The Great Food Crisis of 2011

As the new year begins, the price of wheat is setting an all-time high in the United Kingdom. Food riots are spreading across Algeria. Russia is importing grain to sustain its cattle herds until spring grazing begins. India is wrestling with an 18-percent annual food inflation rate, sparking protests. China is looking abroad for potentially massive quantities of wheat and corn. The Mexican government is buying corn futures to avoid unmanageable tortilla price rises. And on January 5, the U.N. Food and Agricultural organization announced that its food price index for December hit an all-time high.

But whereas in years past, it's been weather that has caused a spike in commodities prices, now it's trends on both sides of the food supply/demand equation that are driving up prices. On the demand side, the culprits are population growth, rising affluence, and the use of grain to fuel cars. On the supply side: soil erosion, aquifer depletion, the loss of cropland to nonfarm uses, the diversion of irrigation water to cities, the plateauing of crop yields in agriculturally advanced countries, and -- due to climate change -- crop-withering heat waves and melting mountain glaciers and ice sheets. These climate-related trends seem destined to take a far greater toll in the future.

There's at least a glimmer of good news on the demand side: World population growth, which peaked at 2 percent per year around 1970, dropped below 1.2 percent per year in 2010. But because the world population has nearly doubled since 1970, we are still adding 80 million people each year. Tonight, there will be 219,000 additional mouths to feed at the dinner table, and many of them will be greeted with empty plates. Another 219,000 will join us tomorrow night. At some point, this relentless growth begins to tax both the skills of farmers and the limits of the earth's land and water resources.

Beyond population growth, there are now some 3 billion people moving up the food chain, eating greater quantities of grain-intensive livestock and poultry products. The rise in meat, milk, and egg consumption in fast-growing developing countries has no precedent. Total meat consumption in China today is already nearly double that in the United States.

The third major source of demand growth is the use of crops to produce fuel for cars. In the United States, which harvested 416 million tons of grain in 2009, 119 million tons went to ethanol distilleries to produce fuel for cars. That's enough to feed 350 million people for a year. The massive U.S. investment in ethanol distilleries sets the stage for direct competition between cars and people for the world grain harvest. In Europe, where much of the auto fleet runs on diesel fuel, there is growing demand for plant-based diesel oil, principally from rapeseed and palm oil. This demand for oil-bearing crops is not only reducing the land available to produce food crops in Europe, it is also driving the clearing of rainforests in Indonesia and Malaysia for palm oil plantations

The combined effect of these three growing demands is stunning: a doubling in the annual growth in world grain consumption from an average of 21 million tons per year in 1990-2005 to 41 million tons per year in 2005-2010. Most of this huge jump is attributable to the orgy of investment in ethanol distilleries in the United States in 2006-2008.

While the annual demand growth for grain was doubling, new constraints were emerging on the supply side, even as longstanding ones such as soil erosion intensified. An estimated one third of the world's cropland is losing topsoil faster than new soil is forming through natural processes -- and thus is losing its inherent productivity. Two huge dust bowls are forming, one across northwest China, western Mongolia, and central Asia; the other in central Africa. Each of these dwarfs the U.S. dust bowl of the 1930s.

Satellite images show a steady flow of dust storms leaving these regions, each one typically carrying millions of tons of precious topsoil. In North China, some 24,000 rural villages have been abandoned or partly depopulated as grasslands have been destroyed by overgrazing and as croplands have been inundated by migrating sand dunes.

In countries with severe soil erosion, such as Mongolia and Lesotho, grain harvests are shrinking as erosion lowers yields and eventually leads to cropland abandonment. The result is spreading hunger and growing dependence on imports. Haiti and North Korea, two countries with severely eroded soils, are chronically dependent on food aid from abroad.

Meanwhile aquifer depletion is fast shrinking the amount of irrigated area in many parts of the world; this relatively recent phenomenon is driven by the large-scale use of mechanical pumps to exploit underground water. Today, half the world's people live in countries where water tables are falling as overpumping depletes aquifers. Once an aquifer is depleted, pumping is necessarily reduced to the rate of recharge unless it is a fossil (nonreplenishable) aquifer, in which case pumping ends altogether. But sooner or later, falling water tables translate into rising food prices.