The year I was born, 1955, the first big disease-eradication program in the world was declared for malaria. After about a decade of work, they realized that, at least in the tropical areas, they did not have the tools to get it done.

There's a unique thing about the UK, where you give a very generous foreign aid budget to support globally, which is spent wisely. We partner with the government here to make sure that that money is spent well.

I don't have a magic formula for prioritizing the world's problems.

Intermittency [in availability for wind and solar] changes the economics, particularly this requirement that the power company at all times be able to require power. That's large.

People often overestimate what will happen in the next two years and underestimate what will happen in ten.

In the philanthropy game, you're going for different outcomes: saving childhood lives, having kids grow up - because they don't have malnutrition or disease - that they achieve their full potential. We take for Warren [Buffett] things that, because he's very intelligent about the world but doesn't get to go out in Africa and see what we see, we've taken and say to him where we stand and it's basically a very positive report that his gift has made a phenomenal difference.

If Africa seeks prosperity, it must provide for the health and nutrition of all – including the poorest.