What changed in the United States with Hurricane Katrina was a feeling that we have entered a period of consequences.

If the only tool we use to analyse what's valuable is a price tag, then those things that don't have price tags begin to look like they have no value.

There is an air of unreality in debating these arcane points when the world is changing in such dramatic ways right in front of our eyes because of global warming.

I have faith in the United States and our ability to make good decisions based on the facts.

We know that he has stored secret supplies of biological and chemical weapons throughout his country.

Surveillance technologies now available - including the monitoring of virtually all digital information - have advanced to the point where much of the essential apparatus of a police state is already in place.

Humankind has suddenly entered into a brand new relationship with our planet. Unless we quickly and profoundly change the course of our civilization, we face an immediate and grave danger of destroying the worldwide ecological system that sustains life as we know it.