h/t to JM for More on the Iconography of IPCC 1990 Figure 7 – scroll down for the breathless prose.
First the background: why does anyone care about figure 7.1.c of the IPCC ’90 report? Well, if you’re a denialist you care, because it represents the true uncorrupted state of climate science before the evil taint of the hockey stick crept in. I suppose if anyone doesn’t believe that and challenges me I’ll have to go crawling in the slime for references, so please don’t make me do it. So, the septic storyline is “true uncorrupted state” -> “corrupt hockey stick”. That works OK with a naive audience; it doesn’t work very well if you put the correct dates in because if you write “true uncorrupted state (1990)” -> “corrupt hockey stick (2001)” even naive people will start to say “hold on there’s a bit of a gap in the middle there, no?” And indeed there is; the gap is filled, in IPCC world, by the 1992 supplementary report and the 1995 second report. Neither of which feature fig 7.1.c or anything like it. So (just to spell this out to make it really obvious) figure 7.1.c had already disappeared from the IPCC narrative well before the hockey stick ever came into being; the hockey stick did not displace it because it was already gone; the hockey stick was not created to displace it because it was already gone. So the entire denialist narrative falls apart, again. Read more about it at the snappily titled Description of the Medieval Warm Period and Little Ice Age in IPCC reports.
Anyway, errm, where was I? Oh yes, The Significance of the Hockey Stick at CA. This post has now been corrected, ungraciously, after I pointed out it was wrong. But now it has been corrected, it makes no sense, because of the unseen presence of the ’92 and ’95 reports, which CA is obliged to ignore. And then we go back to the weird stuff in the last CA post, which seems to be McI scrabbling for credit. He has a very thin publication record but I didn’t think he was that desperate.