By Sharon E. Burke
War on the Rocks
The earliest humans had it rough. They survived a brutal ice age, dwindling to a population estimated at just 10,000, only to experience terrible droughts when the ice began to retreat. So they engaged in the oldest climate adaptation strategy in history: They moved.
This first great human migration out of the Horn of Africa happened some 60,000 years ago, and it was disruptive. Everywhere homo sapiens went, they overwhelmed other hominins, setting the genetic foundation for all modern societies around the world. A wildly successful species, humans now number 7.8 billion, consuming habitat and destroying other species at an increasingly fast clip.
In fact, that catastrophic success has set the stage for the next great human migration, once again driven by an unfavorable climate. Over the next 50 years, as many as 3 billion people may be living in increasingly dangerous hot conditions, and a large number may decide to move. This time, the mass migration has the potential to be even more disruptive than its prehistoric predecessor, given how many more people there are now. Just how disruptive that move will be depends a great deal on how the people in the more temperate parts of the world react, and how wealthier populations within those countries handle unequal exposure to climate impacts, both within their own borders and globally.
Picture: Apollo 17 / Public domain