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.