Tunisia
Tunisia is probably not a country you give a great deal of thought, which is interesting, if you think about it. The country sits at the apex of the African continent, at the center of the Mediterranean Sea, and a mere 80 nautical miles from Sicily and southern Europe.
Given its pivotal location, you'd expect Tunisia to be a major regional power, and you'd be right—if you visited in 300 B.C. Ancient Carthage (present-day Tunis) controlled coastal North Africa, the Western Mediterranean Islands, and portions of Southern Spain.
But today, Tunisia is... Tunisia.
Why that is is worth a ponder.
5000 years ago, north Africa was a very different place. In particular, it was much wetter, and, in many places, much cooler. The coast was lush and fertile, with seasonal rivers and rolling, grassy hills supporting trees and pastures.
If we were exploring the area, we'd find open grasslands and lakes farther inland, and eventually we'd come to a vast interior savannah—drier, but covered in tall grass and populated with thorn trees and herds of antelope, wild cattle, giraffes, and elephants.
By any standard this was a rich environment for human settlement, but it gave rise only to a scattering of small villages, mostly along the coast, and some semi-nomadic tribes elsewhere—nothing particularly organized or notable. Another way to put that would be, in this time and place of relative abundance, large-scale cooperation wasn't necessary.
Put a pin in that, as they say.
5000 years ago (around 3000 B.C.) turned out to be a very consequential time for the residents of North Africa. The African Humid Period came to a close, driven by shifts in the Earth's orbital configuration. Seasonal rivers ran dry; lakes shrunk, grasslands vanished.
By 2000 B.C. the green savannah belt became the Sahara Desert. Perhaps not paradoxically, here is where the rise of an organized North African human civilization begins.
An ecological catastrophe makes the old way of doing things (small villages and pastoral farming) untenable; as an adaptive response, people gather around the remaining resource pools and innovate together.
A key advance for the soon-to-be Carthaginians was maritime technology—the ability to travel the seas and trade. As the drying interior pushed people to the coast, trade and seafaring made it possible for the region to support an ever-larger population—but only if they worked together!
Circa 814 B.C., Carthage is established by Phoenician traders who themselves took to the sea as a response to resource crowding on their native lands. Now, the peninsula's strategic potential is unlocked, and by 300 B.C., the city of Carthage is a vast economic and military power with no regional peers.
It's possible to imagine a very different future from here. Carthage as an enduring regional trade hub, or even a present-day cosmopolitan world power, bridging two mighty continents. Climate change, however, wasn't finished with North Africa. And across the Mediterranean, another great power was rising.
Aridification continues to escalate, and regional farming concentrates on a narrow strip of land along the coast. Conflict with Rome erupts in 264 B.C. over control of Sicily. Rome will ultimately triumph in the subsequent war, turning Carthage into its vassal and breadbasket.
To feed Rome's voracious appetites, Carthaginian land is heavily farmed for the next six centuries, which, combined with worsening drought-pulses, turns fertile ground to wasteland. This time, the collapse persists into modernity.
You might think of the problem this way: civilizations rise when just-the-right-dose of scarcity triggers a serendipitous response of cooperation and innovation; they collapse when cooperation and innovation are no longer sufficient to meet people's needs.
In other words, there's a stress sweet-spot: not too much, not too little.
If you look for this pattern, you'll find it everywhere. Egypt, for example. Or the Maya. But there's no reason to confine your search to civilizations. You can also ponder this phenomenon as it relates to individuals, and how we respond to differing levels of challenge.
Unlike ancient civilizations, we have a great deal of latitude to change context, and often we have the ability to seek out or withdraw from challenge and/or stress. Whether for civilizations or individuals, life rewards those who adapt.
— September 9, 2025
Andy Lewicky is the author and creator of SierraDescents