Julien Emile-Geay (JEG) submitted a lengthy comment concluding with the tasteless observation that “Steve’s mental health issues are beyond PAGES’s scope. Perhaps the CA tip jar pay for some therapy?” – the sort of insult that is far too characteristic of activist climate science. JEG seems to have been in such a hurry to make this insult that he didn’t bother getting his facts right.
Inventory
In the article, I had inventoried Arctic lake sediment series introduced in four major multiproxy studies: Mann et al 2008, Kaufman et al 2009, PAGES 2013 and PAGES 2017, observing that a total of 32 different series had been introduced, showing the split in the first line of the table shown in the article (replicated below). In each case, the series had been declared “temperature sensitive” but 16 had been declared in a subsequent study to be not temperature sensitive after all. In the table, I listed withdrawals by row, showing (inter alia) that three had been withdrawn in P14 (McKay and Kaufman 2014), four in PAGES 2017 (which also reinstated two proxies used in earlier studies) and three in Werner et al 2017 (CP17). In my comments on Werner et al 2017, I distinguished the three series that were discarded from series not used in that study because they were not annual (of which there were nine.)
Here’s JEG’s comment on this table:
Responding to the post, not the innumerable comments (many of which are OT).
It is incorrect to claim that PAGES2k discarded 50% of the lake sediment records.
PAGES 2013, v1.0 had 23 arctic lake records
PAGES 2013, v1.1., rejected 3 (see https://www.nature.com/ngeo/journal/v8/n12/full/ngeo2566.html)
PAGES 2017, v2.0, we rejected another 4 and added 3, for reasons explained in Table S2.
Werner et al CPD 2017 is a climate field reconstruction based on a slightly earlier version of this dataset.
They excluded non-annually resolved records for reasons made clear in the manuscript – there is nothing “strange” about that – unless you want to misconstrue it. The entire point of a compilation like PAGES is that it is relatively permissive, so users who are more stringent can raise the bar and use only a subset of records for their own purposes.
So, out of the original 23, 7 (30.43%) were rejected because of more stringent inclusion criteria, with 3 additions. Anyone is welcome to see what impact this made to an Arctic composite or reconstruction using a method that meets CA standard.
None of his comments rebuts or contradicts anything in my post. JEG says that 3 proxies were discarded in v1.1 – precisely as shown in the third row of the table and discussed in the article. JEG says that 4 proxies were discarded in PAGES 2017 – precisely as shown in the sixth row of the table.
Of Werner et al 2017, he says that they “excluded non-annually resolved records for reasons made clear in the manuscript – there is nothing “strange” about that – unless you want to misconstrue it.” I didn’t “misconstrue it. While I noted that “in their reconstruction, they elected not to use 9 series on the grounds that they lacked annual resolution”, I excluded those nine from the above table. In addition to these nine, Werner et al 2017 discarded three annual series (Hvitarvatn, Blue Lake, Lehmilampi) as defective. JEG says that Werner et al used a “slightly earlier” version of the PAGES 2017 dataset. Be that as it may, Werner et al 2017 did in fact discard these three series as shown in the table for the grounds stated in my post (a “very nonlinear response, short overlap with instrumental, unclear interpretation”, the “exact interpretation unclear from original article” and “annual and centennial signal inconsistent”).
As a housekeeping point, I counted 22 Arctic sediment series in PAGES 2013 (not 23 as stated by JEG). I also counted a total of four additions to PAGES 2017 (two new and two re-instatements as shown in the table above), rather than the “three” additions claimed by JEG.
Most fundamentally, the denominator of my comparison was the inventory of series introduced in the four listed papers, not the inventory in PAGES 2013, which already represented a partial cull of Kaufman et al 2009 and Mann et al 2008. I do not understand why JEG misrepresented this simple point.
Finally, JEG says that the discarding was due to “more stringent inclusion criteria”. Three things. 1) The inclusion criteria in later studies are not necessarily “more stringent” – PAGES 2013 included some short series excluded fromKaufman et al 2009 (which required 1000 years) and PAGES 2017 some even shorter series. Inclusion of short series that do not go back to the medieval period or even AD1500 is less stringent, not more stringent. 2) The stated reasons for exclusion of series in later studies are typically ones that indicate non-compliance with criteria set out in the earlier study, i.e. if a later study correctly determines that the interpretation of the record is “unclear”, its use in the earlier study was an error in the earlier study according to its criteria, not the result of “more stringent” criteria. 3) To keep things in clear perspective, greater stringency is not an antidote to problems arising from ex post screening (see also selection on the dependent variable) and is therefore irrelevant to the main issue. Jeff Id did some good posts on this. Contrary to JEG, I do not advocate “greater stringency” in ex post screening as proper technique. On the contrary, I object to ex post screening (selection on the dependent variable).
Corrigendum
In my article, I said that “McKay and Kaufman (2014) conceded the [Hvitarvatn] error and issued an amended version of their Arctic reconstruction, but, like Mann, refused to issue a corrigendum to the original article.”
Finally, it is entirely incorrect to claim that PAGES 2k did not issue a corrigendum to identify the errors in v1.0 that were corrected in v1.1. They did so here (https://www.nature.com/ngeo/journal/v8/n12/full/ngeo2566.html), where Steve McIntyre was acknowledged about as clearly as could have been done: “The authors thank D. Divine, S. McIntyre and K. Seftigen, who helped improve the Arctic temperature reconstruction by finding errors in the data set.”
I published my criticism of upside-down Hvitarvatn in April 2013, a few weeks after publication of PAGES 2013. (Varves, particularly Hvitarvatn, had been a prior interest at CA). McKay and Kaufman 2014, published 18 months later (Oct 2014), acknowledged this and other errors, but failed to acknowledge Climate Audit on this and other points. On October 7, 2014, I wrote Nature pointing out that McKay and Kaufman 2014 primarily addressed errors in PAGES 2013 (as opposed to being “original”) and suggested to them that such a “backdoor corrigendum” was no substitute for an on-the-record corrigendum attached to the original article. (In making this point, I was thinking about Mann’s sly walking-back of untrue statements in Mann et al 2008 deep in the SI to a different paper, while not issuing a corrigendum in the original paper.) Nature said that they would look into it. I also objected to the appropriation of criticisms made at Climate Audit without acknowledgement. I heard nothing further from them.
In November 2015, over a year later, PAGES 2013 belatedly issued a corrigendum as I had requested in October 2014, including a brief acknowledgement. I was unaware of this until JEG brought it to my attention in his comment. Nature had not informed me that they had agreed with my suggestion and none of the authors had had the courtesy to mention the acknowledgement. Needless to say, I’ve not waited 18 months to issue a correction and have done so right away.
Strange Accusations
JEG concluded his comment with a strange peroration accusing me of “continuing to whine about the lack of acknowledgement”, which he called a “delirium of persecution” and a “mental health issue”, suggesting “therapy”:
Continuing to whine about the lack of acknowledgement is beginning to sound like a delirium of persecution. We can certainly fix issues in the database, but Steve’s mental health issues are beyond PAGES’s scope. Perhaps the CA tip jar pay for some therapy?
Where did this come from?
I’ve objected from time to time about incidents in which climate scientists have appropriated commentary from Climate Audit without proper acknowledgement – in each case with cause. I made no such complaint in the article criticized by JEG. Nowhere in the post is there any complaint about “lack of acknowledgement”, let alone anything that constitutes “continuing to whine about the lack of acknowledgement”.
The post factually and drily comments on the inventory of Arctic lake sediment proxies, correctly observing the very high “casualty rate” for supposed proxies:
This is a very high casualty rate given original assurances on the supposed carefulness of the original study. The casualty rate tended to be particularly high for series which had a high medieval or early portion (e.g. Haukadalsvatn, Blue Lake).
One should be able to make such comments without publicly-funded academics accusing one of having “mental health issues”, a “delirium of persecution” or requiring “therapy”.
PS. Following the finals of the US National Squash Doubles (Over 65s) in March, I severely exacerbated a chronic leg injury and am receiving therapy for it. Yes, some aches and pains come with growing older, just not the ones fabricated by JEG.