The Biggest Megadrought: The mid-Holocene (re)emergence of the Sahara Desert and its climatic and cultural impacts
Peter B. deMenocal, Columbia University
Location: Kline Geology Lab 123
Climate shapes life across a range of time and space scales - seasons pace the cycle of death and renewal, and biodiversity is bounded by latitude. Did climate also shape us? The African Humid Period is one of the best and oldest examples of human cultural responses to climate change. Between 15,000-5,000 years ago the Saharan desert supported grassy, wooded plains, large lakes, and clusters of human settlements due to orbital increases in monsoonal rainfall. While there is an ongoing debate whether the end of this wet phase was fast (centuries) or slow (millennia), the rich archeological record shows that this region was depopulated and, within centuries, the first settlements appear along the Nile River near 5 ka BP. Many “firsts” are associated with these predynastic cultures of the Naqada III Period including the first named kings, pyramids, and hieroglyphs, resulting in political unification and Dynastic rule along the Nile.