Some people see a squatter city in Nigeria or India and the desperation overwhelms them: rickety shelters, little kids working or begging, filthy water and air. Stewart Brand sees the same places and he’s encouraged. The pioneering environmentalist, technology thinker, and founder of the Whole Earth Catalog has written a new manifesto, Whole Earth Discipline, in which he defends genetic engineering, nuclear power, and other longtime nemeses of the green left as good for the planet. Brand also makes a counterintuitive case that the booming slums and squatter cities in and around Mumbai, Nairobi, and Rio de Janeiro are net positives for poor people and the environment….

Wired asked him to elaborate.

Wired: What makes squatter cities so important?

Stewart Brand: That’s where vast numbers of humans—slum dwellers—are doing urban stuff in new and amazing ways. And hell’s bells, there are a billion of them! People are trying desperately to get out of poverty, so there’s a lot of creativity; they collaborate in ways that we’ve completely forgotten how to do in regular cities. And there’s a transition: People come in from the countryside, enter the rickshaw economy, and work for almost nothing. But after a while, they move uptown, into the formal economy. The United Nations did extensive field research and flipped from seeing squatter cities as the world’s great problem to realizing these slums are actually the world’s great solution to poverty.

Wired: Why are they good for the environment?

Brand: Cities draw people away from subsistence farming, which is ecologically devastating, and they defuse the population bomb. In the villages, women spend their time doing agricultural stuff, for no pay, or having lots and lots of kids. When women move to town, it’s better to have fewer kids, bear down, and get them some education, some economic opportunity. Women become important, powerful creatures in the slums. They’re often the ones running the community-based organizations, and they’re considered the most reliable recipients of microfinance loans.

Wired: How can governments help nurture these positives?

Brand: The suffering is great, and crime is rampant. We made the mistake of romanticizing villages, and we don’t need to make that mistake again. But the main thing is not to bulldoze the slums. Treat the people as pioneers. Get them some grid electricity, water, sanitation, crime prevention. All that makes a huge difference.