SOME 3.6 billion ha of the world's drylands -- about a third of the total -- are today lying in a state of degradation. The world would earn some US $42 billion every year in extra income if these lands were nursed back to health. Most of this income loss -- some US $30 billion -- is in the poor countries of Asia and Africa. The UN Environment Programme (UNEP) estimates that US $8.6-18.2 billion are needed every year for 20 years to rehabilitate these lands. The longer we neglect these lands, the costlier it will become to revive them. In 1980, UNEP had said the annual financial requirement to reverse land degradation was about US $4.5 billion -- only about a quarter to a third of what it is now.