Mann says "McIntyre"

Mar 4, 2013
Bishop Hill in Climate: Mann, Climate: McIntyre, Climate: Surface

Readers are no doubt aware that Steve McIntyre is back in the blogging saddle, taking a look at Mann's AGU talk from before Christmas and noting that its rhetorical effect relied upon some amusing presentational choices:

There were two components to Mann’s AGU trick. First...Mann compared model projections for land-and-ocean to observations for land-only. In addition...Mann failed to incorporate up-to-date data for his comparison. The staleness of Mann’s temperature data in his AGU presentation was really quite remarkable: the temperature data in Mann’s presentation (December 2012) ended in 2005! Obviously, in the past (notably MBH98 and MBH99), Mann used the most recent (even monthly data) when it was to his advantage. So the failure to use up-to-date data in his AGU presentation is really quite conspicuous.

Interestingly, Mann has now responded in person (rather than via say RealClimate). Intriguingly, he had decided to mention McIntyre by name, a rare and perhaps significant event I would say. One has to say, it did appear rather silly to refuse to do this.

Mann's response features a lot of huffing and puffing and conjuring up of unidentified "falsehoods", but through all the verbiage he seems to admit the point about the data stopping at 2005:

I will be updating my lecture slides, many of which are indeed somewhat out of date.

...although he is silent on the use of a land-only dataset to compare to land-ocean predictions.

Article originally appeared on (http://www.bishop-hill.net/).