Sixty million people in the developing world are leaving the countryside every year. The squatter cities that have emerged can teach us much about future urban living.
Urban density allows half of humanity to live on 2.8 per cent of the land. Demographers expect developing countries to stabilise at 80 per cent urban, as nearly all developed countries have. On that basis, 80 per cent of humanity may live on 3 per cent of the land by 2050. Consider just the infrastructure efficiencies. According to a 2004 UN report: “The concentration of population and enterprises in urban areas greatly reduces the unit cost of piped water, sewers, drains, roads, electricity, garbage collection, transport, health care, and schools.” In the developed world, cities are green because they cut energy use; in the developing world, their greenness lies in how they take the pressure off rural waste.
The Last Forest (2007), a book by Mark London and Brian Kelly on the crisis in the Amazon rainforest, suggests that the nationally subsidised city of Manaus in northern Brazil “answers the question” of how to stop deforestation: give people decent jobs. Then they can afford houses, and gain security. One hundred thousand people who would otherwise be deforesting the jungle around Manaus are now prospering in town making such things as mobile phones and televisions.
The point is clear: environmentalists have yet to seize the opportunity offered by urbanisation. Two major campaigns should be mounted: one to protect the newly-emptied countryside, the other to green the hell out of the growing cities.