Cities generate most of the global economy, and most of its energy use, resource demands and climate emissions. How we build cities over the next decades will largely determine whether we can deliver a bright green future.

In almost all city governments in America, the small group of people who don't want change are able to block change.

Saying the Tech Bloom is not commercially driven is like saying Mother Teresa had an interest in the poor.

Cities offer us powerful leverage on our most stubborn, wasteful practices. Long commutes in our cars, big power bills from our energy-hogging buildings, shopping trips to buy stuff that'll spend a few short months in our homes and long centuries in our landfills.

I think we're going to start to see a new model of civic advocacy where people get together once in a while to protest, but it's more about an ongoing, sustained engagement in issues, networks and communities about which people care.

By looking at climate change as a clean energy generation problem, we're setting ourselves up not to solve it.

Urban retrofitting: creating different sorts of spaces and uses out of places that are already there.