Cities Are Good for the Environment, But Many City Dwellers Aren’t

(Bloomberg Opinion) -- Dense, transit-oriented development is more environmentally friendly than suburban sprawl. But city dwellers shouldn’t get too smug about that. Just because an urban apartment uses fewer resources than a McMansion doesn’t always mean that its inhabitants use fewer resources than suburbanites.

This is the upshot of a remarkable 2007 analysis of consumption in Australia that I only learned about last week. My source of enlightenment was a not-very-convincing opinion piece by prominent anti-urbanists Joel Kotkin and Wendell Cox. Defending single-family zoning, they write:

In fact, suburban houses, according to data in one Australian study (conducted by coauthor Cox’s consultancy), use less energy than do the dwellings of inner-city urbanites.

This claim is diametrically opposed to the received wisdom of the past couple of decades. It is also, I learned soon after clicking through to Cox’s “study,” false. What Cox’s consultancy produced was really just an interpretation of the Australian Consumption Atlas compiled by the Australian Conservation Foundation and the Centre for Integrated Sustainability Analysis at the University of Sydney, which did not find that suburban houses use less energy than the dwellings of inner-city urbanites.

It did find, however, that residents of the outer suburbs of Australian cities used less energy per-capita than those who lived closer to downtown, which is pretty interesting.

The Consumption Atlas was, as the name indicates, an attempt to map the environmental impact of consumption by households all over Australia. Only 20% of greenhouse-gas emissions, 23% of water use, and 7% of the overall “eco-footprint” of households were attributed to direct household uses such as heating, lighting, and watering the garden. The rest—the vast majority—came from the things that people who lived in those dwellings bought and did. More-affluent people can afford to buy and do more things, and in Australia, more-affluent people tend to live closer to downtown. As a result,

In each state and territory, the centre of the capital city is the area with the highest environmental impacts, followed by the inner suburban areas. Rural and regional areas tend to have noticeably lower levels of consumption.

In the U.S., the relationship between proximity to downtown and affluence is more complicated. In decades before and after World War II, affluent people fled cities for the suburbs, and while that trend has reversed somewhat in recent decades, the wealthiest areas in the U.S. are still generally suburban. New York City has a lower median household income than its metropolitan area, for example, and while Manhattan’s median household income is higher than the metro area’s, it’s still lower than that of several suburban counties. Hunterdon County, New Jersey, an exurban area bordering Pennsylvania, has the metropolitan area’s highest median household income.

So it’s doubtful that mapping overall environmental impacts in the U.S. would deliver such a smooth urban-to-suburban continuum as in Australia. But existing U.S. research that tracks direct energy use for heating, electricity, and local transportation — and finds cities to be much greener per-capita than suburbs — definitely misses out on some of the ways that affluent urbanites can have big environmental footprints even if they take the subway to work. The most obvious is air travel: Transportation researcher Michael Sivak recently calculated that flying from Atlanta to Los Angeles and back in first class (or from San Diego to Frankfurt and back in economy) generates as much carbon dioxide per person as the average car, SUV, or pick-up truck does in a year.

In his analysis of the Consumption Atlas data, Cox acknowledged that incomes and environmental impact were closely linked, but noted that some suburban areas had lower per-capita environmental impact than closer-in neighborhoods with similar household incomes. As explanation he cited a 2005 study that determined that high-rise apartment buildings in Sydney generated more greenhouse gases per dwelling than detached houses. He failed to mention, though, that these high rises tended toward the swanky (88% had swimming pools) and housed only 2% of Sydney’s population, while the same study found all other kinds of multi-family housing, in which 24% of Sydneyites lived, to have lower per-dwelling energy use than detached houses.

No, the main reason why some suburbs had lower per-capita environmental impact than urban neighborhoods with similar incomes was that suburban homes tend to house more people. When a resource like energy or furniture is shared by more people, the per-capita environmental burden drops. Families (and communes!) are more resource-efficient than single-person households. And in general, one- and two-person households are more common in dense urban neighborhoods than in sprawling suburbs.

The implications of this can be a little difficult to get one’s head around. Not having children is often portrayed a way to minimize one’s environmental impact, but in any per-capita accounting, a lack of kids in the house or apartment translates to a bigger impact. While I’m anthropocentric enough to think that attempting to save the environment by not reproducing is to some extent missing the point, I don’t buy that sprawling suburbs are better for the environment just because people there have more kids.

Still, the Consumption Atlas evidence clearly complicates the increasingly standard narrative of cities as environmental saviors. As U.S. cities become more affluent their environmental footprint may grow, and if people who want to have children feel compelled to move to the suburbs, that’s not exactly to the credit of cities either. It’s also worth noting that large metropolitan areas in the U.S. show signs of energy inefficiency relative to smaller ones. Commutes, for example, are longest in the New York, Washington, D.C., and San Francisco metropolitan areas and in metro areas that border them, and shortest in small metros in the middle of the country. Getting food into the city from farms, and other goods from warehouses, surely takes longer (and consumes more energy) there too. Big cities are great, but they’re not the solution to all the world’s environmental challenges.

To contact the editor responsible for this story: Sarah Green Carmichael at sgreencarmic@bloomberg.net

This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.

Justin Fox is a Bloomberg Opinion columnist covering business. He was the editorial director of Harvard Business Review and wrote for Time, Fortune and American Banker. He is the author of “The Myth of the Rational Market.”

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