There's this idea of shifting baselines. It was coined by a guy named Jeremy Jackson. It's the idea that every generation takes what it sees, and says, "Okay, well, that's the norm."

We have all this Paleolithic art that suggests that our ancestors really venerated animals and that they depended on wild animals to survive - as opposed to domesticated animals that we depend on. Would it radically change things if we had more rhinos in our midst? I kind of suspect it would.

[On the birther movement:] Here we are, quadrillions of bytes deep into the Information Age. And yet information, it seems, has never mattered less.

Of the many species that have existed on earth - estimates run as high as fifty billion - more than ninety-nine per cent have disappeared. In the light of this, it is sometimes joked that all of life today amounts to little more than a rounding error.

We're talking really huge global-scale change, and I did not feel that I had the prescription for that kind of action, so I'm going to leave it to the reader.

Increasingly developing countries are asking for aid to help deal with the consequences of climate change, which we don't want to give.

Several decades ago, a detachment of the American right cut itself loose from reason, and it has been drifting along happily ever since. If the birthers are more evidently kooky than the global-warming "skeptics" or the death-panellers or the supply-siders or the Swift Boat Veterans for Truth, they are, in their fundamental disregard for the facts, actually mainstream.