How Much of Earth's Land Surface Is Desert?

Deserts cover approximately 33.5 million square kilometers (12.9 million square miles), representing about one-fifth (20–25%) of Earth's total land surface area. This includes hot deserts (Sahara, Arabian, Australian), cold deserts (Gobi, Patagonian, Great Basin), and polar deserts (Antarctic, Arctic). The Antarctic Desert alone accounts for ~14 million km².