Sometimes, I think my most important job as a CEO is to listen for bad news. If you don't act on it, your people will eventually stop bringing bad news to your attention and that is the beginning of the end.

Polio's pretty special because once you get an eradication, you no longer have to spend money on it; it's just there as a gift for the rest of time.

You don't go to other books and take little pieces because although say a romantic scene may have been many times before all the details of who it is, where it is, are so intertwined in that text that it's easier to write it from scratch.

When I was trying to figure out why lives have improved so much in the last 300 years, where we've gone from a third of kids dying before 5 to - by 1990 it was down to 10% - now it's down to 5%. And saying why, over all history, there were smart people, but that number didn't change. Average life span didn't change. What's magical about what's been deemed the Industrial Revolution? It's really energy intensity.

Sorghum is kind of unusual. It can go to very high heats, but it's not as productive in most environments as maize is.

It's the poorer people in tropical zones who will get really hit by climate change - as well as some ecosystems, which nobody wants to see disappear.

Some people, through luck and skill, end up with a lot of assets. If you're good at kicking a ball, writing software, investing in stocks, it pays extremely well.