57. 13th-Century Environmentalism

Genghis Khan is known around the world as the ruthless leader and founder of the Mongol Empire. His battles and conquests changed the course of history. Surprisingly, he also inadvertently helped the environment. This is dark, but a recent study suggests that Genghis Khan killed so many peasants and soldiers during his conquests that it eliminated enough CO2 “to offset a year’s worth of the world’s gasoline demand today.”

Woah. During the course of his rule, Genghis Khan and his forces killed about 40 million people. That accounted for almost 10% of the world’s population in the 1200s! Genghis Khan created the largest empire in recorded history. It’s no surprise he had to do so by force and violence, but it’s pretty bleak when you think about it on such a large scale.