Rich Seedlings for the Urban Revolution

"[A]lthough scenes of squalor, accumulation of rubbish and polluted waters look like destitution, slums are rich seedlings for the vibrant cities of the future," says Vince. "Many of today's established capitals, including London and New York, launched from similar embryonic beginnings." There are currently 1 billion dwellers in informal housing around the world and the United Nations predicts that one in four people will become an urban squatter by 2030, increasing to one in three by 2050.

When slum dwellers organize together, they can create transformative innovations. For example, in Delhi, the Children's Development Khazana is run by street children and allows 1,000 youth to safely store their earnings. In Pakistan, residents of the Orangi slum built their own sewerage system in the 1980s and successfully reduced infant mortality. "Cooperation, whether to achieve wider policy change and improvement in working conditions or build essential infrastructure, is a slum’s biggest strength and is essential to nurture as cities 'upgrade' their poorest areas," says Vince, though he warns, "That's not to glorify life in these communities."

"Governments are beginning to accept the social wealth of these existing communities," continues Vince, "and realising that the best way to capitalise on that is to incorporate these dynamic, lively parts of the city into the established whole, by providing the tools for growth, integration and citizen strength." Medellin, Colombia, the former murder capital of the world, was transformed "from terrible conditions to light modernity" and "the murder rate has plummeted." However, only those with independent governance and strong finances may have the resources to implement large-scale change.

Vince concludes: "As most of the urban growth in coming decades will be in poor countries, particularly in Asia and Latin America (Africa’s urbanisation is stark and rapid only in a few countries, although this could change), it is associated with a general rise in global resource use as people improve their standard of living. The challenge then is to create the most sustainable cities – ones where people lead dignified lives without generating excessive waste and pollution."