I think consumerism breeds dissatisfaction, and I think that the advertisers play to that. So I cannot be comfortable with that. On the other hand, the cornucopia of products and innovation - I love Apple, for example. That's a temple of consumerism in many ways.

I'm worried about greenwashing. I think we should come down on it very, very hard, whether it's with criminal intent or actively deceptive.

Behavioral change is more important than individual product choices. They both have a role to play.

I think people often underestimate the power of consumers. But I equally say that consumers are like shock troops: You can't keep them agitated and motivated and committed and active forever. There are pulses where they switch on to a particular issue, and just inevitably they switch off.

The biggest weakness of the green-consumer movement, always, is that we tend to pick the easy-to-do things because that's where we can most readily engage people. It doesn't cost them very much to switch products or whatever it happens to be.

I became a vegetarian 55 years ago, and I think it's one of the more important behavioral changes I ever took. The more I see of the beef industry and so on, I believe that to be true.

I think consumerism breeds dissatisfaction, and I think that the advertisers play to that. So I cannot be comfortable with that. On the other hand, the cornucopia of products and innovation - I love Apple, for example. That's a temple of consumerism in many ways.