In more general usage, however, groupthink contains the element of consensus without critically testing, analyzing, and evaluating the ideas and concepts to which they are ascribing ...
I remember when the term was first formulated, and straightaway recognised that this was something that needed a word. Group-think is more active than you describe : the group
defends its philosophical position as if its life depended on it. It automatically rejects any evidence or message that runs counter to it, and will go to any lengths to justify that rejection. Even lying will serve the purpose, since the group-
truth is unassailable so the evidence must exist but is missing. In which case lying serves the truth.
It manifests at all sorts of levels. I've seen it directly in corporations and indirectly through history.
This is the sense in which deniers use it.
... and while this may be rather common among some types of science "fans," I just don't see this behavior as widespread within the upper-level academic or professional scientific communities (not that there aren't occassionally obvious exceptions to this, of course).
I rather fancied the academic life, but money spoke louder.
Well,...without pretty good ice understanding/modelling, your climate understanding/modelling is going to be much more general and imprecise, so its probably not accurate to imply that it is easier to get a comprehensive and precise climate model without having a pretty good ice dynamics understanding built into your climate model.
I disagree. Ice-cover, even in the Arctic, is a pretty minor influence given how little ice-cover we have at this point in the glacial cycle.
... perhaps, especially in the more casual discourse of impacts, mitigation and the whole range of socio-economic issues and I look forward to that becoming the main thrust of discussion with regards to AGW ...
Social sensitivity is a meta-level above Earth sytem sensitivity. That's where lots of detail comes into play. Not so much that it's imponderable, though. Good history (history that's as close to Science as it can be) can help and as the the great Mark Twain said, "History doesn't repeat itself, but it rhymes".
It's not going to be pretty.
The big common point of "alarmism" definitions is the idea of "needless" or "without merit/substantiation."
The way it's commonly used these days is as a prelude to "not what I want to hear", followed by some specious reasoning and/or apocalyptic consequences if any attention is paid.
People that are genuinely concerned about issues with a high likelihood of coming to pass, and a demonstrated history of having occurred under similar conditions in the past, aren't alarmists, merely concerned individuals.
Agreed. We didn't get where we are as a species by never being alarmed. The occasional false-alarm has done little harm in comparison to none at all.
At the moment, major alarms are the continuing fall-out from a major financial bubble collapse, unrest in North Africa and the Middle East, and a potential economic melt-down in Japan. None of which the community of nations is showing any skill at dealing with.
We're screwed.