The battle of the graphs provides a learning opportunity says “American Elephants”, and indeed it does, though possibly not in the way they’re thinking.
I haven’t been able to clearly identify the source of this image (which is the reason for this post: I’ll show you how far back I’ve managed to go, and your job is to go further, or find a reason why my answer is right). The top pane is clear enough; its a borked-up version of MBH from IPCC 2001 or similar. The lower pane is similar to the famous fig 7.1.c from the FAR in 1990. Wiki’s [[Description of the Medieval Warm Period and Little Ice Age in IPCC reports]] has a nice set of pix.
The Manchurian Candidate
My candidate for the source of this nonsense is Monkers, in the Torygraph, with a copy of Photoshop. That’s from 2006, and I can’t find anything earlier. That article includes the pic I’ve inlined above, and the text “The UN’s second assessment report, in 1996, showed a 1,000-year graph demonstrating that temperature in the Middle Ages was warmer than today.” There is no such graph; the 19951 IPCC report used a northern hemisphere summer temperature reconstruction (fig 3.20) from 1400 to 1979 by (Bradley and Jones 1993) (text ripped shamelessly from wiki, but anyway I wrote it).
That’s the source of the combined image. The borked-up thing resembling IPCC ’90 but which Monkers erroneously sourced to IPCC ’95 has a long history that I ought to remember; I’m hoping someone will remind me.
[Update: K points to http://www.visionlearning.com/en/library/Process-of-Science/49/Using-Graphs-and-Visual-Data-in-Science/156 which says that the Torygraph article is indeed the source of the pic, in that graphical form. I may have been wrong about the "long history" of *that* image; its the multiple versions of the real 7.1.c that have the history.]
[Ha ha. another update: the text on that page has mysteriously changed, removing the graph. Isn't that just a bizarre co-incidence? And yes we all believe in fairies. Here's a cite of a wayback if you want to see the original -W]
BTW, if you’re wondering why the “skeptics” want the pic from IPCC ’90 to be part of IPCC’95, the answer is that they want the IPCC to have “suddenly” thrown out the One True MWP as revealed in Holy Writ by Lamb, and replaced it by MBH. Adding in an extra 5 or 6 years rather spoils that picture.
Enter the Void
Enter BIG NEWS VIII: New solar theory predicts imminent global cooling (yes, they really are up to 8 posts now) which presents – somewhat gratuitously – a fig 5 which I’ll include below:
captioned “Figure 5: From the Second Assessment Report of the IPCC, 1996, via here” where “here” is a link to http://junksciencearchive.com/Hide_the_decline.html. You won’t be surprised to find that is, indeed, junk (arf arf) and includes the same pic, introduced by “the IPCC maintained the warming in its Second Assessment Report as follows”. So JoNova (actually its DE) has (to their credit) actually sourced the image, but the source they’ve chosen to rely on is, ermm, junk. And doesn’t source its image. But it looks very much like the bottom half of the Torygraph image cut out. In which case its obviously not from any IPCC report, and has got the provenance of the pic wrong.
Your mother was a hamster
So, it looks like DE has been rather careless with his sourcing. Which is a bit embarrassing for him, as he is trying to be all science-y; look, he’s even got falsifiability criteria, it must be science. And so on. The question then becomes, what is he going to do about it? My best guess is stonewall: pretend that nothing is wrong, and rely on the denizens to just lap it up. That would be petty of him; simply fixing it up would be better and much easier.
[Update: they’ve done the right thing for the pic and updated the graph to the right one, for which I give them some credit. However, the problem now is that they’ve got an updated figure, for which the text makes no sense (see my comment). So, only partial credit.
1. The IPCC Second Assessment Report (SAR) is variously known as IPCC ’95 or ’96. Take your pic.