14. THE MUTATING METROPOLIS

WE’VE SEEN HOW life-forms like cyano, birds, and mammals made it through mass extinctions, and we’ve explored the strategies humans used to deal with threats to our species. But we’ve also seen a lot of failure modes that consigned whole ecosystems and classes of people to death. How will we convert our guardedly hopeful stories of a human future into a real-life plan for survival that avoids some of the worst failure modes?

We’ll start by changing our cities, which are a powerful expression of human symbolic culture and a perfect example of why we have a lot to learn about adapting mass societies to our environments. Cities have always been central to human civilization, but now they’ve become almost indistinguishable from it. Certainly they’re the sources of our greatest economic, scientific, and artistic productivity. They’re also a good way to organize communities when you’re an invasive species with a population that just passed the 7 billion mark. It’s easier to provide standard levels of good hospital care, sanitation, housing, and education to 1.6 million people packed into the island of Manhattan, for example, than to the less than 1 million spread out over the state of Montana. But cities are also a problem. They’re death traps during pandemics and natural disasters like the 2004 Indian Ocean tsunami. Though cities are efficient in their use of energy, they still use far too much of it—especially given that most of them run exclusively on fossil fuels that are not sustainable and harm the environment.

Still, cities have become the dominant form of human community today. In the past decade, the number of people on Earth living in cities surpassed those living outside of them. And those numbers are expected to rise—the United Nations’ Population Division estimates that 67 percent of humanity will live in urban areas by 2050. Certainly it would be better for people and the planet if we could dramatically decrease our population, as Alan Weisman argues in his book The World Without Us, but that idea simply isn’t pragmatic in the next few decades. It would require us to regulate the bodies of billions of women, leading into a morally gray area from which we might never return. For now, we must accept that our population is growing. And that means human survival in the near term depends on whether we can build cities that protect their masses of inhabitants while also preserving and sustaining the environment. In short, we need cities that don’t collapse at the first twitch of an earthquake, that aren’t hives of disease, and that offer sustainable energy and food sources to their citizens.

To get there, we must first understand how cities work and what makes them survive over the long term.

The City Is a Process

A city is more than its brick and mortar. It is the sum of its cultural history. That’s why the urban planning philosopher Jane Jacobs, in her groundbreaking 1961 book The Death and Life of Great American Cities, makes the case that what attracts people to cities is “sidewalk life.” By that, she means the everyday social world of the city, the comings and goings of neighbors, strangers, and events. The city, Jacobs believed, was profoundly social. People flocked to them for the excitement of new kinds of human interaction, not to admire great works of monumental architecture or simply to make money.

Jacobs’s interpretation is just one of many ways to express a certain ineffable aspect of city life. Some call it an emergent property, a system of organization that arises spontaneously out of chaotically interacting parts. Others call it a cultural legacy. And the fantasy author Fritz Leiber dubbed it “megapolisomancy.” The point is that cities draw their vitality from a mix of social, political, and cultural practices that are hard to quantify scientifically. But they are also undeniably products of technology and engineering. They are financial powerhouses too, fueling their inhabitants’ cultural and scientific undertakings in massive, elaborate marketplaces that link cities to each other across the world.

Successful cities are what physicists might call stochastic, meaning a structured, repetitive process that contains an element of randomness. Certain structures appear in cities again and again. Even the very earliest cities, located in what are today Turkey and Peru, contain monumental architecture in honor of religious and political leaders. They also contain private homes where people lived in family units, cooking, sleeping, and raising children together. And yet every city has its own character, its own random, emergent sensibility that’s a product of a particular group of people at a particular time in history. Some cities, like Istanbul and Paris, manage to nourish this stochastic process over centuries and even millennia. Others, like Detroit, flash brightly for a few decades and then crumble into ghost towns. To make our cities long-lived, shaping them into “battle suits for surviving the future” as the industrial designer Matt Jones calls them, we have to respect their stochastic natures. We must build cities with safe, sustainable structures, but always leave room for randomness and social change.

Anthropologist Monica L. Smith, who researches the development of cities in the ancient world, has noted with some frustration that there is really no good way to define what makes an area “urban.” Key components of urban life include a high population density, specialized forms of work, social stratification, and monument building. But listing the ingredients of a city doesn’t adequately address the problem of definition, because cities are what Smith calls “a process.” The brilliant urban planner Spiro Kostof suggested the same thing, writing that “a city, however perfect its initial shape, is never complete, never at rest.” In other words, a city is always shifting, perhaps possessing some aspects of urban life at one time and other aspects later on. Moreover, what felt urban 5,000 years ago probably wouldn’t feel urban today—and indeed, what feels urban in Canada might not feel urban in China. We may know a city when we see it, but the idea of a city is itself a moving target.

Cities were born in two very different regions of the world: along the coast of Peru in South America, and in the area once known as Mesopotamia, where southern Turkey, Syria, and Iraq stand today. The Peruvian cities, clustered along mountain rivers speeding toward the sea, date back to 3200 BCE. They boasted large sunken plazas surrounded by platforms, winding stairs, and rooms that were probably living quarters. The largest of these cities is believed to be Caral, which dates back to 2800 BCE and may have housed up to 3,000 people who left behind art, carvings, and woven textiles. Most likely, Caral and its outlying cities lived on fishing and agriculture, trading goods and ideas back and forth.

Unlike the cities around Caral, which were elaborately planned around large, central public spaces, the even more ancient city Çatalhöyük, in southern Turkey, looks more like a honeycomb made out of mud. Anthropologists believe it was probably constructed in roughly 7500 BCE, and inhabited for hundreds of years after that. The people of Çatalhöyük built their simple one-room houses right next to each other, with no streets in between. Doors were built into the rooftops, and residents clambered across each other’s roofs and down ladders to reach their pantries and beds. When the mud walls of a Çatalhöyük house began to crumble, residents would just build a new structure on top of the old one. Many ancient cities are called “mounds” because over time, ancient city people literally created hills by building new homes upon the ruins of the old. Anthropologists today often find the remains of these cities by using satellite photos to look for suspiciously symmetrical mounds in regions of the world known for early urban development.

One of the great debates among anthropologists is whether urban life or agricultural life came first. Though we may never know the answer—and it may have varied from region to region—most anthropologists today agree that cities like Caral and Çatalhöyük would have required people to develop highly efficient agriculture. After all, farming is only necessary when there are hundreds or even thousands of hungry mouths to feed in one permanent location. Did the city therefore predate the farm? Tantalizing evidence from a southern Turkish site called Göbekli Tepe, dating from 10,000 BCE—a fascinating circular formation of monuments covered in bizarre human-animal imagery—suggests that the very earliest urban formations were built before evidence of agriculture. Still, it’s possible that humans’ first efforts at crop cultivation would be impossible to distinguish from wild plants, meaning the people who visited Göbekli Tepe might have had small farms that we simply can’t recognize from their remains. Debates aside, what’s certain is that by the time people were living in the extremely ancient cities of Caral and Çatalhöyük, farming was the main occupation of most urbanites. Cities cannot exist without agriculture.

An artist’s conception of what the ancient city of Çatalhöyük might have looked like. There were no streets, and people entered their homes through holes in the roofs. (illustration credit ill.10)

(Click here to see a larger image.)

Cities didn’t just change the environment with agriculture; they changed humanity, too. Stanford University anthropologist Ian Hodder, who has led excavations at Çatalhöyük since the early 1990s, believes that cities “socialize” people. Their routines are transformed by what he calls “bodily repetition of practices and routines in the house,” as well as the “construction of memories.” He writes about one house in Çatalhöyük whose residents rebuilt the structure six times over a couple of centuries, each time with exactly the same layout. Like their neighbors, these people shared a religious tradition of burying the bones of their ancestors in the floor of the house. As time passed, the house became more than just a dwelling. It was a monument to previous versions of the house, to the family, and to the city itself. This is a useful way to think about cities in general, and helps illuminate why we attach so much significance to preserving ancient structures in our modern cities. Our cities are monuments to our shared history. Though the bones of our ancestors aren’t literally built into the floors of our homes anymore, they remain there in a symbolic sense. That ineffable megapolisomancy that gives cities their allure comes from the way they are constructed of memories as much as they are constructed from brick and steel.

Cities That Endure

Anthropologist Elizabeth Stone has been excavating ancient cities in the Mesopotamian region, especially Turkey and Iraq, since the early 1980s. When I asked her why some cities manage to survive for thousands of years, she cautioned me that cities don’t ever remain the same over time; they have broken histories, collapsing and rising again. Ancient cities, for example, were organized in a way dramatically unlike cities of today. “If you look at pictures of Baghdad today, you see different districts that are segregated by class. It’s so fundamental that it’s visible from space,” she said. But if you look at the layout of ancient Pompeii, it’s impossible to say where the rich and the poor lived. There is variability between neighborhoods, but there are no visible differences in wealth. As she’s mapped Mesopotamian Era cities, Stone has been struck by how little variability there is in the size of houses. Everybody seems to have homes that are roughly the same dimensions, though some might have more rooms than others.

The differences between ancient and medieval cities are just as stark. The imperialist Rome of antiquity wasn’t the same as the Church-dominated Rome of the Middle Ages. The former glory of the ancient world was reborn as a new city for the medieval world. Medieval city growth moved slowly, often funded by the aristocracy or the church. But starting in the nineteenth century, industrialization pushed city growth into the hands of wealthy entrepreneurs and developers, whose greatest monuments became skyscrapers devoted to various corporate headquarters. This era also witnessed a steep rise in urban populations, culminating in our majority urban population today. And now it’s become a completely different city again. People have always been drawn to Rome because of its dramatic history, but the urban experience during each stage of its life was notably transformed.

Long-lived cities survive by going through periods of collapse and rejuvenation. It’s possible that cities tend to collapse when people have less social and economic mobility. “People at the bottom may retreat into the countryside and leave the sphere that’s controlled by the city,” Stone speculated. As soon as there is more opportunity in the city, peasants return and try to climb the social ladder again. Most cities that last for more than a few hundred years are located at the heart of shifting empires, like Istanbul (formerly Constantinople) or Mexico City (formerly Tenochtitlán). Both cities have been inhabited for centuries, but by peoples from successive, often adversarial political groups. Their fates rise and fall with the empires that claim them. Cities may be built on memory, but they are also processes, always changing.

Longevity isn’t the only measure of a city’s success, however. As Harvard economist Edward Glaeser puts it in his book Triumph of the City: How Our Greatest Invention Makes Us Richer, Smarter, Greener, Healthier, and Happier:

Among cities, failures seem similar while successes feel unique.… Successful cities always have a wealth of human energy that expresses itself in different ways and defines its own idiosyncratic space.

Modern cities survive by offering people a space where they can form social groups that would be impossible outside them. Kostof calls cities “cumulative, generational artifacts that harbor our values as a community and provide us with the setting where we can learn to live together.” The city community’s “values” are part of the urban structure itself. This helps explain why some cities remain politically distinct from their countries, their cultures proving stronger than the culture of their nations. In the last century, West Berlin and Hong Kong found themselves in this situation. Both cities had strong ties to other nations and urban areas, and used those ties to remain relatively democratic cities devoted to capitalist trade, despite being located inside and alongside powerful communist nations. Other examples include cities like New York and Budapest, whose citizens have often defined themselves by being at odds with the countries that contain them. Cities socialize citizens into certain habits of mind, and these can be hard to break. In fact, sometimes a city breaks with its nation rather than breaking away from its own social norms.

Case Study: San Francisco as a City of Tomorrow

How can we ensure that tomorrow’s cities will harbor thriving communities that don’t decay into insignificance like Detroit or disappear into the fog of history like Çatalhöyük? We need to incorporate mutability into urban design. But as we face the future, that mutability must also include ways of building sustainability into the very structure of our cities. Urban geographer Richard Walker believes the San Francisco Bay Area provides a useful template for how that could happen. In his book about San Francisco, The Country in the City, he explains how the Bay Area’s green spaces are as much constructions as the houses and buildings. The region’s designers often built verdant parks on top of barren dunes and scrub, including both “country” and “city” in their plans for how they would convert the wild lands of Northern California into an urban space. The results are visible everywhere in the Bay Area. To get from the BART commuter-train station to Walker’s Berkeley home, I followed a winding path through several public parks full of play equipment and flower beds. Along the way, I passed more bicyclists, pedestrians, and green spaces than I did cars.

Still, the Bay Area isn’t built on environmental principles alone. It’s also a successful region because its residents have consistently been on the cutting edge economically. “Going back to the Gold Rush, San Francisco has always had a big skilled labor force full of young, creative people,” Walker said. “That was true when they were inventing new kinds of mining equipment in the nineteenth century, and it’s true now with financial innovation and retail innovation, as well as electronics and biotech.” The Bay Area’s financial heart is truly in the long, braided terrain of farms, parks, and cities that make up Silicon Valley to the south. They pump cash from the innovative tech and science industries into a region that includes Marin County to the north and Berkeley and Oakland to the east. Today, many young people who are attracted to the culture of San Francisco come to the region to settle in its most famous city. But they commute every day to Silicon Valley in one of hundreds of sleek, Wi-Fi-enabled buses dispatched by Google, Genentech, Apple, and other companies to make commuting easier on their employees—and reduce emissions in the process.

Just as important as its economic success, however, is San Francisco’s status as what Walker called a “wide-open city.” By that, he means a city prepared to tolerate, and even embrace, experimental ideas. In the early twentieth century, the Bay Area was home to the nation’s earliest environmental groups, racially integrated unions, and a large gay community. In this way, San Francisco in the 1920s and ’30s was like Los Angeles and Berlin. But unlike those cities, the Bay Area never suffered a political crackdown on its most rebellious citizens. During the rise of fascism in Berlin, the Nazis drove out (and occasionally murdered) progressives and openly gay activists like the psychologist Magnus Hirschfeld. And in 1950s Los Angeles, the House Un-American Activities Committee persecuted people with leftist sympathies working in Hollywood. Many lost their jobs and had to leave the city. Meanwhile, in San Francisco, the radicalism continued virtually unchecked. Citizens founded environmentalist groups like the Sierra Club, and a general strike in the 1930s brought the city’s bosses to their knees. In the 1960s, an odd set of local environmental groups, industrialists, and politicians came together to battle developers who wanted to top up the bay with landfill so the city could sprawl from the Embarcadero in San Francisco across to Alameda in the east, and all the way down to Redwood City in the south. The environmentalists won that round, and the bay was protected from destruction.

Out of struggles like these arose a city unlike its predecessors, an urban environment that was green almost from its very inception. “The environment in the Bay Area welded many local opposition movements into a larger radical vision of a green city,” Walker explained. “The feeling here wasn’t ‘protect my neighborhood and screw everybody else.’ It was ‘protect my neighborhood and come hike in my green space.’ It was very public-spirited.” By the mid-1960s, the city’s coalition of local green groups had become so powerful that California passed the first of many environmental-protection laws to prevent anyone from ever filling in the bay for development.

In building the Bay Area, urbanites realized that success meant destroying the false division between country and city. But San Francisco is just one example of a city that has changed over time by getting greener. People in many cities, from Tokyo to Copenhagen, want to preserve local environments not just with protection laws, but also with solar power, high-efficiency buildings, and urban farms. Cities of the future are changing to include many aspects of the country within their boundaries.

As we’ll see in the next few chapters, urban planners, architects, and engineers are coming around to the idea that cities must be as much part of their environments as coastlines and trees are. Government and private industry are pumping billions of dollars into the development of energy-efficient buildings, solar power, smart grids, urban gardens, green roofs, and many other eco-technologies. The city of the future, most agree, will be planned the way the Bay Area has been for almost 50 years.

It may seem bizarre for the Bay Area to represent urban life of the future, given that an enormous earthquake or tsunami could wipe out the whole region tomorrow. But as we’ll discover in the next chapter, new engineering techniques could help our cities survive all but the worst natural disasters.