Peak Food

British undercover economist Tim Harford’s recent article, “Malthus’s ghost and baby number 7bn,” about whether the world can feed seven billion people, calls to mind the controversy over Peak Oil.  In 1956 geophysicist M. King Hubbert predicted that US oil production would peak in 1970.  Although his prediction was derided by oil professionals, it turned out to be right on the money.

Hubbert had observed that when a particular oil field reached roughly half of what can economically be produced, production levels off and then declines as producing the remaining half becomes more difficult.  Noting that the discovery of new oil fields in the US had itself peaked in 1930, Hubbert extended his theory to apply to all US oil fields taken as a group.

Peak Oil has now moved to the world stage, where discovery of new oil fields peaked in the 1960s.  When will world oil production level off?  Some say it already has.

The increasing cost and scarcity of post-peak oil production will increase oil prices.  But scarcity caused by the increasing demand of seven billion people will increase prices even more.  That is, Peak Oil’s effect on prices will be trumped by Peak Population.

We were, however, talking about feeding seven billion people, as to which Harford concluded “so far, so good.”  Although the cost of energy used in growing, producing and transporting food is a major component of its cost, food is a renewable resource, not finite like oil and other fossil energy.  Right?

Right -- but the soils in which food is grown can be depleted, and the sources of fresh water to grow it may not be renewable. 

The Green Revolution, powered by high-yield varieties of corn, wheat and rice grown with synthetic fertilizer, fed the surge in world population and livestock after World War II.  But in retrospect, it doesn’t seem so green.  According to a Pew Commission report, it had unwanted ecological impacts “such as aquifer depletion, groundwater contamination, and excess nutrient runoff” precisely because of its reliance on what made it a success -- “monoculture crops, irrigation, application of pesticides, and use of nitrogen and phosphorous fertilizers.”

Now Lester Brown of the Earth Policy Institute raises some startling questions about today’s global economy.  One is whether the US can feed China.  Another is whether China could starve the world.

Following the starvation of 30 million Chinese during Mao Zedong’s Great Leap Forward, Mao refocused China’s agricultural resources on the production of grains.  To create new cropland, China cleared the grasslands in its northwest province.  But overplowing and overpumping of freshwater aquifers in the years since has turned much of its farmland into desert.  Dust storms from northern and western China now envelop Beijing every spring.

The storms are reminiscent of the Dust Bowl in the southern US Great Plains where homesteaders had replaced the prairie grass and other vegetation with endless acres of wheat.  A decade of drought in the 1930s forced 2½ million people to abandon their farms.  This dryland is again being farmed with irrigation from the deepwater or “fossil” Ogallala Aquifer, but fossil aquifers do not replenish themselves.  If the Ogallala goes dry, farming will go back to lower-yield dryland farming if there is sufficient rainfall or cease altogether.         

Land degradation that reduces food-growing productivity is a worldwide concern.  Surveys in the 1980s identified roughly three percent of US soil as degraded and two percent as severely degraded.  A separate analysis showed two-thirds of the degradation was caused by “agricultural activities” (i.e., farming) and most of the rest by livestock overgrazing.  For the world as a whole, degradation is caused by these two factors plus deforestation in approximately equal proportions.

If degradation is not too severe, soil can be maintained and even restored by sound farming techniques such as reduced tillage, fallow periods, cover crops, crop rotation, manuring  and balanced fertilizer application.  But if degradation goes too far, farming will cease altogether.  Soil at that point becomes a non-renewable resource.   

That’s the problem China is facing.  To avoid politically unsettling increases in food prices, it will have to import grain .  The US is the world’s largest grain exporter.

Welcome to Peak Food – which, like Peak Oil and almost every other environmental problem you can think of, is trumped by Peak Population.  “For Americans,” Brown says,

“who live in a country that has been the world’s breadbasket for more than half a century, a country that has never known food shortages or runaway food prices, the world is about to change.  Like it or not, we are going to be sharing our grain harvest with the Chinese, no matter how much it raises our food prices.”

Time to husband our agricultural resources and adopt techniques consistent with a seven billion person world.  Grow food for food, not fuel.  And keep our fresh water free of pollutants from Canadian oil sands and US shale gas mining.