I think that the world is in the middle of a huge transition that we have to make to renewable energy. We have to transition away from fossil fuels very, very quickly.

I don't believe we're only motivated by our own self-interests. Often out of crisis comes this enormous wellspring of generosity and motivation.

In a couple of decades you have half of the wells that are drilled right now, and you're talking about numbers in the millions of wells drilled, leaking. That's a huge crisis in terms of water contamination. There's no way to fix that problem.

When your science runs into a policy roadblock, all of a sudden the science starts to disappear.

There's something really happening and really moving, and it's exciting and it makes me very optimistic because it is going to be the engine for how we really combat climate change. Which is strong communities.

What we've got is the wholesale embrace of fracking domestically, internationally and for export. And this couldn't be further from what we really need to do to address climate change.

I have to have faith that we're going to succeed in transforming where we get our energy from. The big worry is whether or not we're going to do it before it's too late. And I think nobody knows the answer to that.