PerspectiveClimate Change

Out of the African Humid Period

See allHide authors and affiliations

Science  15 Nov 2013:
Vol. 342, Issue 6160, pp. 808-809
DOI: 10.1126/science.1246519

You are currently viewing the summary.

View Full Text

Summary

During the last deglaciation, climatic changes allowed human societies to develop and flourish in the subtropical zone from North Africa to Asia. On page 843 of this issue, Tierney and deMenocal (1) report details of these climatic changes in North Africa. They show that between 21,000 and 11,500 calendar years before present (cal. yr B.P.), millennium-long periods of subtropical aridity corresponded to transient phases of intense iceberg melting into the North Atlantic. The Holocene period, starting ∼11,500 cal. yr B.P., was characterized by a prominent increase in rainfall triggered by summer insolation values higher than those of today. The spatial extent and temporal limits of this period, called the African Humid Period in North Africa, are still debated (see the figure).