Natural soil fertility is now declining on an estimated one-fifth of the world's croplands. Direct evidence of the mounting pressures on the global cropland base is seen in accelerating soil erosion, the spread of deserts, and the loss of cropland to nonfarm uses. (Author/BB)

The report identifies regions in which deserts and arid zones are increasing; discusses social and climatic causes of deserts; and suggests ways to cope with and reverse problems of famine, malnutrition, and drought. Increasingly, land is being sapped of its ability to sustain agriculture and human habitation north and south of the Sahara, in…