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 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.

It's taken us a short time to change the nature of nature. In my lifetime, more change than during all preceding human history put together.

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

Fortunately, we know more about the problems that we have than in all preceding history. We know now the consequences of the things that we put into the air, into the water - of the way we treat life on Earth.

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.

If I seem like a radical it's because I have seen things that others have not.