The Sahara is an important area of North Africa today as it has been for centuries. The customary usage of the “Sahara Desert” is redundant because the Arabic word “ṣaḥra” actually means “desert.” It is composed of numerous smaller deserts, each with its own ecology. Covering most or part of a dozen countries, covering about 3.5 million square miles, and stretching about 3,000 miles from the Atlantic Ocean eastward to the Red Sea, it is the largest hot desert in the world.
With minimal or no rainfall in many parts, the sparse vegetation sustains little life, especially in the sandy areas (ergs), but most of the desert is rocky and the terrain includes wadis, where moisture collects and enables plant growth that in turn allows for some human settlement. Significantly, the Nile River that flows south to north into the Mediterranean Sea through the eastern desert supported the growth of numerous societies, extending back to that of ancient Egypt. Even outside the Nile Valley, about 2.5 million people live there. Other rivers such as the Niger in the Southwest flow westward into the Pacific Ocean. As the extreme aridity corresponds to long-term cycles associated with monsoons, another wet or green phase may be expected in about 15,000 years. Intensive planting along its southern edges is being implemented to partly contain desertification.
Although the terrain seems formidable, it is varied, and in addition to living within or on the desert’s edges, human beings have traversed it for millennia, especially by camel in caravans. The established routes were important not only economically, as they carried trade goods, but politically and religiously; Islam spread across Africa following those routes. Beneath the land as well, tremendous resources are located including fuels—oil, coal, and natural gas; metals such as iron and copper; minerals. especially manganese, phosphate, and uranium.