Euronews.green writes that since 1990, the number of AC units in Europe grew by more than two times, as cooling requirements grew by four times, especially in the northern part of the continent.

Experts at the International Energy Agency (IEA) concluded in 2016 that two-thirds of the world's AC units were found in China, the US and Japan, with Europe being far below these nations in terms of installed units.

The trends continued in 2022, as well, when experts stated that the penetration rate of AC units in the US was 90%, while in Europe, 19%. IEA experts also found that Europe has more air conditioning devices installed in commercial buildings, while in the US, China and Japan, it's household owners who use them more.

Using air conditioning can have adverse effects in several areas, including energy consumption and the urban heat island effect. As more people use AC in the city, this heating effect is being more present, since the warm air released by the devices is being absorbed by surrounding buildings or roads.

This was confirmed by a study conducted by experts at Cired (Centre international de recherche sur l'environnement et le développement). They discovered that the temperatures of Paris at night would rise by 2.4 degrees Celsius if the city's air-conditioned buildings would keep a temperature of 23 degrees Celsius indoors throughout a 38-degree heatwave.

Clara Camarasa, an expert at the IEA, explained how AC units "can put immense pressure on electricity grids and accelerate greenhouse gas emissions, exacerbating the climate crisis. Air conditioners also often need large volumes of water, and some of them, with certain refrigerants, have a particularly warming potential, which is also harmful to the ozone layer."

Still, there are areas where giving up on AC isn't possible, as the technology already helped save tens of thousands of lives every year, according to IEA experts. Using AC reduces the risk of heat-related deaths by 75%, they added.

Urbanists and researchers agree that nature-based solutions can provide cities with the much-needed cooling and oxygen-rich air citizens need in order to effectively fight the effects of the urban heat island.

"Nature-based solutions are attracting increasing interest as a means of combating urban heat islands. Green spaces [and] green roofs can make cities more resilient, as a complement to efficient technologies", Camarasa explains.