We're putting more carbon into the atmosphere than the atmosphere can absorb. And everybody told us when we started, coz we knew nothing when we started - we still don't know very much - but everybody told us 'this is crazy, you don't use a scientific data point, it's a number, people don't respond to numbers'.

There's always the danger that people will simply sign online petitions, the way they used to just mail in checks, and there's the greater possibility we'll just spend our whole lives staring at screens and never get anything done.

Colonialism of one kind or another, imperialism of one kind or another, and slavery, and on and on and on.

I don't think the fossil fuel industry will listen, not until we build up a lot of pressure. I do think we can persuade some shareholders that they don't want to be involved in this enterprise.

At the moment, the 4 percent of us in this country produce a quarter of the world's carbon dioxide - once you look at maps of rising sea levels and spreading mosquitoes, you realize that we've probably never figured out a way to hate our neighbors around the world much more effectively.

The fight around climate change, which I've spent my life on, is somewhat more difficult than gay marriages because no one makes trillions of dollars a year being a bigot, and that's how much the fossil-fuel industry pulls in pumping carbon into the air. But the principle is the same, I think.

We'd won the argument 15 years before, we were just losing the fight. And so it became clear to some of us that we would need to organise to fight, that we weren't going to win.