Urban green space in transition: A cross-continental perspective from eight Global North and South cities

• Global North and South cities show divergent trends in urban green space (UGS) dynamics. • Global South cities experience more rapid UGS decline than Global North cities. • UGS exposure varies significantly across cities, with disparities having equity implications. • Urbanization drives UGS decline, with higher pressures in Global South cities. • Context-specific urban greening strategies are crucial for equitable and sustainable cities. Urban green space (UGS) plays a vital role in enhancing the resilience and livability of cities. However, the distribution and accessibility of these spaces often vary significantly within and between cities, raising concerns about environmental justice and social equity. This study aims to analyze the spatiotemporal dynamics of UGS and assess population exposure and equality implications across eight diverse cities from the Global North (GN) and Global South (GS) over the past three decades. Employing a multimethod approach combining geospatial analysis, remote sensing, and statistical techniques, this study reveals an alarming global trend of decreasing UGS, with GS cities experiencing more rapid decline than GN cities. The analysis of UGS exposure uncovers distinct trends and variations across cities, with GN cities generally having higher exposure but showing a concerning decline over time, while GS cities display mixed patterns. Arid-climate cities Phoenix and Riyadh have managed to maintain low but stable UGS levels despite their unique climatic challenges. Urbanization emerges as a dominant force driving the decline in UGS, with GS cities facing significantly higher pressures than GN cities. The findings highlight the urgent need for comprehensive urban greening strategies that prioritize UGS protection and expansion, innovative policies, community engagement, and data-driven decision-making to promote equitable and sustainable urban environments. This study contributes to the growing research on urban greening by providing a comparative analysis of UGS trajectories and exposure equality implications across diverse cities, underscoring the importance of context-specific approaches and inclusive planning processes.