The city states of the ancient Mayan empire flourished in southern Mexico and northern Central America for about six centuries. Then, around A.D. 900 Mayan civilization disintegrated.

Two new studies examine the reasons for the collapse of the Mayan culture, finding the Mayans themselves contributed to the downfall of the empire.

Scientists have found that drought played a key role, but the Mayans appear to have exacerbated the problem by cutting down the jungle canopy to make way for cities and crops, according to researchers who used climate-model simulations to see how much deforestation aggravated the drought.