If we were driving pure hydrogen automobiles, that automobile would actually help clean up the air because the air coming out of the exhaust would be cleaner than the air going into the engine intake.

I became a vegetarian in 1958 and it was very difficult in those days to really maintain that because there weren't many options... alternatives. But, now, it's a growing trend because... the economics are there. See, there's simply enough people demanding it that it's profitable to supply vegetarians with those products.

Practically every environmental problem we have can be traced to our addiction to fossil fuels, primarily oil.

The earth is a tremendous gift. There is nothing else like it in the known universe. I want to leave it the way I found it.

The people of the future will say, 'meat-eaters!' in disgust and regard us in the same way that we regard cannibals and cannibalism.

The premise is simple: One economy and one environment, and they're interdependent.

I think there will come a time when civilized people will look back in horror on our generation and the ones that have preceded it; the idea that we should eat other living things running around on four legs, that we should raise them just for the purpose of killing them! The people of the future will say 'meat-eaters' in disgust and regard us in the same way that we regard cannibals and cannibalism.