How urban sprawl destroys the environment

Environmental Science: Urban Sprawl

Urban Sprawl: "the spreading of urban developments (as houses and shopping centers) on undeveloped land near a city..." Merriam-Webster Online

Rapid urban growth has had a negative affect on the environment - and when the environment is affected in a negative way, people, too, suffer the consequences. But before this paper covers the issue of specific problems associated with urban sprawl, a little history is appropriate, in terms of how our once beautiful, lush green planet has been altered by the expansion of the human race, and the carelessness of that expansion.

Before humans began to build houses, roads, villages and cities, and in fact before there very few humans at all, trees covered "two-fifths (40%) of the land" on the planet (Victor, et al., 2000). That was eight thousand years ago. Humans have grown by great numbers since then however, and have cut forests in massive quantities for warmth, cooking food, growing crops, building ships and frame houses, and producing paper. Of the original forestland, axes, fires and saws have whittled away half, and "some analysts warn that within decades, the remaining natural forests will disappear altogether."

And that is just one problem affecting the environment. Trees take in carbon dioxide and produce oxygen, and when huge areas of forests have been cut down, all that oxygen that was being produced is not longer there; also, trees taking in carbon dioxide are actually cleaning up the air, because carbon dioxide also carries along with it some pollutants from the air, and so in effect the trees act as "air cleaners" - except, of course, when they're gone.

And once the forests have been cleared away, and villages and towns are built, by the time they reach "city" status, without proper and visionary planning, the metropolis begins to create an ugly "sprawl" out into the countryside; and besides eating up good farm land, exerting pressure on existing water supplies and sewage facilities, taxing transportation systems, school districts and emergency response units, urban sprawl creates air and noise pollution which is harmful to the health of humans and animals.

An article in the journal Environment (Stoel, 1999) points out that "designated metro areas now account for 19% of our nation's vast land area"; that is well higher than the 9% of metro area forty years ago. Some cities are growing very fast; Washington D.C., for example, grew from 3.1 million residents in 1980 to 4.5 million in 1995 - an increase of 47% in fifteen years. Indeed, four out of five American citizens live in a "metro area," and in virtually every metro area, there is urban sprawl.

As to the negative affect of urban sprawl on humans, a study conducted by the federal government in 1998 showed that sitting in traffic on congested freeways cost the average commuter in Washington, D.C. about two full work weeks per year. Just sitting there, stop-and-go, slow-and-go, wasted two full weeks of work time per year; and the "excess fuel consumption due to congestion" added up to $1,055 for each resident of the Washington, D.C. area a year.

But wait - is the money spent on wasted fuel all the harm that is done? No, in fact, "vehicle exhaust remains a serious problem" in the D.C. area. Vehicles are the "main source of air pollution in the Washington region," according to the article in Environment. And there are other environmental impacts from urban sprawl in the D.C. area: a) floods happen more frequently because "a large portion of the land in the Washington area has been paved over," causing rapid run-off of rainfall instead of absorption in the ground; b) the rapidly expanding development of homes means more pesticides on lawns and "more pollutants are washed into the region's waterways"; c) wildlife habitat "has been eliminated or degraded"; d) "aquifers are under pressure"; e) Chesapeake Bay's water quality is not up to the standards the public expects.

Urban sprawl contributes to "forest fragmentation," according to an article in "forest fragmentation occurs when large, continuous forests are divided into smaller blocks, either by roads, clearing for agriculture, urbanization, or other human development," said Chet Arnold, associate director of the Center for Land-use Education and Research at the University of Connecticut. And the fragmentation of forests, in particular by urban sprawl ("urbanization"), "poses a threat to biodiversity primarily in animal populations, as their habitats are chopped up into smaller and smaller pieces."