We have the capacity to alter the nature of nature. No, we don't have just the capacity - we are altering the nature of nature, the natural systems that cause the planet to function in our favor.

I hope that someday we will find evidence that there is intelligent life among humans on this planet.

What we put into the atmosphere in terms of burning fuel is unprecedented.

No water, no life. No blue, no green.

All through college, I had frequently been the only girl in a science class - which wasn't such a bad deal.

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.

The Arctic is a place that historically, during all preceding human history, has largely been an icy realm with an impact on ocean currents. That, in turn, influences the temperature of the planet. The Arctic is now vulnerable because of the excess carbon dioxide in the atmosphere, with a rate of melting that is stunning.