Earth as an ecosystem stands out in the all of the universe. There's no place that we know about that can support life as we know it, not even our sister planet, Mars, where we might set up housekeeping someday, but at great effort and trouble we have to recreate the things we take for granted here.

We want to believe that we can continue doing what we've done for the past thousand years and not worry about the consequences coming back to us.

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.

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.

It's mainly the high-end luxury market now that drives much of the fishing in the sea. It's not feeding the starving millions. It's feeding a luxury market.

We've got to alter our fossil fuel dependence and go to other energy sources.

Life in the ocean makes Earth hospitable. We are sailing along in the universe and we have a blue engine that is making everything alright.