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.

That's when the vast consensus of the world's climatologists, brought together by the UN and The Intergovernmental Panel on Climate Change, really announced that this was going on, and since then the accumulation of data and wickedly hot years has served to only congeal that consensus much more firmly.

Oil companies are radical because they're willing to alter the chemical composition of the atmosphere.

I'm probably the wrong person to ask. My partner in much of this work [climate movement], who really came up with the divestment campaign with me, Naomi Klein, I think has written powerfully about this.

Delhi is locked in a complete choking smog at the moment - they've had to close schools in one of the world's biggest cities. They have their own reasons for needing to get off fossil fuels fast.

For the first time in 150 years, the USDA reported there were more farms in America, not fewer. That has to make you happy.

I did very much like [Barack] Obama's attack on fossil fuel subsidies for fossil fuel companies. We asked for that in demonstrations and petitions, and now we'll try to push it forward.