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.
