Deserts

The Middle East and North Africa are one of the driest regions on earth. Nearly two-thirds of the Middle East and North Africa is desert. A desert is land that receives an average of less than ten inches of rain per year. The Sahara Desert of northern Africa is the largest desert in the world. It stretches across 3.5 million square miles, a area larger than the United States if you excluded Alaska and Hawaii. The Rub 'al-Khali, or "Empty Quarter" is a large desert in Saudi Arabia. It is the largest area of continuous sand on earth.

Desert air contains little moisture, so few clouds form over the land. Without clouds to block the sun, temperatures may reach as high as 125°F during the day. At night, without the clouds to contain the heat, the desert temperature can fall to as low as 40°F.

Extreme temperatures combined with little rainfall make desert life difficult for people, plants, and animals. Yet, some life forms have adapted to even the most severe desert environments. Camels are able to survive long periods without food or water. Many desert plants have long, shallow root systems. This allows the plants to reach out to collect water over great distances. Other desert plants have taproots. Taproots grow very deep so they can tap sources of underground water. Plant life in the desert is usually spread out over great distances. This is why deserts are often described as barren, or lifeless.

When many people think of a desert they often think of endless miles of hot sand, but a desert does not have to be hot or sandy. Most of the land of the Middle East and North Africa is hot, dry desert land, but some deserts look very different. Most of Antarctica is a desert but there is no sand on the continent and the climate of Antarctica is the coldest on earth.

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