Over 20 African nations are partners in an African Union project aiming to span the width of their continent with regenerative agriculture, green jobs and fertile land.  While the original vision of a wall of trees holding back the Sahel proved impractical, the Great Green Wall has become a metaphor for the revival of indigenous land use techniques. This article in The Smithsonian describes little-known progress in Niger, Burkina Faso, Senegal and Mali.