Yet another reason has emerged for the legalization of marijuana, this one from an unlikely source: environmentalists. According to recent research by Kendra McSweeney of Ohio State University, drug trafficking contributes significantly to deforestation in Central America, National Geographic reported.

"There are profound ecological impacts in trafficking corridors," said McSweeney, whose original goal was to research how indigenous peoples and communities were affected by climate change -- until she noticed an unexpected source of deforestation. "We wondered who had the money and impunity to do that, and when we looked into it we found that the answer was narco-traffickers. The flow of drugs through the region resulted in ecological devastation."

Not only must drug operations clear space, but they also require roads and other transportation features to move products and people. Some outfits build fronts, like palm oil factories, to launder money, clearing even more space and harming more habitats. Not helping matters are the guns and criminal aggression associated with such operations, making it difficult for authorities to enforce conservationist policies, according to the study.

Raiding and shutting down rainforest cartels may not be the most effective solution, according to McSweeney. In fact, it may have the opposite effect, for the disbanded drug ring will likely move to a new location, destroying more land in the process. Instead, measures should focus on both empowering and weakening traffickers. In particular, marijuana restrictions should be lifted, which would remove some of the drug's criminal elements and reduce its demand (and thus the traffickers' power), while also helping large scale farms more efficiently grow and sell.

"That hits their bottom line," McSweeney said, referring to looser restrictions on weed. "and reduces their ability to corrupt officials and launder money through forest destruction."