Half a century ago, when I was a sixth former, earnest chaps used to turn up at our school to lecture us on overpopulation, the world’s greatest problem. A few years later, when I was a graduate student studying the politics of the environment the agenda was being set by the likes of Paul Ehrlich whose book The Population Bomb was published in 1968. By the mid-1970s I was in the same institution as Ehrlich, Stanford University, though his status as an agenda-setter was clearly being challenged by more immediate economic problems.
The debate continues to this day, as does Ehrlich, now in his 80s, but still relaying much the same message, in tandem with his wife, Anne. In the age of the internet, of course the debate continues because all debates do, but it is much lower in profile now. It is worth asking where it’s gone on the agenda; you can instantly consult numerous “population clocks” which show the global population to be about 7.2 billion and still rising steadily, which is more or less what the Jeremiahs of half a century ago expected and were worried about. Have we stopped worrying for good reasons or bad?
The question of definition is unavoidable since the criteria of overpopulation are arranged along an elastic continuum. The most common theme is the “carrying capacity” of environments in relation to species (Ehrlich is essentially a macro-biologist and that is where the dominant conceptual frameworks originate.) This may make sense in relation to (say) the elephant population of the Kruger National Park, but it seems fairly obvious that you could never really know the carrying capacity of an environment in relation to a species capable of trade and technical innovation. An alternative is to define carrying capacity in relation to the effect on other species, but this is obviously problematic since at least 95 per cent of all species which have ever existed are extinct and extinction is a crucial mechanism of evolution; in any case, homo sapiens has a great, unique and increasing capacity to create other species. The weakest definition — though, perhaps, the most interesting — is when Ehrlich defines overpopulation as occurring when “human numbers are incompatible with human values”. Naturally, I would prefer a world with only a couple of billion people (and 30 million in the UK), but I wouldn’t give up my reproductive rights for that. And it does raise the logical possibility that any solution to the problem would be more damaging to “human values” than the problem unsolved.
For the most famous exponent of population theory, Thomas Malthus, the consequences were clear: a rather unpleasant, though thoroughly familiar, homeostatic mechanism. As the population increases beyond the capacity to feed it starvation and malnutrition will restore equilibrium. Not nice, but not new. We should remember that in the lifetime of Malthus (born in 1766) it could reasonably be argued that neither the standard of living nor the level of population were greater than they had been 1500 years earlier when the Roman Empire was at its height. When Malthus was born agriculture and transport, for example, were no better than Roman practices, though by the time of his death, in 1834, the story was very different. Our contemporary theorists, however, considering overpopulation in the context of much larger numbers, but also indefinite technical progress, tend to see the consequences in terms of some kind of breakdown or apocalypse. Ehrlich has actually referred to “the collapse of civilisation”, a form of imagery better suited to the cinema than to scholarship. The nearest thing we know of to a “collapse of civilisation”, the end of the Roman Empire in the West, must have looked like homeostasis to some and apocalypse to others, depending on who you were and from what distance you were perceiving events.
Al Gore is probably the most prominent of those still trying to engage us in a debate about population, but I guess most of us are fairly difficult to engage. Familiarity breeds contempt with problems; like the inevitability of death and the mind-boggling size of the universe, n billion people and rising is best forgotten on a day-to-day basis. Thinking constructively about population also poses ideological difficulties for most people, starting with the major religions, but continuing also to their humanist descendants: any account of human rights is surely going to include the right to have children? Ehrlich has been attacked by the Left, including the “green” Left, for not realising that the threat to the planet can only come from the maldistribution of resources, not from numbers. The pro-capitalists attack him for not understanding the indefinitely large possibilities of innovation. We haven’t absorbed any of the rhetoric of the theory of overpopulation and still talk of anything that will increase the death rate, even among the old, as calamity and catastrophe. We are as far away as ever on having the sort of debate about a maximum age envisaged in Anthony Trollope’s The Fixed Period (published in 1882) and it is inconceivable that the committee would agree on 67 & a half, which is what happens in the novel.
In other words the disappearance of overpopulation from the political agenda is largely a consequence of ideological dogma and mental laziness. It is too easy for a politician to say brusquely, as Harold Wilson once did when asked what his government’s population policy was, that he hasn’t got one. But it doesn’t help that most of the demographic gurus persistently overstate their case. Ehrlich has written with horror of an experience of the crowded streets of India, suggesting a kind of psychopathological misanthropy. As with several American, Canadian and Australian writers on this subject he seems to take a peculiar horror in the kind of densities of population sustained in the UK and the Netherlands. In the early stages of his career he predicted “complete collapse” for our country by 2000 and has talked of the Netherlands in similar terms. He has also predicted the worst famine in history in India and vast increases in commodity prices, none of which has actually happened. You would not put him up against Warren Buffet as a prophet or tipster. His defenders have claimed these were “scenarios” to provoke thought, rather than predictions, but their effect has been like that of the boy who cried “wolf”.
The most legitimate reason for optimism is a version of the embourgeoisement thesis which has been around for over a century. This says that education and prosperity break the traditional link between progeny and wealth and create incentives to limit family size. With the help of contraception this leads to a dramatic drop in birth rates. In some times and places, including most of Europe over the last thirty years, this has appeared to work fully, though it was more evident in Britain in the 1970s than since: it is a freak demographic fact that there were twice as many births in 1946, when I was born, than in 1977, when my eldest son was born. The effect has spread to many countries, though not all by any means, and its effects in Europe are largely mitigated by greatly increased migration.
The optimistic scenario is that world population will level out at around 10 billion some time around the middle of this century. But I wouldn’t bank on it. The birth rate equation is fertility multiplied by fecundity, where fertility is the number of women of childbearing age and fecundity is their propensity to have children. Unprecedented disasters apart, fertility is very easily predictable in the medium term and is, of course, rising steadily. Fecundity has proved very unpredictable, the consequence of a myriad of factors including religion and fashion. In any case, the embourgeoisement thesis suggests that people will trade babies for cars and central heating. Which means, of course, that if man-made climate change is the problem which it is now assumed to be, there is nothing we can do about it unless we can attack not just overpopulation in the abstract, but the level of increase which is currently considered inevitable.
The idea that more people is a bad thing is very difficult to accommodate in moral philosophy. I drafted this essay with one granddaughter pottering in the background, playing and talking to herself in a way that I can only describe as endearing and another leaning on my knee and smiling up at me in a way I can only describe as lovable. The idea that I might sacrifice their existence for the benefit of some unknown members of my species in a hundred or a thousand years time is absurd. I do not care about the long-term future of my species, but about the two little girls: “caring” at that level of abstraction is neither rational nor rooted in natural sympathy.
So, here is the solution: a strain of viral pneumonia which spreads aggressively and wipes out 80 per cent of the population, leaving us at Ehrlich’s “acceptable” level of 1.5 billion people. Like an elephant cull it tends to follow genetic patterns of immunity, wiping out whole families, but leaving other families intact. It tends to hit the weak, in Darwinian terms. Go with it? Open the container? Nobody said saving the planet was going to be nice!