Hot World? Blame Cities.

By Joel Kotkin and Ali Modarres
Sunday, October 14, 2007; B01

It's all the suburbs' fault. You know, everything -- traffic congestion, overweight kids, social alienation. Oh, and lest we forget, global warming and rising energy costs, too.

That latest knock against the burbs has caught on widely. With their multiplying McMansions and exploding Explorers, the burbs are the reason we're paying so much for gas and heating oil and spewing all those emissions that are heating up the atmosphere -- or so a host of urban proponents tells us. It's time to ditch the burbs and go back to the city. New York, Boston, Chicago -- these densely packed metropolises are "models of environmentalism," declares John Norquist, the former Milwaukee mayor who now heads the Congress for a New Urbanism.
But before you sell your ranch house in Loudoun County and plunk down big bucks for that cozy condo in the District, take a closer look at the claims of big cities' environmental superiority. Here's one point that's generally relegated to academic journals and scientific magazines: Highly concentrated urban areas can contribute to overall warming that extends beyond their physical boundaries.

Studies in cities around the world -- Beijing, Rome, London, Tokyo, Los Angeles and more -- have found that packed concentrations of concrete, asphalt, steel and glass can contribute to a phenomenon known as "heat islands" far more than typically low-density, tree-shaded suburban landscapes. As an October 2006 article in the New Scientist highlighted, "cities can be a couple of degrees warmer during the day and up to 6¿ C [11 degrees Fahrenheit] warmer at night." Recent studies out of Australia and Greece, as well as studies on U.S. cities, have also documented this difference in warming between highly concentrated central cities and their surrounding areas.

This is critical as we deal with what may well be a period of prolonged warming. Urban heat islands may not explain global warming, but they do bear profound environmental, social, economic and health consequences that reach beyond city boundaries. A study of Athens that appeared this year in the journal Climatic Change suggested that the ecological footprint of the urban heat island is 1 1/2 to two times larger than the city's political borders.

Further, urban heat islands increase the need for air conditioning, which has alarming consequences for energy consumption in our cities. Since air conditioning systems themselves generate heat, this produces a vicious cycle. Some estimate that the annual cost of the energy consumption caused by the urban heat island could exceed $1 billion.

This is not to say that big buildings can't be made more energy efficient by using new techniques, such as high-tech skin designs, special construction materials to reduce energy consumption, green roofs and passive cooling. But one big problem is that making large buildings green also makes them much more expensive, so that they're less and less affordable for middle-class and working-class families.

Low-density areas, on the other hand, lend themselves to much less expensive and more environmentally friendly ways of reducing heat. It often takes nothing more than double-paned windows to reduce the energy consumption of a two- or three-story house. Shade can bring it down even further: A nice maple can cool a two-story house, but it can't quite do the same for a 10-story apartment building.

Focusing on the suburbs has the added virtue of bringing change to where the action is. Over the past 40 years, the percentage of people opting to live in cities has held steady at 10 to 15 percent. And since 2000, more than 90 percent of all metropolitan growth -- even in a legendary new planners' paradise such as Portland, Ore. -- has taken place in the suburbs.
So we shouldn't be trying to wipe out suburbs. Even with changes in government policy, it would be hard to slow their growth. Europe has strict zoning and highly subsidized mass transit -- policies that are supposed to promote denser development -- but even so, their cities are suburbanizing much like American ones. "Sprawl cities," notes Shlomo Angel, an urban planning expert at the Woodrow Wilson School at Princeton University, also are becoming ever more common throughout much of Asia and the developing world.

Here's an Earth-to-greens message: Instead of demonizing the suburbs, why not build better, greener ones and green the ones we already have?

One approach might be to embrace what one writer, Wally Siembab, has dubbed "smart sprawl." Encouraging this sort of development will require a series of steps: reducing commuters' gas consumption with more fuel-efficient cars, dispersing work to centers close to where workers live and promoting continued growth in home-based work. We'll also have to protect open spaces by monitoring development and establishing land conservation based on public and private funding, the latter coming from developers who wish to work in suburbs.
Building what we call "an archipelago of villages" seems far more reasonable than returning to industrial-age cities and mass transit systems. For the most part, the automobile has left an indelible imprint on our cities, and in our ever-more-dispersed economy, it has become a necessity.

This is not to say that transit of some kind -- perhaps more cost-efficient and flexible dedicated busways, or local shuttles -- can't play a role in serving those who can't or would rather not drive. But short of a crippling fuel shortage or some other catastrophic event, it's highly unlikely that we'll ever see the widespread success of heavily promoted strategies such as dense, transit-oriented developments or the wholesale abandonment of the suburbs.

We can accommodate our need for space and still leave ample room for a flourishing natural environment, as well as for agriculture. By preserving open space and growing in an environmentally friendly manner, we can provide a break from the monotony of concrete and glass and create ideal landscapes for wildlife preservation.

Such notions -- developed before the term "green" existed -- go back to a host of visionaries such as Ebenezer Howard, James Rouse, Frederick Law Olmsted, Frank Lloyd Wright and Victor Gruen. And they have already been put into practice. Starting in the 1960s in his development of Valencia, north of Los Angeles, Gruen envisioned a "suburbia redeemed" that mixed elements of the urban and the rural.

Valencia's elaborate network of 28 miles of car-free paseos -- paths designed for pedestrians and bicyclists -- helped make the natural environment accessible to residents. Gruen also recognized the commercial appeal of such an environment. A 1992 ad for the development featured a smiling girl saying: "I can be in my classroom one minute and riding my horse the next. I don't know whether I'm a city or country girl."

Similarly, The Woodlands, a sprawling development 27 miles from downtown Houston, is a model for a greener suburbia in a region not much celebrated for its environmental values. The Woodlands name, said its former president, Roger Galatas, was seen not as "just real estate hype" but as part of a plan to allow development without destroying forest lands and natural drainage.

In the Washington area, Reston and Columbia, the latter the brainchild of legendary Maryland developer James Rouse, have become far more than mere bedroom communities; they have become places, or villages, in themselves.

All these places evoke a more environmentally friendly suburbanism, which also can be promoted in areas that did not benefit from the foresight of a Gruen or a Rouse. Town centers, revived older shopping districts, even re-engineered malls can all be part of a greener, more energy-efficient future in a large number of communities. And this process is already well underway.

Dragooning Americans into a dense urban lifestyle that's attractive to only a relatively small minority isn't the best way to address concerns about energy and resource depletion or global warming. Instead, we need to take gradual, sensible, realistic steps to improve the increasingly dispersed places where most of us choose to live and work.

Joel Kotkin is a fellow at Chapman University and author of "The City:
A Global History." Ali Modarres is associate director of the Pat Brown Institute of Public Affairs at California State University at Los Angeles.

http://www.washingtonpost.com/wp-dyn/content/article/2007/10/12/AR2007101201884_pf.html