Coordinated Port–Industry–City Development from a Green Port Perspective: An Empirical Study of Shanghai Port

In the context of China’s ‘dual carbon’ strategy, sustainable port–city integration has become critical for regional transformation. Based on the green development perspective, this study constructed a “port–industry–city” (PIC) coordinated development indicator system, conceptualizing ports, industries, and cities as distinct but interrelated subsystems. An improved coupling coordination degree model and an obstacle degree model were employed to analyze the coordinated development between Shanghai Port and its associated industries and urban areas during the green transformation process from 2014 to 2023. Three key findings were found: (1) The comprehensive development index of Shanghai Port exhibited a W-shaped fluctuation followed by rapid growth, while the overall PIC system showed a continuous upward trajectory, with the overall development level steadily rising. (2) During Shanghai Port’s green transformation process, the coordination level of the PIC system improved from moderate imbalance to intermediate coordination, though the overall level still requires improvement. (3) Port green transformation, infrastructure, and urban ecology represent primary obstacles requiring targeted, sustainable interventions. This study enriches the research on port–industry–city coordination and provides both theoretical support and a policy foundation for promoting regional sustainable development led by green port initiatives.