Cooling Cities: Sustainable Solutions for Urban Heat in a Warming World

A report by Mario Doueiri, English adaptation by Nadine Sassine

Amid climate change and increasing heatwaves, cities have become hotspots for heat. This phenomenon, known as "urban heat islands," makes temperatures in cities significantly higher than in rural areas. The solution is not always to increase air conditioning, as architectural methods and urban planning can help reduce heat and make cities more livable.

Let us explore some of these solutions together:

The first method is planting vegetation on rooftops. "Green roofs" have been proven to reduce roof temperatures by 30-40 percent. In addition to green roofs, there are also green walls. A 2019 study from the University of Seville showed that green walls reduce indoor temperatures by around 3-5 degrees, improving thermal insulation and purifying the air.

These solutions are not limited to buildings alone. Adding trees and green spaces in streets can also reduce air temperatures by 2-8 degrees, according to a 2021 report from the European Environment Agency. Cities like Paris and Milan have adopted this approach, lowering temperatures by around 1-3 degrees Celsius.

In addition to vegetation, construction methods can also help reduce urban heat. Using reflective materials on roofs and walls has been shown to lower surface temperatures by 10-15 degrees Celsius. In Los Angeles and Phoenix, adopting reflective surfaces resulted in a 10-30 percent reduction in electricity consumption for air conditioning.

Public spaces play a role as well. Adding water features such as ponds and fountains can reduce temperatures by 2-4 degrees, as observed in cities like Lyon and Nantes in France.

Another solution is adding structures that provide shade in streets. According to a 2020 study by the University of Tokyo, this can lower air temperatures by around 5-10 degrees.

All these solutions are important, and there are many more out there. But how feasible is their implementation in Lebanon? In short, there are numerous architectural and planning solutions that help reduce heat. If we combine them, we can create a more comfortable living environment. However, their application is a shared responsibility between the private sector, individuals, unions, municipalities, and the state.