Albedo - (n.)

Meaning "whiteness,” albedo is a measure of the reflectivity of a surface. If a surface has an albedo of 40%, it means that 40% of the light falling on a surface is reflected. The planetary albedo of Earth is its reflectivity as seen from space (near 30%). Also, there is cloud albedo and ground albedo. The ocean, on the whole, has a low albedo, as do forests. The deserts have high albedo, while fresh snow has the highest albedo of the common surfaces on Earth.