman's perspective of environmental effects analysis to develop a new framework to interpret the mechanism of multidimensional urbanization (MU) and carbon emissions (CEs). We first explored the spatial effects of MUs and CEs in the Yangtze River Delta urban agglomeration (YRDUA) and then introduced the "population-land-economic" urbanization variables into the S-STIRPAT model to determine the impact mechanisms of each factor on CEs under different urbanization dimensions. The results show that the spatiotemporal development patterns of MUs and CEs overlap to some extent. The Shanghai-Nanjing line is a high-value area of urbanization with different dimensions, as some edge cities are in low-value areas. However, there are local differences in the different dimensions of urbanization, e.g., population urbanization in the southern area is in a high-value area. CEs show a core-edge structure of "high in the center and low in the north and south". All factors, except for population urbanization, affect CEs locally, and their spillover effects are all positive, except for energy intensity, which has a negative influence on CEs in neighboring regions. Land urbanization has the largest positive impact on CEs, with a total effect coefficient of 0.409; economic urbanization has a coefficient of 0.195, and population urbanization has a coefficient of only 0.070. The findings can help to maximize urbanization growth while minimizing harmful environmental externalities.