Drylands, where in some years at least all precipitation simply evaporates, account for more than one third of the Earth's total land mass. They are home to a large percentage of the world's population, who try to eke out an existence there. More than two billion people live in these areas, and of them some 70 per cent live in rural areas, where they depend directly or indirectly on agriculture for their survival. Developing countries in particular suffer most from the degradation of land and natural resources. The world's fifty least developed countries are particularly threatened by desertification. That threat is especially great in Africa, where 65 per cent of the arable land, 31 per cent of grazing land and 19 per cent of forests are considered to be damaged.
