There are ecosystems like coral reefs [at risk] through ocean acidification. Those are valuable things that we should protect.

People are always coming up to me and saying, 'I heard your dad's speech, and it's really great.' And they'll mention some place I didn't even know my dad was going to.

For one thing, there's an essential human factor in every business endeavor. It doesn't matter if you have a perfect product, production plan and marketing pitch; you'll still need the right people to lead and implement those plans.

We're creating this alliance, GAVI, that has helped buy the vaccines that were in the rich world but not getting to the poor kids, getting a very cheap price and figuring out the cold chain, getting the delivery right, and then funding research for new vaccines. A lot of them are coming along. We've got a meningitis vaccine out, got that through large parts of Africa. That has been a huge success.

The potential financial reward for building the 'next Windows' is so great that there will never be a shortage of new technologies seeking to challenge it.

In the next 15 years, we can halve childhood deaths. That's doable.

As we have taken diarrhea and pneumonia down, even malaria down quite a bit, the portion of the days that are very early in that 5 years - the first month, the first day - it's about half now. Yet that's the part we understand the least.