Budyko–Sellers model and ice–albedo feedback

Summary

The Budyko–Sellers model is a one-dimensional energy balance model in which the temperature depends on latitude. Its albedo jumps from a low to a high value where the surface is cold enough to be covered by ice. Mikhail Budyko and William Sellers introduced such models independently in 1969. The temperature-dependent albedo creates the ice–albedo feedback: cooling extends the ice, the ice reflects more sunlight, and the reflection causes further cooling. Because of this positive feedback the model can have several stable climates for the same sunlight, including a completely ice-covered one.