The Earth is a unique system in the universe, the only planet we know of that's hospitable for humankind.

We have become frighteningly effective at altering nature.

I am not in any hurry to grow up.

The Exxon Valdez spill triggered a swift and strong response that changed policies about shipping, about double-hulled construction. A number of laws came into place.

Since I began exploring the ocean in the 1950s, 90 percent of the big fish have been stripped away. Tuna, sharks, swordfish, cod, halibut, you name it, the numbers have just collapsed. Also, about half of the coral reefs are gone, globally, from where they were just a few decades ago.

Throughout all of human history we've enjoyed certain benign circumstances: an envelope of atmosphere, an envelope of temperature. A kind of resilience that if you cut down trees, then they'll grow back. You take fish, they recover. You put stuff into the atmosphere that you know is not good for us, but we can still breathe. We haven't awakened, generally, to the sense of urgency that does exist.

Look at a child and realize that their future is in your hands. It's not just those who will be here fifty years from now. The decisions we make in the next ten years will shape the next 10,000 years.