The current discussion of “sustainability” focuses on aspects of conserving the environmental status quo. However, the environmental history of the desert belts is characterized by strong environmental fluctuations, and modern technology started to irreversibly change societies living in arid regions, initiating a growth which long since crossed the limits that could be supported by renewable resources. Due to these conditions, it seems unlikely that “sustainability” in the conservative meaning of preserving the status quo will be feasible in the desert belts. In fact, Progressive Development is already implemented, though not recognised as such and without coordinating master plans.