How urban forms shape the cooling efficiency of urban green spaces: Evidence from 1318 global cities

As a key strategy for mitigating urban thermal environments, enhancing the cooling efficiency (CE) of urban green spaces through the optimization of urban forms is crucial. However, at the city scale, studies on how urban morphological characteristics influence green space CE remain limited, particularly regarding the differentiated impact pathways and interactions across various climate types. This study quantified the CE of 1318 cities worldwide and found that a 1% increase in vegetation cover corresponds to an approximate 0.05 °C reduction in urban land surface temperature. Structural equation models (SEM) across different climate classifications were further applied to explore how urban forms can be optimized to enhance CE. The results reveal that urban forms primarily influence CE by modifying local climatic conditions and the quality of green spaces. Building density and the connectivity of urban green spaces exert the strongest effects on CE. In most climate types, more open urban spatial configurations are more favorable for improving CE. Moreover, embedded green spaces with more complex shapes and higher connectivity generally exhibit stronger cooling efficiency.