Tuesday, September 18, 2012

Food security nightmare

Adapted from an article by Lester Brown of Earth Policy Institute

Food security is emerging as a massive threat to the world’s population. Unsustainable farming practices are making the problem worse.

At a time when the world’s farmers are facing a record growth in food demand, they continue to wrestle with the traditional threats to production such as soil erosion. But now they are also looking at three new challenges on the production front. One, aquifers are being depleted and irrigation wells are starting to go dry in 18 countries that together contain half the world’s people. Two, in some of the more agriculturally advanced countries, rice and wheat yield per acre, which have been rising steadily for several decades, are beginning to plateau. And three, the earth’s temperature is rising, threatening to disrupt world agriculture in scary ways.

The countries where water tables are falling and aquifers are being depleted include the big three grain producers—China, India, and the United States. World Bank data for India indicate that 175 million people are being fed with grain produced by overpumping. My own estimate for China is that 130 million people are being fed by overpumping. In the United States, the irrigated area is shrinking in leading agricultural states such as California and Texas as aquifers are depleted and irrigation water is diverted to cities.

Second, after several decades of rising grain yields, some of the more agriculturally advanced countries are hitting a glass ceiling, a limit that was not widely anticipated. Rice yields in Japan, which over a century ago became the first country to launch a sustained rise in land productivity, have not increased for 17 years. In both Japan and South Korea, yields have plateaued at just under 5 tons per hectare. China’s rice yields, rising rapidly in recent decades, are now closely approaching those of Japan. If China cannot raise its rice yields above those in Japan, and it does not seem likely that it can, then a plateauing there too is imminent.

A similar situation exists with wheat yields. In France, Germany, and the United Kingdom—the three leading wheat producers in Europe—there has been no rise for more than a decade. Other advanced countries will soon be hitting their glass ceiling for grain yields. Australia is no exception

The third new challenge confronting farmers is global warming. The massive burning of fossil fuels is increasing the level of carbon dioxide in the atmosphere, raising the earth’s temperature and disrupting climate. It is now in a state of flux. Historically when there was an extreme weather event—an intense heat wave or a drought—we knew it was temporary and that things would likely be back to normal by the next harvest. Now there is no “norm” to return to, leaving farmers facing a future fraught with risk.

High temperatures can lower crop yields. The widely used rule of thumb is that for each 1-degree-Celsius rise in temperature above the optimum during the growing season farmers can expect a 10-percent decline in grain yields. A historical study of the effect of temperature on corn and soybean yields in the United States found that a 1-degree-Celsius rise in temperature reduced grain yields 17 percent. Yet if the world continues with business as usual, failing to address the climate issue, the earth’s temperature during this century could easily rise by 6 degrees Celsius.

In recent years, world carryover stocks of grain have been, only slightly above the 70 days that was considered a desirable minimum during the late twentieth century. Now stock levels must take into account the effect on harvests of higher temperatures, more extensive drought, and more intense heat waves. Although there is no easy way to precisely quantify the harvest effects of any of these climate-related threats, it is clear that any of them can shrink harvests, potentially creating chaos in the world grain market. To mitigate this risk, a stock reserve equal to 110 days of consumption would produce a much safer level of food security.

Although we talk about food price spikes, what we are more likely starting to see is a ratcheting upward of food prices. This process is likely to continue until we succeed in reversing some of the trends that are driving it. All of the threatening trends are of human origin, but whether we can reverse them remains to be seen.

As food supplies tighten, the geopolitics of food is fast overshadowing the geopolitics of oil. The first signs of trouble came in 2007, when world grain production fell behind demand. Grain and soybean prices started to climb, doubling by mid-2008. In response, many exporting countries tried to curb rising domestic food prices by restricting exports. Among them were Russia and Argentina, two leading wheat exporters. Viet Nam, the world’s number two rice exporter, banned exports entirely in the early months of 2008. Several other smaller grain suppliers also restricted exports.
More about food security in Australia can be found here.

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