Plentiful food carries a price - in addition to the cost

At the height of the Hungry Thirties, with the world gripped by the Great Recession, the United States department of agriculture calculated how much a typical family was spending on food. The answer was nearly one quarter of their income.

Eighty years later, with the world once again experiencing a major economic downturn, the USDA continues to calculate what Americans budget for food. The answer now is less than one dollar out of 10.

These figures are pretty typical for the developed world and even much of the developing world. The Swiss spend 10 per cent of their income on food; in Ireland it is about seven euros in 100. Kuwaitis budget about 15 per cent for food, but in the UAE, the average family spends a little under nine dirhams out of 100 on the weekly shop. Only in countries such as Iran, Colombia and Thailand does expenditure on food match the levels of the United States in the 1930s.

So food is cheap, at least for many of us. In these parts of the world, even where unemployment is at levels not seen for half a century, few people are going hungry and no one is starving. Indeed, perversely, in the West, obesity is most often associated with poverty. To be rich is to be thin.

Even where people do genuinely go hungry and starve, the causes can almost always be traced to war and politics. The food is there, somewhere, just not in the right place at the right time. Hence Biafra in the 1960s, Ethiopia in the '80s and more recently, North Korea and Somalia.

Now the age of cheap and plentiful food seems to be drawing to a close. Several reports this week have warned of the potential for serious political and social unrest caused by rising food prices.

The first, the Global Food and Farming Futures study, commissioned by the UK government, predicted a rise in key foods of between 50 per cent and 100 per cent in the next 40 years. Without major changes in food production, it warned, people are going to go hungry on a catastrophic scale. Controversially, it called for greater use of genetically modified (GM) crops to push up yields.

A second study, from the French Agrimonde project, a collaboration between leading research institutes, called for a change of attitude - indeed a revolution - in the way we produce and consume what we eat. With the global population expected to rise by more than two billion in the next 40 years, the alternative, Agrimonde warned, will be food riots and famine.

This is a hard concept to grasp. Inexpensive food is something like clean water from the tap or electricity at the flick of a switch (neither of which, by the way, can be taken for granted in the future). We visit a supermarket and expect the shelves to be well stocked and items well priced.

Only recently have people begun to think about the distortions this causes. Take bananas. My mother, now in her early 80s, can recall the effect of seeing the first bananas arriving in Britain after the end of the Second World War. Her younger sister, who had never seen one before, recoiled in shock and near revulsion at such a peculiar object.

Today bananas are part of a global marketing war. Supermarkets in Britain sell them at below cost price to lure shoppers through their doors. If we buy too many, we throw them away. What was once an exotic tropical treat now sells for the equivalent of less than three dirhams a kilo and the farmers that produce them struggle to stay this side of destitution.

Chicken, once a treat reserved for special occasions, is now sold frozen by the box-load. All too often this involves conditions far removed from the farmyard scenes of a children's picture book, but wire cages and windowless industrial barns. You can buy organic free-range chickens, of course, most probably flown in fresh from Europe, but at eight times the price.

Taking a moral position about food production, though, has generally been reserved for those wealthy enough to do so, and with the leisure time to visit farmers' markets or artisan bakeries. The rest of the population, pressed for cash and equally pressed for time, cannot afford to be so particular.

The positive side of modern farming methods is that they have saved millions of lives. In the late 1950s, India was once again on the brink of famine. The cause was the mass flowering of a species of bamboo whose excess seeds, in turn, boosted vermin populations and whose numerous offspring then devoured other crops.

The solution was discovered by an American scientist, Norman Borlaug, who developed a dwarf variety of wheat that proved resistant to disease and whose stalk did not collapse under the weight of its high-yield crop.

Borlaug, who later won the Nobel Peace Prize, was at the forefront of what become known as the "Green Revolution" or the industrialisation of farming. Similar advances enabled spectacular increases in production of rice and maize in many of the poorer countries of the world. Doom- laden predictions that India would starve unless its population was halved to 200 million by 1980 began to look foolish as the numbers rose to nearly one billion and the country became self-sufficient in wheat.

But our faith in technology is going to be tested. The Green Revolution suddenly no longer seems capable of feeding a world population it played such a large part in boosting. There are concerns about the amount of pesticide required to raise huge areas of cultivation and, because it is now cheaper to feed animals as well as people, meat consumption has soared, accompanied by both health and environmental worries.

Prices of onions, a staple crop in India, rose to record levels this year after damage caused by heavier-than-expected rains and leading to an export ban. It was the same story with rice two years ago, when India, Thailand and Vietnam all imposed a ban on exports to protect supplies to domestic consumers as prices rocketed in the rest of the world.

The widespread adoption of genetically modified crops is now being seen as one solution, a second Green Revolution. The idea of tinkering with nature unsettles many people, yet the evidence that it could cause long-term damage to our ecosystem has yet to emerge.

There are other concerns about the power this gives to multinational corporations. Monsanto, the US biotech company, produces not just a herbicide, Roundup, but a range of seeds that are "Roundup Ready" - in other words, they have been genetically engineered to survive dosing with the weedkiller where other varieties, sold by rival companies, may not.

Still, it seems certain more and more countries will overcome any lingering squeamishness about both GM crops and products made from them. The UAE, which like other Gulf countries is critically dependent on food imports, has said it can see no reason to prevent products containing GM ingredients from being sold here. In the wider world, it has been estimated that two trillion meals containing GM ingredients have been consumed, with no obvious ill effects.

But if GM is the way to avoid hunger among the world's poorest, it would be a shame if this allows the more fortunate of us to ignore what we pile on our plates.

We should be aware that a rise of a couple of dirhams in the price of our designer latte means that Colombia's coffee crop has failed, wonder if we really need fresh strawberries in December, remember that beef cattle do not naturally roam the desert and that Atlantic salmon do not swim in the Gulf. Cheap food should be no reason to cheapen food.

James Langton is a writer for The National who takes his food seriously