12. Genghis Khan Lowered Carbon Emissions in the Bloodiest Way Possible
In a nutshell, Genghis Khan’s Mongol conquests cooled Earth because so many people were killed that it resulted in reforestation. As the author of the study that examined, that put it: “It’s a common misconception that the human impact on climate began with the large-scale burning of coal and oil in the industrial era … Actually, humans started to influence the environment thousands of years ago by changing the vegetation cover of the Earth‘s landscapes when we cleared forests for agriculture“.
The Mongol invasions that swept across Asia, the Middle East, Russia, and into Central Europe, killed an estimated 40 million people. That was in a world whose population was about 400 million, or roughly a twentieth of the one we live in today. If extrapolated to modern population figures, it would be the equivalent of almost 800 million deaths today, or more than eight times the deaths of World Wars I and II combined. That massive body count meant there were significantly fewer people to engage in activities that emitted carbon. Many regions were depopulated, and vast swathes of what had once been cleared and cultivated fields reverted to forests, whose trees and vegetation absorbed carbon dioxide from the atmosphere.