Climate change is the single biggest thing that humans have ever done on this planet. The one thing that needs to be bigger is our movement to stop it.

A world where one tenth of the population gets to be extremely wealthy, and six tenths very poor, is not, in the long run, a stable place.

Everybody was cratered after Copenhagen. If the movie had worked the way that it should have, if it had been scripted by Holywood, the world would have come together and addressed the biggest problem it ever had faced and delegates would have embraced each other, and it all would have been a good happy scene instead of the complete farce and debacle that it turned into - maybe in certain ways, an absolute low point for human diplomacy.

We'd like to get the fossil fuel industry on the back foot for a while, having to deal with us.

Speaking for me, I think the odds of bankrupting Exxon are pretty small, but I think the odds of politically bankrupting them are higher. I think if we can use this as a vehicle to get out the analysis that these guys have 3-5 times as much carbon in the ground as the most conservative government thinks would be safe to burn, then that politically stigmatises them, makes them into the rogue industry that they are.

What makes us different? We're the creature that can decide not to do something that we are capable of doing.

There is no real scientific debate over what is happening; of course there is debate over exactly how it is going to play out in the decades ahead, because this is a large experiment that we haven't done before, and no one knows precisely how one can ever precisely predict what effects this heat will have. But all the science in the last few years, or almost all of it, really serves to show that the effects are larger and more rapid than we had thought even a decade ago.