The Great Migration of the 21st Century

One lesson we should keep in mind as we recover in the aftermath of Sandy is that we are slow learners. Although the vulnerability of many of these communities is undeniable, we have resolved to rebuild the homes. That resolve will no doubt weaken if the region is revisited by similar disasters, and those displaced will be forced to move on. If climate change is at the root, that will happen. There will be a crescendo of such disasters, replaying thousands of times in populated areas across the globe. Hurricane Sandy thus has given us a glimpse into what will be the dominant theme of the twenty first century: forced migration.

Historically, migration has been driven by need, such as a disparity in economic situation, or because the migrating group reached the limits of the land given population growth. The migration may be into uncontested, virgin land; what is referred to as wave migration. Or it may be migration into other populated areas, which can lead to a new elite displacing the existing elite, to changes in status and a redistribution of wealth, but with the two societies existing side by side. A third type of migration, prominent in the barbarian period in the first millennium CE, is not based on economic need or population constraints, but on a nomadic culture pillaging the riches of the lands they invade. The first two are demand-pull, the third is supply-push.

I can envision any of these migration models playing out in the next century. Gradual migration and assimilation, or a gradual replacement of the indigenous population with a new elite, or one of invasion and warfare. Or wave migration; less likely but particularly interesting because the very effects of climate change will open up new, previously uninhabitable land even as flood and drought make other land uninhabitable. The plot of James Bond's “A View to a Kill” comes to mind; there the villain planned to trigger a massive earthquake that would plunge most of the California coastline into the sea, turning his holdings of inland desert into new, prime oceanfront real estate. Climate change and rising sea levels replaces the earthquake and villain with an alternative plot.

How bad can this sort of thing get?

The Last Great Migration: The Barbarians

There has been revisionist history over the past decades recasting the invasion of the barbarians; the use of the term migration in place of barbarian invasion is representative of this shift. And the barbarian invasions were a great migration. But it may be too early to discard the view, depicted in accounts of the time, that the feudal Europe we recognize emerged from the wave of a thousand years of invasion and ethnic cleansing.

The headline statement for this period is that the barbarians laid waste to everything, and over time forest and swamp intruded where there had been civilization. By the ninth century, there were miles of formerly populated countryside devoid of people, and those in one village lived their lives with little knowledge of other villages. In Spain the Vandals divided the country among themselves, but not before they destroyed the land. When the Goths conquered the Vandals, they fled from Spain, crossed the Straits of Gibraltar to Africa, and continued with unrelenting ruthlessness. A contemporary writer gives this account:

They carried their destructiveness into every corner of it; they dispeopled it by their devastations; exterminating every thing with fire and sword. They did not even spare the vines and fruit trees, that those to whom caves and inaccessible mountains had afforded a retreat, might find no nourishment of any kind. Their hostile rage could not be satiated, and there was no place exempted from the effects of it. They tortured their prisoners with the most exquisite cruelly, that they might force from them a discovery of their hidden treasures. The more they discovered the more they expected, and the more implacable they became. Neither the infirmities of age nor of sex; neither the dignity of nobility, nor the sanctity of sacerdotal office, could mitigate their fury; but the more illustrious their prisoners were, the more barbarously they insulted them. The public buildings which resisted the violence of the flames, they leveled to the ground. They left many cities without an inhabitant. When they approached any fortified place, which their undisciplined army could not reduce, they gathered together a multitude of prisoners, and putting them to the sword, left their bodies unburied, that the stench of the carcasses might oblige the garrison to abandon it.

The barbarians were equal opportunity destroyers. No matter what their station, those who survived their invasions uniformly found their living standards diminished as this migration proceeded. The Barbarians were rural and to some extent nomadic, mingling agriculture with hunting and herding. If the land became exhausted, they moved on to clear virgin land while the forest closed in behind them. They lacked many techniques for cultivating and preserving the land. They used slash and burn methods which quickly led to diminishing yields. Before the migration, under the late Roman Republic, the average yield in Italy was four times the seed. After the migration, in thirteenth-century England, yields were at least three times the seed. But in the barbarian age the largest harvests were twice the seed, the lowest ones fell below one and a half times the seed. This means that at least half of the cultivated area served to produce seed, a dearth in production compared both to what existed before and what would exist thereafter.

But, on the bright side...

The barbarians brought about some equalization for the lower classes. Social inequality grew dramatically during the Roman period; ancient Rome had rich aristocrats and well-off freeman farmers, but also had landless laborers and slave labor. The long depression of the barbarian age fostered the growth of a new, intermediate class that combined the now landless freemen and the freed slaves. This new social group became the serfs of Feudal society. The reduced efficiency in agriculture increased the demand for labor; there was work for every man. Indeed, labor often was in such short supply that the landholders had to bid for their services. So, strangely, the barbarians became a leveling force for society even as they broadly diminished the standard of living.

Conclusion

Anyone who lived through the life cycle of the baby boom knows two things about demographics. First, demographic cycles are slow but inexorable. And second, perhaps because they move so slowly, they are often ignored. It was obvious with the emergence of the baby boom post-World War II that over the course of the next five to ten years there would be a tidal wave of bodies coming into elementary schools, and that in ten to fifteen years that tidal wave would hit high schools, then colleges, then the housing market. Yet we lived through split sessions because schools were not built to accommodate this boom, even though there was more than adequate lead time. (And many of the schools that did get built then were torn down once the baby boomers move past school age, just in time to miss the next demographic wave – the children of the baby boomers).

Climate change will progress at an even slower, imperceptible pace. And unlike demographics, where the changes in birthrates are undeniable, climate change exists in a cloud of uncertainty. Not only do some question its existence, but even those who take it as a given cannot clearly project its course. The point is that we miss even the obvious risks if they move slowly enough, and the realities and effect of climate change remain less than obvious. And there are few risks that are as slow moving but substantial as those associated with climate change. The frog in the pot is the operative analogy.

Barbarians overran Europe as far as Scotland to the north and Portugal to the west; the land was carved up and administered by this new elite, with the original landholders displaced and the laborers becoming serfs. The Burgundians and the Visigoths took two thirds of their respective conquests, each Burgundian housed as a “guest” with the former landholder now living in a small part of his former estate. The Vandals seized the best land in northern Africa with no regard for the former inhabitants. The Lombards in Italy took a third of the land. The Franks took possession of much of the land in France.

The newly arrived became lords of their holdings, the previous tenants and farmers became their serfs. In the end this great migration gave us the Feudal Age, a social order that defined Europe for eight hundred years. What will appear a century hence, after the great migration on which we are soon to embark?