The science of demographic projection and the art of scaremongering enjoy a relationship akin to that of the sadist and masochist: first comes the threat, then the relish with which the punishment is anticipated. Thus forecasts of increasing population numbers are guaranteed to produce dystopian visions of social collapse.

The godfather of apocalyptic demographics was the Rev Thomas Malthus, who famously proposed in the late 18th century that unchecked population growth would lead to starvation. Population, he said, was destined to increase exponentially in relation to food supply. In the event, Britain's population grew from a hungry eight million in Malthus's time to today's well-fed 61 million.

The cleric's name long ago became a byword for catastrophic pessimism, but there have been plenty of other doomsayers who have followed in his arithmetically wayward wake. It could be said that a recent editorial in the British Medical Journal emerges from the same tradition. Last month, John Guillebaud, professor of family planning at University College London, called for a reduction in the UK birth rate to help combat global warming.

The lesson to be drawn from Malthus, however, is that we should never underestimate the human capacity to misrepresent the future or our ability to deal with it when it does arrive.

Nevertheless, if human ingenuity is boundless, the planet and, in particular, that small corner lying off the coast of north-west Europe, is not. There is a finite space in which to fit people. The UK, after all, is significantly smaller than France or Germany.

Last week, the European Commission announced its most recent population predictions. Britain came top of the league with an estimated growth in the next 50 years of 16 million people. With a total of 77 million inhabitants, Britain is predicted to become the most populous country in Europe.

To those who view the world through a purely economic prism, these figures are a cause for celebration. As the headline in the Guardian put it: 'Germany shrinks, France grows, but UK population booms', making it sound as if Team GB had added a further gold to its Beijing tally, this time in the reproduction event. The paper pointed out that the projected rise meant 'the UK has less to fear about any "generational wars" brought on by the "demographic timebomb" of ageing and shrinking populations where those in work cannot support the pension needs of retired citizens'.

This has become the rationale for the policy of population expansion. To deal with greater life expectancy, runs the theory, we need to produce or, rather, import more people. But it's worth considering where this cycle will end. How, for example, will a population of 77 million deal with paying for the pensions of its retired citizens? Presumably by expanding to 100 million. Then what?

Still, let's resist the Malthusian temptation to overdramatise the situation and assume that a larger population will not lead to a global warming crisis, that there won't be a shortage of food or shelter, or an increase in disease. Instead, we can frame the problem in more modest terms: will an increase of 16 million people improve the quality of our lives? Will life become more pleasurable, less anxious, more satisfying?

It's impossible to know the future, but there's no excuse for ignoring the present and just now things feel a little cramped in Britain, especially in the south east. Roads are almost permanently clogged, public transport is a mess, schools and hospitals are full and the sense of friction, the tension of reduced personal space, is often palpable. Would these problems be alleviated with another 16 million, the majority of whom would settle in the south?

Such is the draw of the south east that the Policy Exchange think-tank recently suggested that the inhabitants of cities such as Sunderland and Liverpool should move there. Neither is there a shortage of economic migrants from across the rest of the world who also view the south east as their destination point. The European Commission estimated that immigrants would account for 10 million of Britain's 16 million increase in numbers.

And here we come to the main problem of discussing the benefits and drawbacks of population growth. Immigration is inextricably tied to the issue of race. To wonder if 10 million new migrants is a good thing is to stray into territory most notably occupied by racists. In fact, immigration has become a much more complex matter than race; it's not uncommon, as author Mike Phillips noted last week in these pages, to see black Londoners complaining about the presence of white Poles. None the less, it's a sensitive matter and that's one reason the immigration debate has been restricted to the more neutral ground of economics.

Bodies such as the Institute for Public Policy Research maintain there is a net benefit for the economy and there seems little doubt that much of the dynamism of modern Britain is due to the impact of migrants. However, economic success is not the only guide to a nation's health.

As one economic migrant, Nemanja Vidic, Manchester United's Serbian defender, observed of the British last week: 'They just don't have time to feel the joy of life. Through the week they all work so hard. They only talk to people at lunch break. Then in the evening they come home and watch the telly so they can get up early for work the next day.'

The UK economy has modelled itself on the American version, in which GDP growth and population growth are inseparable. But Britain is not America. There is not a sense of unlimited space on these islands or such a such a strong notion of Darwinian individualism.

So the consequences of an entrepreneurial culture based on endless supply of renewable labour are something the nation at large needs to consider and one of those consequences is a population of 77 million.

There's nothing wrong with asking, in the spirit of free inquiry, whether that may not be just a little too much.

· Nick Cohen is away