The long march of the desert

Three billion people, out of a total population of over seven-and-a-half billion residents, live in arid zones throughout the planet. These areas cover 46 per cent of surface lands and are at risk of degrading due to desertification, the transformation into desert of arid or semi-arid zones that are still homes to activities related to crops and livestock. This process is facilitated by natural events such as drought, but also by uncontrolled exploitation by humans. The advance of desertification and the degradation of soil could lead, by mid-century, to a reduction of at least 10 per cent of worldwide harvests, a 30 per cent increase in food prices and poverty for 135 million farmers. The migratory movements that will derive from it will likely bring instability and tension. The Great Green Wall is an ambitious initiative designed to ...