EPIBuilding a Sustainable Future
Lester R. Brown

Chapter 1. Selling Our Future: Food - The Weak Link

As the world struggles to feed all its people, farmers are facing several trying trends. On the demand side of the food equation are three consumption-boosting trends: population growth, the growing consumption of grain-based animal protein, and, most recently, the massive use of grain to fuel cars.

On the supply side, several environmental and resource trends are making it more difficult to expand food production fast enough. Among the ongoing ones are soil erosion, aquifer depletion, crop-shrinking heat waves, melting ice sheets and rising sea level, and the melting of the mountain glaciers that feed major rivers and irrigation systems. In addition, three resource trends are affecting our food supply: the loss of cropland to non-farm uses, the diversion of irrigation water to cities, and the coming reduction in oil supplies.

The first trend of concern is population growth. Each year there are 79 million more people at the dinner table. Unfortunately, the overwhelming majority of these individuals are being added in countries where soils are eroding, water tables are falling, and irrigation wells are going dry. If we cannot get the brakes on population growth, we may not be able to eradicate hunger. 5

Even as our numbers are multiplying, some 3 billion people are trying to move up the food chain, consuming more grain-intensive livestock products. At the top of the food chain ranking are the United States and Canada, where people consume on average 800 kilograms of grain per year, most of it indirectly as beef, pork, poultry, milk, and eggs. Near the bottom of this ranking is India, where people have less than 200 kilograms of grain each, and thus must consume nearly all of it directly, leaving little for conversion into animal protein. 6

Beyond this, the owners of the world’s 910 million automobiles want to maintain their mobility, and most are not particularly concerned about whether their fuel comes from an oil well or a corn field. The orgy of investment in ethanol fuel distilleries that followed the 2005 surge in U.S. gas prices to $3 a gallon after Hurricane Katrina raised the annual growth in world grain consumption from roughly 20 million tons per year to more than 40 million tons in both 2007 and 2008, creating an epic competition between cars and people for grain. 7

Turning to the supply-side constraints, soil erosion is currently lowering the inherent productivity of some 30 percent of the world’s cropland. In some countries, such as Lesotho and Mongolia, it has reduced grain production by half or more over the last three decades. Kazakhstan, the site of the Soviet Virgin Lands project a half-century ago, has abandoned 40 percent of its grainland since 1980. Vast dust storms coming out of sub-Saharan Africa, northern China, western Mongolia, and Central Asia remind us that the loss of topsoil is not only continuing but expanding. 8

In contrast to the loss of topsoil that began with the first wheat and barley plantings, falling water tables are historically quite recent, simply because the pumping capacity to deplete aquifers has evolved only in recent decades. As a result, water tables are now falling in countries that together contain half the world’s people. As overpumping spreads and as aquifer depletion continues, the wells are starting to go dry. Saudi Arabia has announced that because its major aquifer, a fossil (non-replenishable) aquifer, is largely depleted, it will be phasing out wheat production entirely by 2016. A World Bank study shows that 175 million people in India are being fed by overpumping aquifers. In China, this problem affects 130 million people. 9

Climate change also threatens food security. After a certain point, rising temperatures reduce crop yields. For each 1 degree Celsius rise in temperature above the norm during the growing season, farmers can expect a 10-percent decline in wheat, rice, and corn yields. Since 1970, the earth’s average surface temperature has increased by 0.6 degrees Celsius, or roughly 1 degree Fahrenheit. And the Intergovernmental Panel on Climate Change projects that the temperature will rise by up to 6 degrees Celsius (11 degrees Fahrenheit) during this century. 10

As the earth’s temperature continues to rise, mountain glaciers are melting throughout the world. Nowhere is this of more concern than in Asia. It is the ice melt from glaciers in the Himalayas and on the Tibetan Plateau that sustain the major rivers of India and China, and the irrigation systems that depend on them, during the dry season. In Asia, both wheat and rice fields depend on this water. China is the world’s leading wheat producer. India is number two. (The United States is third.) These two countries also dominate the world rice harvest. Whatever happens to the wheat and rice harvests in these two population giants will affect food prices everywhere. Indeed, the projected melting of the glaciers on which these two countries depend presents the most massive threat to food security humanity has ever faced. 11

According to the latest information on the accelerating melting of the Greenland and West Antarctic ice sheets, ice melt combined with thermal expansion of the oceans could raise sea level by up to 6 feet during this century. Every rice-growing river delta in Asia is threatened by the melting of these ice sheets. Even a 3-foot rise would devastate the rice harvest in the Mekong Delta, which produces more than half the rice in Viet Nam, the world’s number two rice exporter. A World Bank map shows that a 3-foot rise in sea level would inundate half the riceland in Bangladesh, home to 160 million people. The fate of the hundreds of millions who depend on the harvests in the rice-growing river deltas and floodplains of Asia is inextricably linked to the fate of these major ice sheets. 12

As pressures on land-based food sources mounted after World War II, the world turned to the oceans for animal protein. From 1950 to 1996 the world fish catch climbed from 19 million to 94 million tons. But then growth came to a halt. We had reached the limits of the oceans before those of the land. Since 1996, growth in the world seafood supply has come almost entirely from fish farms. The spiraling demand for fish feed, most of it in the form of grain and soybean meal, is further intensifying pressure on the earth’s land and water resources. 13

Advancing deserts—the result of overgrazing, overplowing, and deforestation—are encroaching on cropland in Saharan Africa, the Middle East, Central Asia, and China. Advancing deserts in northern and western China have forced the complete or partial abandonment of some 24,000 villages and the cropland surrounding them. In Africa, the Sahara is moving southward, engulfing cropland in Nigeria. It is also moving northward, invading wheat fields in Algeria and Morocco. 14

Farmers are losing cropland and irrigation water to non-farm uses. The conversion of cropland to other uses looms large in China, India, and the United States. China, with its massive industrial and residential construction and its paving of roads, highways, and parking lots for a fast-growing automobile fleet, may be the world leader in cropland loss. In the United States, suburban sprawl is consuming large tracts of farmland.

With additional water no longer available in many countries, growing urban thirst can be satisfied only by taking irrigation water from farmers. Thousands of farmers in thirsty California find it more profitable to sell their irrigation water to Los Angeles and San Diego and leave their land idle. In India, villages are selling the water from their irrigation wells to nearby cities. China’s farmers are also losing irrigation water to the country’s fast-growing cities. 15

Lingering in the background is the prospect of declining oil use as a result of either declining production or efforts to cut carbon emissions—or, more likely, some combination of the two. The tripling of the world grain harvest over the last half-century is closely tied to oil. Today oil figures prominently in the farm economy, used in tillage, irrigation, and harvesting. Once oil production turns downward, countries will compete for a shrinking supply as they try to keep their agriculture producing at a high level. It was relatively easy to expand world food production when oil was cheap and abundant. It will be far more difficult when the price of oil is rising and the supply is declining. 16

Despite the growing need for new techniques to expand production, the backlog of unused agricultural technology is shrinking. In the more agriculturally advanced countries, farmers are using virtually all the available technology to raise land productivity. And agricultural scientists are not finding many new ways to raise yields. In Japan, the first country to launch a sustained rise in grain yield per hectare, rice yield increases have stalled, with little gain over the last 14 years. In China, the rapid rise in rice yields is now history. In both France and Egypt, wheat yields, which are among the world’s highest, have been flat for roughly a decade. For the world as a whole, the rise in grainland productivity dropped from 2.1 percent a year from 1950 to 1990 to 1.3 percent from 1990 to 2008. 17

Some commentators point to genetically modified crops as a way out of this predicament. Unfortunately, no genetically modified grains have dramatically raised yields. Nor are they likely to do so. Scientists using conventional plant breeding techniques have already exploited most of the genetic potential for raising crop yields. 18

The bottom line is that harvest-expanding scientific advances are ever more difficult to come by as crop yields move closer to the inherent limits of photosynthetic efficiency. This limit in turn establishes the upper bounds of the earth’s biological productivity, which ultimately will determine its human carrying capacity. 19

As the world’s farmers attempt to expand the harvest, the trends that negatively affect production are partly offsetting advances in technology. The question now is, Could the environmental damage to world agriculture at some point entirely offset the gains from advancing technology, as it has already in Saudi Arabia and Yemen, where water shortages are shrinking grain harvests, or in Lesotho and Mongolia, where soil erosion is reducing harvests? 20

The question—at least for now—is not will the world grain harvest continue to expand, but will it expand fast enough to keep pace with steadily growing demand.

Business as usual is no longer a viable option. Food security will deteriorate further unless leading countries collectively mobilize to stabilize population, stabilize climate, stabilize aquifers, conserve soils, protect cropland, and restrict the use of grain to produce fuel for cars.

Previous Table of Contents Next


5. U.N. Population Division, World Population Prospects: The 2008 Revision Population Database, at esa.un.org/unpp, updated 11 March 2009.

6. USDA, Production, Supply and Distribution, electronic database, at www.fas.usda.gov/psdonline, updated 12 May 2009; U.N. Population Division, op. cit. note 5.

7. Ward’s Automotive Group, World Motor Vehicle Data 2008 (Southfield, MI: 2008), pp. 239–42; USDA, op. cit. note 6; F.O. Licht, “Too Much Too Soon? World Ethanol Production to Break Another Record in 2005,” World Ethanol and Biofuels Report, vol. 3, no. 20 (21 June 2005), pp. 429–35; U.S. Department of Energy (DOE), Energy Information Administration (EIA), “World Crude Oil Prices,” and “U.S. All Grades All Formulations Retail Gasoline Prices,” at tonto.eia.doe.gov, viewed 31 July 2007.

8. Cropland losing topsoil is author’s estimate; USDA, op. cit. note 6; FAO, The State of Food and Agriculture 1995 (Rome: 1995), p. 175.

9. Lester R. Brown, Outgrowing the Earth (New York: W. W. Norton & Company, 2004), pp. 101–02; Peter H. Gleick et al., The World’s Water 2004–2005 (Washington, DC: Island Press, 2004), p. 88; U.N. Population Division, op. cit. note 5; Andrew England, “Saudis to Phase Out Wheat Production,” Financial Times, 10 April 2008; John Briscoe, India’s Water Economy: Bracing for a Turbulent Future (New Delhi: World Bank, 2005); World Bank, China: Agenda for Water Sector Strategy for North China (Washington, DC: April 2001), pp. vii, xi.

10. Shaobing Peng et al., “Rice Yields Decline with Higher Night Temperature from Global Warming,” Proceedings of the National Academy of Sciences, 6 July 2004, pp. 9,971–75; J. Hansen, NASA’s Goddard Institute for Space Studies, “Global Temperature Anomalies in 0.1 C,” at data.giss.nasa.gov/gistemp/tabledata/GLB.Ts.txt, updated April 2009;  “Summary for Policymakers,” in Intergovernmental Panel on Climate Change, Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (Cambridge, U.K.: Cambridge University Press, 2007), p. 13.

11. U.N. Environment Programme, Global Outlook for Ice and Snow (Nairobi: 2007); Lester R. Brown, “Melting Mountain Glaciers Will Shrink Grain Harvests in China and India,” Plan B Update (Washington, DC: Earth Policy Institute, 20 March 2008); USDA, op. cit. note 6.

12. W. T. Pfeffer, J. T. Harper, and S. O’Neel, “Kinematic Constraints on Glacier Contributions to 21st-Century Sea-Level Rise,” Science, vol. 321 (5 September 2008) pp. 1,340–43; James Hansen, “Scientific Reticence and Sea Level Rise,” Environmental Research Letters, vol. 2 (24 May 2007); Environmental Change and Forced Scenarios Project, “Preliminary Finds from the EACH-FOR Project on Environmentally Induced Migration” (September 2008), p. 16; U.N. Development Programme, Human Development Report 2007/2008 (New York: 2007), p. 100;  World Bank, World Development Report 1999/2000 (New York: Oxford University Press, September 1999); USDA, op. cit. note 6; U.N. Population Division, op. cit. note 5.

13. FAO, FISHSTAT Plus, electronic database, at www.fao.org, updated February 2009.

14. Wang Tao, Cold and Arid Regions Environmental and Engineering Research Institute (CAREERI), Chinese Academy of Sciences, e-mail to author, 4 April 2004; Wang Tao, “The Process and Its Control of Sandy Desertification in Northern China,” CAREERI, Chinese Academy of Sciences, seminar on desertification, held in Lanzhou, China, May 2002; “Scientists Meeting in Tunis Called for Priority Activities to Curb Desertification,” UN News Service, 21 June 2006.

15. Noel Gollehon and William Quinby, “Irrigation in the American West: Area, Water and Economic Activity,” Water Resources Development, vol. 16, no. 2 (2000), pp. 187–95; Sandra Postel, Last Oasis (New York: W. W. Norton & Company, 1997), p. 137; R. Srinivasan, “The Politics of Water,” Info Change Agenda, issue 3 (October 2005); Water Strategist, various issues, at www.waterstrategist.com; “China Politics: Growing Tensions Over Scarce Water,” The Economist, 21 June 2004.

16. USDA, op. cit. note 6; pre-1960 data from USDA, in Worldwatch Institute, Signposts 2001, CD-Rom (Washington, DC: 2001).

17. USDA, op. cit. note 6; pre-1960 data from USDA, op. cit. note 16.

18. USDA, op. cit. note 6; Kenneth G. Cassman et al., “Meeting Cereal Demand While Protecting Natural Resources and Improving Environmental Quality,” Annual Review of Environment and Resources, November 2003, pp. 322, 350; Thomas R. Sinclair, “Limits to Crop Yield?” in American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Physiology and Determination of Crop Yield (Madison, WI: 1994), pp. 509–32.

19. Peter M. Vitousek et al., “Human Appropriation of the Products of Photosynthesis,” BioScience, vol. 36, no. 6 (June 1986), pp. 368–73.

20. USDA, op. cit. note 6; U.N. Population Division, op. cit. note 5.


Copyright © 2009 Earth Policy Institute