
Unintentional hilarity...
The unintentionally hilarious aspect of the warmist letter comparing attacks on Climate Scientists with McCarthyism, is that McCarthy was later proved absolutely correct, at least in so far as his belief that there was a great deal of unacknowledged co-operation between the US civil service and the Soviet government, and that there was a strong pro-Soviet influence in US media and politics.
Where his analysis failed was in imputing malevolent motivations to those involved, and branding them as "un-American" when, for the most part, the diplomats and journalists sincerely believed that they were acting in the best interests of America and Americans, and -- most importantly -- in keeping with the fundamental spirit of America. Acheson and Hiss didn't see themselves as betraying the US, but living up to it's highest ideals.