The specter of sprawl.

t potential environm impacts. Many of the consuming land faster th tions are growing, pushing t urban and suburban pollution fa rural corridors. Chicago and Los An for example, have over the last 20 yea increased their land area more than 10 times faster than their populations. In a particularly striking example of sprawl, Phoenix, Arizona, is encroaching upon the desert at a rate of one acre per hour, leading Michael Fifield, head of the architecture department at the University of Oregon in Eugene, to comment that "the only thing stopping Phoenix is Tucson." Unchecked urban growth is linked to many environmental problems, including increased automobile emissions, deterioration of air and water quality, loss of rural lands, and a declining sense of community. The emerging consensus among citizens, planners, government officials, and environmental groups is that sprawl is unsus-tainable, and coordinated land use planning strategies are needed to check its growth. sprawl begins and ends." Reid has nonetheless come up WIth a widely refer-enced definition for sprawl, which he describes as random development characterized by poor accessibility of related land uses such as housing, jobs, and services like schools and hospitals. Among these undesirable land use patterns he includes commercial strip development, low-density residential developments, and scattered, isolated developments that leapfrog over the landscape. According to Ewing, one thing all of these land use patterns have in common (in addition to automobile dependency) is a lack of open, functional space. For some people, this sense of isolation from the natural environment is a health threat in and of itself. In one study, published in the people.-Causes of Sprawl The historical basis for sprawl may well lie in the decentralization of employment. The host of government policies that have subsidized development, built new roads and highways at the expense of public transit, and paid for the "external" costs of the automobile (such as pollution and commuter parking) have allowed suburban employment centers to gain footholds outside of cities, and to draw large numbers of middle-class workers from the urban core.