Willie have another look at that letter, the eminent signatories are not claiming that climate change is not occurring they are more concerned with NASA's stance on the catastrophic effect of climate change. My take on it is that they consider the science of the extreme cc hypothesis is not settled and that their primary concern is for the reputation of NASA. Some of those signatories established NASA's reputation so to just dismiss them as equivalent to kitchen hands suggests that a hysterical narrative is at play. Yet if you are a paleontologist who is able to secure a government paid position and spruik the hysterical cc narrative then you are considered to be an expert on cc! If you are a failed US presidential candidate looking for relevance post politics then you are considered an expert on cc and if you are an actor who has no scientific background then you are considered an expert on cc. Its not surprising that a significant number of people view with sceptisicm the claims of those who say that cc is out of control and it is only by changing the Western way of life that it will be fixed.