We also have to engage - and I think this is important - in national politics because there is no way to address questions of this scale in the short time that we have to address them without engaging in real political change.

The most blatant examples are increased power and frequency in hurricanes and the increased depth and frequency of heat waves.

I think the same around the world. At 350.org we just trained 500 young people from around the world in Istanbul for a few weeks. We had 5000 applications from young people who wanted to be part of the training. There's real hunger out there.

The laws of Congress and the laws of physics have grown increasingly divergent, and the laws of physics are not likely to yield.

For those of us who worry more about working people than about windfall profits for oil companies, it may net out. A better question is: what does it do to our economy if we manage to overheat the earth? This summer's drought provides a small taste.

[Kids] will grow up into a world that's difficult and wonderful, and they'll make the best of it they can, and hopefully help turn it in the best possible direction.

We have to transition to new technologies, making it more expensive to continue with the old and polluting technologies and cheaper to go to the clean ones.