Data sources: Tucker, C.J., H.E. Dregne, and W.W. Newcomb, 1991. Expansion and contraction of the Sahara Desert from 1980 to 1990. Science 253, 299-301; Hulme, M. and M. Kelly, 1993. Exploring the links between desertification and climate change. Environment 35:6, 5-11, 39-45.
This site last updated June 14, 1997.