Long-term coupling coordination analysis between urbanization and the ecological environment in global cities: insights from remote sensing

Global urbanization has accelerated economic growth while intensifying environmental pressures, leading to uneven urbanization–environment interactions across the Global North and Global South. Although numerous studies have examined urbanization–environment coordination, few provide globally comparable, long-term, and intra-urban assessments within a unified framework. To address this gap, this study evaluates urbanization–environment coordination in Global North and Global South cities at a 1,000 m resolution from 2001 to 2020 using multi-source remote sensing data and a coupling coordination degree (CCD) model. Three main findings emerge. First, global CCD improved steadily from 2001 to 2020. Second, disparities between the Global North and Global South persisted but gradually narrowed, largely driven by accelerated improvements in Global South cities after 2010. Third, intra-urban patterns differed systematically: in emerging Global South cities, CCD improvements were concentrated in central areas, whereas in mature Global North cities, gains were more evident in peripheral zones. These findings indicate that urbanization–environment coordination follows distinct spatial pathways across development contexts and that city-level trends are closely associated with intra-urban spatial dynamics. By linking long-term inter-city trends with intra-urban spatial patterns, this study provides a globally consistent perspective on urbanization–environment coordination and offers implications for spatially differentiated urban planning.