Friday, April 9, 2021

How Resource Depletion Leads to Collapse. The Story of a Lost Kingdom

The Garamantes were a North-African civilization that grew at the time of the Roman Empire. They were powerful enough that the Romans had to build a system of fortifications to defend their possessions on the coast. But the Garamantes ran out of their water resources and they faded, leaving little trace in history, except ruins, some graffiti on rocks, and a few lines written by ancient historians

The idea that a civilization may collapse because of resource depletion is often hard to believe for historians. They seem to believe that society is such a complex entity that it is impossible to find a single reason for it to collapse. And, yet, it is typical of complex systems that an external perturbation generates a cascade of feedback effects that may mask their origin and make it appear as a series of events had somehow cooperated to bring down the whole structure. But it is all the effect of that initial perturbation unbalancing the whole system: it is the straw that brought down the overloaded camel. This is the basic idea of what I call the "Seneca Collapse." 

The Garamantes were a classic case of a civilization that collapsed because they ran out of an unreplaceable resource: in this case, water. They were an interesting case of a society that had grown and prospered in a barren land, in the middle of the Sahara desert. 

But they were able to prosper by means of a sophisticated irrigation system. It is called the foggara technology in North Africa, in Persian it is kārēz and in Arabic Qanat(image from Wikipedia)

It is a sophisticated technology but it has a defect: it uses a non-renewable technology, fossil water. When the Garamantes started deploying these systems of wells and channels, around the last part of the 1st millennium BCE, it may be that the Sahara still contained relatively large underground aquifers inherited from the time when it had been green a lush with forests, about 10,000 years ago. (image source)
The water bonanza led the Garamantes to become a major regional power, enough to force the Romans to build fortifications to defend their coastal possessions and to use as starting points to launch raids into the Garamantes territory. Caesar fought and defeated them, while the last confrontation we know of was a military expedition launched by Emperor Septimius Severus, who is said to have captured the capital city of Garama in 202 AD. But the Romans never settled in that region.

In the end, the prosperity of the Garamantes was short-lived and they declined in parallel with the Roman empire, even though for different reasons. The story is described by David Keys in his article titled "Kingdom of the Sands." Clearly, Keys understands perfectly well how resource depletion takes down kingdoms and empires. It is not so much a question of running out of the resource. It is that you run out of the means to exploit it (in the case of the Garamantes, slaves).

In the end, depletion of easily mined fossil water sounded the death knell of the Garamantian kingdom. After extracting at least 30 billion gallons of water over some 600 years, the fourth-century A.D. Garamantes discovered that the water was literally running out. To deal with the problem, they would have needed to add more man-made underground tributaries to existing tunnels and dig additional deeper, much longer water-extraction tunnels. For that, they would have needed vastly more slaves than they had. The water difficulties must have led to food shortages, population reductions, and political instability (local defensive structures from this era may be evidence for political fragmentation). Conquering more territories and pulling in more slaves was therefore simply not militarily feasible. The magic equation between population and military and economic power on the one hand and slave-acquisition capability and water extraction on the other no longer balanced.

The desert kingdom declined and fractured into small chiefdoms and was absorbed into the emerging Islamic world. Like its more famous Roman neighbor, the once-great Saharan kingdom became, little by little, simply a thing of myth and memory. Along with the rest of the world, Berbers living in the Fazzan today have all but forgotten their ancestors. The kingdom's legacy has faded so dramatically that local residents believe the vast water-extraction system--the pride of the Garamantes--is the handiwork of Romans.

It seems that the city of Garama still existed when it was conquered by the Arabs, during the 7th century AD but, after that, there are no more records about it. 

It is curious how little is left of a kingdom that, once, was powerful enough to challenge the mighty Roman Empire. We have only fragments of knowledge of a civilization that was considered already remote and mysterious during classical times. Today, the Garamantes are mentioned by Jorge Luis Borges in his masterpiece "El Immortal" as people who "keep their women in common and nourish themselves with lions." The Garamantes are one of the civilizations you can choose to play in Sid Meier's Civilization V. And we have a few more snippets, including a recent novel (2018) that features an archaeological search in the former land of the Garamantes. I figure that if there existed a list of the worst novels in history, this one would make it to the top (that's why I don't give you the link, but if you like to harm yourself, ask me privately!)

And so it goes, civilizations grow, become powerful, then they are lost in the sand. That was the destiny of the Garamantes. What will be left of ours, well, it is all to be seen. But they say that humans always march toward the forest, leaving the desert at their back. And the Earth is round.



  1. >I figure that if there existed a list of the worst novels in history, this one would make it to the top (that's why I don't give you the link, but if you like to harm yourself, ask me privately!)

    Ugo, you can't leave us hanging with suspense like this :)


      Maybe one of these days, I'll posts some excerpts. "The dessert of Libya" is an example among many

    2. An excerpt, but it doesn't really reflect the unbelievable dullness of the whole thing.

      As I walk up to the entrance to be kindly greeted by the handsome receptionist in a blue and gold embroidered suit, the silk pink and brown curtains flow in the wind to wrap around me. I was just about to say Hi, when the softness of the curtained door just had me in a trance. The handsome receptionist named Ahabuk, lean and muscular, tan with light green eyes brushed the silk curtains that engulfed me off to the side with a sweet sensual touch that had chills and a sigh run through me as I gazed into his eyes and all my train of thoughts just ceased for the moment. He said to me, “Miss, are these your bags?”, as the taxi driver dropped them off at the front desk before me. I fumbled with my words, as I caught a small drool at the side of my lips, “oh yes”, in an extended form of the phrase while staring deep into his eyes that were lingering to the rest of him. “Um, yes, yes, those are mine.” “I am the researcher you were expecting.”
      “What room will I be staying in?”
      Ahabuk politely responds “I have your room all set up.” “It will be the one through the hallway, to the right.” “It should be sufficient for your needs and expectations, I hope”, as he jilts a smile at me while his light green eyes twinkle in the moonlight. “oh”, I said as I brushed my brown long hair to one side of my shoulder, “

  2. Ozymandias

    I met a traveller from an antique land,
    Who said—“Two vast and trunkless legs of stone
    Stand in the desert. . . . Near them, on the sand,
    Half sunk a shattered visage lies, whose frown,
    And wrinkled lip, and sneer of cold command,
    Tell that its sculptor well those passions read
    Which yet survive, stamped on these lifeless things,
    The hand that mocked them, and the heart that fed;
    And on the pedestal, these words appear:
    My name is Ozymandias, King of Kings;
    Look on my Works, ye Mighty, and despair!
    Nothing beside remains. Round the decay
    Of that colossal Wreck, boundless and bare
    The lone and level sands stretch far away.”

  3. That must have been self-published.

  4. That should not have been published. Editors exist for a reason, and that's an example of why.

    1. Everything that exists has a reason to exist. So, "The Golden Expedition" may have a reason to exist in the grand scheme of the universe. Who knows? Maybe it is a ciphered message from the Aliens of Betelgeuse!