The ancient Maya lived in tropical forests. But they wanted to plant corn. They needed firewood to heat their homes. And they built temples, pyramids, and cities. So they cut down countless trees and clear-cut large areas of land. Experts believe this led to the end of the Maya empire. When a drought struck in 900 CE, the Maya didn’t have the resources they needed to survive. Today, much of the land has returned to rainforest. But 1,100 years after the deforestation, a new study suggests that the soil can’t hold as much carbon as it once did. When the Maya cut down the trees, they changed the ecosystem forever.