You can read about his sadness at great length in Scientist’s rebuttal of Michael Mann’s “denier”and other unsavory labels in his book (note how CL, like “Dr” Roy Spencer, wears his PhD on his sleeve). CL is sad because Mann has been cwuel to him, or about him, in his book. Though this seems to have been more exciting for CL than Mann, since he doesn’t make it in until p 187, and its just about CL’s rubbish temperature reconstruction (see-also Tamino on the “vindication” version).
But the centerpiece of CL’s recent post, which conclusively demonstrates how Mann is wrong and… well, you get the idea, is the one I’ve inlined here. Its from co2science.org/data/mwp/mwpp.php which isn’t a good source. I wondered what the data sources were for the figure, and what “Current Warm Period” (CWP) might be, exactly. No-one seemed to be able to find an answer; a person calling themselves Richard S Courtney was pretty sure it meant 1998 (actually very un-pretty, but never mind), but that makes no sense – the ice cores don’t go up to 1998, in general (I’m assuming there are some ice cores in there, though with no info as to the sources, its hard to say). Its likely that CWP means something like 20th-century average, but as far as I can tell it isn’t possible to be sure; I think they are being deliberately vague. They claim to have 5 proxies showing the MWP was more than 3 oC warmer than the “CWP”, but that doesn’t seem very likely, and since they don’t say what those studies are, I’m not taking it on faith.
In the usual way at WUWT, no-one was interested in querying the basis for a figure, as long as it supported what they wanted to see.
Update: in the comments, PS has found some of the studies with high MWP’s.]