Deserts

Deserts, or lands that receive barely 250 millimetres of precipitation per year on average, evaporate most of the rainfall delivered. Deserts are arid, dry, and parched lands and are on every continent on Earth, covering almost one-fifth of the land. With little water available for plants and other organisms, over one billion people, about a sixth of the world’s population, manage to live in deserts. Sandy deserts with sand dunes only cover 10% of all of the deserts in the world. Deserts can be hot and dry (also known as arid or subtropical), semi-arid, coastal, and cold.