If you have ever noticed that it was hotter in a heavily developed area compared to a mostly natural, nearby area, then you have experienced the “heat island effect”. The heat island effect describes the phenomenon where there are pockets of higher temperatures. The heat island effect mostly occurs in cities, where the built environment absorbs sunlight and radiates heat back into the environment. Since cities have significantly more buildings, roadways, and man-made structures than rural areas, they hold on to more heat than rural areas over a longer period of time.
The heat island effect can have an impact on public health due to extreme heat. Extreme heat can cause heat stroke, heat exhaustion, and heat cramps, among other health impacts. The higher temperatures also lead to higher energy consumption for cooling. Therefore, addressing the heat island effect would also improve public health and could lead to reducing energy consumption.
A great way to reduce the heat island effect while also providing additional environmental and aesthetic benefits is to increase the urban canopy. Planting trees, shrubs, and ground cover can contribute to lowering temperatures in an urban area by providing shade and absorbing sunlight instead of the asphalt and concrete from roadways and buildings. These trees and plants also contribute to stormwater management and the absorption of carbon dioxide, and provide habitat to nearby species.
Another method is to choose lighter-colored building materials or those that have a higher albedo. For example, a white roof absorbs less sunlight than a dark roof. This allows the building and surrounding area to remain cooler. Similarly, sustainable roofing systems such as green roofs and blue roofs are great options to reduce the heat island effect.