Blackwell Reference Online

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When ecologists and geographers discuss human impact on land and water, they begin with agriculture. The Food and Agriculture Organization of the United Nations (FAO) reports that 5,872,738 hectares of the world's 13,048,300 hectares (or slightly more than one third) of land is used for agriculture. According to FAO, another third is in forests and woodlands. The remaining 4,002,828 hectares comprise deserts, tundra, and swamps not habitable by human beings; wetlands and savanna set aside for recreation and wildlife preservation; lands used for mining and manufacturing; and urban areas. In the United States, agricultural uses account for nearly half of the total landmass. In the United Kingdom the figure is 40 percent, though that estimate does not include meadows used for grazing. Excepting multiple-use forests, American urban and recreational lands, plus uninhabited deserts, swamps, and high mountain ranges account for a mere 20 percent of the total.Lester Brown, founder of the Worldwatch Institute and coiner of the phrase “sustainable development,” believes that food production is the key to sustainable land use. Agriculture also uses the largest share of fresh water. Not surprisingly, a large percentage of the world's crops and pasturelands are located in areas of reliable rainfall. Rainfed farms and ranches get first crack at this water, taking their share before rainwater ... log in or subscribe to read full text