Anthropocene Magazine · Climate & nature

Greening suburbs upwind of cities could cool urban areas, study suggests

A new analysis indicates that strategically placing green spaces in suburban areas upwind of cities could reduce urban temperatures by nearly half a degree Celsius across at least half of the city area. This approach aims to mitigate the urban heat island effect, where cities become hotter than surrounding rural landscapes.

The study proposes that the location of vegetation is as crucial as its quantity for urban cooling. Researchers were inspired by the traditional Chinese mountain-water-forest (MWF) framework, where settlements are integrated with natural landscapes. They used a computer model to simulate how converting suburban areas upwind of a city to woodlands would affect urban core temperatures on hot summer days.

The analysis, applied to cities like Beijing and Shanghai, revealed that suburban vegetation creates a cool air mass, which is then transported into the city by prevailing winds. This mechanism was found to be robust across eight diverse mega-cities, including Cairo, Kinshasa, São Paulo, Houston, Sydney, and London, reducing temperatures by an average of 0.4°C across at least half the city area.

However, the effectiveness varies. Shanghai experienced less cooling than Beijing due to misaligned sea breezes and potential planting locations. The strategy is most effective where cities have consistent wind pathways and available space for upwind greening. The study emphasizes the need for creative approaches to create multi-functional landscapes and integrate vegetation, wind, topography, and water into a cohesive climate-regulation system, rather than just isolated green spaces.

AI-samenvatting op basis van de bron.