Urban green recovery was insufficient to increase human greenspace exposure equality: Long-term evidence from megacity Shanghai, China

Providing widespread and equitable greenspaces for urban residents is of great significance for promoting sustainable development and public well-being. Recent studies indicated that some cities had experienced greening, but the temporal dynamics of greenspace and human exposure remain unclear due to the lack of long-term trajectory analysis. This study takes Shanghai, a rapidly developing megacity in China, as the study area to investigate the temporal trajectories of greenspace dynamics and human exposure equality with long-term, high-resolution enhanced vegetation index (EVI) data and population data. The Venn conceptual model was employed to assess how greenspace coverage and population distribution influence human greenspace exposure and equality along the urban-rural gradient. Our findings revealed that despite a decline in EVI in Shanghai from 1984 to 2023, recovery in greenness and greening trend was found in 55.7% areas, which accounted for 87.3% in the urban core and 53% in the suburb, driving significant green recovery in highly urbanized regions. Over the past 20 years, population-weighted greenspace exposure in Shanghai increased, following a spatial pattern of “increase-decrease-increase” from the urban core outward. However, human greenspace exposure equality was not increased with the green recovery around the 2000s. The positive influence of greenspace coverage in the suburb and rural areas was insufficient to offset the negative influence of population distribution, failing to increase equality. Our study clarified the temporal changes in greenspace dynamics and human exposure during urbanization, and highlighted the need to strengthen the human-nature relationship to increase greenspace exposure equality.