The IPCC cannot be expected to be taken seriously if apparently criminal dishonesties of this magnitude are persisted in and widely cited both by senior IPCC officials and by third parties allied to or supportive of the IPCC even long after the dishonesties have been drawn to its attention.
If he wasn't Thatchers CC policy advisor and he isn't a scientist and he doesn't know the difference between forcing and sensitivity, why was he testifying to Congress?
I suppose he is successful because he's a showman and does his show very well and professionally. He entertains (presumably mostly unscientific audiences) with humourous and wittily presented junk science.