The Rational Environmentalist Where in the world can we do the most good? That is the basic question addressed by the Copenhagen Consensus Center, a think tank founded six years ago by the Danish statistician Bjorn Lomborg. To answer the question, the center periodically convenes panels of leading economists, who weigh and prioritize the solutions experts have proposed to the world's biggest problems. Lomborg, a boyish 43-year-old, first burst onto the intellectual scene in 2001 with his best-selling book The Skeptical Environmentalist: Measuring the Real State of the World. There the former Greenpeace member argued persuasively that most of the planetary doom scenarios imagined by ideological environmentalists were contradicted by the available ecological and economic data. The book provoked a furious green backlash, the low point of which was a 2003 ruling by the Danish Committees on Scientific Dishonesty that "the publication of the work under consideration is deemed to fall within the concept of scientific dishonesty." Lomborg was vindicated later that year when the Danish Ministry of Science, Technology and Innovation overturned the ruling, calling it "completely void of argumentation." Ronald Bailey, reason's science correspondent, interviewed Lomborg in a gilt-edged room at the Moltkes Palace in Copenhagen during a lunch break at the 2008 Copenhagen Consensus Conference....