David Doubilet: Underwater, we are seeing the health of the ocean — the health of the planet — close up. We’ve been lucky enough, Jennifer and I, to see it from pole to coral reef. And we are seeing the changes right now. Coral reefs will change, not in the next century but in the next 20 or 30 years. They are the barometer of the planet. And this is what we are working on. We can only truly protect this planet — and this is what we’re learning right now — by reducing our carbon footprint. There is no doubt about it. These are the great sweeping changes that our planet is going through right now: overpopulation, rising temperatures, acidification. I would say this: you win a war by saying “second best today.” And if we can begin to cut down on our carbon footprint, which means that we switch more to solar, to wind, and for our automobiles, probably electricity, that’s going to change. If we have seven million people changing like that, we will reduce the carbon output. We will slow the change in our oceans.