Dominic Lawson: Spare me lectures from deluded actors

Why can't actors stick to acting? They do it so well. That's why we admire and sometimes even worship them – which is when the trouble starts. The subject of that hero-worship starts to believe that he (or she) can use that fame to save the world. The latest victim of this thespian folie de grandeur is Jeremy Irons. In last weekend's Sunday Times he launched himself as a "green campaigner", telling the newspaper that he will be making a documentary about "sustainability" in the style of Michael Moore, but, he insists, "not as silly".

Unfortunately, silly is what Irons goes on to reveal himself to be, although in a manner endorsed by many less famous people; he duly trots out the trite and tired old theme that "there are just too many of us" and that something must be done about "the hugely-growing population worldwide". In fact, Irons asserts that if we do nothing about it, nature will take care of it anyway: "I suspect there'll be a very big outbreak of something. I hope it will be a disease, not war."

Memo to Irons: please try to find out what's really happening in the world before deciding to "do something about it". To this end, he could do no better than buy a copy of Peoplequake, by Fred Pearce. Published earlier this year by Eden Project Books, it tackles the poisonous myth of overpopulation from the perspective of a man who has reported on the issues of the environment and development from 60 countries over the past 20 years.

You don't need Pearce to point out – although he does it very well – how the population of the developed world is in dramatic decline. Thirty years ago, 23 European countries had fertility rates above replacement levels; now, none do. If you use exactly the kind of straight-line extrapolations always favoured by the population-explosion scaremongers, as Pearce points out: "Italy will lose 86 per cent of its population by the end of the century, Spain will lose 85 per cent, Germany 83 per cent and Greece 74 per cent."

Irons told the Sunday Times that we in the developed nations would need to set up a "ring-fence and keep everybody out" from an increasingly "starving" world "who will want to come to us". The opposite is the case: the European economy and public services will find it increasingly necessary to import the labour (and talent) that its own plunging fertility rates will have denied it.

Japan, which faces a similar demographic implosion, but which is profoundly hostile to the idea of mixing races on its own territory, has for this reason invested vast sums in robotics – nothing less than an attempt to "breed" a new kind of electronic Japanese workforce. Good luck to them; but I imagine that the overwhelming majority of our own ageing population would rather have NHS nurses who don't whir and bleep and ask us in Dalek-type tones how we are this morning and what would we like for breakfast.

In any case, is it really likely, as Irons (in common with many other much less beautiful people) asserts, that an ever-expanding African population will flood here simply to avoid death by starvation? Again, let Fred Pearce do the environmental maths: "The idea of overpopulated Africa simply is not true. The continent contains 11 of the world's least densely populated nations and only one of the 20 most densely populated. That last is Mauritius, which is also one of Africa's richest countries. Africa's problem is bad agriculture, not too many people."

I know this defies conventional wisdom, but something is not true just because most people say that it is, and it does not become truer as a result of constant reiteration over many years. In fact, the idea of Africa starving as a result of overpopulation has become increasingly more preposterous, as the evidence to the contrary piles up. In More People, Less Erosion, the geographer Michael Mortimore and the development economist Mary Tiffen examined in detail the Kenyan rural district of Machakos. In the 1930s, their colonial soil scientist forebears had described this area as "an appalling example" of environmental disaster in the making. They had blamed this on "multiplication of the natives", who were "rapidly drifting to a state of hopeless and miserable poverty and their land to a parched desert of rocks, stones and sand". Yet it has been precisely because of their growing human resources – yes, people are a resource, believe it or not – that the inhabitants of Machakos were able, without any help from the ecologically-defeatist British, to dig terraces to reduce soil erosion and to create sand dams to capture rainwater.

When Pearce visited this part of Kenya, that had been thought condemned to starvation by the Malthusian colonialists, he found that its supposedly doomed subsistence farmers were "producing so much food that they were selling vegetables and milk in Nairobi, mangos and oranges to the Middle East, avocados to France and green beans to Britain. For them, 'multiplication' of their numbers has been part of the solution rather than the problem."

Irons' bleak forecast of "war" as nature's way of dealing with Africa's supposed demographic crisis might have been based on a misreading of the causes of the massacres in Rwanda: it had the most rapidly growing population on the continent, which led some distant commentators to portray the conflict between the Hutus and the Tutsi as a fight over dwindling resources. Yet food production in Rwanda had grown by almost 5 per cent a year in the decades before the massacres, significantly more than the rate of increase in the population. As Pearce points out, "On the eve of the massacres, Rwanda was one of the best-fed countries in central Africa, with more than 2,000 calories per person per day." Don't expect such facts to drag the neo-Malthusians out of their pit of inspissated gloom: it's being so cheerful as keeps them going.

Come to think of it, Jeremy Irons is a very suitable standard-bearer for these eternal misanthropes: his particular talent on film is to exude moroseness from every pore. The Sunday Times found it irresistible to point out that this film star who would lecture the world about its scandalous over-use of resources "owns seven houses, including a pink castle" and a number of cars, including a 13-year-old Range Rover. By implication it seemed to be setting him alongside such A-list hypocrites as Bono (who harangues governments to pay more of their taxpayers' money to the third world in development aid, even as his accountants exotically reroute U2's earnings via the Netherlands Antilles to minimise the tax on those vast royalties), or Al Gore, who uses private jets as he criss-crosses the world to lecture us on the evils of carbon-emission.

Yet the problem with Jeremy Irons is not that he is a hypocrite. It is that he is profoundly mistaken. I don't accuse him of being thoughtless; although his remark that he hopes it will be "disease" rather than war which wipes out allegedly redundant populations might not endear him to the nations he says he wants to save. There are some fairly ghastly types who enthusiastically proclaimed that Aids was just nature dealing with excessive breeding on the part of Africans; Jeremy Irons would do well to continue his magnificent career as an actor, rather than join the ranks of philosopher-fools.

d.lawson@independent.co.uk