Reposted in full from CitiWire, 12 February, 2011
'The cities of the world are on a great growth tear, gobbling up land as a dizzying rate.
The expansion has ground to a crawl in recession-impacted America and Europe. But just check what’s happening across the developing world.
Most attention gets focused on “megacities” of 10 million-plus people, such as Mexico City, Cairo, Mumbai, Karachi, Calcutta, Dhaka and Shanghai — and all have grown, with huge suburban peripheries.
But cumulatively, the unfolding land consumption will be the most extreme in cities above 100,000 and below the 10 million mark. There are 3,646 of these in the world. And many tell amazing growth tales.
Take Accra, capital of Ghana. Between 1985 and 2000 (latest available count), its population grew 50 percent — from 1.8 to 2.7 million. But its urban land cover spiraled 135 percent.
Using a Landsat-based sampling of physical expansion of 120 word cities between 1990 and 2000, Shlomo (Solly) Angel and his associates at the Lincoln Institute of Land Policy found they were all growing physically at least twice as fast as their populations were actually increasing.
It’s a startling trend. If it continues, it means the world’s total urban land cover could double between now and 2030. Taking the entire period 2000 to 2050, and looking just at the potential land use demand in developing countries, it might increase as much as 326 percent, according to the analysts’ conclusion in their new report, “Making Room for a Planet of Cities,” based on research originally commissioned by the World Bank.
They suggest the trend is inevitable — that density of cities, anywhere, declines rapidly when people can escape packed inner-city neighborhoods to find more space but still have access to jobs. It occurred rapidly in the U.S. when omnibuses, horse-drawn cars, trolleys and then commuter buses and rail lines began to proliferate in the late 1800s. And when automobiles became Everyman’s property, especially after World War II, we suburbanized so fast that for some years people saw little future at all in the old central cities. Only in recent years, with help from New Urbanism and the smart growth movement, have we begun to revalue traditional, more compact neighborhoods.
But what’s the prescription for the developing world? With its explosive population growth, is there any choice but “let ‘er rip” — quickly open up land for new settlements, maybe even ahead of demand, to prevent land price escalation?
That’s the thrust of the Lincoln Institute report. It calls for expanding metropolitan limits enough to accommodate up to 30 years of urban expansion. It’s filled with admonitions not to duplicate what it calls the “containment” approach of European cities or the U.S. smart growth movement.
The authors do, though, suggest some order to the expansion free-for-all. They recommend that cities, well in advance of population advance, should designate an ample array of parks and other “green” areas for livability.
Plus, they say that cities should map out and reserve an arterial grid of major roadways, about 1 kilometer apart, to assure future mobility for trucks, autos and strong public transit systems.
Presetting a “grid” is a sound idea– American cities actually did it historically, inviting development to fill in (rather than the post-World War II style of letting private developers dictate urban form).
What the Lincoln Institute report seems to lack is fine grain sensitivity — the very issues advanced by the smart growth advocates it disparages. It’s an eye-opener on massive land needs of our times, notes, Eduardo Rojas of the Inter-American Development Bank, but it tends to embrace “low cost energy and cheap transportation assumptions.”
Its emphasis on big multi-lane arterial roads might, for example, be intimidating for cyclists and pedestrians. Enrique Penalosa, former mayor of Bogota, has suggested exclusive bike and pedestrian roadways planned early on for developing areas — a way to improve livability, health, and safety.
The report fails to mention the value of planning early and carefully for suburban town centers, interspersed through its arterial pattern, serving as shopping, transit and social gathering spots. It doesn’t caution, as a curb on lands that should be opened up, the dangers of development in flood and landslide-prone areas. It dismisses the value of more compact development (for example mid-height apartment buildings) as one of the world’s best ways to curb carbon emissions. And it largely ignores local agriculture, which may loom large as a food security — and quality of life — issue for the world’s urban dwellers.
Still, by soberly reminding us of the spiralling needs for land to accommodate the world’s multitudes of city dwellers — as they rise from 3 billion in 2000 to 5 billion in 2030, then to 6.4 billion by 2050 — it performs a vital public service.
Or in the words of Billy Cobbett, director of the Cities Alliance which supported the report, it represents a “pragmatic and affordable” direction “to achieve a planet of cities, not a planet of slums.”'
The expansion has ground to a crawl in recession-impacted America and Europe. But just check what’s happening across the developing world.
Most attention gets focused on “megacities” of 10 million-plus people, such as Mexico City, Cairo, Mumbai, Karachi, Calcutta, Dhaka and Shanghai — and all have grown, with huge suburban peripheries.
But cumulatively, the unfolding land consumption will be the most extreme in cities above 100,000 and below the 10 million mark. There are 3,646 of these in the world. And many tell amazing growth tales.
Take Accra, capital of Ghana. Between 1985 and 2000 (latest available count), its population grew 50 percent — from 1.8 to 2.7 million. But its urban land cover spiraled 135 percent.
Using a Landsat-based sampling of physical expansion of 120 word cities between 1990 and 2000, Shlomo (Solly) Angel and his associates at the Lincoln Institute of Land Policy found they were all growing physically at least twice as fast as their populations were actually increasing.
It’s a startling trend. If it continues, it means the world’s total urban land cover could double between now and 2030. Taking the entire period 2000 to 2050, and looking just at the potential land use demand in developing countries, it might increase as much as 326 percent, according to the analysts’ conclusion in their new report, “Making Room for a Planet of Cities,” based on research originally commissioned by the World Bank.
They suggest the trend is inevitable — that density of cities, anywhere, declines rapidly when people can escape packed inner-city neighborhoods to find more space but still have access to jobs. It occurred rapidly in the U.S. when omnibuses, horse-drawn cars, trolleys and then commuter buses and rail lines began to proliferate in the late 1800s. And when automobiles became Everyman’s property, especially after World War II, we suburbanized so fast that for some years people saw little future at all in the old central cities. Only in recent years, with help from New Urbanism and the smart growth movement, have we begun to revalue traditional, more compact neighborhoods.
But what’s the prescription for the developing world? With its explosive population growth, is there any choice but “let ‘er rip” — quickly open up land for new settlements, maybe even ahead of demand, to prevent land price escalation?
That’s the thrust of the Lincoln Institute report. It calls for expanding metropolitan limits enough to accommodate up to 30 years of urban expansion. It’s filled with admonitions not to duplicate what it calls the “containment” approach of European cities or the U.S. smart growth movement.
The authors do, though, suggest some order to the expansion free-for-all. They recommend that cities, well in advance of population advance, should designate an ample array of parks and other “green” areas for livability.
Plus, they say that cities should map out and reserve an arterial grid of major roadways, about 1 kilometer apart, to assure future mobility for trucks, autos and strong public transit systems.
Presetting a “grid” is a sound idea– American cities actually did it historically, inviting development to fill in (rather than the post-World War II style of letting private developers dictate urban form).
What the Lincoln Institute report seems to lack is fine grain sensitivity — the very issues advanced by the smart growth advocates it disparages. It’s an eye-opener on massive land needs of our times, notes, Eduardo Rojas of the Inter-American Development Bank, but it tends to embrace “low cost energy and cheap transportation assumptions.”
Its emphasis on big multi-lane arterial roads might, for example, be intimidating for cyclists and pedestrians. Enrique Penalosa, former mayor of Bogota, has suggested exclusive bike and pedestrian roadways planned early on for developing areas — a way to improve livability, health, and safety.
The report fails to mention the value of planning early and carefully for suburban town centers, interspersed through its arterial pattern, serving as shopping, transit and social gathering spots. It doesn’t caution, as a curb on lands that should be opened up, the dangers of development in flood and landslide-prone areas. It dismisses the value of more compact development (for example mid-height apartment buildings) as one of the world’s best ways to curb carbon emissions. And it largely ignores local agriculture, which may loom large as a food security — and quality of life — issue for the world’s urban dwellers.
Still, by soberly reminding us of the spiralling needs for land to accommodate the world’s multitudes of city dwellers — as they rise from 3 billion in 2000 to 5 billion in 2030, then to 6.4 billion by 2050 — it performs a vital public service.
Or in the words of Billy Cobbett, director of the Cities Alliance which supported the report, it represents a “pragmatic and affordable” direction “to achieve a planet of cities, not a planet of slums.”'
No comments:
Post a Comment
Please leave your comment here. Please note these stories are posted for information rather than for debate; if you wish to disagree with something posted, no problem, but since I post both things that I do and don't support, it would be appreciated if the criticism was about the issue.