#4. History's Fiercest Climate Activist

Greta Thunberg and Al Gore have nothing on one of the world’s earliest climate warriors. What if I told you that Genghis Khan–the guy who casually expanded the Mongol Empire like I expand my To-Be-Read list–also helped lower humanity’s carbon footprint? Now, it would be a stretch to say that that was his primary motive, but I like to think that my boy Genghis knew what he was doing.

So how does mass devastation on an unprecedented level result in a greener Earth? As the Mongol hordes laid waste to the armies of Eurasia, they displaced millions of terrified peasants as they fled the onslaught. Entire regions of farmland were abandoned, and with no one left to plow the fields, Mother Nature began her comeback tour. Trees reclaimed huge swaths of agricultural land, and those forests acted as giant carbon sinks, scrubbing CO₂ from the atmosphere at a scale we could only dream of today.

How much CO₂ are we talking about here? Well, according to some estimates, the conquests of Genghis Khan resulted in the removal of about 700 million tons of carbon from the atmosphere. That’s equivalent to the annual global carbon emissions of the entire world today from gasoline. So, in a roundabout way, Genghis Khan might just hold the title for history's most effective, albeit unintentional, climate activist.

Of course, I’m not saying we should adopt Genghis Khan’s methods—there are far more peaceful ways to combat climate change that don’t involve, you know, actual combat. But you have to admit, it’s kind of wild that a man known for conquering half the known world might also get a nod for helping cool the planet—whether he intended to or not.

So don't pat yourself on the back too much the next time you drag your recycling to the curb. You haven't even conquered the known world yet.

(Genghis Khan and the boys riding to save the environment)