There are too many people on the planet, and that is why we are out there drilling at 5000 feet in the Gulf of Mexico. There are too many people, and it is not at all an acceptable thing to say so. The Left doesn’t like it, neither does the Right, in so far as those quaint terms are relevant in this context. And the Catholic Church really, really doesn’t like it.

There are too many of them, to be sure, spitting betel juice and flipping tortillas all the live long day; but there are also too many of us, fussing with our handheld whatevers as we jostle one another amid the stalls of Camden Town or pour off the N-Judah streetcar at day’s end, down the block from me here in San Francisco, where a great deal of tortilla flipping goes on and, doubtless, the more than occasional instance of betel juice expectoration.

There are 6,853,132,362 (oops, make that 72) as I write this, at least according to the US Census Bureau. There were too many people in 1960 when the Cambridge scholar F.L. Lucas published his essay ‘The Greatest Problem’ in a collection of the same name, when the population was 3,021,500,000 or so. And it was certainly on the mind of Malthus when he first published his Essay on the Principle of Population in 1798, when the world population was less than a billion; as it would have been to Jonathan Swift in 1729 (world population 685,280,500) when he put forth his Modest Proposal to deal with the population problem in Ireland.

The taboo against discussing overpopulation sometimes goes by the name of the Hardinian taboo, after Garrett Hardin (Stanford, Berkeley, Chicago) who wrote on ecology, biology and ethics. The remorselessly sensible John Gray discusses the matter at length in a 2002 essay entitled ‘Homo Rapiens And Mass Extinction: An Era of Solitude’:

Given the magnitude of change [loss of biodiversity], one would expect it to be at the center of debate. In fact, it is very little discussed... There are many reasons for this peculiar state of affairs, including the ingrained human habit of denying danger until its impact is imminent; but the chief reason is that is has become fashionable to deny the reality of overpopulation.

Gray goes on to point out that

opposition to population control is concentrated in the rich parts of the world, notably the US... In their use of resources they are themselves the most overpopulated. Their affluence depends on appropriating a hugely disproportionate share of the world’s non-renewable resources.

The late Pope John Paul II called the notion of overpopulation a ‘myth’, and in a letter to his bishops in 1993 called contraception ‘evil’. He brought both messages along with him on 102 pastoral visits outside Italy in the course of his long tenure, especially to Latin America and Sub-Saharan Africa.

There was not a taboo regarding the discussion of overpopulation in the late 1960s and early 1970s, quite the contrary. When I was an undergraduate it was in the air, everywhere it seemed, along with the despoiling of nature. One couldn’t walk into an on-campus screening of this or that euroflick without first enduring some Sierra Club-type short about laundry detergent suds pouring into pristine streams. I recall one in particular about garbage landfill sites choking the magnificent San Francisco Bay. I have not heard of any further such concern regarding this since arriving here 30 years ago, but I shouldn’t imagine the problem has gone away.

Paul Ehrlich’s The Population Bomb (1968) sold over two million copies. The Stanford biologist didn’t quite get it right – the high-yielding grains of the Green Revolution, for instance, forestalled mass starvation – and Ehrlich himself became some something of a figure of ridicule, but unfairly so. When he wrote the book in 1968 the world population was 3.5 billion, four decades later it stood at 6.7 billion. The environmental problems persist: pollution, waste, water scarcity, mass extinction of species, deforestation, global warming – you know the drill.

You will take note of the currently fashionable term ‘sustainability’. Thomas Friedman of the New York Times is very keen on sustainability, while trying as best he can to rehabilitate his reputation post-Iraq. And he is right this time around: we do need to raise the tax on gasoline, pour billions into R&D, live more sensibly etc. But developing countries will account for 94 per cent of future population growth, Africa alone expected to grow from 740 million in 1995 to 2.27 billion in 2050. I don’t know that the disinclination to bring up the subject of overpopulation is so much a Hardinian taboo or a matter of intellectual fashion as a collective unspoken UH-OH...