Desertification

Impacts

An area severely impacted by desertification is the African Sahel, the semi-arid band that borders the southern margin of the Sahara Desert and extends from Senegal to Eritrea. For many centuries, the nomadic herders followed the northward and southward shifting rains and grasslands. However, during the 1960s and 1970s, the population of the region dramatically [Page 104]increased, especially in urban areas. In 1976, after the first famine, the Institute of the Sahel was founded. The members are the eight countries of the Sahel: Mali, Niger, Burkina Faso, Chad, the Gambia, Mauritania, Guinea-Bassau, and Senegal. The Cape Verde Islands of the Atlantic are also undergoing desertification as the dust clouds from the Sahara suppress rains.

In West Africa, the long-term decline in rainfall from the 1970s to the 1990s caused a southward shift of the Sahelian, Sudanese, and Guinean ecological zones by approximately 15–21 miles. This shift resulted in a loss of grassland, acacia, other flora, and species of fauna. In regions of southern Africa, there is a moderate to high risk of desertification in approximately half of the sub-humid and semi-arid regions.

For the period 1990–2002, the average annual population growth in North Africa was the world's highest, at 2.9 percent. This explosion led to overgrazing, which severely degraded the land. The droughts returned in the early 1990s, and the water table in some areas sank below the root networks of the trees, which shriveled and died where they stood. In the eastern part of the region in Somalia, political unrest and starvation led to the deaths of 300,000 people and 3.5 million cattle.

Agriculture is a critical component of local livelihoods and the national Gross Domestic Product (GDP) in many countries in Africa. The portion of agriculture accounting for the total GDP is different for various countries, but estimates show an average contribution of 21 percent of GDP. This sector is particularly sensitive to land degradation, which results in the loss of productivity. Areas undergoing desertification are ranked such that a moderate hazard area has an average of 10 to 25 percent drop in agricultural productivity; a high hazard area has a 25 to 50 percent drop; and a very high hazard area has more than a 50 percent decline in agricultural output. Other natural resource challenges such as pests, crop diseases, poor soil fertility, and a lack of access to infrastructure providing water are usually aggravated by periods of prolonged drought and desertification. Currently, almost half (46 percent) of Africa's land area is vulnerable to desertification.

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