A (Very) Short History of the Collapse of Civilizations, and Why it Matters

by Davidmanheim2 min read30th Aug 202016 comments

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Civilizational Collapse & RecoveryHistoryExistential Risk
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If we are worried about risks to society as a whole, one valuable question is whether there have been historical analogues and/or near misses. The current dislocation, prompted by the pandemic, but by no means limited to that, seems like a worrying piece of evidence. In the post, I review the basic fact that previous collapses have occurred, and then talk a bit more about whether the evidence matters.

Related Posts: Pawntoe4's On Collapse Risk (C-Risk), landfish's Update on civilizational collapse research, MichealA's Sources on Civilizational Collapse Risks, and Denkenberger's Loss of Industrial Civilization and Recovery (Workshop)


Can civilizations collapse? (Yes.)

Local collapses have long-occurred, from the collapse of Mesopotamia more than four millennia ago, due to drought and agricultural failures, to the decline of Greece, due largely to political infighting, to the fall of the Roman, Ghanan, Malian, or Songhai Empires, each due to a combination of politics, economics, and external invasions. In each case, the populations suffered, many died, and none ever recovered their pre-eminence. This seems like an obvious catastrophe, but short of an existential risk.

However, a collapse like that of the Roman empire has effects that last for centuries even when recovery occurs. The recovery came slowly, despite the Merovingians, then Carolingians, then the Holy Roman Empire and the Muslim world attempting to continue or build upon various parts of Roman civilization and scholarship - and each themselves collapsing before even reaching the level the Romans managed. Global civilization could fall far more precipitously, with even less ability to recover.

How Frequent are Collapses?

This is unclear, and plausibly important. Luke Kemp at Cambridge CSER has a short review of ancient civilizations, which seems fairly useful at getting a better handle on this. But similar to my argument about people's former underestimation of risks from natural pandemics, I think there are good reasons to treat the historical evidence as partial, and as a lower bound rather than a strong prior.

It seems unclear how often these were supplanted, conquered, or dissolved / crashed. Documentation of crashes is partial, and depends on having records that are clear. Many conquered nations were plausibly ready to collapse, and simply failed to have a hydraulic empire dynamic that made collapse, rather than revolt or invasion, the only option. Today's civilization is similar in some ways, but as the world gets smaller, there is no outside culture to invade.

What does this imply about Modern Civilization?

As noted above, it seems unclear how historical events matter for larger scale risk now in various ways- not that they aren't evidence, but it's unclear how to use the base rates usefully. Many of these failure modes which were local then, and didn't have knock-on impacts, could be more critical now. On the other hand, they may be less critical given interconnections.

Modern global civilization is more robust to many types of failure, more unified, and in some ways more fragile. A local collapse could be contained, as happened after the devastation of Europe during World War Two, or the former Soviet block after the fall of communism. In each case, the shock was absorbed by the larger global economy, and the local impacts were drastic and lasted decades, but the decline in living standards was short term, on the order of a single lifetime, and it seems clear that global progress more than compensated in the medium term.

A global collapse, however, would plausibly leave no outsiders or successors to pick up the baton, as Rome did for Greece. The lack of successors to pick up the pieces, along with the availability of weapons that could wipe out all human life, and global-scale threats like climate change, makes a modern collapse at least plausibly far more dangerous for humanity's future. And even if the collapse isn't global, even a single major actor's collapse, like the fall of the Soviet Union, or the seemingly still-ongoing collapse of the United States, greatly increases certain risks.

The Future / Post-Script

I just wrote a paper on technological collapse and fragility, entitled The Fragile World Hypothesis, making the much more abstract case that there is at least one mode where a water-empire collapse happens to humanity, and is an existential rather than just catastrophic threat. In the paper, which was just published in print, I argue that fragility of technological systems is increasing, and it does so in ways we should be worried about far more for the future. I won't repeat that argument here.

The above post is mostly from some notes from that paper which were cut because they were not critical for the main claims, but I think they are worth presenting as a reminder that collapse isn't as rare as we might assume. It also seems worth building more understanding around the cases which occurred in the past, and how it does or doesn't inform our current concerns - I'd be happy to see people do more work on this. This seems like a great place for a non-technical social scientist research project to make a significant contribution - but only if it's done a bit more rigorously than a post like this one. Feel free to be in touch.)

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