Sahara made slow transition from green to desert: study

0 Comments | AFP, May, 2008

WASHINGTON (AFP) — The Sahara became the world's biggest hot desert some 2,700 years ago after a very slow fade from green, according to a new study which clashes with the theory that desertification came abruptly.

Six thousand years ago, the massive arid region dominating northern Africa was quite green, a patchwork of trees and savannas as well as many sparkling lakes.

The region, larger than Australia, also was inhabited, according to the European-US-Canadian team of scientists behind a study in Science dated May 9.

Most of the physical elements that could tell the tale of the Sahara's geographic evolution have been lost. The scientists studied layers of sediment in one of the largest remaining Sahara lakes, Yoa, in a remote spot in northern Chad, which...