Outgrowing the Earth

Humanist, May-June, 2005 by Al Huebner

Outgrowing the Earth: The Food Security Challenge in an Age of Falling Water Tables and Rising Temperatures by Lester R. Brown (New York: W. W. Norton, 2005); 239 pp.; $15.00 paper

DURING THE SECOND HALF of the twentieth century the world economy grew by a factor of seven while the Earth's natural life-support systems remained static. Water use tripled but the capacity of the hydrological system to produce fresh water changed little. The demand for seafood increased fivefold leading to the collapse of fisheries in many parts of the world. Fossil fuel burning increased emissions of the greenhouse gas carbon dioxide fourfold, leading to a buildup in the atmosphere and a rise in the Earth's average temperature. And world population increased from 2.5 billion to 6 billion.

Despite a modest decrease recently in the overall growth rate, there are still over 70 million more people to feed each year. And as 2005 began the world food supply continued to tighten as grain demand expanded at a robust pace and production slowed and, in some crucial regions, even reversed. In his new book, Outgrowing the Earth, analyst Lester Brown (founder and president of the Earth Policy Institute and the American Humanist Association's 1991 Humanist of the Year) warns readers about the deadly consequences of this growing food insecurity. The political instability, economic disruption, and resultant number of lives that will be lost are likely to eclipse the many other problems afflicting humanity.

Vast quantities of fresh water (70 percent of the world's reserves) are needed to produce food, leading Brown to warn that "a future of water shortages will also be a future of food shortages." With river water fully exploited, if not overexploited, farmers have increasingly turned to underground sources for irrigation. As a result, water tables are falling precipitously in scores of countries that together contain more than half of the world's people. Specifically, Chinas water tables are falling throughout the North China Plain, the source of half that nation's wheat and a third of its corn. India's water tables are falling and wells are going dry by the thousands in states including the Punjab, the nation's breadbasket. And in the United States the overpumping of the vast High Plains aquifer has become a matter of enormous agricultural concern. (Scientists also warn that the recent Asian tsunami caused such contamination of fresh water reserves in that region that it may be years or decades before they recover.)

As for the effect of greenhouse gas carbon dioxide on grain yields, Brown reports that the negative effect of higher temperatures overrides any possible positive impact increased carbon dioxide has on production. Studies of experimental fields indicate that a one-degree-Celsius rise in temperature lowers wheat, rice, and corn yields by 10 percent, and an empirical historical analysis of the effect of temperature on corn and soybeans shows an even slightly greater reduction. In view of this, the temperature increases predicted for coming decades is extremely bad news.

Brown stresses that the individual elements threatening food security are made all the more dangerous by interactions that amplify the impact. While increasing populations obviously put pressure on the need for food, they also require more space for housing and roads at the expense of cropland and diversion to cities and towns of water previously used to grow food. In China, for example, a 1994 plan to develop an auto-centered transportation system similar to that in the United States is being challenged as to whether the country has enough land both to feed its people and to support such a system, much less deal with the increased congestion and pollution. In states like Colorado and California, cities are buying from farmers enormous quantities of water that were previously used for irrigation. Brown emphasizes that, in many countries of the world, "farmers are now faced with not only a shrinking water supply but also a shrinking share of that shrinking supply."

China faces still another threat to food production that it has in common with many other countries. The overgrazing of rangeland, overplowing of cropland, overcutting of trees, and overpumping of aquifers make the land more vulnerable to erosion. Dust storms in Asia and Africa deposit millions of tons of topsoil on distant regions, transforming valuable rangeland and cropland into dust bowls. Deserts are advancing in Africa both north and south of the Sahara, in the central Asian republics, in India, and in western and northern China. In fact, desert expansion in China has accelerated to where the Gobi, marching eastward, is now within 150 miles of Beijing, and some deserts there are starting to converge.

Stopping the threat to food security depends on restoring four key agricultural resources: cropland, water, rangeland, and the Earth's climate system. What's the likelihood of success in restoring all four? Brown points out that there hasn't yet been much success in restoring any of them. One would think that falling water tables and rivers and wells running dry would ring alarm bells, launching immediate and vigorous water conservation measures. Yet not one of the scores of countries with dwindling water reserves has succeeded in reversing this threat. As for confronting global warming, the provisions of the Kyoto Treaty (which took effect February 16, 2005) aren't adequate to accomplish much--particularly with the United States, the largest emitter of greenhouse gases, refusing to sign on. In discussing alternative energy, Brown notes that the United States was once the front runner in development of wind power but has been surpassed by many European nations "not because it cannot compete technologically with Europe ... but because of a lack of leadership in Washington."