You don't change the world by hiding in the woods, wearing a hair shirt, or buying indulgences in the form of 'Save the Earth' bumper stickers. You do it by articulating a vision for the future and pursuing it with all the ingenuity humanity can muster.

To be young and aware is to know you’re being lied to; to know that a bright green future is possible; to know that we can reimagine the world, rebuild our cities, redesign our lives, retool our factories, distribute innovation and creativity and all live in a world that is not only better than the alternative, but much better than the world we have now.

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

Optimism is a political act. Those who benefit from the status quo are perfectly happy for us to think nothing is going to get any better. In fact, these days, cynicism is obedience.

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

There's no law of physics that says we have to be an unsustainable society - in fact, quite the opposite. The planet's ready to work with us if we're ready to think differently, but we do have to make that jump and start to do things in new ways.

Deep walkability describes a city that is built in such a way that you can move from one area to another on foot, on bicycle, on transit and have an experience that remains a pleasant one, that you feel you are welcome not just in the neighborhood but moving between neighborhoods.