The three environmental shifts discussed in earlier posts in this sequence—the ecological impacts of a sharply warmer and dryer climate, the flooding of coastal regions due to rising sea levels, and the long-term consequences of industrial America’s frankly brainless dumping of persistent radiological and chemical poisons—all involve changes to the North American continent that will endure straight through the deindustrial dark age ahead, and will help shape the history of the successor cultures that will rise amid our ruins. For millennia to come, the peoples of North America will have to contend with drastically expanded deserts, coastlines that in some regions will be many miles further inland than they are today, and the presence of dead zones where nuclear or chemical wastes in the soil and water make human settlement impossible.
All these factors mean, among other things, that deindustrial North America will support many fewer people than it did in 1880 or so, before new agricultural technologies dependent on fossil fuels launched the population boom that is peaking in our time. Now of course this also implies that deindustrial North America will support many, many fewer people than it does today. For obvious reasons, it’s worth talking about the processes by which today’s seriously overpopulated North America will become the sparsely populated continent of the coming dark age—but that’s going to involve a confrontation with a certain kind of petrified irrelevancy all too common in our time.
Every few weeks, the comments page of this blog fields something insisting that I’m ignoring the role of overpopulation in the crisis of our time, and demanding that I say or do something about that. In point of fact, I’ve said quite a bit about overpopulation on this blog over the years, dating back to this post from 2007. What I’ve said about it, though, doesn’t follow either one of the two officially sanctioned scripts into which discussions of overpopulation are inevitably shoehorned in today’s industrial world; the comments I get are thus basically objecting to the fact that I’m not toeing the party line.
Like most cultural phenomena in today’s industrial world, the scripts just mentioned hew closely to the faux-liberal and faux-conservative narratives that dominate so much of contemporary thought. (I insist on the prefix, as what passes for political thought these days has essentially nothing to do with either liberalism or conservatism as these were understood as little as a few decades ago.) The scripts differ along the usual lines: that is to say, the faux-liberal script is well-meaning and ineffectual, while the faux-conservative script is practicable and evil.
Thus the faux-liberal script insists that overpopulation is a terrible problem, and we ought to do something about it, and the things we should do about it are all things that don’t work, won’t work, and have been being tried over and over again for decades without having the slightest effect on the situation. The faux-conservative script insists that overpopulation is a terrible problem, but only because it’s people of, ahem, the wrong skin color who are overpopulating, ahem, our country: that is, overpopulation means immigration, and immigration means let’s throw buckets of gasoline onto the flames of ethnic conflict, so it can play its standard role in ripping apart a dying civilization with even more verve than usual.
Overpopulation and immigration policy are not the same thing; neither are depopulation and the mass migrations of whole peoples for which German historians of the post-Roman dark ages coined the neat term völkerwanderung, which are the corresponding phenomena in eras of decline and fall. For that reason, the faux-conservative side of the debate, along with the usually unmentioned realities of immigration policy in today’s America and the far greater and more troubling realities of mass migration and ethnogenesis that will follow in due time, will be left for next week’s post. For now I want to talk about overpopulation as such, and therefore about the faux-liberal side of the debate and the stark realities of depopulation that are waiting in the future.
All this needs to be put in its proper context. In 1962, the year I was born, there were about three and a half billion human beings on this planet. Today, there are more than seven billion of us. That staggering increase in human numbers has played an immense and disastrous role in backing today’s industrial world into the corner where it now finds itself. Among all the forces driving us toward an ugly future, the raw pressure of human overpopulation, with the huge and rising resource requirements it entails, is among the most important.
That much is clear. What to do about it is something else again. You’ll still hear people insisting that campaigns to convince people to limit their reproduction voluntarily ought to do the trick, but such campaigns have been ongoing since well before I was born, and human numbers more than doubled anyway. It bears repeating that if a strategy has failed every time it’s been tried, insisting that we ought to do it again isn’t a useful suggestion. That applies not only to the campaigns just noted, but to all the other proposals to slow or stop population growth that have been tried repeatedly and failed just as repeatedly over the decades just past.
These days, a great deal of the hopeful talk around the subject of limits to overpopulation has refocused on what’s called the demographic transition: the process, visible in the population history of most of today’s industrial nations, whereby people start voluntarily reducing their reproduction when their income and access to resources rise above a certain level. It’s a real effect, though its causes are far from clear. The problem here is simply that the resource base that would make it possible for enough of the world’s population to have the income and access to resources necessary to trigger a worldwide demographic transition simply don’t exist.
As fossil fuels and a galaxy of other nonrenewable resources slide down the slope of depletion at varying rates, for that matter, it’s becoming increasingly hard for people in the industrial nations to maintain their familiar standards of living. It may be worth noting that this hasn’t caused a sudden upward spike in population growth in those countries where downward mobility has become most visible. The demographic transition, in other words, doesn’t work in reverse, and this points to a crucial fact that hasn’t necessarily been given the weight it deserves in conversations about overpopulation.
The vast surge in human numbers that dominates the demographic history of modern times is wholly a phenomenon of the industrial age. Other historical periods have seen modest population increases, but nothing on the same scale, and those have reversed themselves promptly when ecological limits came into play. Whatever the specific factors and forces that drove the population boom, then, it’s a pretty safe bet that the underlying cause was the one factor present in industrial civilization that hasn’t played a significant role in any other human society: the exploitation of vast quantities of extrasomatic energy—that is, energy that doesn’t come into play by means of human or animal muscle. Place the curve of increasing energy per capita worldwide next to the curve of human population worldwide, and the two move very nearly in lockstep: thus it’s fair to say that human beings, like yeast, respond to increased access to energy with increased reproduction.
Does that mean that we’re going to have to deal with soaring population worldwide for the foreseeable future? No, and hard planetary limits to resource extraction are the reasons why. Without the huge energy subsidy to agriculture contributed by fossil fuels, producing enough food to support seven billion people won’t be possible. We saw a preview of the consequences in 2008 and 2009, when the spike in petroleum prices caused a corresponding spike in food prices and a great many people around the world found themselves scrambling to get enough to eat on any terms at all. The riots and revolutions that followed grabbed the headlines, but another shift that happened around the same time deserves more attention: birth rates in many Third World countries decreased noticeably, and have continued to trend downward since then.
The same phenomenon can be seen elsewhere. Since the collapse of the Soviet Union, most of the formerly Soviet republics have seen steep declines in rates of live birth, life expectancy, and most other measures of public health, while death rates have climbed well above birth rates and stayed there. For that matter, since 2008, birth rates in the United States have dropped even further below the rate of replacement than they were before that time; immigration is the only reason the population of the United States doesn’t register declines year after year.
This is the wave of the future. As fossil fuel and other resources continue to deplete, and economies dependent on those resources become less and less able to provide people with the necessities of life, the population boom will turn into a population bust. The base scenario in 1972’s The Limits to Growth, still the most accurate (and thus inevitably the most vilified) model of the future into which we’re stumbling blindly just now, put the peak of global population somewhere around 2030: that is, sixteen years from now. Recent declines in birth rates in areas that were once hotbeds of population growth, such as Latin America and the Middle East, can be seen as the leveling off that always occurs in a population curve before decline sets in.
That decline is likely to go very far indeed. That’s partly a matter of straightforward logic: since global population has been artificially inflated by pouring extrasomatic energy into boosting the food supply and providing other necessary resources to human beings, the exhaustion of economically extractable reserves of the fossil fuels that made that process possible will knock the props out from under global population figures. Still, historical parallels also have quite a bit to offer here: extreme depopulation is a common feature of the decline and fall of civilizations, with up to 95% population loss over the one to three centuries that the fall of a civilization usually takes.
Suggest that to people nowadays and, once you get past the usual reactions of denial and disbelief, the standard assumption is that population declines so severe could only happen if there were catastrophes on a truly gargantuan scale. That’s an easy assumption to make, but it doesn’t happen to be true. Just as it didn’t take vast public orgies of copulation and childbirth to double the planet’s population over the last half-century, it wouldn’t take equivalent exercises in mass death to halve the planet’s population over the same time frame. The ordinary processes of demography can do the trick all by themselves.
Let’s explore that by way of a thought experiment. Between family, friends, coworkers, and the others that you meet in the course of your daily activities, you probably know something close to a hundred people. Every so often, in the ordinary course of events, one of them dies—depending on the age and social status of the people you know, that might happen once a year, once every two years, or what have you. Take a moment to recall the most recent death in your social circle, and the one before that, to help put the rest of the thought experiment in context.
Now imagine that from this day onward, among the hundred people you know, one additional person—one person more than you would otherwise expect to die—dies every year, while the rate of birth remains the same as it is now. Imagine that modest increase in the death rate affecting the people you know. One year, an elderly relative of yours doesn’t wake up one morning; the next, a barista at the place where you get coffee on the way to work dies of cancer; the year after that, a coworker’s child comes down with an infection the doctors can’t treat, and so on. A noticeable shift? Granted, but it’s not Armageddon; you attend a few more funerals than you’re used to, make friends with the new barista, and go about your life until one of those additional deaths is yours.
Now take that process and extrapolate it out. (Those of my readers who have the necessary math skills should take the time to crunch the numbers themselves.) Over the course of three centuries, an increase in the crude death rate of one per cent per annum, given an unchanged birth rate, is sufficient to reduce a population to five per cent of its original level. Vast catastrophes need not apply; of the traditional four horsemen, War, Famine, and Pestilence can sit around drinking beer and playing poker. The fourth horseman, in the shape of a modest change in crude death rates, can do the job all by himself.
Now imagine the same scenario, except that there are two additional deaths each year in your social circle, rather than one. That would be considerably more noticeable, but it still doesn’t look like the end of the world—at least until you do the math. An increase in the crude death rate of two per cent per annum, given an unchanged birth rate, is enough to reduce a population to five per cent of its original level within a single century. In global terms, if world population peaks around 8 billion in 2030, a decline on that scale would leave four hundred million people on the planet by 2130.
In the real world, of course, things are not as simple or smooth as they are in the thought experiment just offered. Birth rates are subject to complex pressures and vary up and down depending on the specific pressures a population faces, and even small increases in infant and child mortality have a disproportionate effect by removing potential breeding pairs from the population before they can reproduce. Meanwhile, population declines are rarely anything like so even as the thought experiment suggests; those other three horsemen, in particular, tend to get bored of their poker game at intervals and go riding out to give the guy with the scythe some help with the harvest. War, famine, and pestilence are common events in the decline and fall of a civilization, and the twilight of the industrial world is likely to get its fair share of them.
Thus it probably won’t be a matter of two more deaths a year, every year. Instead, one year, war breaks out, most of the young men in town get drafted, and half of them come back in body bags. Another year, after a string of bad harvests, the flu comes through, and a lot of people who would have shaken it off under better conditions are just that little bit too malnourished to survive. Yet another year, a virus shaken out of its tropical home by climate change and ecosystem disruption goes through town, and fifteen per cent of the population dies in eight ghastly months. That’s the way population declines happen in history.
In the twilight years of the Roman world, for example, a steady demographic contraction was overlaid by civil wars, barbarian invasions, economic crises, famines, and epidemics; the total population decline varied significantly from one region to another, but even the relatively stable parts of the Eastern Empire seem to have had around a 50% loss of population, while some areas of the Western Empire suffered far more drastic losses; Britain in particular was transformed from a rich, populous, and largely urbanized province to a land of silent urban ruins and small, scattered villages of subsistence farmers where even so simple a technology as wheel-thrown pottery became a lost art.
The classic lowland Maya are another good example along the same lines. Hammered by climate change and topsoil loss, the Maya heartland went through a rolling collapse a century and a half in length that ended with population levels maybe five per cent of what they’d been at the start of the Terminal Classic period, and most of the great Maya cities became empty ruins rapidly covered by the encroaching jungle. Those of my readers who have seen pictures of tropical foliage burying the pyramids of Tikal and Copan might want to imagine scenes of the same kind in the ruins of Atlanta and Austin a few centuries from now. That’s the kind of thing that happens when an urbanized society suffers severe population loss during the decline and fall of a civilization.
That, in turn, is what has to be factored into any realistic forecast of dark age America: there will be many, many fewer people inhabiting North America a few centuries from now than there are today. Between the depletion of the fossil fuel resources necessary to maintain today’s hugely inflated numbers and the degradation of North America’s human carrying capacity by climate change, sea level rise, and persistent radiological and chemical pollution, the continent simply won’t be able to support that many people. The current total is about 470 million—35 million in Canada, 314 million in the US, and 121 million in Mexico, according to the latest figures I was able to find—and something close to five per cent of that—say, 20 to 25 million—might be a reasonable midrange estimate for the human population of the North American continent when the population implosion finally bottoms out a few centuries from now.
Now of course those 20 to 25 million people won’t be scattered evenly across the continent. There will be very large regions—for example, the nearly lifeless, sun-blasted wastelands that climate change will make of the southern Great Plains and the Sonoran desert—where human settlement will be as sparse as it is today in the bleakest parts of the Sahara or the Rub’al Khali of central Arabia. There will be other areas—for example, the Great Lakes region and the southern half of Mexico’s great central valley—where population will be relatively dense by Dark Age standards, and towns of modest size may even thrive if they happen to be in defensible locations.
The nomadic herding folk of the midwestern prairies, the villages of the Gulf Coast jungles, and the other human ecologies that will spring up in the varying ecosystems of deindustrial North America will all gradually settle into a more or less stable population level, at which births and deaths balance each other and the consumption of resources stays at or below sustainable levels of production. That’s what happens in human societies that don’t have the dubious advantage of a torrent of nonrenewable energy reserves to distract them temporarily from the hard necessities of survival.
It’s getting to that level that’s going to be a bear. The mechanisms of population contraction are simple enough, and as suggested above, they can have a dramatic impact on historical time scales without cataclysmic impact on the scale of individual lives. No, the difficult part of population contraction is its impact on economic patterns geared to continuous population growth. That’s part of a more general pattern, of course—the brutal impact of the end of growth on an economy that depends on growth to function at all—which has been discussed on this blog several times already, and will require close study in the present sequence of posts.
That examination will begin after we’ve considered the second half of the demography of dark age America: the role of mass migration and ethnogenesis in the birth of the cultures that will emerge on this continent when industrial civilization is a fading memory. That very challenging discussion will occupy next week’s post.