Nearly all of the Algerian Saharan territory is surrounded by state made wall (dune) of 2-5 meters high. Morocco also has similar and several walls: https://en

Nearly all of the Algerian Saharan territory is surrounded by state made wall (dune) of 2-5 meters high. Morocco also has similar and several walls: https://en.wikipedia.org/wiki/Moroccan_Western_Sahara_Wall https://en.wikipedia.org/wiki/Moroccan_Western_Sahara_Wall If there is money and resources to build and maintain such walls, there should be more will and good intentions to build green walls which are more useful.