How Long Can the World Feed Itself?

By Gwynne Dyer, 10 October 2006

http://www.gwynnedyer.com/articles/Gwynne%20Dyer%20article_%20%20Feeding%20the%20World.txt  (2009-10-31)

We are still living off the proceeds of the Green Revolution, but

that hit diminishing returns twenty years ago. Now we live in a finely

balanced situation where world food supply just about meets demand, with no

reserve to cover further population growth. But the population will grow

anyway, and the world's existing grain supply for human consumption is

being eroded by three different factors: meat, heat and biofuels.



For the sixth time in the past seven years, the human race will

grow less food than it eats this year. We closed the gap by eating into

food stocks accumulated in better times, but there is no doubt that the

situation is getting serious. The world's food stocks have shrunk by half

since 1999, from a reserve big enough to feed the entire world for 116 days

then to a predicted low of only 57 days by the end of this year.



That is well below the official safety level, and there is no sign

that the downward trend is going to reverse. If it doesn't, then at some

point not too far down the road we reach the point of absolute food

shortages, and rationing by price kicks in. In other words, grain prices

soar, and the poorest start to starve.



The miracle that has fed us for a whole generation now was the

Green Revolution: higher-yielding crops that enabled us to almost triple

world food production between 1950 and 1990 while increasing the area of

farmland by no more than ten percent. The global population more than

doubled in that time, so we are now living on less than half the land per

person than our grandparents needed. But that was a one-time miracle, and

it's over. Since the beginning of the 1990s, crop yields have essentially

stopped rising.



The world's population continues to grow, of course, though more

slowly than in the previous generation. We will have to find food for the

equivalent of another India and another China in the next fifty years, and

nobody has a clue how we are going to do that. But the more immediate

problem is that the world's existing grain supply is under threat.



One reason we are getting closer to the edge is the diversion of

grain for meat production. As incomes rise, so does the consumption of

meat, and feeding animals for meat is a very inefficient way of using

grain. It takes between eleven and seventeen calories of food (almost all

grain) to produce one calorie of beef, pork or chicken, and the world's

production of meat has increased fivefold since 1950. We now get through

five billion hoofed animals and fourteen billion poultry a year, and it

takes slightly over a third of all our grain to feed them.



Then there's the heat. The most visible cause of the fall in world

grain production -- from 2.68 billion tonnes in 2004 to 2.38 billion tonnes

last year and a predicted 1.98 billion tonnes this year -- is droughts, but

there are strong suspicions that these droughts are related to climate

change.



Moreover, beyond a certain point hotter temperatures directly

reduce grain yields. Current estimates suggest that the yield of the main

grain crops drops ten percent, on average, for every one degree Celsius

that the mean temperature exceeds the optimum for that crop during the

growing season. Which may be why the average corn yield in the US reached a

record 8.4 tonnes per hectare in 1994, and has since fallen back

significantly.



Finally, biofuels. The idea is elegant: the carbon dioxide

absorbed when the crops are grown exactly equals the carbon dioxide

released when the fuel refined from those crops is burned, so the whole

process is carbon-neutral. And it would be fine if the land used to grow

this biomass was land that had no alternative use, but that is rarely the

case.



In South-East Asia, the main source of biofuels is oil palms, which

are mostly grown on cleared rainforest. In the United States, a "corn

rush" has been unleashed by government subsidies for ethanol, and so many

ethanol plants are planned or already in existence in Iowa that they could

absorb the state's entire crop of corn (maize, mealies). In effect, food

is being turned into fuel -- and the amount of ethanol needed to fill a big

four-wheel-drive SUV just once uses enough grain to feed one person for an

entire year.



There is a hidden buffer in the system, in the sense that some of

the grain now fed to animals could be diverted to feed people directly in

an emergency. On the other hand, the downward trend in grain production

will only accelerate if it is directly related to global warming. And the

fashion for biofuels is making a bad situation worse.



It's only in the past couple of centuries that a growing number of

countries have been able to stop worrying about whether there will be

enough food at the end of the harvest to make it through to next year. The

Golden Age may not last much longer.

_________________________________

Gwynne Dyer is a London-based independent journalist whose articles

are published in 45 countries.