Outgrowing the Earth: The Food Security Challenge in an Age of Falling Water Tables and Rising Temperatures


Lester R. Brown

Chapter 1. Pushing Beyond the Earth’s Limits: Losing Agricultural Momentum

Environmentalists have been saying for years that if the environmental trends of recent decades continued the world would one day be in trouble. What was not clear was what form the trouble would take and when it would occur. It now seems likely to take the form of tightening food supplies, and within the next few years. Indeed, China’s forays into the world market in early 2004 to buy 8 million tons of wheat could mark the beginning of the global shift from an era of grain surpluses to one of grain scarcity. 4 

World grain production is a basic indicator of dietary adequacy at the individual level and of overall food security at the global level. After nearly tripling from 1950 to 1996, the grain harvest stayed flat for seven years in a row, through 2003, showing no increase at all. And in each of the last four of those years, production fell short of consumption. The shortfalls of nearly 100 million tons in 2002 and again in 2003 were the largest on record. 5

With consumption exceeding production for four years, world grain stocks dropped to the lowest level in 30 years. (See Figure 1–1.) The last time stocks were this low, in 1972–74, wheat and rice prices doubled. Importing countries competed vigorously for inadequate supplies. A politics of scarcity emerged—with some countries, such as the United States, restricting exports. 6

In 2004 a combination of stronger grain prices at planting time and the best weather in a decade yielded a substantially larger harvest for the first time in eight years. Yet even with a harvest that was up 124 million tons from that in 2003, the world still consumed all the grain it produced, leaving none to rebuild stocks. If stocks cannot be rebuilt in a year of exceptional weather, when can they? 7

From 1950 to 1984 world grain production expanded faster than population, raising the grain produced per person from 250 kilograms to the historical peak of 339 kilograms, an increase of 34 percent. This positive development initially reflected recovery from the disruption of World War II, and then later solid technological advances. The rising tide of food production lifted all ships, largely eradicating hunger in some countries and substantially reducing it in many others. 8

Since 1984, however, grain harvest growth has fallen behind that of population, dropping the amount of grain produced per person to 308 kilograms in 2004, down 9 percent from its historic high point. Fortunately, part of the global decline was offset by the increasing efficiency with which feedgrains are converted into animal protein, thanks to the growing use of soybean meal as a protein supplement. Accordingly, the deterioration in nutrition has not been as great as the bare numbers would suggest. 9

The one region where the decline in grain produced per person is unusually steep and where it is taking a heavy human toll is Africa. In addition to the nutrient depletion of soils and the steady shrinkage in grainland per person from population growth in recent decades, Africa must now contend with the loss of adults to AIDS, which is depleting the rural work force and undermining agriculture. From 1960 through 1981, grain production per person in sub-Saharan Africa ranged between 140 and 160 kilograms per person. (See Figure 1–2.) Then from 1980 through 2001 it fluctuated largely between 120 and 140 kilograms. And in two of the last three years, it has been below 120 kilograms—dropping to a level that leaves millions of Africans on the edge of starvation. 10

Several long-standing environmental trends are contributing to the global loss of agricultural momentum. Among these are the cumulative effects of soil erosion on land productivity, the loss of cropland to desertification, and the accelerating conversion of cropland to nonfarm uses. All are taking a toll, although their relative roles vary among countries.

Now two newer environmental trends—falling water tables and rising temperatures—are slowing the growth in world food production, as described later in this chapter. (See also Chapters 6 and 7.) In addition, farmers are faced with a shrinking backlog of unused technology. The high-yielding varieties of wheat, rice, and corn that were developed a generation or so ago are now widely used in industrial and developing countries alike. They doubled and tripled yields, but there have not been any dramatic advances in the genetic yield potential of grains since then. 11

The use of fertilizer, which removed nutrient constraints and helped the new high-yielding varieties realize their full genetic potential during the last half-century, has now plateaued or even declined slightly in key food-producing countries. Among these are the United States, countries in Western Europe, Japan, and now possibly China as well. Meanwhile, the rapid growth in irrigation that characterized much of the last half-century has also slowed. Indeed, in some countries the irrigated area is shrinking. 12

The bottom line is that it is now more difficult for farmers to keep up with the growing demand for grain. The rise in world grainland productivity, which averaged over 2 percent a year from 1950 to 1990, fell to scarcely 1 percent a year from 1990 to 2000. This will likely drop further in the years immediately ahead. 13

If the rise in land productivity continues to slow and if population continues to grow by 70 million or more per year, governments may begin to define national security in terms of food shortages, rising food prices, and the emerging politics of scarcity. Food insecurity may soon eclipse terrorism as the overriding concern of national governments. 14


*Data and additional resources have been omitted from this mobile version of our website to ensure the most optimal experience. To view this page with its entire information, please visit the full website.