Tim Radford
Tough Choices: Facing The Challenge of Food Security
(Earthscan, R75)
Duke University in the United States has a rice diet house. People who tend to obesity check in and guinea pig-out on rice cooked without salt, and fruit, and lose weight and gain life expectancy. Most people in most countries of the world make do on around 200kg of grain per year. In the US and parts of Europe, however, most people consume 800kg of grain a year each — grain converted into beef, mutton, pork, chicken, cheese, milk and eggs.
Tough Choices is a kind of reality check: a pocket guide to the problems on the political plate. It is a useful addendum to recent books such as Joel Cohen’s How Many People Can The Earth Support? (Norton) and The Future Population of the World: What Can We Assume Today? edited by Wolfgang Lutz (Earthscan).
Between 1950 and 1990 the world grain harvest tripled. But at the start of 1996, world grain stocks were the lowest on record. World output of beef and mutton went from 24-million tons in 1950 to 62- million tons in 1990. This growth has almost stopped. So the number of people with a steak in the future is already falling, as world populations soar.
But man does not live by bread alone: he needs water. Water is already a huge problem and getting more problematic almost everywhere. In 1980 only 43% of the globe had “reasonable access” to safe drinking water. Humans can scrape by on a few litres every day, but it takes 500 litres of water to grow 1kg of wheat. Rice farmers use 5 000 litres for 1kg of basmati or arborio.
Beef farmers are the ones who really spend water like money: 1 000 kilocalories of T- bone steak — 250 grams — costs 5,1m3 of water, or 19 times as much as it takes to make 1 000 kilocalories of bread.
The numbers of poor and hungry have grown all through the fat years of the green revolution, and all the guesses about soil erosion, energy demands and water budgets point to a gloomy likelihood: that the lean years are about to begin.
Meanwhile the increases go on. In the last decade, the growth in population equalled the population of the whole world in 1600. Every five days there are another million or more mouths to feed. Boiled rice, anyone?