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

If you were running a solar company you may be okay - you may be able to keep growing. The question for physics is: Can you grow fast enough to begin to catch up with the damage?

Our weird problem is an abundance of resources and a shortage of hard economic reasons not to use them.

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 spend a lot of time playing defence against bad things. So, in the US, one of the focusses has been this huge Keystone Pipeline project, another has been the coal ports on the Pacific Ocean.

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.

There is no ideal Christmas; only the one Christmas you decide to make as a reflection of your values, desires, affections, traditions.