Barbarian invasions
Many authors have predicted the energy descent will result in mass migrations, leading to large scale population replacement. John Michael Greer has thus stated he considered an Arab conquest of Europe as a distinct possibility… There is certainly an American bias here. America certainly experienced a large scale population replacement in the last three centuries, with natives being progressively swamped out by immigrants from the other side of the sea. This hasn’t happened in Europe for five millenniums.


