David Appell has taken umbrage at my comment that I haven’t seen anything as extreme as the original Mann Hockey stick in the literature, saying that Mann’s work has been replicated ‘by many different groups’. I’m wondering whether that is true in the same way that Mann “was exonerated by all investigations”. Let’s look.
Here is the original Michael E. Mann Hockey stick:
A few things to note, because they get very important later on. First of all, the scale – notice that the tip of the hockey stick blade reaches a maximum of about 0.75-0.8C on the temperature anomaly scale. Note also the absence of the medieval warm period, little ice age, etc.
I’m going to repeat myself here, since I don’t want any semantic wrangling: I have seen a suspicious uptick in the twentieth century but nothing quite on the scale of what Mann shows.
Here is the hockey stick from the PAGES2K consortium cited by Appel:
Here are various prior reconstructions that show that even Mann isn’t peddling his stupid stick anymore, not when other people cna check his work:
A couple of things to note. First of all, look at the scale – the maximum value for the temperature anomaly is higher than that listed in the original graph. Second, notice that the current anomaly is listed as being pretty much that of a 1000 years ago. Third, notice the “Mann EIV” bit; even Mann isn’t defending his original hockey stick anymore (more on that later).
Here we have the hockey sticks from Marcott et al, also cited by Appel:
Some look like Mann’s, in terms of the blade, but other don’t. And again, there is the large warming 1000 years ago that Mann’s original graph doesn’t have.
Only one of these even gets close to Mann’s graph and it is the one that does the highly annoying thing of adding on instrumental records directly onto proxy ones (drop it – given that this is such a controversial method, there should be stone cold proof independent of this one). Notice again the restricted range.
Here’s another one, from Esper et al:
Speaks for itself, I think. And the paper specifically stressed the presence of the Medieval Warm Period (Argument from Appel: the MWP was a local phenomena of the Northern Hemisphere. My response: Half the planet isn’t ‘local’ no matter how you define it. Also, Mann’s graph only works in the Northern Hemisphere, as has been previously admitted).
Here’s another one from Jones et al, in collaboration with Briffa:
Just to really put this one into context, the black line is the instrumental record, and without that you don’t get a peak different from that of the PAGES2K consortium cited at the top.
Three more from Tan et al, published in Geophysical Research Letters:
The title of that paper, by the by, is a beaut: Cyclic rapid warming on centennial-scale revealed by a 2650-year stalagmite record of warm season temperature.
…And so on. All taken directly from top notch journals. Believe you me, I can keep on doing this, and, indeed, already have. Just to quote the National Academy of Sciences, again, in their investigation of Mann:
“The IPCC used it as a visual prominently in the report […] I think that sent a very misleading message about how resolved this part of the scientific research was. “
Did they ever. Take another look over the graphs above. Then look at Mann’s published one. Then take a look at this:
That is the graph Mann was peddling in the IPCC to make his case.
So, in response to Appel’s comments, this anonymous author can read the literature for himself, and stands by his comments that nothing there is as dramatic as that presented by Mann.
UPDATE AND CORRECTION:
Many thanks to David Appell for pointing out that I was wrong in my original attribution up there. That is a horrible oversight of mine, and I am happy to correct here. Here is the full PAGES2K, consisting of a composition of measurements from all seven continents:
The real one is at the bottom. Note the measurements added to the end. And just for the record, here are the individual reconstructions:
Your mileage may vary of course, but from what I’m seeing, about three or four of those don’t look like any sort hockey stick, let alone Mann’s.
Many thanks to David Appell for pointing this out.