The Maya, who originated around 2600 B.C. in current day Southeastern Mexico, grew to prominence and size during the next three millennia, building temple step-pyramids and developing highly accurate astronomical and calendar systems. Why some of their larger cities were abandoned a thousand years ago is largely a mystery. Though weather shifts have been proposed previously, the stalagmite findings may offer the data that was lacking, said Douglas Kennett, the lead study author....
The scientists found that a wetter period corresponded with an increase in food production, and population growth, from 450 to 660 AD. During this time, cities such as Tikal, Copan and Caracol expanded, and the ancient civilization reached the pinnacle of its power, covering all of Guatemala, Belize, parts of Honduras, El Salvador and Mexico.
A drying period occurred during the next four centuries, punctuated by droughts. Mayan records show an increasing number of wars being fought in this period, and eventually larger cities gave way to smaller settlements, Kennett said.
“You have a loss of a large number of these polities,” he said. “You get this major reduction in the production of these stone monuments -- that’s a reflection of kings losing control and losing power at these primary centers.”
The final blow came with a 90-year drought that started in 1010 AD, leading to the decline of the last of the major Mayan centers.