Many millions of people have been and are being forced to leave their land and homes because of environmental degradation. Deforestation, mining and other activities in the tropics lead to loss of soil fertility, erosion, flooding, depletion of animal life and many other features which make living in these areas marginal and eventually impossible. As people establish farms on tropical forest land, they are forced to move onward as the land rapidly becomes unsuitable for agriculture, an endless cycle of destruction and desertion. The World Watch Institute (Ryan, 1992) has estimated that, by 1989, at least ten million people had been forced to abandon land because of environmental factors. Eight million of these had left their land in Africa, Asia and Latin America due to land degradation. The other two million had relocated because of “natural” disasters, most of which were of human origin.