During the summer of 2025, extreme heat waves overwhelmed power grids across North America, Europe, and the Middle East, highlighting the urgent need for innovative cooling solutions. As global warming intensifies, the demand for air conditioning rises, placing further strain on energy infrastructure. However, a technology rooted in ancient practices and enhanced by modern science offers a promising alternative: radiative cooling.

Radiative cooling leverages the natural phenomenon of heat dissipation through specialized materials. Paints, coatings, and textiles designed with radiative properties can scatter sunlight and release heat without requiring external energy input. "Radiative cooling is universal—it exists everywhere in our daily life," said Qiaoqiang Gan, a professor of materials science and applied physics at King Abdullah University of Science and Technology in Saudi Arabia. Gan explained that objects naturally absorb solar heat during the day and radiate it back into the environment at night. This process, he noted, is responsible for the condensation observed on cars parked outdoors overnight, where the metal roofs cool below the ambient air temperature, leading to dew formation.

Humans have been utilizing radiative cooling for millennia. In desert regions of Iran, North Africa, and India, people historically produced ice by leaving shallow pools of water exposed to the clear night sky, capitalizing on radiative cooling to freeze the water. Modern advancements in materials science have significantly enhanced the efficiency and applicability of this age-old technique.

The implications of widespread radiative cooling adoption are substantial. By reducing reliance on conventional air conditioning, radiative cooling can alleviate pressure on power grids, lower energy consumption, and decrease greenhouse gas emissions. Further research and development are focused on improving the performance and durability of radiative cooling materials, as well as exploring new applications in buildings, transportation, and clothing.