EARLIER THIS YEAR the more excitable US media were full, for a day or two, of the latest news from Arkansas. From the settlement of Tontitown, to be precise, where a woman called Michelle Duggar had just announced she was expecting her eighteenth child – due to be born in January 2009. At the time, the Duggars’ seventeen children were aged between nine months and twenty years, and Michelle, aged forty-one, had been pregnant for eleven years of her life. She says she and her husband, Jim Bob, will continue to have children as long as God wills it.

The Duggars, not surprisingly, are something of a media phenomenon. They have recently been filmed by the Discovery Health Channel which devotes part of its website to ‘fun facts’ about the family – the estimated number of Duggar diapers (nappies) to date, for example (90,000) or the number of family laundry loads (200 a month). They also have their own website which details their complex household organisation, blames contraception, since abandoned, for an early miscarriage and declares: “We believe that each child is a special gift from God and we are thankful to Him for each one.”

There is a quality of parable about the Duggars, however, which, at a time of rising food prices and growing global food shortages, is worth exploring. Sadly, their website doesn’t say how much food they get through but the answer, clearly, is – an awful lot. Indeed, if the Duggar progeny had the same attitude to procreation as Michelle and Jim Bob, they would strip the planet bare. It’s been calculated that if the Duggars’ offspring each had eighteen children, their descendants, after just ten generations, would number 3,570,467,000,000 (3.6 trillion) – 533 times the current world population.

SOME SUCH CALCULATION, of course, inspired the clergyman economist Thomas Malthus to write An Essay on the Principle of Population in 1798. Malthus’ thesis was that population growth will tend to outrun food supply and is only kept in balance with the environment by ‘checks’. These may be unpleasant – war, famine, disease – or they may involve sensible precautionary actions, for example family planning. Responsible societies, Malthus thought, took the precautionary route.

Given the ballooning of a full-blown global food crisis this year, one might have thought the lessons of Malthus on population, food and human survival would have gained wider traction. World population – increasing by some 75 to 80 million each year, not far off one new London a month – has grown from 2.5 billion in 1950 to around 6.8 billion today and will reach 9.2 billion in 2050, according to the UN. Per capita food production has been decreasing for many years, as have world grain stocks. Ecological footprint analysis tell us that the human population hit the limits of planetary capacity about twenty years ago – roughly the same time as per capita food production started shrinking – and since then has been in ‘overshoot’: currently humanity is taking out some 25% more resources than the Earth can renewably provide, a figure predicted to rise to around 80% by mid-century. Soils are being eroded and denatured on a massive scale. At some point, surely, these trends would run together on the graph and something big and bad would happen.

Not so, unfortunately, if you listen to mainstream environmental opinion. Malthus’ Essay on the Principle of Population was an early environmental classic which is now routinely rubbished by environmentalists and liberal opinion – indeed, ‘Malthusianism’, and concern about population growth generally, is regarded in some quarters as a form of green fascism, with ‘Malthusians’, granted cult-like status, at best batty or cranks, at worst scary and vaguely homicidal. Much of this stigma arises from the bizarre misconception that if you warn about the dangers of overpopulation (what Malthus called the “positive checks” of war, famine and disease), you somehow also think they are a good thing – a version of shooting the messenger who brings bad news.

Silence at best, outright hostility at worst. Why? One clue lies with the Duggars. If children are gifts from God, who wills their arrival, it’s akin to sacrilege to restrain one’s fecundity. Procreation, in other words, is bound up with some deeply held beliefs, to do with personal freedoms as well as religion, and you challenge these at your peril.

The magazine Ethical Consumer recently carried a thoughtful and mildly worded article asking whether people should moderate their family size for environmental reasons and received several letters from readers attacking such “extreme” views and threatening to cancel their subscriptions. Whether such reactions are a measure of the growth of fundamentalism – or anthropocentrism – is a matter for debate. What’s certain is that organisations which rely on members of the public for support and funding – environment and development NGOs, for example – have registered these sensitivities and steer well clear of the issue. ‘Pragmatism’ may be a charitable description of such a strategy.

There are, however, more fundamental factors at work. One of the elements that made Malthus’ essay a specifically environmental classic was its prescient awareness of limits. At the end of the 18th century much of the planet remained to be mapped or explored, yet as Malthus strikingly remarked, “A man who is locked up in a room may be fairly said to be confused by the walls of it, though he may never touch them…”[italics added]. An urgent sense of planetary limits was a driving force behind the environmentalism of the 1960s and 1970s but in today’s environmental orthodoxy it has been partially or wholly supplanted by a faith in technology or lifestyle changes. It’s only a short step, therefore, to saying that human numbers don’t really matter: it’s how those human numbers live and, more importantly, consume that counts.

Hence, while expert bodies – the UN’s Food and Agriculture Organization, for example – have listed population growth as a cause of this year’s suddenly burgeoning food crisis, environment and development groups have almost universally ignored or downplayed it, either as a cause or a solution. And since both political action and public awareness take their cues from civil society campaigning, ordinary citizens could almost be forgiven for thinking there is no link between their decisions about family size and the price of a loaf of bread. A recent US poll found that although 60% of Americans aged eighteen to twenty-four understand that there is a strong link between a growing global population and climate change, only 35% believe that having fewer children themselves would help protect the environment.

WHAT LIES BEHIND the silence of the greens? Undoubtedly how we live matters: the mediating role played by ecological footprint in measuring impact on the planet was probably less well understood in the early days of environmentalism. Person for person, we now know, rich people do more damage than poor people. But the growing sophistication of footprinting methodologies has led to babies being thrown out with bathwater. Particularly as footprint sizes converge – as the poorer become richer – the role played by overall numbers in the impact equation will increase even further. And as we understand more about footprint, we will see that some aspects of it are more elastic or variable than others; some, indeed, may verge on the irreducible. There is a basic ‘need’, for example, for shelter, water, sanitation, hygiene – and food. Yet attitudinal surveys have demonstrated how today’s ‘needs’ were yesterday’s ‘wants’. As standards and expectations rise globally, who knows which of today’s aspirations will tomorrow be classed as indispensable adjuncts to daily living?

What this suggests is that there is an ineradicable environmental impact, or footprint, from the mere existence of a human being and that this is likely to grow. Twenty Duggars will require far more food than two Duggars or even ten Duggars, while a Duggar family of two children rather than eighteen won’t need anything like 90,000 nappies, or 200 laundry washes a month. That this needs saying at all is a measure of how far some contemporary greens have drifted from reality. Even if the Duggars manage to ‘green’ their lifestyles, there will always remain a chain of support systems and an armoury of infrastructure – a wind turbine here, a pipeline there, a recycling plant somewhere else – that will be forever Duggar, and the more Duggars, the greater the quantity of support systems and infrastructure. If we want to prevent the Earth being wholly Duggared, we need to take numbers into account, as well as lifestyles and technologies.

REDUCTIONIST THINKING – A failure to see the wood for the trees – is involved in the second key factor behind the greens’ silence on population and food: the belief, often asserted as a self-evident truth, that Malthus was wrong. Critics argue that humanity has not perished, despite the enormous increase in world population since he wrote (it was about a billion in 1800), and that like those of many subsequent ‘doom-mongers’ – not least Paul Ehrlich, author of the 1960s’ classic The Population Bomb – his predictions of mass starvation have proved unfounded. And to be fair, the failure of similar predictions – not least the exhaustion of primary resources – to materialise on time has given many a stick with which to beat environmentalists and is some reason to be circumspect about such warnings.

The truth is, however, that famine has not been abolished. Even before the current food crisis – at the height of the fossil-fuel era – UN figures showed that over 800 million people worldwide went to bed hungry every night and some 2 billion were malnourished. Through lowered life expectancy, compromised immune systems and high rates of maternal and child mortality, such figures fed through into millions of premature or avoidable deaths – at a time when Malthusian fears had been deemed groundless.

Moreover, because a forecast is late in arriving does not mean it is wrong. Studies of past cultures such as Jared Diamond’s Collapse suggest, as Malthus argued, that civilisations tend to increase their population up to available resource limits – at which point they either collapse, wholly or partially, or innovate and survive, albeit in altered form. Something like this happened in the transition from a hunter-gatherer to an agricultural society. Similarly, after Malthus wrote, the fossil-fuel age arrived in earnest, underpinning and catalysing the global surge in population. Many observers now believe that, as the fossil-fuel age unravels under the twin constraints of climate change and peaking of supplies, the world will be left with what James Howard Kunstler, author of The Long Emergency, calls a “surplus” population – many more people than the Earth can sustain.

Fossil-fuelled technology, notably that based on oil and chemicals, hid this dramatic leap into overshoot, but at what cost? The Green Revolution is widely touted as disproof of Malthus, for example, apparently enabling far more to be fed, but it has taken a heavy toll in health, environmental and socio-economic terms – exhausting and depleting soils, normalising the use of chemical fertilisers and pesticides, sucking small farmers into dependency on multinational seed and chemical companies. In the Punjab, in India, one of the Green Revolution’s testing grounds in the1960s, concerns about pollution and illness caused by agricultural chemicals have led to a growing reaction against high-input, ‘techno-centric’ farming, and a switch to more organic systems. Surveys in the UK attest to the collapse in key nutrient levels in British produce over the last half-century. Intensive food-production systems – battery farming, aquaculture – have become virtual bywords for disease and pollution. Even the supposedly healthiest ‘wild’ foods – oily fish, for example – now have to be accompanied by health warnings because of their mercury and PCB content.

The question we should be asking is not how many people the world can feed but how many it can feed well. Or, as one Punjabi doctor expresses it, “What are you achieving by feeding people at the cost of their health?” Somewhat paradoxically Norman Borlaug, who won the Nobel Peace Prize for fathering the Green Revolution, takes a Malthusian perspective, viewing his work as buying humanity time in which to solve the population problem and advocating the stabilising of population before human numbers outstrip the food supply.

What would stable numbers be? Optimum Population Trust calculations suggest a sustainable world population may be as low as 1.7 billion. Gaia scientist James Lovelock has put global overpopulation at 80%, giving a sustainable figure of under 1.4 billion. Peter Salonius, a Canadian forest researcher, believes humanity has been in overshoot since the dawn of agriculture 10,000 years ago and has survived only by “mining” its soils. Like fossil fuels, the vast nutrient store contained in soils represents a unique and unrepeatable gift that has been hugely depleted by agricultural erosion. “Without petroleum, and after we stop mining arable soils,” he argues, “the Earth will only support the 100–300 million people it did before the advent of cultivation agriculture.”

THE GLOBAL FOOD crisis of 2008 is a good time to re-examine – and maybe redefine – the costs and benefits involved in the transition to an agricultural society. Agriculture gave us cities and civilisation and also, latterly, an impressive array of product choice, at least in the industrialised world. But can it replicate the nutrient wealth of pristine natural systems – the wild food riches that underpinned the hunter-gatherer way of life – and what are the penalties if it cannot? How much of our current disease burden – particularly the plethora of apparently novel conditions that have appeared in recent years – is attributable to the quest for food quantity rather than food quality? What has driven the quest for quantity? And what are the prospects for human health in a world where genuinely wild food, with all its trace nutrients and mysteries of local climate and geology, has become a memory – because of an exhausted biosphere and the dead hand of an interfering, narrowing and simplifying agriculture?

In all this, population growth may be the hidden mover that acts invisibly but powerfully with a series of overlapping ripple effects whose causes and origins are obscure to most of those who experience them. One does not blame the Duggars, or even the large family next door, for the price of one’s loaf, but ultimately they bear a responsibility. So do we all. History suggests that population growth has repeatedly shoved humanity into a corner – not least in forcing us to abandon the hunter-gatherer way of life – and is doing so again now, pushing us under the banner of necessity towards genetic modification, soil-less hydroponics, the ploughing-up of set-aside and all the other paraphernalia of high-technology, denatured intensive farming systems. Our own actions, in other words, are coming back to haunt us. It’s time we managed things better.

David Nicholson-Lord is an environmental writer and policy director of the Optimum Population Trust. www.optimumpopulation.org