Albedo ((free)) Jun 2026

A similar effect occurs on land. Clean, fresh snow covers forests and tundra in winter. As spring arrives earlier due to warming, the snow melts, revealing dark soil or evergreen trees. Those trees have an albedo as low as 0.10. Suddenly, the Northern Hemisphere’s boreal forests stop reflecting sunlight and start aggressively absorbing it, sending spring temperatures soaring.

To visualize albedo, consider these common Earth surfaces: Albedo

The Earth's average albedo is approximately 0.3, which means that about 30% of the solar radiation that hits the planet is reflected back into space. This value is a composite of the albedos of various surfaces, including oceans, continents, ice sheets, and clouds. The albedo of different surfaces varies greatly, ranging from around 0.1 for dark forests to 0.9 for fresh snow. A similar effect occurs on land

The solution is straightforward: increase urban albedo. "Cool roofs" are painted white or coated with reflective materials. Los Angeles famously painted miles of streets with a grayish-white sealant to raise the albedo of asphalt. Studies show that raising a city’s average albedo by just 0.10 can lower peak summer temperatures by 2–3°C, saving billions in energy costs and reducing smog. Those trees have an albedo as low as 0

This math of whiteness governs our climate. The poles stay frozen partly because ice reflects sunlight away, a process called the ice-albedo feedback . It’s a virtuous circle for cold: more ice means more reflection, which means more cold, which means more ice. But when that ice melts, the exposed dark ocean drinks in the heat, accelerating warming and melting yet more ice. The mirror becomes a sponge.

Humans have learned to weaponize albedo—both accidentally and intentionally.