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.

Copenhagen has done a remarkable job creating streets that are focused on bicycles and pedestrians.

There’s more to being an environmentalist than occasionally signing an online petition and mailing your check to the Sierra Club. Really the most effective environmental actions you can take have to do with crafting your home and surroundings, your workplace decisions and your investment habits.

The planet's biggest problems have to do with sustainability, environmental decline, global poverty, disease, conflict and so forth. Really, they're all interconnected - it's one big problem, which is that the way we're doing things can't go on.

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.

For most people, using the Internet broadens their sense of who 'we' is and actually ends up leaving us in a place of greater compassion and understanding. It leaves us more connected to a larger group of people and more at one with a lot more people in our community.

By fundamentally changing how we design the places and systems that enable our daily lives, we can slash emissions way beyond the immediate carbon savings - because our own personal emissions are just the tip of a vast iceberg of energy and resources consumed far from our view.