Did you know? A bicycle is a marvel of engineering efficiency, one where an investment in 22 pounds of metal and rubber boosts the efficiency of an individual mobility by a factor of three. On my bike I estimate that I get easily 7 miles per potato. For more information view the text and data in Chapter 6 of Plan B 4.0: Mobilizing to Save Civilization.
Chapter 7. Raising Water Productivity: Introduction
Water scarcity, a consequence of the sevenfold growth in the world economy over the last half-century, will be a defining condition of life for many in this new century. The simultaneous emergence of fast-growing water shortages in so many countries requires a wholly new approach to water policy, a shift from expanding supply to managing demand. Managing water scarcity will affect what we eat, how we dispose of waste, and even where we live.1
Historically, the common response to water scarcity was to expand supply: to build more dams or drill more wells. Now this potential is either limited or nonexistent in most countries. Where rivers are drained dry and water tables are falling, the only option is reducing the growth in demand by raising water productivity and stabilizing population. With most of the 3 billion people projected to be added by 2050 due to be born in countries where wells are already going dry, achieving an acceptable balance between people and water may depend more on slowing population growth than any other single action.2
After World War II, as the world looked ahead to the end of the century, it saw a projected doubling of world population and frontiers of agricultural settlement that had largely disappeared. The response was to launch a major effort to raise land productivity, one that nearly tripled it between 1950 and 2000. Now it is time to see what we can do with water.3
1. Erik Assadourian, "Economic Growth Inches Up," in Worldwatch Institute, Vital Signs 2003 (New York: W.W. Norton & Company, 2003), pp. 44-45.
2. Population from United Nations, World Population Prospects: The 2002 Revision (New York: February 2003).
3. Land productivity from U.S. Department of Agriculture (USDA), Production, Supply, and Distribution, electronic database, updated 13 May 2003.
Copyright © 2003 Earth Policy Institute