The cool technologies that could protect cities from dangerous heat

Last year was the hottest on record and 2024 is shaping up to be even more extreme.

Scientists are working hard to develop innovative ways to cool cities and slash electricity use in the warming world.

Advances range from high-efficiency air conditioners to special materials that keep surfaces colder than their surroundings without using electricity.

A supercool aerogel cooled surfaces to up to 16 C below the ambient air temperature.

The material uses less energy and reduces pollutants compared with other supercool materials that use additives.

The discovery could be a boon for places that don’t have air conditioning, and could improve thermal comfort and even human health.

Shape-shifting materials are taking a different approach to cool homes and buildings.

They are using phase-change inks’ consisting of suspended nanoparticles that change phase depending on the temperature, shifting from a superconductor at cool temperatures to a metal at hotter temperatures.

In the future, Taha hopes to apply this ink as a window coating.