Disclaimer: I am now retired, and am therefore no longer an expert on anything. This blog post presents only my opinions, and anything in it should not be relied on.
Note: My focus in these “reading new thoughts” posts is on new ways of thinking about a topic, not on a review of the books themselves.
Kyle Harper’s “The Fate of Rome” provides new climate-change/disease take on that perennial hot topic “reasons for the fall of Rome.” Its implications for our day seem to me not a reason to assume inevitable catastrophe, but a caution that today’s seemingly resilient global economic structures are not infinitely flexible. I believe that the fate of Rome does indeed raise further questions about our ability to cope with climate change.
Climate Change’s Effect on the Roman Empire
As I understand it, “Fate of Rome” is presented as a drama in 5 acts:
1. A “Roman Climatic Optimum” or “Goldilocks” climate in the Mediterrean allows the development of a state and economic system, centered on Rome and supporting a strong defensive military, that pushes Malthusian boundaries in the period up to about 150 AD.
2. A transitional climatic period arrives, and runs for 200 years. For several decades, the Plague of Cyprian (smallpox) rages and some regions tip into drought, leading to 10-20% population losses, and massive invasion against a weakened military. Order is then restored at a slightly lower population level from that in 150 AD.
3. At about 240 AD, another plague (probably viral hemorrhagic fever) arrives, accompanied by widespread drought in most key food-supplying regions (Levant, north Africa, and above all Egypt). Northern and eastern borders collapse as the supply of soldiers and supplies dries up. Again, recovery takes decades, and a new political order is built up, breaking the power of Roman senators and creating a new city “center” at Constantinople.
4. At around 350 AD, a Little Ice Age arrives. Climate change on the steppe, stretching from Manchuria to southern Russia, drives the Hsiungnu or Huns westward, pushing the existing Goth society on Rome’s northern border into Roman territory. Rome’s western empire collapses as this pressure plus localized droughts leads to Gothic conquests of Gaul, Spain, North Africa, and Italy. Rome itself collapses in population without grain shipments from abroad, but the economic and cultural structure of the western Roman state is preserved by the Goths. In the early 500s, as the Eastern Empire recovers much of its population and economic strength, Justinian reconquers North Africa and much of Italy, again briefly and partially reconstituting the old Roman Empire.
5. At 540 AD or thereabouts, bubonic plague driven by changes in climate for its animal hosts in central Asia arrives from the East. The details of the illness are horrific and it is every bit as devastating as the Black (also bubonic) Plague in medieval times – 50-60 % of the population dead, affecting rich and poor, city and rural equally, with recurrence over many decades. Only Gaul and the north, now oriented to a different economic and social network, are spared. Villas, forums, and Roman roads vanish. The Eastern frontier collapses, again due to military recruit and supply decimation, and a prolonged deathbed struggle with Persia ends in the conquest of most of both by Islam in the early 600s. The only thing remaining of the old Roman state and its artifacts is a “rump” state in Anatolia and Greece.
Implications for Today
As Harper appears to view it, the Roman Empire was a construct in some ways surprisingly modern, and in some ways very dissimilar to our own “tribe”-spanning clusters of nation-states. It is similar to today in that it was a well-knit economic and cultural system that involved an effective central military and tax collection, and could effectively strengthen itself by trade in an intercontinental network. It is dissimilar in that the economic system (until near the end) funneled most trade and government through a single massive city (Rome) that required huge food supplies from all over the Mediterranean; in that for most of its existence, the entire system rested on the ability of the center to satisfy the demands of regional “elites”, thus impoverishing the non-elite; and in that they had none of our modern knowledge of public health and medicine, and thus were not able to combat disease effectively.
What does this mean for climate change affecting today’s global society? There is a tendency to assume, as I have noted, that it is infinitely resilient: Once disaster takes a rest in a particular area, outside trade and assistance complement remaining internal structures in recovering completely, and then resuming an upward economic path. Moreover, internal public health, medicine, and disaster relief plus better advance warnings typically minimize the extent of the disaster. The recovery of utterly devastated Japan after WW II is an example.
However, the climate-change story of Rome suggests that one of these two “pillars of resilience” is not as sturdy as we think. Each time climate-change-driven disasters occurred, the Roman Empire had to “rob Peter to pay Paul”, outside military pressures being what they were and trade networks being insufficient for disaster recovery. This, in turn, made recovery from disaster far more difficult, and eventually impossible.
Thus, recovery from an ongoing string of future climate-change-driven disasters may not be sufficiently able to be internally driven – and then the question comes down to whether all regional systems face ongoing disasters unable to be handled internally, simultaneously. Granted, the fact that our system does not depend on regional elites or fund a single central city are signs of internal resilience beyond that of Rome. But is the amount of additional internal resilience significant? This does not seem clear to me.
What remains in my mind is the picture of climate-change-driven bubonic plague in Rome’s interconnected world. People die in agony, in wracking fevers or with bloody eyeballs and bloody spit, or they simply drop dead where they are, in twos and threes. Death is already almost inevitable, when the first symptoms show, and there is no obvious escape. If by some miracle you live through the first bout, you walk in a world of the stench of unburied bodies, alone where two weeks ago you walked with family, with friends, with communities. All over your world, this is happening. And then, a few years later, when you have begun to pick up the pieces and move back into a world of many people, it happens again. And again.
If something like that happens today, our world is not infinitely resilient. Not at all.