We're mathematically past the point where the accumulation of individual actions can add up quickly enough to make a difference. The individual action that actually matters is not being an individual. It's joining together with other people in groups large enough to change the political dynamic around climate change.

Global warming is no longer a philosophical threat, no longer a future threat, no longer a threat at all. It's our reality.

what you do every day is what forms your mind and precious few of us can or would spend most days outdoors.

Between [Speaker of the House] Paul Ryan, [Senate Majority Leader] Mitch McConnell, and Donald Trump's team, I don't see a lot of openings for making real progress.

The polling data shows not an unbelievable level of concern [on climate issue] but a general awareness of this problem. And now I think it's up to all sorts of people who really care about these things to continue on this new ground to try and make this the central political issue it needs to be.

I'm guessing the most efficient way would be to transfer an awful lot of technology, but also direct aid to deal with climate emergencies already underway. Hillary [Clinton] has already said $100 billion a year would be appropriate.

The idea that China and India will just abandon climate action is not true, because they're doing it for more reasons than we are.