If Darwin could get into a submarine and see what I've seen, thousand of feet beneath the ocean, I am just confident that he would be inspired to sit down and start writing all over again.

There's a vested interest in trying to keep people smoking cigarettes.

The image of Earth from space transformed our view of ourselves. It is maybe the most important image that exists - because we can see ourselves in context in a way that otherwise would be really hard to explain. It should inspire us to wonder about it, to want to know everything we can about it and do everything we can to take care of it.

For humans, the Arctic is a harshly inhospitable place, but the conditions there are precisely what polar bears require to survive - and thrive. 'Harsh' to us is 'home' for them. Take away the ice and snow, increase the temperature by even a little, and the realm that makes their lives possible literally melts away.

We still have 10 percent of the sharks. We still have half of the coral reefs. However, if we wait another 50 years, opportunities might well be gone.

This much is certain: We have the power to damage the sea, but no sure way to heal the harm.

Nearly all of the major kinds of life, divisions of life, phyla of animals, occur in the sea. Only about half of them can make it to land or freshwater.