The Heat Island Group at Lawrence Berkeley National Laboratory works to cool buildings, cities, and the planet by making roofs, pavements, and cars cooler in the sun.
On a sunny summer afternoon, urban air can be 1-3°C (2-5°F) warmer than nearby rural air. The elevated air temperatures associated with this summer “urban heat island” (UHI) make air conditioners work harder to keep buildings cool, which can strain the power grid. They also accelerate the formation of smog, degrading air quality. Visit: Cool Science: Urban Heat Island
On a typical sunny summer afternoon, a clean white roof that reflects 80% of sunlight will stay about 30°C (55°F) cooler than a gray roof that reflects only 20% of sunlight. Visit: Cool Science: Cool Roofs
High solar reflectance can cool pavements, mitigating the summer urban heat island effect by reducing the flow of heat from pavement to air. Visit: Cool Science: Cool Pavements
Increasing the solar reflectance of a car’s shell keeps it cooler when parked in the sun. This permits the use of a smaller air conditioner that draws less power and improves the vehicle’s fuel economy. Visit: Cool Science: Cool Cars
The benefits of cool surfaces are not restricted to buildings and cities; more reflective, cool surfaces result in less heat flowing into the atmosphere, keeping the planet cooler. Visit: Cool Science: Global Cooling