At first thought, the ideal Green future does not look like a city. Cities are made of asphalt and concrete; the nature that manages to exist within a city is confined to parks and gardens. But the answers to the problems that face the American city—rampant crime and spreading urban blight—are intertwined with the movement to create a sustainable future. Urban revitalization, done in a way that creates an environmentally-friendly city, is too important a part of a sustainable future to overlook, especially in a city like Baltimore, a place where wide swathes of the city lie underutilized and in some cases, completely unused. Cities are inherently more environmentally friendly than suburbs and exurbs. The average square foot of land in a city houses more people than one in the suburbs. Zoning laws in suburbs tend to designate land as single-use—as residential, or commercial, for example. Cities tend to have mixed-use streets and neighborhoods, taking advantage of every inch of space. One hundred people living in a city will take up less space than one hundred people living in a suburb. In addition, the simple fact that stores and homes and parks and other recreational centers are clustered closely in a city means that people walk more. People use bicycles for transportation, or take advantage of the greater availability of public transportation. A person, finding himself out of bread one night, does not have to get into his car to reach a grocery store or a market that could be miles away, utilizing more gas. The beginning of the suburbs depended on the automobile—it is no less different now. The growth of the suburbs is a huge factor in the loss of green space in the United States. The buildings of large homes set on large plots of land, new malls, new roads is contributing in a major way to habitat loss, among other threats to the environment. Limiting their growth is extremely important, and limiting their growth means drawing people back to cities. How, then, to draw people back to cities? If city living is so much more convenient than suburban living, why do people leave the city for the suburbs? Crime, most people would say, urban decay and blight. In order to limit the growth of suburbs, we as a society must create a sustainable city—one that people don’t leave. Sustainable, of course, is a word that has come to be synonymous with the conservation movement, but is used here to indicate a city that will more than endure—will continue to grow. New Urbanism, a movement that began in the 1980s, is a movement that seeks to describe a sustainable city. Many of the principles of New Urbanism are based on “old” urbanism—the city as it existed before cars, and are similar to the aims of the sustainable environment movement. A New Urbanist neighborhood is defined by interconnected streets and discernible centers, with public transportation within walking distance of all people, and enough shops to fulfill most of the needs of the community. Several communities have been built according to these standards, such as Seaside, Florida, and Kentlands, a community in Gaithersburg, Maryland. But there is one factor that negates the potential environmentalism of these projects; they were built on new land. Instead of applying these principles to developments that are destroying the habitat and ecology of an area, it is important to apply them to rundown areas of cities. If, in addition to applying these tenets to the revitalization of these areas, we build them according to the Leadership in Energy and Environmental Design (LEED) Green Building Rating System’s standards, this has a positive impact on the environment and draws people who have left a city because of urban problems such as blight and crime back, which in and of itself is environmentally friendly. It is extremely important that we revitalize our cities in a green way—a large city is still not environmentally friendly if it is full of waste and smog.