Now, we put out a lot of carbon dioxide every year, over 26 billion tons. For each American, it's about 20 tons. For people in poor countries, it's less than one ton. It's an average of about five tons for everyone on the planet. And, somehow, we have to make changes that will bring that down to zero.

The Global Fund is a central player in the progress being achieved on HIV, TB and malaria. It channels resources to help countries fight these diseases. I believe in its impact because I have seen it firsthand.

Countries which receive aid do graduate. Within a generation, Korea went from being a big recipient to being a big aid donor. China used to get quite a bit of aid; now it's aid-neutral.

In low-income countries, getting to a health post is hard. It's very expensive.

Rich countries can afford to overpay for things.

If you withdraw the incredible focus on polio, it will spread back, and in poor countries you'll get something like 100,000 cases a year. So by being very intense and getting the cases down to zero, what you do is you avoid all the future cases.

Some very poor countries run great vaccination systems, and some richer ones run terrible programs.

Certainly I'll never be able to put myself in the situation that people growing up in the less developed countries are in. I've gotten a bit of a sense of it by being out there and meeting people and talking with them.

I don't believe in creating dynastic wealth. I don't really believe that in a society that aspires to be meritocratic and that believes in equality of opportunity - my kids have had advantage over 99 percent of the kids in the country...