The Exxon Valdez spill triggered a swift and strong response that changed policies about shipping, about double-hulled construction. A number of laws came into place.

The very energy sources that have gotten us to where we are now are also, if we continue doing what we're doing, a shortcut to the end of all that we hold near and dear.

When I arrived on the planet, there were only two billion. Wildlife was more abundant, we were less so; now the situation is reversed.

'Green' issues at last are attracting serious attention, owing to critically important links between the environment and the economy, health, and our security.

What we once used as weapons of war, we now use as weapons against fish.

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.

Ice ages have come and gone. Coral reefs have persisted.