Green Development Synergies and Regional Disparities in the Yangtze River Delta Urban Agglomeration

The comprehensive green transition of China necessitates synergistic development among carbon reduction (CR), pollution reduction (PR), green expansion (GE), and economic growth (EG). This study evaluates the spatiotemporal dynamics of this synergy in the Yangtze River Delta urban agglomeration from 2005 to 2021 through a multidimensional assessment framework. Employing coupling coordination degree analysis, spatial econometrics, and geographically weighted regression models, we investigate the spatiotemporal patterns and driving factors of coordinated development in the region. Our findings reveal steady annual improvements in the comprehensive evaluation of these four dimensions, indicating positive progress in green development. The coupling coordination degree demonstrates distinct spatial heterogeneity, characterised by strengthening southeast-northwest variations and clear migration patterns. Spatial correlation analysis shows fluctuating synergistic relationships during the study period. Innovation level and educational investment emerge as significant factors influencing coupling coordination. We recommend enhanced investment in technological innovation and education, alongside strengthened cross-regional cooperation and resource sharing, to accelerate green transformation and achieve sustainable development goals.