As far as the climatologists go, the old guard of professors and mentors trains the new guard, and they are savage to anyone who doesn't follow in their lock step group think. Just do a google search for climatologists who have been excommunicated for disagreeing with the herd. PhDs typically enter the work force when they are ~28, not 40, so those who had just started working in the field in 1979 (the tail end of the ice age scare) would be 65 or just retiring this year and would have been leading the departments for the last 20 years.
Well, those entering the field at 28 are not "the same scientists who were running around in the 70s saying that the next ice age was upon us", in fact they are the next generation of scientists who have found different stuff. You started out saying "I can't believe these people, they keep changing their mind!", and I am just pointing out that they are not even the same people! You know, your argument about forced group think seems fundamentally flawed if your best example is one where you feel as though a consensus opinion actually changed. You can't reasonably say "they all think the same and never change due to peer pressure and other similar influences" and also at the same time say "they used to think one thing and now they think something else." Both of those statements might be reasonable criticisms individually, but they do kind of work against each other.
By the way, Wikipedia at least claims that Global Cooling was never any sort of widely held opinion of climatologists: https://en.wikipedia.org/wiki/... - so while there might have been press reports of cooling being a possible problem, "Academic analysis of the peer-reviewed studies published at that time shows that most papers examining aspects of climate during the 1970s were either neutral or showed a warming trend." So before you go blaming those fickle for flip-flopping all the time, perhaps your should re-examine what the scientists at the time were mostly saying - and it doesn't seem like they were all saying it was going to get chilly.
As for a google search for "climatologists who have been excommunicated for disagreeing with the herd", I have not been able to find any, though I don't deny that it is possible. The thing is, in my experience of academia, it is pretty darn hard to do anything about tenured researchers doing crazy shit, and there are not insignificant numbers of people in the sciences who like to take a contrarian position against almost anything. The fact of the matter is that over at least the last decade, a number of valid criticisms of climate research have been made, and work has been done to address them. The number of climatologists who have had doubts about the "consensus" has been decreasing, as one would expect if the consensus was broadly correct.
Sure, it is possible that the whole thing is a hoax perpetrated by "big solar" against the virtuous carbon crowd. But I have to ask, if the consensus opinion was in fact broadly correct, how would everyone's behaviour be different? What would convince you that there was not some nefarious data manipulation going on?