I try not to be either optimistic or pessimistic. I try not to think about outcomes on that scale. My job, it seems to me, is to wake up every morning and figure out how to cause as much trouble for the fossil fuel industry as I can.

Without a movement pressing for change, there's little hope. We've got to work the political system to make this happen fast. The physics and chemistry are daunting. The resources on the other side are very large.

Other thing we need to understand is that the financial power of the fossil fuel industry has so far prevented even any minor progress. They have a sweetheart deal unlike any other business on Earth: they're allowed to dispose of their waste for free, to use the atmosphere as an open sewer. And they will do all they can to defend that special privilege.

We'll look for almost any reason not to change our attitudes; the inertia of the established order is powerful. If we can think of a plausible, or even implausible, reason to discount environmental warnings, we will.

The movers and shakers on our planet, aren't the billionaires and generals, they are the incredible numbers of people around the world filled with love for neighbor and for the earth who are resisting, remaking, restoring, renewing and revitalising.

The end of nature sours all my material pleasures. The prospect of living in a genetically engineered world sickens me. And yet it is toward such a world that our belief in endless material advancement hurries us. As long as that desire drives us, here is no way to set limits.

I try not to be either optimistic or pessimistic. I try not to think about outcomes on that scale. My job, it seems to me, is to wake up every morning and figure out how to cause as much trouble for the fossil fuel industry as I can.