We've been in lots of places that I suppose, by Oxford standards, would be considered illiterate, but everyone's completely conversant with the idea that here is a number, and that number is above it, and that's too high. It's not a very complicated idea.

With each month that passes, a solar panel gets 2 or 3 percent cheaper. So while we're holding the fossil fuel industry in check, the engineers in the renewable energy world are undercutting them from the other side.

The real tight interface is between the book and the reader-the world of the book is plugged right into your brain, never mind the [virtual reality] bodysuit.

All the things that we've done as a species have had a limited scope. We're talking about melting the ice caps, raising the level of the seas dramatically, changing the distribution of every other species on Earth, perhaps wiping out one-third or half of them. The changes at work are geologic in scale. The level of change required to deal with it is enormous, too. It will require change in every country. It will require a degree of global cooperation that we haven't seen before.

The ability to write compelling emails may be the single most useful talent an organizer can possess.

It was huge mistake to avoid working with the rest of the world because (a) we're the largest source of the problem: 4% of us who are in the U.S. produce 25% of the world's carbon dioxide.

We spend probably more of our time than we should, just because it's close to home, worrying about the West. But it's equally important to figure out how we're going to free up the resources to let the developing world leapfrog the fossil fuel age. That's at least as mathematically important, and at least as morally crucial.