Gavin Schmidt, Michael Mann, and Scott Rutherford have written a comment letter to the Annals of Applied Statistics to the Hockey Stick busting McShane and Wyner paper covered on WUWT in August.
It’s quite something. Here’s the M&W graph:
It only took reading the first paragraph of the Team paper for me to get cheesed off. Emphasis mine:
McShane and Wyner (2010) (henceforth “MW”) analyze a dataset of “proxy”climate records previously used by Mann et al (2008) (henceforth “M08”) to attempt to assess their utility in reconstructing past temperatures. MW introduce new methods in their analysis, which is welcome. However, the absence of both proper data quality control and appropriate “pseudoproxy” tests to assess the performance of their methods invalidate their main conclusions.
Why am I cheesed off?
The sheer arrogance of claiming improper “data quality control” when Mann himself has issues with his own papers such as incorrect lat/lon values of proxy samples, upside down Tiljander sediment proxies, and truncated/switched data, is mind boggling. It’s doubly mind boggling when these errors are well known to thousands of people, and Mann has done nothing to correct them but then speaks of data quality control issues in rebuttal. And yet Schmidt defends these sort of things on RC. It’s like the Team never read the McShane Wyner paper, because they clearly said this about data issues:
We are not interested at this stage in engaging the issues of data quality. To wit, henceforth and for the remainder of the paper, we work entirely with the data from Mann et al. (2008)
So MW used Mann’s own data, made it clear that their paper was about methodology with data, and not the data itself, and now the Team is complaining about data quality control?
The Team egos involved must be so large that the highway department has to put out orange road cones ahead of these guys when they travel. And they wonder why people make cartoons about them:
They go on to whine about the MWP being “inflated”.
MW’s inclusion of the additional poor quality proxies has a material affect on the reconstructions, inflating the level of peak apparent Medieval warmth, particularly in their featured “OLS PC10”
Well, here’s the thing gents; you don’t KNOW what the temperature was during the MWP. There are no absolute measurements of it, only reconstructions from proxy, and the Team opinion on what the temperature may have been is based on assumptions, not actual measurement. You can’t set yourself up as an authority on knowing whether it was inflated or not without knowing what the temperature actually was. They also rail about “poor quality proxies” (their own) used in MW. Like these?
Half the Hockey Stick graphs depend on bristlecone pine temperature proxies, whose worthlessness has already been exposed. They were kept because the other HS graphs, which depend on Briffa’s Yamal larch treering series, could not be disproved. We now find that Briffa calibrated centuries of temperature records on the strength of 12 trees and one rogue outlier in particular. Such a small sample is scandalous; the non-release of this information for 9 years is scandalous; the use of this undisclosed data as crucial evidence for several more official HS graphs is scandalous. And not properly comparing treering evidence with local thermometers is the mother of all scandals.
Read the entire Team response here, comments welcome.
http://pubs.giss.nasa.gov/docs/notyet/inpress_Schmidt_etal_2.pdf
Backup location in case it falls down a rabbit hole: inpress_Schmidt_etal_2
For balance, the McShane and Wyner paper is available here: http://wattsupwiththat.files.wordpress.com/2010/08/mcshane-and-wyner-2010.pdf ======================
h/t to poptech
======================
UPDATE: Here are some other views:
Jeff Id, The Air Vent:
http://noconsensus.wordpress.com/2010/09/23/ostriches/
Luboš Motl, The Reference Frame:
http://motls.blogspot.com/2010/09/schmidt-mann-rutherford-just-clueless.html
Some comments about the circular reasoning and their avoiding of the key points:
http://motls.blogspot.com/2010/09/schmidt-mann-rutherford-just-clueless.html
Rule of holes.
#2 If you detect a higher temperature, you are in too deep.
Instead of a hockey stick graph, Mann should have made a shovel graph.
And you should know the answer to that comment!!! HAHAHA!!
That “bad data” defense is putting the The Team deep, deep, deep into laughingstock territory. The Team would have been better off to have just come out and accused M&W of being drunk. At least that way, they wouldn’t have drawn attention to their own data.
To paraphrase, “It’s the method, stupid!”
fredfriendly says:
“It is really like the Star Wars part where Obi One says “nothing to see here, move along…”
I think you mean “These are not the data you’re looking for..”
What can one say except that the Team are a splendid example of Pathological Science …
Pointman
RC has beclowned itself too many times to be taken seriously, but Tingley’s critique of Lasso regression is accurate. Indeed, his work and that of Bo Li (a colaborator of Ammann) demonstrate that the climate community does have access to competent statisticians. Its interesting to note, however, that neither (at least to my knowledge) neither Tingley nor Li have ever published an attempt at reproducing a Mannly hockey stick. (Though Li did show that even in theory borehole data is useless. Regardless, my guess is that attempts have been made and the results (when proper error bars are computed) are completely ambiguous.
So M&W took all of Mann’s data and applied the correct statistical tools and all Mann can do is bitch about the data!
When I read the M&W paper it was clear that there was no validation of the data as the exercise was to show the errors in the way that Mann had done his manipulation of the data. Let’s see what new bit of sophistry Mann uses to wriggle out of this little peccadillo.
The claim is repeatedly made here that McShane and Wyner used the same Data as Mann 2008 and so criticisms based on data quality are invalid. Try reading the comment, people …
In the frozen 1000 AD network of 95 proxy records used by MW, 36 tree-ring records were not used by M08 due to their failure to meet objective standards of reliability. These records did not meet the minimal replication requirement of at least 8 independent contributing tree cores. That requirement yields a smaller dataset of 59 proxy records back to AD 1000 as clearly indicated in M08. MW’s inclusion of the additional poor quality proxies has a material affect on the reconstructions, inflating the level of peak apparent Medieval warmth,
So that claim is false, Mann08 includes a plot without Bristlecones, which supports the conclusions of the paper, so that one is false too. Remove these and the ad-hominems about ego etc, and what remains?
Old school tactics.
Best defense is a good offense.
You can see the comments further down the road…
“We’ve ALWAYS been extremely concerned about data quality, and have pointed to this issue many times.”
JimB
Rules of Political holes:
#1 Dig Faster!
#2 Dig Deeper!
#3 Dig Wider!
#4 Blame the Previous Administration!
#5 Blame the Media!
#6 Blame the one wearing the trousers! Or the skirt! Or . .
#7 Keep Digging!
Phil Clarke says:
I suggest you go back and read MW again. You have misunderstood or deliberately misrepresented what was written.
Someone explain to me and maybe others how anyone would know if a tree ring indicated warmth or merely wetness for a given year. Seems trees in warm dry years don’t grow much but neither do cold wet years. Is this just a bunch of malarkey?
We speak of global average temperatures but these trees came from a micro climate, right? What gives there? We can’t seem to accurately know the global temperature with thousands of actual thermometers but we can if calibrated to 13 trees with rings? Spooky!
Sorry for the ignorance, I have skipped over all of this “tree ringing” until now but it seems that dead things are now rising from their graves and it’s finally getting interesting.
stephen richards says:
September 23, 2010 at 3:12 am
Phil Clarke says:
I suggest you go back and read MW again. You have misunderstood or deliberately misrepresented what was written.
I’m curious to know what other ways there are to interpret it myself. I seek enlightenment
I actually read the paper.
The message I got is that the new method gets similar results as the old method provided the the new method is applied to exactly the same data set as the old method. Gavin is of the view that MW included in their analysis some suspect data that they should not have.
And maybe the new method could have been tested better for validity. But otherwise the new method looks OK.
Sorry guys, I tend to ignore bluster, ridicule and sarcasm.
As some one more sagacious than I once said “It is better to stay silent and let people think you are a fool than to open your mouth and prove it” These people have no shame. These people are more than digging a hole, they are digging the demise of their futures. The penny has dropped for most of the populace and the scam is outed. They are behaving like rats on a sinking ship, clinging to life lines no matter how slender.
Such is always the fate of those whom profit in fame and fortune with a lie.
As Anthony said in his post, in their paper, MW made it abundantly clear that they used the M08 dataset as given, and in its entirety:
We are not interested at this stage in engaging the issues of data quality. To wit, henceforth and for the remainder of the paper, we work entirely with the data from Mannet al. (2008)3.
This is by far the most comprehensive publicly available database of
temperatures and proxies collected to date. It contains 1,209 climate proxies
(with some going back as far as 8855 BC and some continuing up till
2003 AD). It also contains a database of eight global annual temperature
aggregates dating 1850-2006 AD (expressed as deviations or ”anomalies”
from the 1961-1990 AD average4). Finally, there is a database of 1,732 local
annual temperatures dating 1850-2006 AD (also expressed as anomalies
from the 1961-1990 AD average)5. All three of these datasets have been substantially
processed including smoothing and imputation of missing data
(Mann et al., 2008). While these present interesting problems, they are not
the focus of our inquiry. We assume that the data selection, collection, and
processing performed by climate scientists meets the standards of their discipline.
Without taking a position on these data quality issues, we thus take
the dataset as given.
In their response to the MW paper, Schmidt et al have used their old trick of creating a straw man, which they then proceed to attack.
I don’t understand what there is to get cheesed off about as the words:
“However, the absence of both proper data quality control and appropriate “pseudoproxy” tests to assess the performance of their methods invalidate their main conclusions”
Simply mean that Mann et al have finally admitted that their work is invalid. There is no escape from that now. The post should be re-titled (and re-written) to reflect the this admission by the Team that the conclusions of their work (i.e. AGW, CC, CD) are not valid. This is a major breakthrough as the Team have declared themselves to be sceptics at last.
Well done to all at WUWT.
LazyTeenager says:
This is very interesting, in view of this, from the M&W paper
This statement appears to be contradicted by Schmidt, who says
Can someone please clarify this apparent contradiction. M&W state that they used the same dataset as M08, but Gavin says M08 omitted 36 records because they weren’t good enough. Who is correct here?
What did I do wrong with the blockquotes? Moderator please feel free to fix the quotes above.
[Reply: Fixed. Just use “blockquote” without the “cite”. ~dbs, mod.]
On the plus side, the SMR paper claims to have archived the code and data used. It was probably required because it is a statistical journal, but it certainly is welcome and will give Steve McIntyre something to analyze.
Also, if you look down at Figure 1 on page 12, you see the figures after the corrections SMR suggests. Guess what? Recent (proxy) temps still do not look exceptionally warm compared to the WMP error bars. Is it my imagination, or is that graph a lot less alarming than the one published in 1998?
I imagine MW will have a response to this paper. Perhaps they will admit making an error or two. Or perhaps it will be a public dunking for SMR. Stay tuned.
I’m not sure this is a complete check mate, it is more like the end of the game where you have your queen left and you can’t quite seem to pin down their king (the last remaining piece) because they keep jumping back and forth between the same two spots to drag out the game. They know they have lost, but they just can’t quite, so to help them I believe McShane and Wyner should respond calling it as it is, as such:
Schmidt, Mann, and Rutherford
Your response seems to miss the point of our paper. That by taking your data, bad quality and all, one can conclude that the greater error lies not in the quality as much as in the adjustments of that data based on assumptions that are not agreed upon by other men of knowledge; namely, in case of further misunderstanding, the temperatures of the Medieval Period. Of this we would be glad to debate, but if you insist on furthering the scandal of the bad quality of data, we would also be glad to work to find a better set and continue to point out the flaws in the adjustments, that we assume will remain the same.
I figure this won’t end the game, but a little salt on a wound won’t hurt.
This reminds me of an old story. A dairy farmer had a reputation for short weighting the butter he sold. One day, the baker found a way to deal with this. When the dairy farmer came in to order his bread, he used the farmer’s butter for weights to measure with. Shortly after the bread was delivered, the farmer came in, loudly protesting about how he had been cheated, in front of a store full of customers. The baker then quietly pointed out that his weights had been loaned to another and he’d used the farmer’s butter instead. As the story spread, the farmer had to leave town.
Ambiguity grumble:
—-
They also rail about “poor quality proxies” (their own) used in MW. Like these?
—-
At first I thought this was from Schmidt et al, but I couldn’t find it in their paper. Then couldn’t find it in MW, then followed the link “these” to http://wattsupwiththat.com/2009/10/30/yamal-treering-proxy-temperature-reconstructions-dont-match-local-thermometer-records/ which is a Lucy Skywalker guest post. The quote is from the opening.
Schmidt et al probably didn’t read read that post, it could’ve save them a lot of effort.
Are you sure this isn’t a Fawlty Towers episode?