For ending poverty on a global scale, wouldn't weather and chemistry seem like a decent place to start? Consider immunobiology and agriculture.

Also: I know it's a cheap shot, but I had a good laugh when I saw a book called "The Blue Death" on his shelf.

I assume it's only a tiny slice of his library. Inferring from the fact he's the world's richest geek, and that he's spent $30 million on a set of da Vinci papers,

https://en.wikipedia.org/wiki/Codex_Leicester