When you have the facts on your side, argue the facts. When you have the law on your side, argue the law. When you have neither, holler.

I was born a poor black child.

Fifteen per cent of the population believe the moon landing was actually staged in a movie lot in Arizona and somewhat fewer still believe the Earth is flat. I think they all get together with the global warming deniers on a Saturday night and party

The ability of big money to shape perceptions - where you have four anti-climate lobbyists for every single member of the House and Senate - is a big factor.

Anyone who deals with the climate crisis has an internal dialogue between hope and despair, because the challenge is so huge and the danger is so great and the stakes are so high. But I have always resolved that in favour of hope, and actually I'm more hopeful now than I was a decade ago when the solutions were visible on the horizon, but you had to seek reassurance that the technology experts that they're coming, they'll be here.

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.

George Bush taking credit for the wall coming down is like the rooster taking credit for the sun rising.