Humans as Agents in the Termination of the African Humid Period

Humans responsible for the desertification of the Sahara: Where available, the evidence suggests that there is systematic homogenization of the floral composition of terminal AHP landscapes commensurate with the spread of shrubbery and reduced precipitation. Subsistence choices were predicated on ecological conditions, and early pastoral economies took root against the backdrop of a progressively drying climate. Because humans have been documented as exerting significant pressures on the NPP of prehistoric and historic landscapes elsewhere in the world, it is conceivable that they were also catalysts in accelerating the pace of devegetation in the Sahara at the end of the AHP. This, in turn, would have enhanced albedo, dust entrainment and retarded inland monsoon convection (Kutzbach et al., 1996; Braconnot et al., 1999; Foley et al., 2003; Pausata et al., 2016), pushing pastoralists into new territories to begin the cycle again. The Neolithic quest to maximize ACP may have pounded the final nails into the NPP coffin, and desertification of the Sahara was the end result of the cumulative process.

Leave a Reply