Can your city help keep you cool?

My city has an amazing river valley. It offers many recreation trails, treed areas, and open spaces. Even outside of the river valley, many neighbourhoods have access to smaller green spaces. Green space is not evenly distributed with lower socioeconomic status communities often having less access than higher ones, known as the luxury effect. Sadly, this is a pattern that repeats around the world on both city scales and between regions of the world.

Li and colleagues (2024) used remote sensing data to assess the amount of urban greenspace and the cooling effects. This is important because the urban heat island effect already increases temperatures in cities, where infrastructure absorbs and maintains higher temperatures. Adding climate change into the mix means temperatures will have severe impacts on health, well-being, and productivity. What they found is that countries in the Global North, which, on average tend to wealthier, have more urban green space compared to countries in the Global South. Global South cities also tend to be closer to the equator and will, therefore, experience higher temperatures to begin with.

How much of a difference does this make? The researchers found that cities in the Global South have 70% of the cooling capacity from greenspaces compared to the Global North cities. Of course, the climates are different, and the way vegetation grows will be different, but even within a region, there were differences in cooling capacity related to green spaces. The best-performing city in a region could have as much as 10 C greater cooling capacity compared to the worst-performing neighbours.

While it would be difficult to completely change the planning of a city, increasing the quantity and quality of greenspaces could play an important role in mitigating some of the risks of climate change. However, there needs to be significant effort in making sure that these changes are done with equity in mind.