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.

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

In the food case in particular, one of the technologies that could help there - genetic technologies that could create better crops with higher yields and less need for water and fertilizer - is tremendously feared. Very little of that fear is scientifically grounded.

On almost every environmental issue I care about, in fact, I've been wrong at one point or another. I used to think that climate change was no big deal, that most environmental problems were massive exaggerations, that oil reserves were effectively unlimited, and more.

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

When you're managing a large number of people, you learn that incentives matter tremendously. You really want people to be rewarded for doing the right thing for the customers and the organization.