We have to figure out ways to scare and entice our leaders more effectively than the fossil fuel industry has managed to scare and entice them. They've got the big checkbooks. We've got to have the big crowd.

A voluntary simplification of life-styles is not beyond our abilities, but it is probably outside our desires.

Delhi is locked in a complete choking smog at the moment - they've had to close schools in one of the world's biggest cities. They have their own reasons for needing to get off fossil fuels fast.

The fight around climate change, which I've spent my life on, is somewhat more difficult than gay marriages because no one makes trillions of dollars a year being a bigot, and that's how much the fossil-fuel industry pulls in pumping carbon into the air. But the principle is the same, I think.

With each month that passes, a solar panel gets 2 or 3 percent cheaper. So while we're holding the fossil fuel industry in check, the engineers in the renewable energy world are undercutting them from the other side.

Alone among businesses, the fossil-fuel industry is allowed to dump its main waste, carbon dioxide, for free.

My goal was to have as many of the primary sources as I could made available for people to look at and understand. Climate change is probably the most important thing that's ever happened, and yet people's understanding of it and its history remains a little fuzzy.