No, Bjorn Lomberg is not kooky. He is a well-respected scientist who has dared to put good science ahead of Politically Correct Science. He is of course hated by the Greenies -- the Truth is often hard for them to swallow. But how refreshing.
I met a television meteorologist on a train a couple years ago, he thought well of Lomberg and recommended his book to me at the time. The TV meteorologist's feeling was that some scientists push the global warming affected by man theory because they think they can get grants that way.