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 debate's over. The people who dispute the international consensus on global warming are in the same category now with the people who think the moon landing was staged on a movie lot in Arizona.

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.

Is there some magic wand they can wave on it and presto! - physics is overturned and carbon dioxide doesn't trap heat anymore? And when we see all these things happening on the Earth itself, what in the hell do they think is causing it? The scientists have long held that the evidence in their considered word is "unequivocal," which has been endorsed by every national academy of science in every major country in the entire world.

I'm going to be focused on doing everything I possibly can to help solve the climate crisis.

We sometimes emphasize the danger in a crisis without focusing on the opportunities that are there. We should feel a great sense of urgency because it is the most dangerous crisis we have ever faced, by far. But it also provides us with opportunities to do a lot of things we ought to be doing for other reasons anyway. And to solve this crisis we can develop a shared sense of moral purpose.

Cigarette smoking is a significant contributor to global warming!