The demographic response to Holocene climate change in the Sahara

The timing and development of Holocene human occupation in the now hyperarid Sahara has major implications for understanding links between climate change, demography and cultural adaptation. Here we use summed probability distributions from 3287 calibrated C-14 dates from 1011 archaeological sites to demonstrate a major and rapid demographic shift between 10,500 and 5500 years BP. This event corresponds with the African Humid Period (AHP) and is sub-continental in scale, indicating climate as the prime factor driving broad-scale population dynamics in northern Africa. Furthermore, by providing a high temporal resolution proxy for effective carrying capacity our population curve offers an independent estimate of environmental change in northern Africa, indicating a temporal delay in the terrestrial response to atmospheric climate change. These results highlight the degree to which human demography is a function of environment at the appropriate scale of observation in both time and space and sheds important new light on the social response to global environmental change. (C) 2014 The Authors. Published by Elsevier Ltd.