Expanding Urban Green Cover Could Prevent Over 1.1 Million Heat-Related Deaths, Global Study Finds

Melbourne, May 1 – Expanding green spaces in cities could save more than 1.1 million lives globally from heat-related illnesses, according to a landmark study by researchers at Monash University, Australia. Published in The Lancet Planetary Health, the study analyzed data from over 11,000 urban areas worldwide and found that increasing urban vegetation by 30% could avert up to 1.16 million deaths caused by extreme heat between 2000 and 2019.

The research, spanning two decades, is the first to model both the cooling and health-modifying effects of urban greenery on a global scale. It reveals that even modest increases in green cover-by 10%, 20%, and 30%-can reduce average warm-season temperatures by 0.08°C, 0.14°C, and 0.19°C respectively, resulting in the prevention of 0.86 million, 1.02 million, and 1.16 million heat-related deaths.

Lead author Professor Yuming Guo emphasized the urgent public health implications:

“This gives us a more comprehensive assessment of its benefits in mitigating heat-related mortality. Preserving and expanding greenness might be potential strategies to lower temperature and mitigate the health impacts of heat exposure,” he said.

Most Impact in Asia and Europe

The study found that urban regions in Southern Asia, Eastern Europe, and Eastern Asia would see the greatest reduction in heat-related deaths with increased vegetation. In these areas, the combination of dense populations and high vulnerability to heat makes greening strategies especially critical.

Heat Exposure: A Growing Global Crisis

Heat exposure is already a significant public health threat, linked to around 500,000 deaths annually-about 0.91% of all global deaths between 2000 and 20191. Under the most severe climate change scenarios, heat-related mortality could rise dramatically, especially in Southeast Asia, where projections suggest up to 16.7% of total deaths could be attributed to extreme heat by the end of the century.

The Science Behind Urban Cooling

Urban greenery cools cities by shading surfaces, reflecting sunlight, and promoting evapotranspiration-the release of moisture from plants and soil, which cools the surrounding air. These processes help counteract the urban heat island effect, where concrete and asphalt trap and radiate heat, making cities significantly hotter than surrounding rural areas.

Beyond Cooling: Additional Health Benefits

The study also highlights that increased urban vegetation can improve mental well-being, encourage physical activity, foster social interaction, and reduce air pollution-factors that cumulatively enhance urban livability and resilience.

Professor Guo concluded,

“Preserving and expanding urban green cover is not just an environmental or aesthetic issue-it is a matter of public health and survival in the era of climate change.”

Disclaimer:
This article is based on findings from a global modelling study led by Monash University and published in The Lancet Planetary Health. The projected figures are estimates derived from statistical models and satellite data; actual outcomes may vary depending on local conditions, urban planning policies, and future climate scenarios. Readers are encouraged to consult the original study and related sources for further information.