May 15 - Researchers in Mexico say the mighty Mayan civilization that thrived in central America for 2700 years from 1800 BC, might have been brought down by climate change. Based on research deep underground, the scientists say there's evidence of long-term drought during the period of population decline. Tara Cleary reports.
Ruins of the vast Mayan civilisation - which at its peak, between 250 and 950 AD, ruled much of central America. But then, about a thousand years ago, these temples and palaces were inexplicably abandoned. The mystery of the Mayan disappearance has fascinated scientists for hundreds of years. Now researchers say that these caves in Mexico could hold the answers. Yucatan state investigator Martin Medina Elizalde thinks the nation of 15 million people may have been victims of climate change. He says their society, which was built on agriculture, may have been decimated by drought. The clues are in the stalagmites. SOUNDBITE: PROFESSOR OF INVESTIGATIONS FOR THE CENTRE OF INVESTIGATIONS FOR YUCATAN STATE, MARTIN MEDINA ELIZALDE, SAYING (Spanish): "The chemical composition of stalagmites holds information on climate change and the environment, for example oxygen isotopes reflect the quantity of rain on the surface, reflecting changes in the vegetation and carbon isotopes can also reflect changes in the vegetation. A cave such as this, these sorts of formations, are a book of information about the climate. We can codify these chemicals to reconstruct the climate from years past and also climate change in the environment." Investigators say there was a drop in annual rainfall of between 25 and 40 percent in the region in the ninth century AD -- the period corresponding to the fall of the ancient civilisation. But Medina Elizalde says the complexity of the Mayan culture makes it hard to definitively cite any single reason for its decline. SOUNDBITE: PROFESSOR OF INVESTIGATIONS FOR THE CENTRE OF INVESTIGATIONS FOR YUCATAN STATE, MARTIN MEDINA ELIZALDE, SAYING (Spanish): "Droughts perhaps weren't the only reason for the disintegration of the Mayan civilisation but there is an interest to see if drought or socio-political events contributed to the fall of the civilisation." Today the Mayan cities are a popular destinations for tourists - and for scientists, looking for clues to the civilisation's demise. Tara Cleary, Reuters.