Bjorn Lomborg, a Scandinavian environmentalist, made the following proposal: “The world faces a number of serious problems such as pollution, hunger and disease. Which problem should be addressed first? There are 800 million people starving, 2.5 billion people lacking sewerage, and billions affected by climate change. We all wish that there were money enough to solve all problems. But our means are limited. Therefore policy-makers prioritize every day, but not always on the best basis. Copenhagen Consensus will provide a framework to allow us to make better prioritizations.”

The following rankings resulted:

1. Control of HIV/AIDS
2. Providing micro nutrients
3. Trade liberalization
4. Control of malaria
5. Development of new agricultural technologies
6. Small-scale water technology for livelihoods
7. Community-managed water supply and sanitation
8. Research on water productivity in food production
9. Lowering the cost of starting a new business
10. Lowering barriers to migration for skilled workers
11. Improving infant and child nutrition
12. Reducing the prevalence of low birth weight
13. Scaled-up basic health services
14. Guest worker programs for the unskilled
15. Optimal carbon tax
16. The Kyoto Protocol
17. Value-at-risk carbon tax