Heterogeneity study on mechanisms influencing carbon emission intensity at the county level in the Yangtze River Delta urban Agglomeration: A perspective on main functional areas

Identifying the regional heterogeneity characterizing the mechanisms influencing carbon emissions is crucial to the scientific formulation of emission reduction targets and strategies. The studies that have been conducted have limitations in terms of regional classification criteria and study scales, and their findings are limited to reflect the actual situation. In this study, the perspective of main functional area is chosen as the entry point to carry out regional classification. First, the 305 county-level administrative districts in the Yangtze River Delta urban agglomeration (YRDUA) are categorized into four different types of main functional areas according to official standards. Then, the differences in carbon emission intensity (CEI) within and outside each main functional area are analyzed. The STIRPAT model (Stochastic Impacts by Regression on Population, Affluence and Technology) is used to analyze the differences in the impact mechanisms of various carbon emission influencing factors in the four main functional areas. The results show that there are significant differences in the CEI of different main functional areas, indicating the feasibility and necessity of studying carbon emission from the perspective of main functional area. The key development area (KDA) and optimized development area (ODA) dominate the evolution of regional CEI, especially KDA should be the core area for carbon reduction. There are significant differences in the mechanisms influencing CEI in different main functional areas, especially in terms of population density, industrial structure and government intervention. Our study provides a scientific basis for the subregional regulation of carbon emissions from the perspective of main functional area.