UNEP officials have called for $480 billion to be spent on 'anti-desertification' measures over the next twenty years.The claim, used by officials at UNEP in support of their demands for funds, that the Sahara is expanding, inexorably southwards, is based on evidence of dubious scientific validity. More rigorous scientific studies show no such desert encroachment. It is untrue that peasants and nomads, acting out of stupidity and ifnorance, and the primary cause of land degradation in the developing world.