First that you have misjudged the chronology on how the IPCC formed, second, echoed by many, that it was too broad brushed (von Storch and Kloor), it doesn't take into account how the IPCC bureaucracy has turned over several times over the years (
Eli Rabbet), you've never provided proof as to how the IPCC's control extends out into the academic realm, and it completely overlooks all the other possibilities, ie, the strength of the science is robust and the risk dire enough to receive to the amount of funding, attention, etc. and any other option at the time would have been outrageous, especially considering that what has been predicted is currently happening.