The Sahel is a region of semiarid grassland and desert along the edge of the Sahara Desert. Sahel means "shore" in Arabic, which probably refers to the ocean of sand it borders. South of the Sahel you will find central African rainforests, and the Atlantic Ocean and the Red Sea are to the west and east, respectively. The area covers about 1.1 million square miles (3 million square km) and includes Mali, Mauritania, Niger, Senegal, Sudan, Burkina Faso, Chad, the Gambia and Guinea-Bissau.
The region's inhabitants number 50 million people. It is one of the least affluent places in the world; public utilities are in short supply and open sewers are common. Most people subsist by means of agriculture or putting animals to pasture (pastoralism). Some are itinerant animal herders, but most survive by growing crops such as sorghum, millet and cotton.
While many scientists believe changes in ocean temperature are mostly responsible for patterns of decreased rainfall in the African Sahel, human behaviors are also to blame. Poverty conditions in the region often lead to overfarming, overgrazing, and other unsustainable practices, which contribute to negative drought conditions. Population numbers in the Sahel are expected to double to 100 million people in 2020 and then double again to 200 million people by 2050 [source: IRIN].
The World Health Organization (WHO) predicts that as temperatures rise and drought conditions continue, outbreaks of cholera and dengue fever will become more common [source: IRIN]. Workers are crowding urban areas due to dried up lands. Food, water, productive soil and grass for grazing are scarce. All of these factors contribute to a cycle in which the climate worsens human conditions, and resulting human behaviors worsen the climate.
Some government officials and private citizens are trying to reverse this destruction. Eleven African nations have joined forces to promote the creation of a Great Green Wall (GGW) that would stretch the width of the continent, from Senegal to Djibouti; this "wall" would be a 9.3 mile (15 kilometer) strip of forest that could help stop the southward spread of the Sahara [source: Godoy]. A method called farmer-managed natural regeneration (FMNR) promotes planting trees alongside crops to retain and improve sandy soil. As of 2005, the border between Niger (where farmers controlled their own land and planted trees) and Nigeria (where FMNR was not widely practiced) was clearly visible in satellite photos. Chris Reij of VU University Amsterdam estimates that farmers in Niger have reclaimed 12.5 million acres (5 million hectares) of land and planted 200 million trees [source: Hertsgaard].
Nomads in Chad migrate with the rains that grow grass for cattle. (Michael Nichols/National Geographic/Getty Images)
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