Make no little plans, Daniel Burnham famously suggested. When it comes to fast-growing cities in the developing world, planners really do need to think big.
That was the message from Shlomo “Solly” Angel, lead author of the report, Making Room for a Planet of Cities, at a launch event hosted by Cities Alliance and the World Bank in Washington. Planning fast-growing cities for the next 50 years is necessary though daunting.
“If you go to a mayor and try to have realistic urban land projections, he may say, ‘I don’t want to grow. I don’t have the budget,’” Angel said. But cities must face up to the coming surge of urban population growth by planning now for inevitable expansion, he said, with generous metropolitan limits, an arterial street grid that can support transit, and selective protection of open space.
If the past is any guide, the expansion will be significant. For the last five years, Angel and his research team looked at GIS-based maps, satellite images, and historical maps to create four new data sets: 120 cities over 100,000 people or more, from 1990 to 2000; density trends in 20 U.S. cities from 1910 to 2000, based on census tracts; a global sample of how 30 cities expanded from 1800 to 2000; and a snapshot of urban land cover in over 3,600 cities in 2000, based on satellite images. All the data, images, and methodology of the research can be viewed at the Atlas of Urban Expansion.
The team looked at five key attributes – urban land cover, density as measured by population in relation to built-up areas, centrality (distance from city center), fragmentation (the amount of open space within cities), and compactness. The bottom line: average densities declined as population and wealth grew, not just in the U.S. as part of the familiar pattern of sprawl but worldwide. On average most cities increased their area 16-fold – they simply found they needed to make more room. Bangkok grew 16 times over since 1944. Expansion can outpace population growth -- the U.S. consumes the most urban land, but China, Brazil, and India follow right behind.
Looking to the future, Angel does not suggest that future cities in the developing world should sprawl out unnecessarily. The U.S. suburbanized on the basis of the liberating mobility of the car, while more recent market and demographic trends suggest preference for more density. “Others shouldn’t reduce densities as much as we did. Our densities are too low, too low to support transport. We are alone (in that respect), however. We should not export our answer of containment – smart growth that is good to protect the Everglades is not relevant for India.” It makes sense to focus on infill and densification in Tacoma, Angel said, but not so much in Mumbai.
More realistic preparation for urban expansion is mostly a matter of math. Over half the planet’s 6 billion-plus population currently lives in cities, including many millions in informal settlement. The world's urban population is expected to double in 43 years; the urban population in developing countries is expected to double between 2000 and 2030. Accordingly, urban land cover will double in 19 years, and the built-up area of the major cities in the developing world will triple.
“We need to make minimal preparations,” Angel said.
Failure to plan for expansion is evident in gridlock-plagued Bangkok and the 8th circular beltway in Beijing, in San Salvador, where zoning regulations are ignored, and in Sao Paulo, where there has been little effective protection of open space within municipal boundaries.
Examples of better forward-looking preparations, Angel said, include the New York Commissioners Plan Realistic plan of 1811, which basically planned out the grid northward from Lower Manhattan covering the entire island (all of which came to be; Barcelona’s Ensanche plan of 1859; Singapore’s open space planning of parks and recreation areas; and the transit-supporting grid of Toronto, home to the 3rd largest public transport system in North America.
Abha Joshi-Ghani, manager of the Urban Development and Local Government unit at the World Bank and a member of a panel of experts responding to Angel’s presentation, said the key was to think creatively. “Urbanization is the defining phenomenon of this century,” she said. "For this rapid and inevitable urban expansion to lead to equitable, inclusive and green growth - we need to respond in innovative ways, embracing new paradigms."
Respondent Eduardo Rojas, noting that the restriction of land can end up hurting the poor, said there must be a new and improved institutional framework to plan for infrastructure in particular that will be needed well beyond current jurisdictional boundaries.
William Cobbett, manager of Cities Alliance, a global coalition of cities and their development partners housed at the World Bank, said the new paradigm suggested by Angel’s research should address the current reflex in many cities, which is to keep out the poor. Planning for future urban growth and introducing long-term scenarios beyond the term of local elected officials can set the stage for an alternative to the Mike Davis vision of a Planet of Slums, Cobbett said. “There’s an opportunity to have a game-changing debate about urbanization,” he said.
Gregory K. Ingram, president of the Lincoln Institute, said in his welcoming remarks that he believes the research will “revolutionize the analysis of spatial structures of cities,” currently lacking a strong normalized framework.
More coverage of the event, the report, and the online atlas can be viewed at this report prepared by the World Bank.