JamulBlog has posted Harold Lewis' resignation letter sent to the American Physical Society. Lewis resigned after 67 years because he felt their position on global warming is not scientific enough for a scholarly society such as the APS. It is well worth a read.
Lewis believes, as I do, that it is possible to be simultaneously scientific and skeptical of the mainstream catastrophic anthropogenic global warming position. There aren't a lot of people holding both of those beliefs, but there are some of us.