Companies watch what consumers are doing like a hawk. Just as one letter to a politician can signal an insipient problem, for companies, a trend where people are beginning to switch away from one of their key products to a rival offering on the basis of either claims or real improvements on performance, that's significant.

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'm part of the consumer culture. I was part of the baby boom generation. I have a car when I shouldn't, a couple of computers; I can't be anti-consumerist in that sense.

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 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 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.

So, you could call me optimistic and hopeful and probably just a little bit naïve, but I'm coming from the space that the best way to predict the future is to get out there and just do it yourself.