The United Nations Water Conference (in Argentina in March 1977) and the United Nations Conference to Combat Desertification (in Kenya in August 1977) reflect the worldwide attention that recent global food shortages and growing populations have drawn to the destruction of arable and potentially arable land. This collection of articles focuses on a primary form of such destruction: desertification-the creation of desert-like conditions in arid or semiarid regions either by changes in climate patterns or by human mismanagement, or both. The contributors-representing a range of disciplines-examine and evaluate the social, political, economic, environmental, and technical problems related to the causes and effects of desertification.