{"id":13369,"date":"2023-10-14T07:37:50","date_gmt":"2023-10-14T12:37:50","guid":{"rendered":"https:\/\/blog.uvm.edu\/aivakhiv\/?p=13369"},"modified":"2023-10-14T07:51:40","modified_gmt":"2023-10-14T12:51:40","slug":"the-population-blimp","status":"publish","type":"post","link":"https:\/\/blog.uvm.edu\/aivakhiv\/2023\/10\/14\/the-population-blimp\/","title":{"rendered":"The population bli(m)p"},"content":{"rendered":"\n

When I was younger, I would occasionally hear from fellow environmentalists that the \u201creal problem\u201d was human overpopulation. (The standard answer, from the well informed, was: nope, it\u2019s inequality, extractive capitalism, institutional inertia, patriarchal values, colonialism, et al. \u201cOverpopulation\u201d was a symptom, not the disease.) <\/p>\n\n\n\n

The population-mongers have mostly faded since then, as the \u201cdemographic transition<\/a>\u201d argument has proven itself pretty convincing (people with greater opportunities for a real life end up having fewer children, and more and more countries have taken that path). And as most environmentalists have come to see the role of culture, politics, and economics in shaping our problems.<\/p>\n\n\n\n

But I still find it stunning to see a diagram like this one, in a NY Times article<\/a> from a few weeks ago.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

It shows a range of projections of global human population growth, with almost all of them peaking in the coming decades — at 10 billion around 2085 — and then falling way, way down, in fact to below 110 million within a matter of centuries.<\/p>\n\n\n\n

According to the author, Dean Spears<\/a>, who is an economist at University of Texas Austin’s Population Research Center<\/a> but who is working from data produced by leading demographic studies, \u201cper year births\u201d may have already peaked, as early as 2014, and \u201cpeak human population\u201d is expected to be achieved between 2060 and 2090. (I find it hard to believe that we won\u2019t hit 10 billion by 2050. I hope to be around to see.)<\/p>\n\n\n\n\n\n\n\n

From then on, if current below-replacement level trends continue, it\u2019s all downhill. This author projects a potential human population of under 1 billion within less than three centuries of \u201cpeak.\u201d That\u2019s one-eighth of today\u2019s population — with no killing involved in getting there (just dying, which we\u2019ve been doing ever since the whole lively ball of life got rolling). (Killing might of course continue, but it\u2019s both a lousy and a stupid way to do things, as it encourages poor decision-making by the survivors.)<\/p>\n\n\n\n

The reason this decline could happen so quickly is the same reason why population grew so quickly: it grows, and declines, geometrically. It only takes a certain number of generations for a 3-child-per-couple average (multiplied by the billions of humans around) to spiral out of control. By the same token, it only takes a similar number of generations for a 1.5-child-per-couple average to bring numbers way back down again.<\/p>\n\n\n\n

The under 110 million number still seems far-fetched to me. But like the ecological \u201csustainability bottleneck<\/a>\u201d that we\u2019re going through, it seems we are also going through a “population bottleneck.” If we get out alive, we may get out quite well. The worry about \u201cWho will work to support all those old<\/em> people?\u201d in a low-population (but healthy, long-lifespan, and info-rich) world, is a legitimate one. But the author makes clear that if we start planning for a low-population world now, we\u2019ll figure out ways to manage it. And since these trends aren\u2019t deterministic, we could always decide otherwise, or tweak the details to make them workable.<\/p>\n\n\n\n

There is, of course, an unstated background assumption to all such population projections. This is the assumption that the world of the coming centuries will be stable enough — and that ecological conditions will remain conducive enough to human survival — for demographic trends like these to be at all predictable. If those conditions go away, then all bets are off.<\/p>\n\n\n\n

But the whole idea that we are living through a blip (or spike<\/a>), a brief historical bubble<\/a>, is one I find comforting. It\u2019s one that seems true with resource use, and with so much else, too. (I do wonder if the authors aren’t going out on a limb when they write that<\/a> “Indeed, four-fifths of all births — past, present, and future — would have already happened.” The assumption of a certain life-span for humanity seems, well, let’s say, interesting.)<\/p>\n\n\n\n

And even in a worst case scenario, my cosmic argument<\/a> still applies: that even if we don\u2019t \u201cget out alive,\u201d there are so many other life-harboring planets in the universe that some of them will<\/em> get out alive from this kind of predicament — a predicament that can be expected from any planet-spanning technological civilization (as Adam Frank has argued<\/a>) — and that they might share whatever they learn with others. (There’s an assumption in there, too.) Not every experiment succeeds, and not every mutation avoids an evolutionary dead end. But some definitely will. Why else do we even try?<\/p>\n\n\n\n

Let us rejoice in difficult blips. They are the background against which peace, contentment, harmony, and creativity become possible.<\/p>\n\n\n\n

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