The US really has to get out in front. We are the biggest per person, by a substantial amount, greenhouse emitters, and we give the most foreign aid, not per person but in absolute.

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.

I have this very positive view of the world getting better and better. The list of things that could be huge setbacks is not very long: A nuclear war, climate change and epidemics.

In the same way that when the car got going, people thought it would be an electric car, people thought it would be a steam car. Actually, the dark horse in that race was internal combustion, but because of the energy density of gasoline and discovery of oil in large amounts at that point in first Pennsylvania and then Texas, it won out over those other two, to the point that those other two are actually viewed as obscure footnotes in history.

I think Ebola is a great example of where the world really needs to come together. The three countries where this outbreak took place have had a lot of civil war, very weak health systems. And so, it did take a while for people to understand ....that eventually what we saw was a very unique Ebola epidemic. I think it is quite impressive what's being pulled together, and I think we will be able to get this under control.

America's high schools are obsolete. By obsolete, I don't just mean that they're broken, flawed, or underfunded, though a case could be made for every one of those points. By obsolete, I mean our high schools-even when they're working as designed-cannot teach all our students what they need to know today.

When AIDS emergency broke out and was killing millions in Africa, the Global Fund was created so that a level of generosity would show up and buy the medicines to save those lives.