answer:Apparently, a lot: “The newest environmental threat is suburban sprawl. Large-scale road building and other landforms designed around the automobile are said to be responsible for the American abandonment of the city. With this abandonment comes all manner of environmental degradation: air pollution from daily commutes, conversion of farmland to suburban uses, altered wildlife habitat, depletion of fossil fuel resources, and a host of associated environmental concerns. The Sierra Club’s publication, The Dark Side of the American Dream, cites “unplanned, rapid growth and poor land-use management” as responsible for “increased traffic congestion, longer commutes, increased dependence on fossil fuels, crowded schools, worsening air and water pollution, lost open space and wetlands, increased flooding, destroyed wildlife habitat, higher taxes, and dying city centers.” These problems, in turn, are “threatening the quality of life and eroding the national progress we’ve made protecting our environment under legislation such as the Clean Water Act, the Clean Air Act, and the Endangered Species Act.” Source