At the time of Jack the Ripper, a hard time for London, there lived in that city a mild-mannered stenographer named Ebenezer Howard. He's worth mentioning because he had a large and lingering impact on how we think about cities.
Howard was bald, with a bushy, mouth-cloaking mustache, wire-rim spectacles, and the distracted air of a seeker. His job transcribing speeches did not fulfill him. He dabbled in spiritualism; mastered Esperanto, the recently invented language; invented a shorthand typewriter himself. And dreamed about real estate. What his family needed, he wrote to his wife in 1885, was a house with "a really nice garden with perhaps a lawn tennis ground." A few years later, after siring four children in six years in a cramped rental house, Howard emerged from a prolonged depression with a scheme for emptying out London.
London in the 1880s, you see, was booming, but it was also bursting with people far more desperate than Howard. The slums where the Ripper trolled for victims were beyond appalling. "Every room in these rotten and reeking tenements houses a family, often two," wrote Andrew Mearns, a crusading minister. "In one cellar a sanitary inspector reports finding a father, mother, three children, and four pigs! Elsewhere is a poor widow, her three children, and a child who had been dead thirteen days." The Victorians called such slums rookeries, or colonies of breeding animals. The chairman of the London County Council described his city as "a tumour, an elephantiasis sucking into its gorged system half the life and the blood and the bone of the rural districts."
Urban planning in the 20th century sprang from that horrified perception of 19th-century cities. Oddly, it began with Ebenezer Howard. In a slim book, self-published in 1898, the man who spent his days transcribing the ideas of others articulated his own vision for how humanity ought to live—a vision so compelling that half a century later Lewis Mumford, the great American architecture critic, said it had "laid the foundation for a new cycle in urban civilization."
The tide of urbanization must be stopped, Howard argued, by drawing people away from the cancerous metropolises into new, self-contained "garden cities." The residents of these happy little islands would feel the "joyous union" of town and country. They'd live in nice houses and gardens at the center, walk to work in factories at the rim, and be fed by farms in an outer greenbelt—which would also stop the town from expanding into the country. When one town filled to its greenbelt—32,000 people was the right number, Howard thought—it would be time to build the next one. In 1907, welcoming 500 Esperantists to Letchworth, the first garden city, Howard boldly predicted (in Esperanto) that both the new language and his new utopias would soon spread around the world.
He was right about the human desire for more living space but wrong about the future of cities: It's the tide of urbanization that has spread around the world. In the developed countries and Latin America it has nearly crested; more than 70 percent of people there live in urban areas. In much of Asia and Africa people are still surging into cities, in numbers swollen by the population boom. Most urbanites live in cities of less than half a million, but big cities have gotten bigger and more common. In the 19th century London was the only city of more than five million; now there are 54, most of them in Asia.
And here's one more change since then: Urbanization is now good news. Expert opinion has shifted profoundly in the past decade or two. Though slums as appalling as Victorian London's are now widespread, and the Victorian fear of cities lives on, cancer no longer seems the right metaphor. On the contrary: With Earth's population headed toward nine or ten billion, dense cities are looking more like a cure—the best hope for lifting people out of poverty without wrecking the planet.
One evening last March, Harvard economist Edward Glaeser appeared at the London School of Economics to promote this point of view, along with his new book, Triumph of the City. Glaeser, who grew up in New York City and talks extremely fast, came heavily armed with anecdotes and data. "There's no such thing as a poor urbanized country; there's no such thing as a rich rural country," he said. A cloud of country names, each plotted by GDP and urbanization rate, flashed on the screen behind him.
Mahatma Gandhi was wrong, Glaeser declared—India's future is not in its villages, it's in Bangalore. Images of Dharavi, Mumbai's large slum, and of Rio de Janeiro's favelas flashed by; to Glaeser, they were examples of urban vitality, not blight. Poor people flock to cities because that's where the money is, he said, and cities produce more because "the absence of space between people" reduces the cost of transporting goods, people, and ideas. Historically, cities were built on rivers or natural harbors to ease the flow of goods. But these days, since shipping costs have declined and service industries have risen, what counts most is the flow of ideas.
The quintessence of the vibrant city for Glaeser is Wall Street, especially the trading floor, where millionaires forsake large offices to work in an open-plan bath of information. "They value knowledge over space—that's what the modern city is all about," he said. Successful cities "increase the returns to being smart" by enabling people to learn from one another. In cities with higher average education, even the uneducated earn higher wages; that's evidence of "human capital spillover."
Spillover works best face-to-face. No technology yet invented—not the telephone, the Internet, or videoconferencing—delivers the fertile chance encounters that cities have delivered since the Roman Forum was new. Nor do they deliver the nonverbal, contextual cues that help us convey complex ideas—to see from the glassy eyes of our listeners, for instance, that we're talking too fast.
It's easy to see why economists would embrace cities, warts and all, as engines of prosperity. It has taken a bit longer for environmentalists, for whom Henry David Thoreau's cabin in the woods has been a lodestar. By increasing income, cities increase consumption and pollution too. If what you value most is nature, cities look like concentrated piles of damage—until you consider the alternative, which is spreading the damage. From an ecological standpoint, says Stewart Brand, founder of the Whole Earth Catalog and now a champion of urbanization, a back-to-the-land ethic would be disastrous. (Thoreau, Glaeser points out gleefully, once accidentally burned down 300 acres of forest.) Cities allow half of humanity to live on around 4 percent of the arable land, leaving more space for open country.
Per capita, city dwellers tread more lightly in other ways as well, as David Owen explains in Green Metropolis. Their roads, sewers, and power lines are shorter and so use fewer resources. Their apartments take less energy to heat, cool, and light than do houses. Most important, people in dense cities drive less. Their destinations are close enough to walk to, and enough people are going to the same places to make public transit practical. In cities like New York, per capita energy use and carbon emissions are much lower than the national average.
Cities in developing countries are even denser and use far fewer resources. But that's mostly because poor people don't consume a lot. Dharavi may be a "model of low emissions," says David Satterthwaite of London's International Institute for Environment and Development, but its residents lack safe water, toilets, and garbage collection. So do perhaps a billion other city dwellers in developing countries. And it is such cities, the United Nations projects, that will absorb most of the world's population increase between now and 2050—more than two billion people. How their governments respond will affect us all.
Many are responding the way Britain did to the growth of London in the 19th century: by trying to make it stop. A UN survey reports that 72 percent of developing countries have adopted policies designed to stem the tide of migration to their cities. But it's a mistake to see urbanization itself as evil rather than as an inevitable part of development, says Satterthwaite, who advises governments and associations of slum dwellers around the world. "I don't get scared by rapid growth," he says. "I meet African mayors who tell me, 'There are too many people moving here!' I tell them, 'No, the problem is your inability to govern them.'"