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

Chapter 5. Protecting Cropland: Introduction

On April 18, 2001, the western United States—from the Arizona border north to Canada—was blanketed with dust. The dirt came from a huge dust storm that originated in northwestern China and Mongolia on April 5. Measuring 1,800 kilometers across when it left China, the storm carried up to 100 million tons of topsoil, a vital resource that would take centuries to replace through natural processes. 1

Almost exactly one year later, on April 12, 2002, South Korea was engulfed by a huge dust storm from China that left people in Seoul literally gasping for breath. Schools were closed, airline flights were cancelled, and clinics were overrun with patients having difficulty breathing. Retail sales fell. Koreans have come to dread the arrival of what they now call “the fifth season,” the dust storms of late winter and early spring. 2

These two dust storms, among some 20 or more major dust storms in China during 2001 and 2002, are one of the externally visible indicators of the ecological catastrophe unfolding in northern and western China. Overgrazing and overplowing are converting productive land to desert on an unprecedented scale. Other dust storms are occurring in Africa, mostly in the southern Sahara and the Sahelian zone. Scientists estimate that Chad alone may be exporting 1.3 billion tons of topsoil each year to the Atlantic Ocean, the Caribbean islands, and even Florida in the United States. Wind erosion of soil and the resulting desert creation and expansion are shrinking the cropland base in scores of countries. 3

Another powerful pressure on cropland is the automobile. Worldwide, close to 400,000 hectares (1 million acres) of land, much of it cropland, are paved each year for roads, highways, and parking lots. In densely populated, low-income developing countries, the car is competing with farmers for scarce arable land. 4

The addition of more than 70 million people each year requires land for living and working—driving the continuous construction of houses, apartment buildings, factories, and office buildings. Worldwide, for every 1 million people added, an estimated 40,000 hectares of land are needed for basic living space. 5

These threats to the world’s cropland, whether advancing deserts, expanding automobile fleets, or housing developments, are gaining momentum, challenging some of the basic premises on which current population, transportation, and land use policies rest.


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1. Ann Schrader, “Latest Import From China: Haze,” Denver Post, 18 April 2001; Paul Brown, “4x4s Replace the Desert Camel and Whip Up a Worldwide Dust Storm,” (London) Guardian, 20 August 2004.

2. Howard W. French, “China’s Growing Deserts Are Suffocating Korea,” New York Times, 14 April 2002.

3. Brown, op. cit. note 1.

4. Calculations for paved area by Janet Larsen, Earth Policy Institute, based on U.S. Department of Transportation, Federal Highway Administration (FHWA), Highway Statistics 1999 (Washington, DC: 2001), on Mark Delucchi, “Motor Vehicle Infrastructure and Services Provided by the Public Sector,” cited in Todd Litman, Transportation Land Valuation (Victoria, BC, Canada: Victoria Transport Policy Institute, 2000), p. 4, on Ward’s Communications, Ward’s World Motor Vehicle Data (Southfield, MI: 2000), on Jeffrey Kenworthy, Associate Professor in Sustainable Settlements, Institute for Sustainability and Technology Policy, Murdoch University, Australia, e-mail message to Larsen, and on David Walterscheid, FHWA Real Estate Office, discussion with Larsen.

5. United Nations, World Population Prospects: The 2002 Revision (New York: 2003); land requirements are author’s estimate.


Copyright © 2004 Earth Policy Institute