Study reveals global urban vegetation dynamics from 1990 to 2021

BEIJING -- A recent study has indicated that nearly half of global urban vegetation is browning, while about 40 percent is greening.

The findings were obtained by a research team from the Chinese Academy of Sciences' Institute of Geographic Sciences and Natural Resources Research after a comprehensive analysis of vegetation dynamics with high-resolution data at a 30-meter scale across 11,235 cities globally between 1990 and 2021.

Researchers found that urban vegetation greening is geographically uneven, with the Global South accounting for 36.77 percent and the Global North representing 45.65 percent.

In addition, despite a considerable expansion of green spaces in cities, the percentage of people who actually reap the benefits of this greening remains relatively small.

Researchers have also highlighted a notable link between economic development and urban vegetation greening, with cities boasting higher GDP per capita typically experiencing more substantial vegetation growth.

Moreover, urbanization and nitrogen deposition present a complex impact: while these factors may drive vegetation decline in urban peripheries, they can, conversely, foster vegetation expansion in city centers.

The study showed that compared to browning or unchanged regions, greening areas significantly alleviate the urban heat island effect, particularly during summer daytime.

According to the research team, this suggests that long-term efforts to promote urban vegetation greening can not only help address climate change but also improve the quality of urban living environments.

The study was published in the journal Proceedings of the National Academy of Sciences.