Don't get caught flat-footed when you're roped into a one of those 'let's sit around and talk about the problems of the world' discussions. Economists have been huddled in Copehhagen doing cost-benefit analyses on programs wealthy countries can pursue to help developing countries ameliorate such challenges as Disease, Malnutrition, Sanitation and Water, etc. The Economist has has been following and supporting the Copenhagen Consensus project and I think I can break this thing down for you so you can pass as an expert on it in 10 minutes or less.
Here's your background article: "Putting the world to rights: What would be the best ways to spend additional resources on helping developing countries? Some answers."
All you need to know to be conversant is that the thing is going on, it's the brainchild of a controversial Dane name of Bjorn Lomborg, author of The Skeptical Environmentalist, the expert panel assembled to review submissions included 3 Nobel prize winners, and the Economist recommends a focus on the consensus top bang-for-your-buck programs. They are: Control of HIV/AIDS, Providing Micro-Nutrients, Trade Liberalisation, and Control of Malaria.
Given the recent release of The Day After Tomorrow and Kim Stanley Robinson's Forty Signs of Rain, to be topical I think you need to highlight your understanding of the reasons why Global Warming/Climate Issues were rated so low by the panel: "the issue is real ... but not so urgent that such massive abatement costs need to be incurred right now," those costs being associated with carbon taxes and the Kyoto Protocol.
Me, I'd throw in that it should come as no surprise The Economist is in love with anything or anyone that promotes Trade Liberalisation and governments reducing the tax burden on any business anywhere (see the background article for more on this), and therefore we might be wise to take their support cum grano salis. That Lomborg's basic premises have been roundly debunked and many feel, with good reason, he is simply trying to discredit and divide the environmentalist movement is another reason to step back and view the results, and the Economist's approval, with a healthy dose of skepticism.
There you have it, you may not be an expert on solving the world's problems, but you know where the 'real experts' stand!