Ancient rains made Sahara livable
By Bruce Bower
Today, no one lives in the parched eastern Sahara desert of Egypt, Sudan, Libya, and Chad. But between 10,500 and 7,300 years ago, monsoon rains transformed this region into a lush magnet for people, a new investigation suggests.
A gradual decline in rainfall and water sources from 7,300 to 5,500 years ago pushed Sahara residents into a few still-verdant outposts, say Rudolph Kuper and Stefan Kröpelin, both of the University of Cologne in Germany. This population shift contributed to the rise of Egyptian civilization by around 5,000 years ago, the researchers propose in the Aug. 11 Science.