How much of the world is coverd by desert?

Approximately one-third of the Earth's land surface is covered by deserts. Deserts are regions that receive very little rainfall, typically less than 250 millimeters (10 inches) per year. They are characterized by sparse vegetation, extreme temperatures, and a lack of permanent water sources. The largest deserts in the world include the Sahara in Africa, the Arabian Desert in the Middle East, and the Gobi Desert in Asia. Deserts can be found on all continents except Antarctica.