Study Finds a Pattern of Severe Droughts in Africa

For at least 3,000 years, a regular drumbeat of potent droughts, far longer and more severe than any experienced recently, have seared a belt of sub-Saharan Africa that is now home to tens of millions of the world’s poorest people, climate researchers reported in a new study.
That sobering finding, published in the April 17th issue of Science, emerged from the first study of year-by-year climate conditions in the region over the millenniums, based on layered mud and dead trees in a crater lake in Ghana. Although the evidence was drawn from a single water body, Lake Bosumtwi, the researchers said there was evidence that the drought patterns etched in the lakebed extended across a broad swath of West Africa.
http://www.nytimes.com/2009/04/17/science/earth/17drought.html?ref=science