It's as if we think the laws of physics are subject to debate and amendment and political contributions can sway the laws of physics.

If the people that believed the moon landing was staged on a movie lot had access to unlimited money from large carbon polluters or some other special interest who wanted to confuse people into thinking that the moon landing didn't take place, I'm sure we'd have a robust debate about it right now.

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?

It took me a bit to realize how big the changes have been in the last decade. In so many places - electricity from solar and wind is cheaper than electricity from fossil fuels, and now the batteries are coming down in costs very quickly. So it's very exciting news that needed to be told.

Future generations may well have occasion to ask themselves, "What were our parents thinking? Why didn't they wake up when they had a chance?" We have to hear that question from them, now.

We the human species, are confronting a planetary emergency-a threat to the survival of our civilization that is gathering ominous and destructive potential...the earth has a fever. And the fever is rising...Indeed, without realizing it, we have begun to wage war on earth itself.

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