If mass media, social isolation in the suburbs, alienating workplaces and long car commutes create a bunker mentality, the Internet does the opposite.

Carbon zero simply means that the emissions you are releasing either are zero or balance out to zero.

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.

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.

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.

We get so little news about the developing world that we often forget that there are literally millions of people out there struggling to change things to be fairer, freer, more democratic, less corrupt.

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.