At a Glance

Mystery has surrounded the downfall of the classical civilization, with researchers hotly debating what might have happened to the people.Theories have included invasion, war, environmental degradation and collapsing trade routes.A new study says annual precipitation decreased between 41 percent and 54 percent during the period of the collapse.

A lengthy, extreme drought may have contributed to the collapse of the Maya civilization, a new study says.

Mystery continues to swirl aroundthe downfall of the classical civilization, with researchers hotly debating what might have happened to the dynasty that once ruled in Mexico. Some theories have included invasion, war, environmental degradation and collapsing trade routes, but one theory that has prevailed is the possibility of a catastrophic change in climate.

David Hodell, director of Cambridge’s Godwin Laboratory for Palaeoclimate Research and the senior author of thestudy,was the first to provide physical evidence in 1995 of a link between a lengthy period of drought at Lake Chichancanab in the Yucatán Peninsula, where Mayas were based, and the collapse of the civilization.

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Lake Chichancanab in Mexico’s Yucatán Peninsula where the Maya were based.

(University of Cambridge)

Most recently, researchers including Hodell from Britain'sUniversity of Cambridge and others from the University of Florida took the professor's theory a step forward by developing a method that measures different isotopes of water trapped in gypsum, a mineral that forms during times of drought when water levels lower. The research team used their method to measure the isotopes at at the center of Maya lands, according to a press release.

Their findings published last week in the journal Science revealed that between 41 percent and 54 percent relative to today during the period of the Maya civilization’s collapse. They also noted periods of up to 70 percent rainfall reduction during peak drought conditions and a 2 percent decreasein relative humidity.

“The role of climate change in the collapse of Classic Maya civilizationis somewhat controversial, partly because previous records are limited to qualitative reconstructions,” said lead author Nick Evans, a doctorate student in Cambridge’s Department of Earth Sciences. “Our study represents a substantial advance as it provides statistically robust estimates of rainfall and humidity levels during the Maya downfall.”

It was during the 9th century that a major political collapse occurred in the central Maya region. The civilization's famed limestone cities, the ruins of which still dot the Yucatán Peninsula's landscape today,were abandoned and dynasties were ended. While the Maya people survived beyond the downfall, their political and economic power was ended.

The researchers say their findings can be used to "better predict how these drought conditions may have affected agriculture, including yields of the Maya’s staple crops, such as maize."