AGU conference on climate and civilizations
Ancient trash piles yield Everglades trees, plus 'green' Vikings and more in meeting news
By Science News
AGU Chapman Conference on Climates, Past Landscapes, and Civilizations, Santa Fe, N.M., March 22, 2011
The drying of Africa
SANTA FE — About 2 million years ago seesawing ocean temperatures caused eastern Africa to dry out, new research suggests, setting the stage for early human evolution. Before that time, the world’s tropical oceans were pretty much the same temperature from east to west across their basins. But then for unknown reasons strong gradients developed; the western Pacific warmed up, for instance, while the east cooled. That shift changed tropical weather patterns and dried out eastern Africa. Peter deMenocal of the Lamont-Doherty Earth Observatory in Palisades, N.Y., reported the finding, which may resolve a longstanding mystery, on March 22. —