If true it would be understandable that projects plant green belts in order to defend the Sahel from the invasion. In reality the situation is much more complex. In some places such as parts of North Africa and Mauritania the Sahara directly threatens farming land. It is in fact a natural green belt that protects farmers from the Sahara. This zone is species rich and many perennials growing there produce food in abundance.
Several species grow larger there despite the lower rainfall than in the agricultural zone.
The fauna includes gazelles and desert partridges. The vegetation protects the environment so little wind or water erosion occurs. A UNEP publication confirms that the natural green belt extends across the Sahel. It exists because it is closer to the desert than the agricultural zone and therefore too dry for sustainable millet production. Careless use, however, could easily destroy this zone.