What I'd like to talk about is really the biggest problems in the world. I'm not going to talk about "The Skeptical Environmentalist" - probably that's also a good choice. (Laughter)

But I am going talk about, what are the big problems in the world? And I must say, before I go on, I should ask every one of you to try and get out pen and paper because I'm actually going to ask you to help me to look at how we do that. So get out your pen and paper. Bottom line is, there is a lot of problems out there in the world. I'm just going to list some of them. There are 800 million people starving. There's a billion people without clean drinking water. Two billion people without sanitation. There are several million people dying of HIV and AIDS. The lists go on and on. There's two billions of people who will be severely affected by climate change - so on. There are many, many problems out there.

In an ideal world, we would solve them all, but we don't. We don't actually solve all problems. And if we do not, the question I think we need to ask ourselves - and that's why it's on the economy session - is to say, if we don't do all things, we really have to start asking ourselves, which ones should we solve first? And that's the question I'd like to ask you. If we had say, 50 billion dollars over the next four years to spend to do good in this world, where should we spend it? We identified 10 of the biggest challenges in the world, and I will just briefly read them. Climate change, communicable diseases, conflicts, education, financial instability, governance and corruption, malnutrition and hunger, population migration, sanitation and water, and subsidies and trade barriers. We believe that these in many ways encompass the biggest problems in the world. The obvious question would be to ask, what do you think are the biggest things? Where should we start on solving these problems? But that's a wrong problem to ask. That was actually the problem that was asked in Davos in January.

But of course, there's a problem in asking people to focus on problems. Because we can't solve problems. Surely the biggest problem we have in the world is that we all die. But we don't have a technology to solve that, right? So the point is not to prioritize problems, but the point is to prioritize solutions to problems. And that would be - of course that gets a little more complicated. To climate change that would be like Kyoto. To communicable diseases, it might be health clinics or mosquito nets. To conflicts, it would be U.N.'s peacekeeping forces, and so on. The point that I would like to ask you to try to do, is just in 30 seconds - and I know this is in a sense an impossible task - write down what you think is probably some of the top priorities. And also - and that's, of course, where economics gets evil - to put down what are the things we should not do, first. What should be at the bottom of the list? Please, just take 30 seconds, perhaps talk to your neighbor, and just figure out what should be the top priorities and the bottom priorities of the solutions that we have to the world's biggest issues.

The amazing part of this process - and of course, I mean, I would love to - I only have 18 minutes, I've already given you quite a substantial amount of my time, right? I'd love to go into, and get you to think about this process, and that's actually what we did. And I also strongly encourage you, and I'm sure we'll also have these discussions afterwards, to think about, how do we actually prioritize? Of course, you have to ask yourself, why on earth was such a list never done before? And one reason is that prioritization is incredibly uncomfortable. Nobody wants to do this. Of course, every organization would love to be on the top of such a list. But every organization would also hate to be not on the top of the list. And since there are many more not-number-one spots on the list than there is number ones, it makes perfect sense not to want to do such a list. We've had the U.N. for almost 60 years, yet we've never actually made a fundamental list of all the big things that we can do in the world, and said, which of them should we do first? So it doesn't mean that we are not prioritizing - any decision is a prioritization, so of course we are still prioritizing if only implicitly - and that's unlikely to be as good as if we actually did the prioritization, and went in and talked about it.

So what I'm proposing is really to say that we have, for a very long time, had a situation when we've had a menu of choices. There are many, many things we can do out there, but we've not had the prices, nor the sizes. We have not had an idea. Imagine going into a restaurant and getting this big menu card, but you have no idea what the price is. You know, you have a pizza, you've no idea what the price is. It could be at one dollar, it could be 1,000 dollars. It could be a family-size pizza. It could be a very individual-size pizza, right? We'd like to know these things.

And that is what the Copenhagen Consensus is really trying to do - to try to put prices on these issues. And so basically, this has been the Copenhagen Consensus' process. We got 30 of the world's best economists, three in each area. So we have three of world's top economists write about climate change. What can we do? What will be the cost? And what will be the benefit of that? Likewise in communicable diseases. Three of the world's top experts saying, what can we do? What would be the price? What should we do about it, and what will be the outcome? And so on.

Then we had some of the world's top economists, eight of the world's top economists, including three Nobel Laureates, meet in Copenhagen in May 2004. We called them the dream team. The Cambridge University prefects decided to call them the Real Madrid of economics. That works very well in Europe, but it doesn't really work over here. And what they basically did was come out with a prioritized list. And then you ask, why economists? And of course, I'm very happy you asked that question - (Laughter) - because that's a very good question. The point is, of course, if you want to know about malaria, you ask a malaria expert. If you want to know about climate, you ask a climatologist. But if you want to know which of the two you should deal with first, you can't ask either of them, because that's not what they do. That is what economists do. They prioritize. They make that in some ways disgusting task of saying, which one should we do first, and which one should we do afterwards?

So this is the list, and this is the one I'd like to share with you. Of course, you can also see it on the website, and we'll also talk about it more, I'm sure, as the day goes on. They basically came up with a list where they said there were bad projects - basically, projects where if you invest a dollar, you get less than a dollar back. Then there's fair projects, good projects and very good projects. And of course, it's the very good projects we should start doing. I'm going to go from backwards so that we end up with the best projects.

These were the bad projects. As you might see the bottom of the list was climate change. This offends a lot of people, and that's probably one of the things where people will say I shouldn't come back, either. And I'd like to talk about that, because that's really curious. Why is it it came up? And I'll actually also try to get back to this because it's probably one of the things that we'll disagree with on the list that you wrote down.

The reason why they came up with saying that Kyoto - or doing something more than Kyoto - is a bad deal is simply because it's very inefficient. It's not saying that global warming is not happening. It's not saying that it's not a big problem. But it's saying that what we can do about it is very little, at a very high cost. What they basically show us, the average of all macroeconomic models, is that Kyoto, if everyone agreed, would cost about 150 billion dollars a year. That's a substantial amount of money. That's two to three times the global development aid that we give the Third World every year. Yet it would do very little good. All models show it will postpone warming for about six years in 2100. So the guy in Bangladesh who gets a flood in 2100 can wait until 2106. Which is a little good, but not very much good. So the idea here really is to say, well, we've spent a lot of money doing a little good.

And just to give you a sense of reference, the U.N. actually estimate that for half that amount, for about 75 billion dollars a year, we could solve all major basic problems in the world. We could give clean drinking water, sanitation, basic healthcare and education to every single human being on the planet. So we have to ask ourselves, do we want to spend twice the amount on doing very little good? Or half the amount on doing an amazing amount of good? And that is really why it becomes a bad project. It's not to say that if we had all the money in the world, we wouldn't want to do it. But it's to say, when we don't, it's just simply not our first priority.

The fair projects - notice I'm not going to comment on all these - but communicable diseases, scale of basic health services - just made it, simply because, yes, scale of basic health services is a great thing. It would do a lot of good, but it's also very, very costly. Again, what it tells us is suddenly we start thinking about both sides of the equation. If you look at the good projects, a lot of sanitation and water projects came in. Again, sanitation and water is incredibly important, but it also costs a lot of infrastructure. So I'd like to show you the top four priorities which should be at least the first ones that we deal with when we talk about how we should deal with the problems in the world.

The fourth best problem is malaria - dealing with malaria. The incidence of malaria is about a couple of [million] people get infected every year. It might even cost up towards a percentage point of GDP every year for affected nations. If we invested about 13 billion dollars over the next four years, we could bring that incidence down to half. We could avoid about 500,000 people dying, but perhaps more importantly, we could avoid about a billion people getting infected every year. We would significantly increase their ability to deal with many of the other problems that they have to deal with. Of course, in the long run, also to deal with global warming.

This third best one was free trade. Basically, the model showed that if we could get free trade, and especially cut subsidies in the U.S. and Europe, we could basically enliven the global economy to an astounding number of about 2,400 billion dollars a year, half of which would accrue to the Third World. Again, the point is to say that we could actually pull two to three hundred million people out of poverty, very radically fast, in about two to five years. That would be the third best thing we could do.

The second best thing would be to focus on malnutrition. Not just malnutrition in general, but there's a very cheap way of dealing with malnutrition, namely, the lack of micronutrients. Basically, about half of the world's population is lacking in iron, zinc, iodine and vitamin A. If we invest about 12 billion dollars, we could make a severe inroad into that problem. That would be the second best investment that we could do.

And the very best project would be to focus on HIV/AIDS. Basically, if we invest 27 billion dollars over the next eight years, we could avoid 28 new million cases of HIV/AIDS. Again, what this does and what it focuses on is saying there are two very different ways that we can deal with HIV/AIDS. One is treatment, the other one is prevention. And again, in an ideal world, we would do both. But in a world where we don't do either, or don't do it very well, we have to at least ask ourselves where should we invest first. And treatment is much, much more expensive than prevention. So basically, what this focuses on is saying we can do a lot more by investing in prevention. Basically for the amount of money that we spend, we can do X amount of good in treatment, and 10 times as much good in prevention. So again, what we focus on is prevention rather than treatment, at first rate.

What this really does is that it makes us think about our priorities. I'd like to have you look at your priority list and say, did you get it right? Or did you get close to what we came up with here? Well, of course, one of the things is climate change again. I find a lot of people find it very, very unlikely that we should do that.

We should also do climate change, if for no other reason, simply because it's such a big problem. But of course, we don't do all problems. There are many problems out there in the world. And what I want to make sure of is, if we actually focus on problems, that we focus on the right ones. The ones where we can do a lot of good rather than a little good. And I think, actually - Thomas Schelling, one of the participants in the dream team, he put it very, very well. One of things that people forget, is that in 100 years, when we're talking about most of the climate change impacts will be, people will be much, much richer. Even the most pessimistic impact scenarios of the U.N. estimate that the average person in the developing world in 2100 will be about as rich as we are today. Much more likely, they will be two to four times richer than we are. And of course, we'll be even richer than that.

But the point is to say, when we talk about saving people, or helping people in Bangladesh in 2100, we're not talking about a poor Bangladeshi. We're actually talking about a fairly rich Dutch guy. And so the real point, of course, is to say, do we want to spend a lot of money helping a little, 100 years from now, a fairly rich Dutch guy? Or do we want to help real poor people, right now, in Bangladesh, who really need the help, and whom we can help very, very cheaply? Or as Schelling put it, imagine if you were a rich - as you will be - a rich Chinese, a rich Bolivian, a rich Congolese, in 2100 thinking back on 2005, and saying, "How odd that they cared so much about helping me a little bit through climate change, and cared so fairly little about helping my grandfather and my great grandfather, whom they could have helped so much more, and who needed the help so much more?"

So I think that really does tell us why it is we need to get our priorities straight. Even if it doesn't accord to the typical way we see this problem. Of course, that's mainly because climate change has such good pictures. We have, you know, "The Day After Tomorrow" - it looks great, right? It's a good film in the sense that I certainly want to see it, right, but don't expect Emmerich to cast Brad Pitt in his next movie digging latrines in Tanzania or something. (Laughter) It just doesn't make for as much of a movie. So in many ways, I think of the Copenhagen Consensus and the whole discussion of priorities as a defense for boring problems. To make sure that we realize it's not about making us feel good, it's not about making things that have the most media attention, but it's about making places where we can actually do the most good.

The other objections, I think, that are important to say, is that I'm somehow - or we are somehow - positing a false choice. Of course, we should do all things, in an ideal world - I would certainly agree. I think we should do all things, but we don't. In 1970, the developed world decided we were going to spend twice as much as we did, right now, than in 1970 on the developing world. Since then our aid has halved. So it doesn't look like we're actually on the path of suddenly solving all big problems.

Likewise, people are also saying, but what about the Iraq war? You know, we spend 100 billion dollars. Why don't we spend that on doing good in the world? I'm all for that. If any one of you guys can talk Bush into doing that, that's fine. But the point of course, is still to say, if you get another 100 billion dollars, we still want to spend that in the best possible way, don't we? So the real issue here, is to get ourselves back and think about what are the right priorities. I should just mention briefly, is this really the right list that we got out? You know, when you ask the world's best economists, you inevitably end up asking old, white American men. And they're not necessarily, you know, great ways of looking at the entire world.

So we actually invited 80 young people from all over the world to come and solve the same problem. The only two requirements were that they were studying at the university, and they spoke English. The majority of them were, first, from developing countries. They had all the same material but they could go vastly outside the scope of discussion, and they certainly did, to come up with their own lists. And the surprising thing was that the list was very similar - with malnutrition and diseases at the top and climate change at the bottom. We've done this many other times. There's been many other seminars and university students, and different things. They all come out with very much the same list. And that gives me great hope, really, in saying that I do believe that there is a path ahead to get us to start thinking about priorities. And saying, what is the important thing in the world? Of course, in an ideal world, again we'd love to do everything. But if we don't do it, then we can start thinking about where should we start?

I see the Copenhagen Consensus as a process. We did it in 2004, and we hope to assemble many more people, getting much better information for 2008, 2012. Map out the right path for the world. But also to start thinking about political triage. To start thinking about saying, "Let's do not the things where we can do very little at a very high cost, not the things that we don't know how to do, but let's do the great things where we can do an enormous amount of good, at very low cost, right now.

At the end of the day, you can disagree with the discussion of how we actually prioritize these, but we have to be honest and frank about saying, if there's some things we do, there are other things we don't do. If we worry too much about some things, we end by not worrying about other things. So I hope this will help us make better priorities, and think about how we better work for the world. Thank you.