section_path: Major deserts
section_name: Major deserts
paragraph_text: Major deserts
  
  Deserts occupy about one third of Earth's land surface. Bottomlands may be salt -covered flats. Eolian processes are major factors in shaping desert landscapes. Polar deserts (also seen as "cold deserts") have similar features, except the main form of precipitation is snow rather than rain. Antarctica is the world's largest cold desert (composed of about 98% thick continental ice sheet and 2% barren rock). Some of the barren rock is to be found in the so-called Dry Valleys of Antarctica that almost never get snow, which can have ice-encrusted saline lakes that suggest evaporation far greater than the rare snowfall due to the strong katabatic winds that even evaporate ice.
  
  Deserts, both hot and cold, play a part in moderating Earth's temperature, because they reflect more of the incoming light and their albedo is higher than that of forests or the sea.