The ancient Maya civilization may have risen - and fallen - in response to climate change, report scientists.
The findings appear in the Science journal, and show that the early classic Maya period - about A.D. 450 to 660 - "was remarkably wet. There was a proliferation of population, an increase in agriculture and a rise in divine kings that became prominent leaders."
But then things dried up.
The researchers compared the climate record with an existing "war index" - a log of hostile events based on how often certain keywords occurred in Maya inscriptions on stone monuments - and found a strong correlation between drought and warfare between cities.