If [a student's] college’s endowment portfolio has fossil-fuel stock, then their educations are being subsidized by investments that guarantee they won’t have much of a planet on which to make use of their degree.

In the end, climate change is a math problem.

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

I've got no advice. You guys know where you are and what will work. Just know that there are people all over the place working on this and that there's a great deal of solidarity around the world and we should try to build this big, sprawling movement that looks like the kind of energy system that we want - building lots of solar panels on lots of rooftops that are all interconnected.

In the States, the movement's actually gotten much much much stronger. There really was no climate movement so to speak before that - I think because everybody assumed that reasonable heads would prevail and do the right thing - and why would you need to have a huge movement in order to cause our leaders to deal with the most serious problem that they face. In a rational world you wouldn't. They would deal with it.

We've built a new Earth. It's not as nice as the old one; it's the greatest mistake humans have ever made, one that we will pay for literally forever.

When you have solar panels, your electricity gets there for free, no one's figured out how to meter the sun yet. And that's good.