What's more, ecologist Liliana M. Dávalos and colleagues have for the first time quantified indirect deforestation tied to coca farming, such as clearing land for growing food crops near coca plantations.

"In southern Colombia we found geographically that there is just more probability of losing the forest close to [coca cultivation]," said Dávalos, of the State University of New York in Stony Brook.

"And the more coca around you, the more forest you're likely to lose—the sheer amount of coca in the vicinity has an effect."

(Related: "Cocaine, Spices, Hormones Found in Drinking Water.")

That means coca cultivation is taking a heavy toll on plant and animal species in one