The ancient Maya were an innovative people. They constructed intricate cities throughout the tropical lowlands of the Yucatán Peninsula, communicated using one of the world’s first written languages, and created two calendar systems by studying the stars. But despite their achievements, the thriving Mayan civilization mysteriously collapsed sometime between the eighth and ninth centuries. We still don’t know exactly why.
The general consensus is that the Mayan collapse was caused by a number of things, including disease, war, and other sociopolitical conflicts. One natural factor may have contributed to all of these issues: drought. A particularly bad drought would have made it difficult for the Maya to collect enough drinking water and to irrigate their crops. It also could have encouraged the spread of disease and increased the strain between Mayan leaders and their people.
Now, a new study quantifies just how harsh the Mayan droughts were.
“We already knew that final stages of the Terminal Classic Maya period were characterized by severe droughts,” Fernando Gázquez-Sánchez, a study author and geochemist at St. Andrew University in Scotland, told Gizmodo. “However, our investigation evaluates the intensity of these dry periods.”
By analyzing sediment from Lake Chichancanab in the Yucatán Peninsula, Gázquez-Sánchez and his colleagues found that compared to today, annual rainfall decreased by between 41 percent and 54 percent over the multi-decade Mayan drought. When the drought was most severe, rainfall plummeted by as much as 70 percent, the researchers wrote in their study published Thursday in Science.
“This really represents the next step in understanding how drought affected the Ancient Maya,” Peter Douglas, a geochemist from McGill University who did not work on the study, told Gizmodo. “The authors are using very refined analytical techniques… and the result is that the droughts must have been very bad.”