Let’s build cities for people (not cars)
7 January 2011
How big can cities get? Aristotle thought a population of 10,000 was too small for a vibrant democratic city and 20,000 too big. On the other hand, Jeff Kenworthy, the renowned Australian environmental scientist who with his colleague Peter Newman has done groundbreaking work on city size and sustainability, told me once that they he and Peter were surprised and a little disturbed because their research showed that the most efficient size for cities was so large as to not yet be identified. We simply haven’t gotten there yet.
That, of course, is counter intuitive for anyone who’s ever looked up and observed the plumes of air pollution that now emanate from cities, spreading, braiding, and blending across the globe into a seamless blanket of gray-yellow-brown. Cities as we now build them are so voracious in appetite, so demanding of energy, that we’re forced to risk environmental disasters like the British Petroleum oil well that blew out in the Gulf of Mexico in April 2010 in order to sustain them. Given all that, the idea of building them even bigger seems foolish, perhaps even dangerous. It also suggests that what we think of as efficient for production, employment and economics is not in tune with ecological efficiency. Thinking of cities as healthy parts of an ecological system might bring those ideas back into alignment.
Whatever the optimal size of the 21st century city, it must be measured in relation to quite a few other factors. Ecologists see organisms as interrelated parts of living systems. We should view the elements of our urban ecosystems in this way too. Doing so helps to explain the disparity between Aristotle and Kenworthy. The urban ecosystem is vastly more complex today than in the days of ancient Greece.
As a teenager my first real job was to dig up and draw pictures of American Indian artifacts that dated back almost a thousand years for the Archeology Lab of the Museum of New Mexico. The “cultural artifact list,” as we called it, included bows and arrows, the pit houses we were unearthing, the flattish mortars and pestles for grinding corn called manos and metates, a few articles of clothing, pottery, sacred objects, and not too much more.
Compare that to today’s industrial city, which has an artifact list so long it would take hundreds of volumes to record it all—from our cell phones and iPods to the scores of appliances and tools in even a modestly equipped kitchen to furniture, computers, cars, stores, gas stations, earth moving equipment, and, well, you get the idea. To house and provide work and other spaces for the billions of people performing all the required tasks to produce, distribute, sell, and consume everything on the artifact list, we need cities. Any other form of organizing ourselves is simply too inefficient. Scattered among small, far-flung villages, we couldn’t assemble ourselves or the resources and tools necessary to fulfill our desires and expectations for stuff, including that which we need and that which we simply want.
(The thing to notice here is that the city has become the real engine of economic productivity. It brings the tools and the people who operate them closer together while providing order and channeling energy and materials though the built environment. Few other than Jane Jacobs have stressed this fact, which is too much to defend here in this short essay. But cite it I must and declare it is important.)
Is the city too big for what it produces? The answer is no. Large size is required for such a staggeringly large artifact list, but here is the essential point: the size of both is a disaster for the planet. Today’s city produces an artifact list that’s too large to be either sensible or healthy. That list ranges from the uplifting and practical to the ridiculous and destructive. So one of the most important decisions we can make is what to trim from that long menu of artifacts. Perhaps the first item we should scratch off the list is the automobile and its attendant infrastructure of massive highway systems and parking structures, not to mention carbon pollution.
It’s important to understand that shrinking the artifact list will result in cities of generally lower population. But it’s not enough merely to shrink the cities we have now—we need to rearrange the pieces. Today’s cities have dense urban centers ringed by ever-expanding, car-dependent, undifferentiated miles of inefficient urban and suburban sprawl. This structure is environmentally unsustainable and not conducive to pleasurable human activity. We need to break up that sprawl into a galaxy of cities, towns, and villages. Doing so would free up vast swaths of land for parks, agriculture, and wildlife, all of which would be easily accessible to people without having to resort to long, slow, polluting car rides.
Shrinking Cities
Welcome to healthy shrinking cities. We in America may be at the turning point in that wave of urban sprawl that began to engulf the countryside after the Second World War, powered by US government policies including subsidized single-family housing, massive highway-building and very cheap gasoline. Over the following decades, cities sloshed ever outward, in California for example, right up against the Sierra Foothills.
Now, though, that wave is reversing, with new development and population growth rolling back toward the centers. As a result of this reversal, the geographical footprint is shrinking. In the United States, this shift started, ironically, when the auto industry that built the cars that caused cities to swell into enormous space-consuming, highway-engorged giants in the first place dumped their workers for cheap labor overseas. It ushered in the age of the Rust Belt. That pattern has now been accelerated by the recent downturn. As oil prices inevitably rise, the trend will only be strengthened.
We’re familiar with the Detroits, Youngstowns, Flints, and other cities with big shrink. Now we also have cities in hot climates with too little water like Las Vegas, Phoenix, and those of the California Central Valley where sprawl is most pronounced and foreclosures are the worst in the country. In many cases, prices, population, and even buildings are all shrinking at once. Drive down some of the ghost suburbs and you see tumble weeds lodged in swinging screen doors, tall grasses taking over the yards and driveways, and spiderwebs filling dark corners.
The people in such cities understandably see these wrenching changes as a disaster that must be reversed. But I believe the shrinking city phenomenon offers an opportunity, not just to restore agriculture and natural lands that shouldn’t have been paved over in the first place, but a chance to build the right structures in the right places. It’s an opportunity to take advantage of all the things we’ve learned about cities in the past 60 years. I heard the great urban planner Paolo Soleri speak way back in 1965 about the benefits of a compact city designed for pedestrians—ie, humans—instead of sprawling, anonymous suburbs built for cars. I took his notions seriously.
The suburb/city with its inefficient, hugely distributed systems of pipes, wires, and pavement stretching toward the horizon was powered by artificially cheap energy. Geographically, it was much larger than a compact city made up of apartments and mixed-use buildings and neighborhoods with the same. And in the compact city, inhabitants could walk and bike to most destinations. In Soleri’s notion, the compact city was more like cities in Europe than those then spreading in a thin veneer across the United States. The car would be replaced as the primary mode of motorized transportation by the streetcar and the elevator.
If we could push the idea of the compact city of enormous variety—Soleri used the words “complexity” and “density”—the whole thing could run on something like a tenth of the energy, all renewable, and cover just a fifth of the land, compared to a sprawl city of the same population, making it possible to have nature and agriculture immediately next door. Just take the stairs or an elevator ride and you could walk or bike out in the country in a matter of a few short minutes.
Soleri’s words impressed me and, to this day, I remain convinced that restaurants, shops, promenades with fantastic views, and rooftop gardens could be connected by bridges between clusters of buildings several floors over the bustling pedestrian streets. It would be easy to build if we weren’t, instead, building cities that spread ever-outward with freeway interchanges costing hundreds of millions of dollars each, parking structures, and streets for cars. Bottom line: we need a geographically smaller city, but that is possible only if we shift from two-dimensional design dependent on cars to a more three-dimensional city designed around the human body. The new city needs to grow upwards, not outwards.
The differences between these two conceptions of what a city should be—the pedestrian-centered city versus the car-centered city—are profound. A car’s body is about 30 times heavier than a human’s, moves ten times as fast in normal operation, and takes up about 60 times the volume standing still—and much more when moving. Too big! The city designed around the car and its need for movement, fuel, and parking must be understood for the unhealthy—catastrophically unhealthy—alternative it is; the consequences of which are unfolding around us: climate change, a collapsing biosphere, and rapid resource exhaustion.
On the other hand, a city that is designed around the dimensions of the human body and its need for clean air and water as well as healthy food holds tremendous potential to improve the lives of its citizens as well as the health of the planet. Most environmentalists believe the best we can do with cities is to make them less damaging. In fact, well-designed cities could be net contributors to soil building and biodiversity, making them a benefit to people and nature simultaneously.
Understanding proportionality
So far, we’ve talked about cities mainly in the context of the United States. But, in fact, the fastest-growing metropolises are elsewhere. They are also being built around the automobile—and, as such, they are a growing disaster for our planet. China is promoting cars and building streets and highways as fast as it can and India is also building a car culture. Brazil is cutting down forests and converting land used for food to land used for fuel while drilling in the Atlantic at levels three times deeper than the BP well that blew out. The Russian government recently announced that it is buying 2.5 million acres for low-density, car-dependent, single-family housing to instill the value of home ownership in its people. Add up the populations of these four countries and you get approximately 2.7 billion people. That’s about nine times the number people who live in the United States. The rapidly accelerating trend toward car-dependent cities in these four countries is one of the most dangerous trends of our times.
But there is another way. Rather than repeat the mistakes of the West on a grander scale, the new cities that are rising and the older ones that are evolving can be structured on a new, more sustainable model, one that doesn’t depend on the gasoline engine. Here’s how I think it would look:
Urban centers would become denser. They would serve as residential centers as well as work and retail centers. Meanwhile, the acres and acres of asphalt parking lots, lawns, and low, land-consuming strip malls spread out over vast acreage would give way to farm- and parkland. Features like creeks would work their way back into the landscape. Downtowns would be revitalized with new investment and would enhance the work and residential lives of the inhabitants. Those downtowns would no longer be strangled with space-wasting freeway interchanges. There would be no need for the immense volume of sheltered space that is now wasted on the parking of cars.
Elsewhere, major district centers would become small cities or towns in their own right and neighborhood centers would become villages of varying sizes, each with its own character. Buildings would, on average, be higher, houses would be replaced by apartments and cars by bicycles, walkable streets, streetcars, and elevators. Pleasurable and beautiful places like rooftop gardens and restaurants, multi-story solar greenhouses and bridges with spectacular views connecting buildings would predominate, along with renewable energy and closed-in organic agriculture. It would be the start of a new green economy.
Such cities would be places to further the ecological health of human society and whatever we mean by “nature” on this planet. But, equally important, such cities would be places to grow and develop ever more “human” humans. Thus we help further both ecological health and our own evolution at the same time.
How big could these cities be? Only if we start building them will we begin to learn the answer.
Em prédio protegido no PDM, com projecto de 1934 do Arquitecto Cassiano Branco. Uma das obras de referência do Modernismo em Lisboa. Ainda não está classificado pelo Ministério da Cultura / IGESPAR. "Pérolas a Porcos"?
Com grande parte dos imóveis abandonados, devolutos, sem qualquer vida, não é de admirar que esta zona urbana da Calçada da Glória se tenha transformado em vítima fácil de vandalismo. A CML tem tentado mitigar a infestação galopante por graffiti na zona com regulares limpezas e pinturas. Mas enquanto estes prédios se mantiverem devolutos, sem lojas e sem residentes, não há que ter esperança de dias melhores. Toda a Calçada da Glória está classificada como Monumento Nacional devido ao emblemático Elevador da Glória. 
