During the summer of 2025, extreme heat waves overwhelmed power grids across North America, Europe, and the Middle East, highlighting the growing strain on energy infrastructure due to global warming and increased air-conditioning demand. A technology rooted in millennia-old principles, enhanced by 21st-century advancements, offers a potential solution: radiative cooling. This method utilizes paints, coatings, and textiles engineered to scatter sunlight and dissipate heat without requiring additional energy.

Radiative cooling is a naturally occurring phenomenon, according to Qiaoqiang Gan, a professor of materials science and applied physics at King Abdullah University of Science and Technology in Saudi Arabia. "Radiative cooling is universal—it exists everywhere in our daily life," Gan said. He explained that objects naturally absorb heat from the sun during the day and release some of it back into the atmosphere at night. This process is exemplified by the condensation that forms on cars parked outdoors overnight, as their metal roofs dissipate heat, cooling the surfaces below the ambient air temperature and leading to dew formation.

Humans have been leveraging this basic natural process for thousands of years. In desert regions of Iran, North Africa, and India, people historically manufactured ice by leaving pools of water exposed to clear desert skies overnight, capitalizing on radiative cooling. Modern science is now refining this concept through advanced materials.

The implications of widespread adoption of radiative cooling technologies are significant. By reducing the need for conventional air-conditioning, these materials could lessen the strain on power grids, lower energy consumption, and decrease greenhouse gas emissions. Further developments in material science are focused on enhancing the efficiency and durability of radiative cooling coatings and textiles, making them more practical and cost-effective for widespread use in buildings, vehicles, and clothing.