A desert is a landscape where little precipitation occurs and, consequently, living conditions create unique biomes and ecosystems. The lack of vegetation exposes the unprotected surface of the ground to denudation. About one-third of the land surface of the Earth is arid or semi-arid. This includes much of the polar regions, where little precipitation occurs, and which are sometimes called polar deserts or “cold deserts”. Deserts can be classified by the amount of precipitation that falls, by the temperature that prevails, by the causes of desertification or by their geographical location.
Here are the top 20 largest deserts in the world.
| Rank | Desert | Type | Area |
| 1. | Antarctic Desert | Polar ice and tundra | 14,200,000 km2 (5,482,651 sq mi) |
| 2. | Arctic Desert | Polar ice and tundra | 13,900,000 km2 (5,366,820 sq mi) |
| 3. | Sahara Desert | Subtropical | 9,200,000 km2 (3,552,140 sq mi) |
| 4. | Great Australian | Subtropical | 2,700,000 km2 (1,042,476 sq mi) |
| 5. | Arabian Desert | Subtropical | 2,330,000 km2 (899,618 sq mi) |
| 6. | Gobi Desert | Cold winter | 1,295,000 km2 (500,002 sq mi) |
| 7. | Kalahari Desert | Subtropical | 900,000 km2 (347,492 sq mi) |
| 8. | Patagonian Desert | Cold winter | 673,000 km2 (259,847 sq mi) |
| 9. | Syrian Desert | Subtropical | 500,000 km2 (193,051 sq mi) |
| 10. | Great Basin | Cold winter | 492,098 km2 (190,000 sq mi) |
| 11. | Chihuahuan Desert | Subtropical | 453,248 km2 (175,000 sq mi) |
| 12. | Karakum Desert | Cold winter | 350,000 km2 (135,136 sq mi) |
| 13. | Colorado Plateau | Cold winter | 337,000 km2 (130,116 sq mi) |
| 14. | Sonoran Desert | Subtropical | 310,000 km2 (119,692 sq mi) |
| 15. | Kyzylkum Desert | Cold winter | 300,000 km2 (115,831 sq mi) |
| 16. | Taklamakan Desert | Cold winter | 270,000 km2 (104,248 sq mi) |
| 17. | Ogaden Desert | Subtropical | 256,000 km2 (98,842 sq mi) |
| 18. | Thar Desert | Subtropical | 238,254 km2 (91,990 sq mi) |
| 19. | Puntland Desert | Subtropical | 200,000 km2 (77,220 sq mi) |
| 20. | Ustyurt Plateau | Temperate | 200,000 km2 (77,220 sq mi) |
