Did climate change kill the Maya ?

With their awe-inspiring architecture and sophisticated concepts of astronomy and mathematics, the Maya were undoubtedly among the great ancient civilizations of Mesoamerica. At the peak of their glory, around 800 A.D., the Maya ranged from Mexico's Yucatán peninsula to Honduras. Then, almost in an instant, a society of some 15 million people imploded, leaving deserted cities, trade routes, and immense pyramids in ruins. The sudden demise is one of the greatest archeological mysteries of our time. What caused the collapse of the great Maya civilization? The answer, say researchers, is climate change. According to a new study published in the current issue of Science, a long period of dry climate, punctuated by three intense droughts, led to the end of the Maya society. "Climate change is to blame for one of the most catastrophic collapses in human history," said Gerald Haug, a professor of geology at the University of Potsdam, Germany, and one of the study's authors.

The drought hypothesis is not new. Sediments taken by scientists in 2001 from a lake on the Yucatan peninsula showed that a series of extended droughts coincided with major cultural upheavals among the Maya people. But the study of that lake also found man-made effects, such as deforestation and soil erosion, and therefore didn't reflect a "pure climate signal," according to Haug. For the new study, the scientists instead analyzed sediment core from the Cariaco Basin off northern Venezuela, where the record is cleaner.