A sustainable development perspective on urban-scale roof greening priorities and benefits
This provides a data-driven framework for sustainable urban planning, though it is incremental in applying existing methods to a new context.
The study assessed urban-scale roof greening in Hong Kong using geospatial data, finding that 85.3% of buildings have potential for greening, which could increase greenspace exposure by ~61% and generate hundreds of millions in annual economic benefits, but with limited effects on heat mitigation (~0.15°C) and carbon offsets (~0.8%).
Greenspaces are tightly linked to human well-being. Yet, rapid urbanization has exacerbated greenspace exposure inequality and declining human life quality. Roof greening has been recognized as an effective strategy to mitigate these negative impacts. Understanding priorities and benefits is crucial to promoting green roofs. Here, using geospatial big data, we conduct an urban-scale assessment of roof greening at a single building level in Hong Kong from a sustainable development perspective. We identify that 85.3\% of buildings reveal potential and urgent demand for roof greening. We further find green roofs could increase greenspace exposure by \textasciitilde61\% and produce hundreds of millions (HK\$) in economic benefits annually but play a small role in urban heat mitigation (\textasciitilde0.15\degree{C}) and annual carbon emission offsets (\textasciitilde0.8\%). Our study offers a comprehensive assessment of roof greening, which could provide reference for sustainable development in cities worldwide, from data utilization to solutions and findings.