Future Urbanity & Sustainable Environment (FUSE) Lab, Division of Landscape Architecture, Department of Architecture, Faculty of Architecture, The University of Hong Kong, Hong Kong SAR, China.
Urban Systems Institute, The University of Hong Kong, Hong Kong SAR, China.
Nat Commun. 2023 Oct 13;14(1):6460. doi: 10.1038/s41467-023-41620-z.
Greenspace plays a crucial role in urban ecosystems and has been recognized as a key factor in promoting sustainable and healthy city development. Recent studies have revealed a growing concern about urban greenspace exposure inequality; however, the extent to which urbanization affects human exposure to greenspace and associated inequalities over time remains unclear. Here, we incorporate a Landsat-based 30-meter time-series greenspace mapping and a population-weighted exposure framework to quantify the changes in human exposure to greenspace and associated equality (rather than equity) for 1028 global cities from 2000 to 2018. Results show a substantial increase in physical greenspace coverage and an improvement in human exposure to urban greenspace, leading to a reduction in greenspace exposure inequality over the past two decades. Nevertheless, we observe a contrast in the rate of reduction in greenspace exposure inequality between cities in the Global South and North, with a faster rate of reduction in the Global South, nearly four times that of the Global North. These findings provide valuable insights into the impact of urbanization on urban nature and environmental inequality change and can help inform future city greening efforts.
绿地在城市生态系统中起着至关重要的作用，已被公认为促进可持续和健康城市发展的关键因素。最近的研究表明，人们越来越关注城市绿地暴露的不平等问题；然而，城市化在多大程度上影响了人类对绿地的暴露程度以及随时间推移相关不平等的程度仍不清楚。在这里，我们结合基于 Landsat 的 30 米时间序列绿地制图和人口加权暴露框架，量化了 2000 年至 2018 年间全球 1028 个城市人类对绿地的暴露变化和相关的平等性（而非公平性）。结果表明，物理绿地覆盖率有了大幅增加，人类对城市绿地的暴露也得到了改善，导致过去二十年来绿地暴露不平等程度有所降低。然而，我们观察到，在全球南方和北方城市之间，绿地暴露不平等程度降低的速度存在差异，南方城市的降低速度更快，几乎是北方城市的四倍。这些发现为城市化对城市自然和环境不平等变化的影响提供了有价值的见解，并有助于为未来的城市绿化工作提供信息。
