On Monday, the political scientist Roger Pielke Jr. published an interesting Substack article on the climate implications of downward-spiralling global fertility. Pielke, a fellow of the conservative American Enterprise Institute, has a reputation as a climate-change skeptic; but rather than being someone with an out-of-the-mainstream alternative theory of climate, his modus operandi is to actually read, absorb and believe the canonical United Nations climate-forecasting publications, using them to challenge alarmist claims made in the newspapers by activist zanies with no scientific bona fides.
(You may have noticed that world-on-fire climate catastrophists no longer take very much care to cite chapter and verse in the latest updates from the Intergovernmental Panel on Climate Change; the once-sacred IPCC, voice of the professional climatological consensus, has somehow become too moderate for the activist vanguard.)
I mention this only to fill in Pielke’s background for those who might follow that link. What’s interesting about his article, which amounts to a series of back-of-envelope calculations, is precisely that it discusses the relationship between global fertility and climate change, two topics that you will see mentioned five times apiece in a day if you consume a heavy news diet. Our current consensus-based climate scenarios, whether from the IPCC or other thinkery shops, are predicated on fertility estimates that are becoming obsolete rapidly as near-real-time information on sinking population growth flows from the world’s nation-states.
That information has very obvious consequences for the Earth’s climate: you don’t have to have Pielke’s professional background to figure that out. Scientists are still writing professional monographs predicated on a world with a population of 13 billion souls, but it is starting to look more as though the planet will peak at around 9 billion and then go into numerical decline.
In the past 100 years, we used fossil fuels to expand Earth’s carrying capacity from two billion to 8.2 billion. The challenges of decarbonizing the global economy (and achieving other ecological goals like wildland preservation) become a lot less daunting if we never have to plan to feed and warm that ten billionth person. Period.
There are, of course, other economic implications of continued fertility decline. It’s a particularly vexing problem for western welfare states predicated on old-age pensions that weren’t designed for present-day life expectancies (which may themselves be reaching an impenetrable biological frontier). And we’re now seeing the emergence of a “pro-natality” politics that favours state investment — one might say “even more amazingly enormous state investment” — in family formation. Alas, a lot of different public-policy solutions to declining fertility have been tried from the time of Augustus Caesar to today, and none of them seem to work all that well, anywhere you look.
Me, I was born on a planet of 3.8 billion people, and I’m never sure why anyone ought to be afraid of ending up on one. Much of the pro-natality discourse is, for the moment, confused and vibes-based, which is not to say that there’s nothing to it. What no one seems to acknowledge very much is that a low world-population ceiling will very obviously help solve a lot of collective problems, even if you never believed in the bogus ’70s consensus on overpopulation catastrophe.
The proto-environmentalists of that period, more concerned with food supplies than with harms from greenhouse gases, were mostly big believers in zero population growth: they favoured consciously restrained or even forcibly curtailed fertility. The climate advocates of our time, by contrast, have devoted little attention to global population as a parameter. They never preach “ZPG” as desirable, having taken for granted that the essential solutions to climate change will involve central economic planning and severe human impoverishment in a world of increasing numbers.
That is still the typical environmental gospel, although we are awakening from it — but, meanwhile, concern about climate change is an obvious factor driving fertility decline. Whether or not to have an nth baby is almost always a question of fine balance, and breeding-age folk have been whelped on apocalyptic visions of a near-future Earth too blazingly hot for human life (along with a dopey generic sense that life is getting continually worse rather than fantastically better).
Of course, there are other contending factors in population decline, including some we may just not know about: everyone’s entitled to pet theories about microplastics or sperm counts. But the global fertility decline seems to be awfully geographically widespread to have a single dominant environmental cause. Some of it is surely just that the human species may be collectively adopting half-conscious ZPG-ish beliefs, in response to a genuine planetary crisis, without ZPG being explicitly advocated. Whether this is good news or bad is up to you: the surprise, as I say, is that it’s not talked about more.
— Colby Cosh
