An uncomfortable truth

As the planet's resources dwindle, a debate on population control is needed more than ever

On a recent Question Time programme an audience member put a question about Jonathon Porritt's recommendation that parents have no more than two children in order to help limit world population. Pretty uniformly the panel members made fun of the idea, misconstruing Porrit's proposal as some kind of nightmarish state policing or euthanasia programme. Yet there are good reasons for arguing that a stabilisation or gradual reduction in population would be the best way to address the carbon emissions problem. Calculations have been made that any given land mass has a certain carrying capacity, based on its ability to support its inhabitants' needs. So one estimate is that Britain can ideally support 17 million people. Let's say for the sake of argument that this is incorrect, yet it raises the question of whether there are any limits as to how many people this land can support. Currently we have about 61 million. Would 80 million be fine? 100 million? 200 million? How would we know? Who should decide?

Why does such a discussion always feel uncomfortable? Is it because there are emotive associations with immigration and racism, with eugenics and the Holocaust, with totalitarian regimes and genocide? Wasn't attempted population control a nightmare in China (population 1.3 billion) and a failure in India (1.15 billion)? Didn't Malthus get it wrong in the early 19th century and Paul Ehrlich in the 1960s? "Nobody's going to tell me how many children I can have" is also a very common refrain. So a serious and necessary debate gets silenced.

In Los Angeles in January 2009, Nadya Suleman gave birth to octuplets following fertilisation treatment. It was later discovered that she was a single parent who already had six children. The unavoidable moral and economic question follows: "Should a single person with no visible means of financial support be permitted to have 14 children?" Some will say yes, on various grounds, and it's unlikely that this unique case will have much significance on global carbon emissions. Plus there is what is known as population offsetting – plenty of nuns, monks, gay people, infertile couples and others have no children, so this can be balanced by others who have large families. Similarly, there are a small number of women that opt for voluntary sterilisation because they believe it's morally correct for them not to add to an already too large population. And there are those that advocate non-breeding for the planet's sake, such as The Voluntary Human Extinction Movement – motto "may we live long and die out". You may also hear the argument that wars, traffic accidents, diseases and famine are nature's or God's way of controlling population.

How many of us are born unwanted, or are treated badly? The Sartrean observation that we are de trop can be amplified when you consider that you are one of 6.7 billion human beings. Unless you really believe that a God exists who intended your existence, you must realise that in the grand scheme of things you and I are hardly essential, and all the more so as population increases. Of course we are usually very important to our loved ones. But in harsh times like the present many of us are in a precarious economic situation, and quite dispensable as employees. As we age we realise that in spite of talk about the dignity of all, the old can become a burden to themselves and others. This is reflected in the growing problem of pensions provisions, for which there are currently no obvious answers.

Some disability groups strongly object to any discussion about population limits, fearing that it disguises an insidious prejudice against those with disabilities. Indeed any consideration of "lifeboat ethics" (who would have to be thrown overboard first?) uncomfortably reminds us that in extremely harsh situations some become superfluous. It's horribly uncomfortable to ask – even to think – how many seriously disabled or very old people with expensive support needs any society can carry. But any one of us can become frail, disabled, unproductive and in need of more than we can contribute. Having too many of us in this position becomes a socioeconomic problem. To think in this vein is not disablism or ageism, but necessary worst case planning. Similarly, governments need contingency plans for the treatment or disposal of large numbers of injured or dead people following natural disasters. These are human species health and safety issues.

A flip side to these questions, however, is how many of us would rather not continue with our lives for one reason and another (terminal disease, paralysing disability, chronic mental illness, life imprisonment), but currently have no choice other than to suffer, or commit suicide in a furtive and messy way. Even if we want to reject the possibility of dignified, state approved and assisted suicide, why can't we air the discussion publicly? Is it religion that bars the discussion? Not according to Paul Badham's Is There a Christian Case for Assisted Dying? Is it due to public distaste, or a wisdom that recognises we shouldn't "go there", as if merely to mention it is to start on some fascistic slippery slope?

And again, let's remind ourselves that longevity gradually increases, so that in many countries 20 to 30 years have been added to the lifespan during the last century. Some "ambitious" scientists like Aubrey de Grey already theorise about extending the lifespan to as much as 1,000 years. Their vision is that we would live extremely long, healthy, happy lives and become sick only towards the very end. What doesn't feature in their time-greedy visions is the mathematics of how the Earth is going to accommodate all these near-immortals and their presumably numerous offspring. But put aside the fantasy aspects here. Even fairly modest increases in longevity add to our numbers, and many of those living longer will eventually, probably, have dementia or other old age-related illnesses. But no such reasoning makes us want to stop living indefinitely or multiplying untenably.

Do we in Britain, a relatively small land area, want a population like Japan's 130 million? Could it be sustained? What constitutes problematic overcrowding? Japan has relatively little immigration – does that make for a harmoniously high population? Are countries like Canada (33 million) and Sweden (9 million) good welfare societies because they have relatively small populations? Why do politicians worry when national populations begin to fall slightly? Presumably academics study all these matters but we don't often see their work included in media and public debates. It doesn't matter who lives in Britain or any other country. It's not about racism. It's simply about how many bodies can sustain themselves in that place. If climate scientists' projected scenarios of flooding, crop failure, famine and disease are reasonably accurate, then we surely need to ask hard questions about sustainable ratios of population to land mass, food production and related survival matters.

There's absolutely no question of culling large families, genocide, or destroying civil liberties. These are unhelpfully emotive reactions that prevent a necessary, informed debate. This is about consciousness raising. It's about sensible voluntary limits to population growth.