There's no happy ending where we prevent climate change any more. Now the question is, is it going to be a miserable century or an impossible one, and what comes after that.

Climate change is a huge problem, an almost insoluble problem.

Climate change is a huge problem, an almost insoluble problem, for two reasons. One is the habits of the West in terms of consumption. The other is the incredible iniquity between poor countries and rich countries on this planet.

Probably nothing that we have ever managed to do quite equals the basic undermining of the physical stability of the planet on which most of the world's poor people depend.

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

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.