a non-renewable resource. What Timberlake calls "environmental bankruptcy" has come about as a result of an intricate process of land degradation whereby the biological potential of the continent and its ability to support populations is severely diminished. There are also two major undertakings that a government can try in order to not only prevent and slow, but to actually restore pastoral areas and eventually farming areas that are currently desert. Desertification affects three principal areas of the continent, namely, Mediterranean Africa, the Sudano-Sahelian region and Africa south of the Sudano-Sahelian. If there is little or nothing that can be saved, the situation changes into that of the Dust Bowl. The rapidly growing demand for charcoal among urban populations is leading to severe desertification within a 40-50km radius of many large urban centres in eastern Africa and the Sahel. Quite often the measures do not start from a base that is founded on traditional practice, with all its well-known adaptations that have given it a resistance to drought stress. This limited success in combating desertification has been attributed to lack of funds on the one hand and an inequitable international economic order on the other.
Observers describe hillside fields that have been eroded down to bedrock in the course of a decade or two. While both are key factors, there are other important issues. In some parts of the Sudano-Sahelian region, soil erosion figures as high as 450 tons per ha per year are not unusual. The first is intervention on "topography and soils: contour terracing, scarification, plowing, water-spreading techniques, and fertilization. At the United Nations Conference on Environment and.
One-third of this area is hyper-arid deserts (672 million ha). Once eroded, its loss is permanent. At sites in the Western Kalahari, daily maximum and minimum surface temperatures over bare ground are reported to increase significantly with height above ground level. Trees help trap soil and prevent it from washing or blowing away. They are natural and artificial recovery. There are extensive agricultural drylands, almost three quarters of which are already degraded to some degree. Like African governments, donors prefer projects that will yield quick visible results that can easily be economically quantified. Little account is taken of the needs, skills, experience, wisdom and aspirations of the affected people. This land has lost 25 or more of its fertility and the process is still going.