The Sahel region is the semi-arid part of western and north-central Africa that is located between the Sahara in the north, and the humid savannah of the south— much of it being in what was formerly French West Africa.
It covers the region from the Atlantic Ocean, covering northern Senegal, southern Mauritania, Mali, Burkina Faso (formerly Upper Volta), southern Niger, northeastern Nigeria, south-central Chad, and through to the Sudan. Some descriptions have it including a small part of southwestern Morocco (formerly Western Sahara), and going through to Eritrea.
In the second part of the 20th century, with a large increase in the population of the Sahel, there has been massive soil erosion and desertification. Much tree and scrub cover has been removed to allow for the collection of firewood and for the creation of more farmland. Subsequent rainstorms have taken away much of the topsoil, destroying the fertility of the land and turning much of it into wasteland. Overgrazing has continued to make the situation worse, accentuated by bad land management. This in turn has led to the expansion of the Sahara in spite of a number of attempts to prevent this.
A bad drought in 1968 led to the destruction of many of the crops grown in the Sahel, and, with more years of drought in the early 1970s, the problems became worse. In 1972 the entire Sahel received almost no rain, and in the following year the Sahara started increasing up to 60 miles (100 km) a day in the south. Some 100,000 people died from starvation and related diseases in 1973, and, although international relief aid managed to help, severe drought and famine hit the Sahel again in the period 1983–85. In recent years, as the situation has become far worse, it has been associated with global warming and greenhouse gases, although direct human activity is certainly to blame.
The situation was so bad that in 1973 the United Nations Sahelian Office (UNSO) was created to try to address the problems facing the Sahel. The International Fund for Agricultural Development was founded in 1977 to deal with this and similar environmental problems; in the 1990s the United Nations Convention to Combat Desertification (UNCCD) was adopted. Although the UNCCD has managed to make progress, the ecological crisis has exacerbated many tribal and other tensions in the region, such as in Darfur.