This program explains what a desert is, why it occurs, what kinds of plant and animal life it sustains, and how that life is adapted to—or adapts to—the lack of water. The primary focus is on the effects of growing populations in arid or semi-arid regions: lack of vegetation leads to overgrazing, humus mineralizes, rare rainfall creates runoff and washes away the remaining topsoil, the soil becomes hard and impermeable to water, dries out, and becomes infertile. Thus the desert grows.

The desert of Thar in northwest India is a case study of the problem, with a population of over 10 million plus 20 million cattle. How can the people of this region survive? How do they feed themselves and their animals? What do they use for shelter and fuel? This example, and that of the Bichnoïs—who have created green oases in the desert—are used to show what can be done. (28 minutes)