Miyawaki Forests are biodiverse, native, pocket-sized forests that reestablish full, functioning ecosystems in the areas they are planted. Image: reNature

Urban green spaces more accessible to more people globally

3 November 2023

HKU researchers in collaboration with colleagues at Tsinghua University conducted a study of over 1,000 cities worldwide and found improved green space exposure across their data set with a general decrease in inequalities between cities.

Over half of the global population currently resides in urban settings with an influx of nearly 200,000 individuals each day. Urban green spaces are important for psychological and physiological well-being and have broader ecological benefits. One of the 17 United Nations sustainable development goals is to make cities and human settlements inclusive, safe, resilient and sustainable. The amount of urban green space is a useful measure.

Cities at an initial stage of development are characterised by extensive built-up areas followed later by the construction of significant artificial green landscapes. The HKU study provides an insight into the availability of urban green space over a period of two decades. The findings were published in Nature Communications.

The research team developed a methodology incorporating 30-meter-resolution Landsat satellite time-series greenspace mapping and a population-weighted exposure framework to quantify the changes in human exposure to urban green space from 2000 to 2018. The team examined 1028 cities.

Temporal changes of physical greenspace coverage (GC) and greenspace exposure (GE) for global 1028 cities from 2000 to 2018. Image: Chen et al, Nature Communications

Global findings indicated a substantial increase in green space coverage, an improvement in human exposure to urban green space and a marked reduction over the past two decades in inequalities between cities.

Dr Bin Chen of the Division of Landscape Architecture of HKU who led the research team said,“Our earlier work also published in Nature Communications highlighted contrasting green space exposure inequalities between cities of the Global North and Global South. The current research offers a comprehensive, longitudinal view of how this exposure and its associated inequalities have evolved over time”.

“This research is timely and offers invaluable insights, serving as a beacon for government bodies, urban planners, and private sector developers. It emphasizes the adoption of comprehensive urban strategies to not only increase but also enhance the quality of green spaces, all in pursuit of the sustainable development goals,” said Professor Peng Gong, Chair Professor of Global Sustainability and Vice-President (Academic Development) of HKU.