An annotated bibliography is presented of 252 references, computer-produced from the University of Arizona's Arid Lands Information System (ALIS), with accompanying text that reviews briefly both cause and effect of world desertification. Causes fall into two categories: long-term (in the geologic sense) climatic change as supported by meteorological, archaeological, gemorphological, vegetational, palynological, and dendrochronological evidence in the literature; and those activities of man's historic occupance of arid and semiarid regions that have contributed to degeneration of marginal lands: agricultural and irrigation practices, grazing, fire, nomadism, and sand stablization and reforestation. Beyond these two categories, there is a third: climatic fluctuation - - short-term weather patterns induced by uncertain rainfall and followed by cyclic droughts from which marginal areas may not recover is subjected to continued attempts at intensive use that cannot be sustained by a dry year or a succession of dry years. Portions of this document are not fully legible.