Civil disobedience has an honourable history, and when the urgency and moral clarity cross a certain threshold, then I think that civil disobedience is quite understandable, and it has a role to play.

The Bush-Cheney administration had betrayed some basic American values. So there was hunger for change.

I've learned the importance of changing people's minds at the grassroots level so that whoever does run will have a much better chance of encountering public opinion that reaches a critical mass and brings about a change not only in White House policies but in the Congress and in the state legislatures and all around the world.

[T]he scientific enterprise will never be completely free of mistakes. What is important is that the overwhelming consensus on global warming remains unchanged.

Any of us who work on the task of solving the climate crisis have at times an internal struggle between hope and despair. But that's one of the things that connects this climate movement to the previous great moral revolutions, like the civil rights movement and more recently the gay rights movement. So those who feel despair should be of good cheer, as the Bible says. Have faith, have hope. We are going to win this.

I'm sorry I ever invented the Electoral College.

What's really important is how our country gets through Trump period, because nothing's getting done in Washington. Every day it's another set of tweets and another set of controversies. And they're not getting anything done.