For as long as I can remember, overpopulation has been one of those Very Bad Things That We Really Ought To Worry More About. True, as issues go, rampant population growth isn’t as high profile as it was, but it’s still hard to resist the idea that the world’s problems would be easier to fix if there just weren’t so many of us.
So it’s confronting to be told that a) we can all stop worrying about humanity’s relentless expansion, and b) what we should be losing sleep over is the opposite: fewer and fewer people on Earth.
That’s the big message in this slender volume from two University of Texas demographer-economists, Dean Spears and Michael Geruso. They spell it out from their second paragraph: “Birth rates have been falling everywhere around the world. Soon, the global population will begin to shrink.”
Part one of that message is no surprise. Everyone knows birth rates have been declining, and not just in the wealthier Western world. Part two may be more challenging if you were raised on fears of the “population bomb”, but the logic behind it is clear.
The population grows when the average woman has more than enough children to replace herself and a partner. Right now, that magic number is just over two children per woman, to allow for the (diminishing) risk that some won’t make it to reproductive age.
But, say the authors, “two-thirds of the world lives in countries where fertility is already below replacement”, including the two most-populous nations, India and China. The birth rate is below two in many other places: about 1.6 children per woman in the US, 1.5 in the EU, just 0.7 in South Korea and Hong Kong and 1.6 in New Zealand.
True, the average fertility rate for Africa is above four, and even higher in some nations, but the trend is the same; a few decades ago, the African rate was more than six children per woman.
Birth rates have been falling, say Spears and Geruso, “for as long as anyone has been measuring them”, and for no obvious reason. It wasn’t contraception, they argue (the decline started before birth control was widely available); it wasn’t the decline of marriage (still common in India, and the birth rate is falling there, too); not feminism and rising economic opportunities for women (South Korea is no feminist paradise, and it has one of the world’s lowest birth rates); not neoliberalism; not western individualism. “Nobody – no expert, no theory – fully understands why birth rates, everywhere, in different cultures and contexts, are lower than ever before.”
Whatever the reason for the fall, they offer this telling piece of data: in 2012, 146 million children were born – more than in any year before then. But that was also more than the number born in the following year, or the year after that. “The year 2012 may well turn out to be the year in which the most humans were ever born – ever as in ever for as long as humanity exists” (their italics).
So what happens next? For a while, not a lot, because even though the number of births is falling, it’s still greater than the number of people dying, so the global population will keep rising.
But eventually – “eventually” being this century, possibly in just a few decades – the population will peak. Estimates vary, but the consensus seems to be somewhere above 10 billion people, compared with today’s 8.2 billion. That will be the very tip of the “spike” in the book’s title.
After the peak, as long as humanity keeps breeding at less than the replacement rate, the population will shrink, and keep on shrinking. “It will not spontaneously halt at some smaller, stable size. It will not fall to 6 billion or 4 billion or 2 billion and hold there.”
If you’ve been around for a few decades, you’ve seen the world’s population grow at an ever-increasing rate. Soon, our descendants will be able to watch as the movie runs in reverse and the population graph plunges. At which point you might think: “Great stuff – fewer people means lower climate-change emissions, more room for nature, less poverty, no more traffic jams and cheaper real estate.”
Think again, urge the authors. For one thing, they say, depopulation won’t fix climate change, largely because the climate challenge is occurring right now and any meaningful fall in the global population will take generations.
They also argue that a smaller population would have fewer resources to deal with some future crisis: 10 billion of us might have what it takes to clean up past emissions, or deflect a looming asteroid; a much smaller population might not. “Nor will [depopulation] raise living standards by dividing what the world can offer across fewer of us.” Economies require working young people to keep economies with ageing populations functioning. The authors also claim that a shrinking population would be less innovative than a stable one, on the grounds that when it comes to innovation, the more people, the better.
Not content with describing the issue, they’re clear that this book is meant as a call to action, to do something to stabilise the population – not necessarily at today’s numbers, but to arrest the slide at some point. If you agree, you’d have to accept that history isn’t on your side. Birth rates have been falling for centuries, and nations that have tried to nudge that trend line – up or down – haven’t had much success.
What’s to be done? Well, don’t count on technology to do the job. Science may make it easier to have babies, but that doesn’t mean we’ll choose bigger families.
In Israel, free in-vitro fertilisation treatment resulted in women having children later in life but not more of them; the fertility rate is high by rich-world standards, at 2.8 children per woman, but no higher than it was before free IVF.
Nor are the authors advocating some Handmaid’s Tale strategy of enforced fertility. They argue women need more power, not less, if we’re to have any chance of arresting population decline.
One of the big obstacles to parenting is the opportunity cost – all the other, more fun things you could be doing if you weren’t so busy raising children. The authors say, “The most plausible way humanity might stabilise – and the only way this book endorses – is if societies everywhere work to make parenting better”. By which they mean offering more support to reduce the burden of parenthood, so that billions of people decide having children looks more appealing than it did, and those billions of individual choices add up to a rebound in birth rates.
Call me cynical, but that all sounds decidedly fuzzy. As the authors concede, no country offers any evidence that more support for parents results in more births. Not better parental leave, not affordable childcare, not subsidised preschool – none of it seems to make much difference if boosting the population is what you’re after.
And when birth rates have been falling for so long, and almost universally, it’s a brave call to believe humanity can bend the trend back upwards.
You may be convinced by this book’s argument that the world would be a worse place with fewer people. I’m not, but that’s beside the point, because I’m even less convinced that we’re capable of doing much about it.
