Scientists never stop asking. They're little kids who never grew up.

We have found ways to capture, kill and market ocean wildlife on an unprecedented scale. It's an absolute catastrophe.

We are blessed with a place that is open to the universe and, despite this, supports this very thin envelope of air we call atmosphere, which holds just the right amount of oxygen for us to breathe.

The ocean is our life support system. No blue, no green. It's really a miracle that we have got a place that works in our favor.

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.

America gains most when individuals have great freedom to pursue personal goals without undue government interference.

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.