I just think that a much more important part of the problem we face, which was evident 10 years ago and is even more evident now, is that the way we share information among ourselves as American citizens has been radically transformed. The line between news and entertainment has almost dissolved, where ratings now have a big impact on what kinds of stories are covered and not stories.

Science is warning us that if we do not quickly reduce the global warming pollution that is trapping so much of the heat our planet normally radiates back out of the atmosphere, we are in danger of creating a permanent 'carbon summer'.

Political will is a renewable resource, and everyone can have it in abundance if they so choose.

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

We face a climate crisis now that is the most serious challenge our civilization has ever confronted. And the greatest country in the world [America] has to remain a part of this unprecedented global agreement to deal with it.

George W. Bush promised us a foreign policy with humility. Instead, he has brought us humiliation in the eyes of the world. He promised to restore honor and integrity to the White House. Instead, he has brought deep dishonor to our country and built a durable reputation as the most dishonest president since Richard M. Nixon.

I take no pleasure in the fact that the scientific predictions I’ve relayed to popular audiences turn out to be true.