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.

Some people accuse me of exaggeration, so let me be clear. Those people seek nothing less than the complete and utter destruction of the American way of life.

The truth is that we're at a critical juncture in the history of our species and if we don't act soon, we could inhabit a world we don't recognize anymore. But the most important truth is that we are capable of stopping climate change before the worst of its consequences are locked in. The solutions exist - all we need is the will to do something about it.

It seems an easy choice - sacrifice the tree for a human life - until one learns that three trees must be destroyed for each patient treated. Suddenly we must confront some tough questions. How important are the medical needs of future generations?

The truth is that we're at a critical juncture in the history of our species and if we don't act soon, we could inhabit a world we don't recognize anymore.

There's an old African proverb that says "If you want to go quickly, go alone. If you want to go far, go together." We have to go far - quickly. And that means we have to quickly find a way to change the world's consciousness about exactly what we're facing, and why we have to work to solve it.

I am Al Gore, and I used to be the next president of the United States of America.