These Landsat images from 1972 to the present show environmental change in areas around the world. As urban areas spread out, more time is spent in cars, and traffic congestion occurs over a larger area. Adding new lanes to highways doesn't solve the problem. Air pollution in urban areas remains a problem. What's more disturbing is that pollution now affects smaller communities outside major metropolitan areas.
Air pollution can trigger asthma attacks.
In December 1999, Vice President Al Gore described figures indicating the loss of farmland to development. This problem is not just concentrated near large urban centers but also in mid-size cities. You can read the press release of the vice president's briefing or see highlights of the actual report on the USDA's Natural Resources Conservation Service site. Urban sprawl destroys more than 100,000 acres of wetlands annually. Some of America's most important ecosystems, such as the Chesapeake Bay and the Everglades, are now threatened by urban sprawl.