Re: the sums are insane
I can't really agree with you there. I think there are a lot of problems, both moral and pragmatic, caused by famine, and what little effect it has on population growth is better handled in ways that don't involve starvation.
My problem with the suggestion is that I don't believe it's true. I would still be pleased if it turned out to be. Problems you can solve permanently with a bit more effort now are one of my favorite types of problems (the ones you don't have to do anything to fix are the best, of course). I just don't think famine is one of those because it's often caused by recurring factors that keep happening, a less pleasant type of problems. It's as if I was told that, if I washed a hundred dishes today, I wouldn't have to do it ever again. If that was true, I'll get started, but I know that there's no way that would actually work. As I said in my last comment, if the suggestion was true, then although I do not have $150 billion to put into it, I would support doing so because, in fifteen years, we'd break even and we would have stopped starvation, both intensely positive in my mind.
I dislike when people promise things they know won't happen. If someone knowledgeable actually thinks that can happen, I'm interested to see their long-term plan and I am hoping it to be convincing. Otherwise, it reminds me of the people who low-bid a contract, knowing that people will be more amenable to increasing the costs and dragging things out once part of the thing has been built. I've seen it done with positive goals, for example during a charity fund raiser when they claimed that, if people donated a million pounds, they could fix a major problem. They couldn't have, but the expected revenue of this appeal was around £20k, so they never had to try. Probably, making that case got more donations and they used these for valuable causes I deeply support. I still felt uncomfortable with their rhetoric.