“Today I challenge our nation to commit to producing 100 percent of our electricity from renewable energy and truly clean carbon-free sources within 10 years.”

Civil disobedience has an honourable history, and when the urgency and moral clarity cross a certain threshold, then I think that civil disobedience is quite understandable, and it has a role to play.

The will to act is a renewable resource.

The struggle to save the global environment is in one way much more difficult than the struggle to vanquish Hitler, for this time the war is with ourselves. We are the enemy, just as we have only ourselves as allies.

We can believe in the future and work to achieve it and preserve it, or we can whirl blindly on, behaving as if one day there will be no children to inherit our legacy. The choice is ours; the earth is in balance.

Consider what kind of car you get. Buy cars and other products that have the least impact environmentally.

I have always been fascinated with those who try to look over the horizon and see things that are coming at us.

The good news is, we have everything we need now to respond to the challenge of global warming. We have all the technologies we need, more are being developed…. But we should not wait, we cannot wait, we must not wait.

Our world faces a true planetary emergency. I know the phrase sounds shrill, and I know it’s a challenge to the moral imagination.

A zebra does not change its spots.

In a time of darkness, you don’t curse the darkness, you light a candle.

At some point, a false belief collides with physical reality.

We are running out of time, we must have a planetary solution to a planetary crisis.

I strongly believe in the separation of church and state. But freedom of religion does not mean freedom from religion, there is a better way.

The planet is in distress and all of the attention is on Paris Hilton.

The fate of mankind, as well as religion, depends on the emergence of a new faith in the future. Armed with such a faith, we might find it possible to resanctify the earth.

During my service in the United States Congress, I took the initiative in creating the Internet.