Urban centers have always been hubs of innovation, creativity, and wealth, but they are also hubs of crime, disease, and environmental pollution. Cities can be models of resource efficiency—the average Manhattanite uses only 29 percent of the energy an average American uses in a year—but they also concentrate the need for huge amounts of power, water, food, and other resources. In the developing world, cities are changing faster than scientists can understand the diverse factors driving those changes, and to complicate matters further, many of those forces operate in contradictory directions and at differing scales.
In short, cities are the quintessential complex adaptive system. Which makes them, in many ways, the perfect place to explore resilience.
Brian Walker is former program director and chair of the Resilience Alliance, a loose international coalition of natural and social scientists who, in their own words, “collaborate to explore the dynamics of social-ecological systems.” In 2005, recognizing the growing impact of urbanization, the Alliance held a series of brainstorming sessions, laying the groundwork for the “Urban Network,” based out of the Stockholm Resilience Center, an interdisciplinary research group that formed at Stockholm University in 2008.
The Urban Network has research sites in 12 cities: Bangalore, New Dehli, Cape Town, Johannesburg, Chicago, New York City, Phoenix, Canberra, Helsinki, Istanbul, and Stockholm. These cities span the globe and differ vastly in terms of culture, history, and economic development. The ultimate goal, according to Thomas Elmqvist, lead researcher of the Network, is to do a comparative analysis of these cities. How are they similar or different with respect to handling development? How do they compare it comes to withstanding shocks and surprises?
“As humans, we should try to understand how to manage systems in order to avoid passing thresholds,” says Elmqvist. But this is especially difficult in urban contexts, which have already been so transformed by humans that they’ve breached most of the thresholds ecologists are familiar with. When great expanses of concrete and steel now exist where trees and streams once did, new tipping points must be defined for places that are, as Elmqvist puts it, “already tipped.”
Case studies are now underway in each of the Network’s 12 participating cities. But in deciding what kind of data to gather, researchers have had to ask themselves: What would a city look like through the lens of resilience?
A city’s lifeblood is a continuous flow of stuff—fuel, consumer products, people, and services that enter it either actively, through human effort, or passively through natural processes like solar radiation, atmospheric currents, and precipitation. Ecologists often talk about these resource flows in terms of inputs and outputs. They’ve developed several budgetary models of accounting for them, including the well-known “ecological footprint.”
The resilience approach, according to ecologist Guy Barnett of the Urban Network’s Canberra research team, focuses less on the resources that cities consume and more on the interdependencies along the chain of supply and demand. Dependence on a single type of fuel as an energy source, for instance, creates a highly vulnerable system—especially if fuel prices are volatile or if the supply is prone to disruption.