Every day, people in Chicago consume immense quantities of food that arrive from nearby farms, large agri-businesses further afield, and producers around the world. Oranges are sent from citrus groves in Florida, chicken parts from processing plants in South Carolina, bananas from growers in the Dominican Republic, olive oil from Italy, wine from the Loire Valley in France, and grapes from Chile. Cab drivers, automobile commuters, and truck drivers purchase gasoline that began as crude oil in Canada, the Gulf of Mexico, Venezuela, and Saudi Arabia and was refined in Louisiana and Texas. Furniture is shipped from Sweden, machinery from Germany, train cars from Canada, and clothing from Turkey. For the people of Chicago to live well and its visitors to eat and sleep, conduct business, and enjoy the tourist experience — for the city to function – raw materials and finished products have to be imported from places beyond the city limits.

Chicago is unexceptional; all cities draw resources and commodities from far-flung places. Their ecological footprints — the land area devoted to their care and feeding — exceeds by many magnitudes the area occupied by their residents. For very large cities like Los Angeles and Dallas, their footprints are vast. The disposal of the human waste, plastic food packaging, construction debris, and discarded paper and the water run-off and air pollution attendant to their functioning further expand the places brought into their environmental frame. Outmoded computers are sent to China for recycling, air pollution drifts across the region, and used clothing is shipped overseas to developing countries….

These material flows – a city’s metabolism — are essential for human life. Moreover, they have destructive consequences such as ground water pollution, summer heat island effects, the accumulation of toxic substances, and high energy consumption. Numerous multi-story buildings and large-scale transportation systems are what define a city in contemporary times, thus making cities much more energy-dependent than rural areas. Evidence further suggests that the metabolism of cities is intensifying, particularly as more and more people move into them….

Yet, cities are touted as saviors of the environment; that is, as our only hope for sustainable urbanization. As one observer has commented, “cities represent the best chance of realizing the aspiration of global sustainability.” For many observers, they are the only form of human settlement with the potential to minimize energy use, encroach as little as possible on the natural environment, and integrate human activity with ecological settings. Purportedly, they are also the only settlement form able to absorb an ever-expanding population. Low-density suburbs, small towns, and rural villages fall well short of these goals when compared to dense, compact cities. The call from popular commentators and scholars alike is for cities to be sustainable and resilient. The first protects, as much as possible, the natural environment for future generations, while the second keeps them from falling apart in the face of disaster and disruption. Together, sustainability and resilience establish the basis for additional urban growth. Having these qualities, large cities are neither a threat to the environment and, by extension, to human functioning, nor a source of insecurity. Rather, they are the places, the sole places, where sustainability makes sense….

One might expect that cities with large, wealthy populations and particularly a large middle-class would produce more political support for protecting the environment while generating tax revenues sufficient to develop programs that encourage sustainability. This does, in general, seem to be the case. The cities known for their sustainability initiatives are places like Seattle, New York City, Portland (OR), and Austin where housing prices are high, households are relatively affluent, and local government competent and engaged. At the same time, in poor and shrinking cities – Detroit and Cleveland come to mind – lacking these qualities – local foundations, nonprofit advocacy groups, and universities have mounted initiatives to address environmental quality. And in wealthy cities, particularly those that are growing rapidly, such as Phoenix and San Jose, local political and economic elites often sacrifice environmental protection for growth. … These are, of course, political decisions….

Which is it then? Are cities a curse on land, air, water and mineral resources, not to mention on animals, birds, plants and creatures of the sea – an insult to nature? Contrarily, are they the best alternative that humans have for protecting the natural environment and its many resources and ecologies? What can be done in the face of continued population growth and the unrelenting urbanization that together fuel consumption and deplete and degrade the material world? My argument: Cities are always destructive; they cannot be otherwise. At the same time, cities hold out the promise of sustainability.

Robert A. Beauregard is a professor emeritus of Urban Planning at Columbia University. He is the author of Cities in the Urban Age: A Dissent, from which this reprint from Urban Matters is excerpted. Reprinted with permission from Cities of the Urban Age: A Dissent, by Robert A. Beauregard, published by the University of Chicago Press, 2018 by the University of Chicago. All rights reserved.