Controversial environmentalist Bjorn Lomborg understands the science of climate change and is under no delusions about the risks it poses. But he has long argued -- and continues to do so at Copenhagen this week -- that fixing it is not worth the cost. His argument is that a climate deal will be too costly for poorer nations and that we should instead put our resources towards programs to alleviate poverty and starvation, which he insists are more important. He lays out his argument in the Wall Street Journal today, but he's much more compelling in video. Here's his original 2005 TED Talk that started it all and, below that, his Sunday debate with the New York Times's Paul Krugman.