Large cities often experience the heat island effect, a meteorological phenomenon in which temperatures in a city rise in comparison to the surrounding countryside.
A densely built sidewalk can absorb solar radiation and heat up the environment by re-emitting heat. This phenomenon increases the air temperature and provokes global climate change.
In a new work, the authors examined how the sidewalk can cool the environment. The researchers focused on so-called cool sidewalks, which reflect more solar radiation and generate less heat than conventional surfaces.
The study found that such sidewalks can reduce air temperatures in the cities of Boston and Phoenix to 1.7°C and 2.1°C, respectively. They can also cut greenhouse gas emissions, dropping total emissions to 3% in Boston and 6% in Phoenix.
The authors of the new work studied three types of cool sidewalks: reflective asphalt, ordinary concrete, and reflective concrete. Depending on the development, remoteness and density of buildings, it is possible to determine the ideal coverage option for each area of the city.