Rise and fall of Maya civilization linked to climate change


In a recent study, an international group of researchers examined the timelines represented by both Mayan hieroglyphics and a stalagmite from a cave in Belize. The group found that a period of extreme weather, lasting several decades, preceded the collapse of the Maya civilization.

Stalagmites form in caves as mineral-rich water drips from stalactites hanging from the cave ceiling. The minerals in the water collect over time and form a rocky spire that reaches towards the stalactite above it. The researchers generated a 2,000 year record of rainfall using the stalagmite from the Belize cave — located just over a kilometre from Uxbenka, the earliest known Mayan state in the lowlands of the country — by dating oxygen isotopes every 100 micrometres along its length.

They then compared this rainfall record to carvings at several Mayan sites, using the Maya Hieroglyphic Database Project at the University of California - Davis' Native American Language Center. They found that during times of increased rainfall — between 300 and 660 A.D. — the Mayan culture prospered and grew, and during periods of reduced rainfall — from 660 to 1000 A.D. — there was greater political competition, warfare between states, social unrest and an eventual collapse of their society.

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"It has long been suspected that weather events can cause a lot of political unrest and subject societies to disease and invasion," said study co-author Martha Macri, who is director of the UC Davis Native American Language Center.

"But now it's clear. There is physical evidence that correlates right along with it. We are dependent on climatological events that are beyond our control."

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"It's a cautionary tale about how fragile our political structure might be," said co-author Bruce Winterhalder, a professor of anthropology at UC Davis.

"Are we in danger the same way the Classic Maya were in danger? I don't know. But I suspect that just before their rapid descent and disappearance, Maya political elites were quite confident about their achievements."