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.

Fossil fuel is very seductive stuff. [John Maynard] Keynes once said that, as far as he could tell, the average standard of living from the beginning of human history to the middle of the eighteenth century had perhaps doubled. Not much had changed, and then we found coal and gas and oil and everything changed. We're reaping the result of that, both ecologically and socially.

To me, it's more important to take the 60-70% of people who really understand that there's a problem [of climate change] and get some percentage of them active than to try and stamp out the last embers of pre-scientific thought.

We have to figure out ways to scare and entice our leaders more effectively than the fossil fuel industry has managed to scare and entice them. They've got the big checkbooks. We've got to have the big crowd.

In the States we've had by far the largest demonstrations in the last few years. The largest civil disobedience actions about anything in US history in the last 30 years have all been centred around the climate.

The essential thing we need to understand is that the climate crisis is not some future threat, but a very present peril, the biggest one humans have ever encountered. Until we understand that, we'll dawdle.

Solar power seems to be truly bipartisan in its appeal.