In an ideal world, dealing with all the world's woes would be simple. We would solve them all.
We should win the war against hunger, end conflicts, stop communicable diseases, provide clean drinking water, step up education and halt climate change, writes Bjorn Lomborg, author of The Skeptical Environmentalist.
Yet we manifestly don't do all these things.
Thus, I would welcome a discussion on global priorities, which is the focus of my new book: How to spend $50bn and make the world a better place.
We have to start asking the hard question: If we don't do it all, what should we do first?
We live in a world with limited resources. We have a moral obligation to spend each pound doing the most good that we possibly can. We need to start talking about prioritisation.
Our Nobel Laureates came out with a prioritisation list. A forum of young college students from around the world came out with their list; UN ambassadors from nations with half the world's population provided theirs.
The lists are different, but have broad similarities - with health, hunger, education and water on top, and climate and financial instability at the bottom.
Notice that none of the panels are saying that these are not all serious problems, which we ideally should deal with. They are simply asking: if we can't do it all, where should we start?
What makes it difficult is that it is not just about putting things at the top but also choosing which things go further down. This may sound blindingly obvious but is hard work when you get down to it.
Also, we talk about prioritising "doing-good-for-the-world" money.
We essentially spend lots of money in the West, which is not intended to do good for all. This is true for money we spend on UK highways, UK health care and our private spending for vacations and food. But it is also true for UK military expenditure (which is clearly not spent primarily to do good for the rest of the world).
So while it might be tempting to say we should do all good things, we should spend less on the military, that is really too easy - the military spending doesn't come from the same 'do-good' pot. We are talking about how to spend extra money.
Thus, this list is not implying we should recast the world and only do what is on top. Instead it means, as we do more, we should focus our increased efforts on the top priorities first.
So. What do you think? What would your priority list look like?
