That, to me, is a kind of brilliant environmental ju-jitsu - using the energy of the market and the profit-motive to get businesses to invest in preserving and improving natural systems.

When it comes to trying to manage how our entire planet-wide market and all the people and businesses in it deal with nature and our natural resources - we first and foremost need to change the incentives.

Often an idea has impact far larger than the person who originated it.

I was much more of a naïve techno-optimist than I am now. I still believe that technology can help us come out of this situation with a richer humanity with less impact on the planet, but now I think it has to be paired with effective policy in order to achieve that.

I think the environmental movement is now so large and diverse that it's hard to talk of it as a single entity.

There are really two kinds of optimism. There's the complacent, Pollyanna optimism that says "don't worry - everything will be just fine" and that allows one to just lay back and do nothing about the problems around you. Then there's what we call dynamic optimism. That's an optimism based on action.

Often we need to use policy to level the playing field, or to be sure that a technology is managed in a responsible way.