Abstract

Urban greenspaces play a critical role in public health, ecological sustainability, and climate resilience. In a major study spanning two decades, Song et al. (2025) harnessed satellite data to assess how urban and peri-urban green spaces have evolved in 12 Chinese cities from 2000 to 2020. By integrating high-resolution Landsat and Global LAnd Surface Satellite (GLASS) remote sensing datasets through an innovative spatiotemporal fusion method, the researchers created a 30-meter resolution vegetation dataset that maps both the extent and seasonal duration of greenspaces—known as “green days.”