I've heard him use this metaphor a few times, and it's intriguing. Here's him talking about it in a Wired magazine interview.
My positive view of it is that maybe we walked ourselves into the darkness. We’re consuming resources in the same way a caterpillar consumes its resources, by devouring the leaf that it lives upon. If we are part of a natural, emerging process, then maybe that process knows what it is doing. Maybe the way humans are fusing with technology is part of the growth, and we may not manage to exhaust the planet. The planet is a big thing. It has survived several massive extinctions, and still managed to come back. Of course, it’s not the planet that we have to worry about. It’s us. But we’re turning into something else, and I can see the bleeding edge of that transformation in the way we’re bonding with our communications technology.
But, you know, I’m willing to consider the bleak alternative. Maybe humans are a kind of planetary cancer, something that’s gone wrong. Maybe we’re all of us vile monsters, including our moms and the Dalai Lama. I think that’s a way of looking at humanity that came about after World War II, an existentialist, nihilistic view which has persisted for a long time, helped along by the media. And it may not be true. We still don’t know. But that doesn’t mean that we all shouldn’t campaign and do our best to use resources intelligently. That doesn’t mean we stop being political, but it should always be taken into account that self-lacerating guilt isn’t improving anything either.
I’ve been accused of encouraging apolitical apathy by some critics but they’re generally people who have no intention of getting up off their own arses to make things better anyway. I agree that oil companies should be brought to account if their plans to rape the Antarctic affect our future well-being but I have a feeling that much larger processes are working themselves out. The self-aggrandizing idea that humans are somehow different from the rest of the natural world continues to cause us no end of problems.