Albedo planet would drop to about 0 °C. In contrast, if the entire Earth was covered by water — a so-called aquaplanet — the average temperature on the planet would rise to almost 27 °C. For land surfaces, it has been shown that the albedo at a particular solar zenith angle "θ" can be approximated by the proportionate sum of two terms: the directional-hemispherical reflectance at that solar zenith angle, formula_1, and the bi-hemispherical reflectance, formula_2, with formula_3 being the proportion of direct radiation from a given solar angle, and formula_4 being the proportion of diffuse illumination. Hence, the actual albedo
Ice–albedo feedback Internal feedback processes may also potentially occur, as land ice melts and causes eustatic sea level rise, and also potentially induces earthquakes as a result of post-glacial rebound, which further disrupts glaciers, ice shelves, etc. Ice–albedo feedback Ice–albedo feedback is a positive feedback climate process where a change in the area of ice caps, glaciers, and sea ice alters the albedo. This change in albedo acts to reinforce the initial alteration in ice area. Cooling tends to increase ice cover and hence the albedo, reducing the amount of solar energy absorbed and leading to more cooling. Conversely, warming tends to