I managed to go see Stewart Brand's talk last night, "City Planet," a look at the co-evolution of cities and human societies. It was a wide-ranging discussion, with much to contemplate; Stewart's an engaging speaker, and he's clearly been thinking about these issues for some time. Long Now will have an audio recording of the talk up soon, but for now, here are some of the idea highlights:
The planet is urbanizing quickly: 3% of Earth's population lived in cities in 1800; 14% lived in cities in 1900; nearly half the planet's population lives in cities today; two-thirds will live in cities by 2030. Every week, around a million new people arrive in cities.
This is driven both by personal economics -- cities have the jobs, and it's increasingly hard to survive economically in rural areas -- and by global economics. Globalization is giving greater power to cities, as communication networks and market transactions bypass nations in favor of city-to-city connections. Multinational companies go to where the workers and consumers are; NGOs go to where the need is greatest. Rural areas are emptying out so quickly that some governments are offering free rural land to people to get them to return to the countryside and "hollowed-out" towns.
"Nations have borders. Cities have centers."
Urbanization is the chief reason why global population growth is flattening, and will likely peak at around nine billion people. Cities are "population sinks;" the birthrate of new urban dwellers drops to replacement level (an average of 2.1 children per woman) and lower. Globally, urban fertility rate is around 1.85 children per woman. The reasons for this are manifold: in the country, a large family is an asset, while in the city, a large family is a liability; cities generally have less room for big families; women in cities have more opportunities for education, economic empowerment, and cultural independence -- all of which directly correlate with lower birth rates.
Stewart argues that the "squatter cities" which form in rapidly-urbanizing areas are among the most vital parts of the 21st century city. He asserts that these global slums and shantytowns are, for most residents, temporary, that pockets of urban poverty are transitions from even worse rural poverty to a better existence in the city. Squatter cities are usually self-constructed and self-organized, better reflecting the needs of the residents than government-built housing; they're also engines of community, where support is provided by extended family, neighbors and religious institutions.
While we may think of cities as unmoving, they actually change pretty quickly. Across Europe, 2-3% of building stock is replaced annually, and the rate is even greater in the US and in the developing world. Cities grow on top of their own past; what is continuous is the pattern (roads, core & periphery) even if the fabric changes.
Environmentally, evidence suggests that the footprint of city dwellers is lower than the footprint of country dwellers, due to the effects of density. The majority of environmental research, however, has focused on "natural" spaces; very few of the ecological science papers written over the past few decades have looked at the ecology of cities. There's a real need to make certain that cities are humane and green, and to protect the newly-emptied countryside.
When asked about suburbs, Stewart noted that historically, suburban peripheries tend to grow into urban centers, citing Joel Garreau's Edge Cities. This is possible when the pattern of suburban areas allows flexibility and change. "Levittowns," once the symbol of post-World War II suburbia, have generally evolved into very livable communities. Gated "communities," conversely, have overly-restrictive CC&Rs (residential rules) making change and evolution next to impossible. Stewart calls this the difference between thinking of the residences as homes and thinking of them as real estate.
The underlying thread of the talk was Stewart's "pace of change" map, showing the different speeds at which different aspects of human society evolve. Cities enable the fast aspects of human life, while remaining rooted in the slower. Cities which focus too much on one end or the other become brittle, and are prone to failure in crisis.
He broke down the difference between fast institutions and slow institutions thusly:
fast slow learns remembers proposes disposes absorbs shocks integrates shocks discontinuous continuous innovation constraint revolution constancy has all the attention has all the power
