As a planet, the earth has an average albedo of 0.30, which means that approximately 30% of all incoming solar radiation is immediately reflected back into space, while the remaining 70% is absorbed by the earth and re-emitted as infrared radiation.
Image shows albedo of earth's land masses. Blue indicates low reflectivity and green-white indicates high reflectivity. Courtesy of NASA
Arctic and antarctic snow and ice cover make a significant contribution to earth's albedo. Snow reflects 40-95% of the light that hits it and ice reflects 20-45%. In this way, polar snow and ice have a major impact on earth's overall climate.
Your Turn
Question: How would a warmer climate affect earth's polar albedo?
Hint: Think about the effect of warmer temperatures on snow and ice cover.