Cities are already up to 10C hotter than surrounding areas. As temperatures rise, here are four ways to cool cities down – saving both lives and energy.
If you’ve felt uncomfortably hot in a city this summer, chances are it’s not just because of the weather. Look around any urban centre and you’ll see the built environment itself exacerbates summer temperatures. Vehicles stuck in traffic emitting heat. Airconditioners pumping waste heat into the air. Concrete and asphalt across almost every surface, absorbing and radiating the sun’s rays. Urban canyons formed between tall buildings, trapping heat at the street level.
All these factors contribute towards a phenomenon called the “urban heat island” effect, which results in cities being up to 10C hotter than the surrounding countryside. How do we to tackle this?