'In this lovely land of Mareotis, full of villages and splendid churches, so abundant is the soil that wine is produced and is of such quality that it is racked and kept that it may grow old.' That was how, 2,000 years ago, the Roman geographer Strabo described the now desert land to the west of Alexandria.
Today land degradation is on a global scale. In the Sahara, for instance, since the beginning of this century an area the size of Britain, France and Germany has been lost to agriculture. Not because of any long-term change in climate but because of the impact of man. Local people say that Musa Jumbra is 100 years old. He lives in a village called Al Gitarat and it is dying. His family have moved to more fertile land long ago - or to the cities. Although he is not likely to hear about it, next month the United Nations holds a conference to try and tackle the problems of desert encroachment. What options do they have? For their decisions will affect us all - one person in seven lives in the semi-desert land and they manage a third of the world's livestock.
Film cameraman MIKE SPOONER Film editor SIMON HAMMOND Producer RICHARD TAYLOR
Series editors MICHAEL ANDREWS and ANTHONY ISAACS