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Matt Ridley is the author of provocative books on evolution, genetics and society. His books have sold over a million copies, been translated into thirty languages, and have won several awards.

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Feeding of the nine billion

I had this article in the Times on 14 January:

The person who tips the world population over seven billion may be born this year. The world food price index hit a record high last month, according to the Food and Agriculture Organisation. Bad harvests in Russia and Australia, combined with rising oil prices, have begun to cause shortages, export bans and even riots. Does starvation loom?

No. Never has the world looked less likely to starve, or our grandchildren more likely to feed well. Never has famine been less widespread. Never has the estimated future peak of world population been lower.

It is true that the world population may pass seven billion some time in the next twelve months, but the rate of growth is decelerating. World population is now growing at just over 1% a year, down from roughly 2% in the 1960s. The actual number of people added to the world population each year has been dropping for more than 20 years.

This deceleration took demographers by surprise. As recently as 1980 many were still forecasting that the current century would see 15 billion people and rising. Only in 2002 did the United Nations realise that its models were wrong to assume that birth rates would not drop below 2 children per woman in many countries. Now the UN estimates that the population will most probably peak at 9.2 billion in about 2075 before starting a slow decline. Population quadrupled in the twentieth century; it will not even double in this.

Everywhere, the fall in the birth rate is dramatic. Countries like Iran and Sri Lanka now have total fertility rates below two children per woman. Bangladesh is now down to 2.7 from 6.8 in 1955. Nigeria's birth rate has halved. These `demographic transitions' are proving as predictable as they are mysterious. They seem to happen because women stop fearing their babies will die, and because they move to cities, get educated, get access to birth control and get richer. In other words, the causes are benign; coercion, of the kind so many `experts' have long urged, is neither necessary nor helpful.

As for food prices, that `record high' is nothing of the kind - if you take inflation into account. Food prices are up in real terms since 2000, but they are still about 30% below the level in 1980 and 85% down since 1900. In terms of wages, the decline has been even steeper.

Despite a doubling of the population, global food production per head is 30% up on what it was in the 1950s.

Besides, the current spike in food prices is caused by prosperity, not desperation. Newly-rich Chinese and Indians are eating more meat, boosting demand for grain to feed livestock. Meanwhile still-rich Americans and Europeans are indulging their farmers and green activists by taking food and turning it into motor fuel, a policy that pushes up food prices, hurts taxpayers and encourages habitat destruction.

You can bet your farm that all over the northern hemisphere farmers are planting more acres this winter - that's the effect high prices always have (and spare a nod of gratitude to speculators, whose antics bring forward those extra plantings). So food prices will drop again.

Farm yields have been marching upwards for decades and will continue to do so. In the past sixty years, the total harvest of the big three crops that provide the bulk of our calories - maize, wheat and rice - has trebled, yet the acreage planted has hardly changed.

This trend is going to continue partly thanks to low-tech changes already in the pipeline. Helped by Chinese investment, improved transport to get African crops to market with less waste will make a big difference. As will tractors, which boost production by 25% or so - because they free the land for human food that would otherwise be needed to feed bullocks or horses.

African farmers will start to use much more fertilizer, as western farmers do, which makes it possible to sustain yields without exhausting the soil. A few years ago environmentalists argued that fertiliser would soon run short, because it is made using natural gas, a fossil fuel. But the discovery of how to extract abundant shale gas has turned that argument on its head: there are probably many decades' worth of natural gas now available to make fertilizer.

There are high-tech changes afoot too. Maize and rice that have been genetically modified to resist pests and use less water, soybeans with better amino acid balance for pig food, wheat that can resist rust - all these are coming. Benighted Europe may reject these GM crops for superstitious reasons but surely not for long. The environmental benefits alone are now stark: GM crops can be pest resistant without the use of sprays that kill harmless insect bystanders.

The more yields increase, the more land can be set aside from food production for reforestation and national parks. This is happening already. National parks are expanding steadily, and land that was once farmed is being returned to forest, especially in countries like Britain and America. That is a huge contrast to a century ago, when farming kept up with population only by expanding into new areas of steppe, pampas and prairie.

Don't forget another factor. Carbon dioxide levels in the air are rising. CO2 is a raw material that plants use to make sugars, which is why many greenhouse owners pump CO2 over their crops to boost production. The results of more than 600 experiments with rice, wheat and soybeans exposed to the sort of carbon dioxide levels expected by 2050 (an extra 300 parts per million) all show remarkably consistent 30+% increases in yield. And the higher the CO2, the less water a plant loses in absorbing it, so water stress will improve too. Plus, if global warming happens, it is likely to produce more rainfall, so that regions like the Sahel will continue to become greener, as it has in recent decades.

For all these reasons food production will probably continue to rise faster than population in the decades ahead. There will still be price spikes caused by bad weather or foolish policies, and there will be challenges: policies that encourage innovation cannot be taken for granted. Yet so long as trade is free and innovation flourishes, by 2050 it is easily possible that we can feed nine billion people with more and better food from less land.