Over the past few years, I’ve tried to keep an eye on and review new millennium proxies, posting a number of reviews on high-resolution ocean sediments and new tree ring proxies.
I’ve reported on new tree ring data archived by Jacoby, Rob Wlson, David Meko, Connie Woodhouse and others, leading to some interesting interventions here by Rob Wilson and Mike Pisaric. I’ve kept an eye on ice core data, speleothems and lake sediments as well, periodically canvassing the WDCP site for new additions. So I think I can claim to be as up to date as anyone on new 1000-year proxies, and, by extension, Climate Audit readers are relatively well informed on this topic. There are some relevant new proxies, but not as many as one would think. Also, as Wilson and Pisaric were quick to point out, many new tree ring proxies were not collected as temperature proxies. (More on this matter on another occasion.)
So I was a bit startled when Gavin Schmidt boasted of an increase of 800 or so new proxies in Mann et al 2008 calling for “applause” for the paleoclimatological community:
The number of well-dated proxies used in the latest paper is significantly greater than what was available a decade ago: 1209 back to 1800; 460 back to 1600; 59 back to 1000 AD; 36 back to 500 AD and 19 back to 1 BC (all data and code is available here). This is compared with 400 or so in MBH99, of which only 14 went back to 1000 AD. The increase in data availability is a pretty remarkable testament to the increased attention that the paleo-community has started to pay to the recent past – in part, no doubt, because of the higher profile this kind of reconstruction has achieved. The individual data-gatherers involved should be applauded by all.
Where did these 800 or so proxies come from? How could I have missed the addition of 800 new series to WDP when I was keeping track of additions at least every quarter over the past three years?
Of the total increase (about 794, depending a little on how the MBH population is determined), as shown in the pie chart below, about 83% are tree ring proxies. The next largest increase comes from the Luterbacher series, replacing the long Jones-Bradley instrumental series – not really proxy series at all. The additions to ice core, coral, speleo and sediment series are all relevant and I’ll review them separately. Today I want to look at where the additions to the tree ring population came from.
Figure 1. Pie chart of proxy count increase by lass.
The next pie chart subdivides the tree ring increase by continent, showing that over half of the total increase came form the North American tree ring network, one that we’ve kept a particularly close eye on for obvious reasons. The other interesting aspect of this graphic is that there was actually a slight (and surprising) decrease in the number of Asia tree ring sites. MBH contained 61 Vaganov series; none of these were retained. There were quite a few Briffa MXD grid sites added in Asia which left matters close to being flat, but still a slight decrease. Curiously no Schweingruber RW series – sites chosen to be temperature sensitive – were included. (These were the sites that originally gave rise to worries about divergence. I suppose the argument would be that these sites are covered by the MXD versions but not all sites are so covered (and, for many sites, multiple indices are used, so there is no rule in Mann et al 2008 limiting a site to one series. I’ll do a separate post on this some time.)
As a bit of a change of pace from the North American network, let’s look at the additions to the Australia-New Zealand network. Here the number of series increased by 48 from 18 to 66. How had I missed this explosion of Australian dendro activity in the past 10 years? Well, I hadn’t. Every single “new” series in Mann et al 2008 ends in 1993 or earlier. Some of the “new” Australian sites (ausl005 ausl010 ausl012 ausl013 ausl019) were collected by Lamarche (of bristlecone fame) back in the 1970s. I then checked at the ITRDB version control to see whether the “new” Mann et al 2008 series had perhaps been archived after 1998, which wouldn’t justify Gavin’s boast but might at least explain the addition. Nope. All the Lamarche series were in the original archive and would have been available to MBH. So series that did not qualify for MBH for some reason or other were permitted in to Mann et al 2008, grossing up the count.
While Mann et al 2008 report tree ring selection criterion (“series must cover at least the interval 1750 to 1970”) , they did not include a material change report discussing any changes in selection criteria from MBH98, the reasons for such changes and their impact. Mann etl al 2000 say of MBH98 selections:
The first year of the chronology was before AD 1626, and it contained at least 8 segments by 1680;
It appears that this criterion has been relaxed somewhat in Mann et al 2008 and this has opened the door for many series that were not included in MBH98 (and which are not directly relevant to medieval-modern comparisons).
We get similar patterns in the other networks. Europe increased from 7 to 90 series, but only 4 series are 1995 or later: a 1995 series from Rob Wilson (germ040), the only Rob Wilson series used in the analysis, a 1996 Kirchhefer series and 3 Kuniholm series from the Aegean (not obvious temperature proxies.)
South America increased from 13 to 78 sites, but all are 1995 or earlier and all but 4 1991 or earlier. Again, the addition of these sites appears to result from changed inclusion criteria.
Now for North America. MBH98 used 281 series ( 11 Jacoby sites and mexi001 directly; 3 Stahle precipitation reconstructions and 219 (232 reported to have been used) in 3 PC networks (North American – 232 (219 used), Stahle SWM – 24, Stahle TXOK – 16). Mann08 uses 694 North American series, an increase of 413 series. The majority of the additional series end before 1985, many in the 1970s, and were in existence long before MBH98 publication. Indeed, only 15% of the new North American tree ring series extend after 1995. Of the new North American series, most appear to be located below altitudinal treeline and are at best precipitation proxies.
There are many puzzling omissions: important data from Alaska and Canada archived by Jacoby and d’Arrigo, by Rob Wilson and Greg Wiles is inexplicably not used, while Mann et al 2008 added series after series that are at best precipitation proxies. In part, the failure to include the Jacoby, Wilson, Wiles etc data is because of a very stale cutoff date: Mann et al 2008 say that they used ITRDB data set as of 2003. which left these series out.
But why have a 2003 cutoff for a study published in Sept 2008 (with calculations as of Dec 2007)? It’s not that hard to keep up to date – I’ve regularly collated ITRDB additions into my tree ring data collation and I don’t have hundreds of thousands of dollars of NSF grants. Mann et al have been lavishly funded by NSF to do exactly the sort of collation that they failed to do. Why didn’t they? It’s not even a matter of heavy equipment or Starbucks availability. This is just computer work. So why not use at least a 2007 ITRDB version? Baffling.
In any event, readers (and Gavin Schmidt) should clearly understand this: only a negligible number of new proxies were collected after MBH98 (about 32, mostly U.S. tree ring). So the increase to 1209 proxies in Mann et al 2008 is not a “remarkable testament” to recent paleoclimate work – it has virtually nothing to do with it, even to the extent of ignoring most primary work that has actually been done in the past decade.
I don’t mind acknowledging primary data collectors. Indeed, I’ve generally been positive in such reviews (as opposed to reviews of the narrow Team) and, despite what my critics may think, this has not gone entirely unnoticed among primary collectors. At the 2007 AGU conference, as I mentioned previously, several eminent oceanographers complimented me on my reviews of ocean sediment literature. My point here is not to disparage primary collectors, but merely to observe that the Mann increase has virtually nothing to do with recent work by primary collectors and has a great deal to do with casting a wider net over old collections, even collections made in the 1970s.
Gavin’s boast is an empty one.
Climate Audit 
39 Comments
The Gavin quote seems like clean-out-the-fridge stew: A bunch of stuff that doesn’t really fit and tastes terrible.
Here, let me cut out the words and information that doesn’t belong and make a proper stew.
There, that’s better. Interesting, isn’t it.
Re: Sam Urbinto (#1),
Ok, let’s see if we can decipher what he’s saying from your summary. There’s greater data availability, despite the fact that almost all the data used in the new paper was available when MBH98 was published. So he must have been meaning some other data availability. Might I suggest that Steve’s persistence in calling for data availability made Mann08 use more data in answer, despite the fact they didn’t use the small amount of new data themselves. And the “higher profile” of that kind of reconstruction, while it might refer on one level to public interest and IPCC inclusion, is also a reference to the high profile concerning lack of data and code availability and of statistical value. IOW, to summarize your summary, I suggest he’s saying, “You want data? Here’s data! Now go away and let your superiors get on with saving the world.”
Re: Dave Dardinger (#2),
I should have dropped “availability” or changed it to “data {usage}”. I missed that one.
But as to the rest, it seems more like a summary of a thank you to Steve for helping to make reconstructions more well known and of better quality. With some information that seems less than factual thrown in for some reason with the seeming result of obfuscating the gratitude.
For Gavin. You’re welcome.
The prevalence of North American series among what has been added seems even stranger given the argument made elsewhere that NA is only a small part of the entire world. Why add even more data to a region that in comparison is already well covered?
Re: Soronel Haetir (#3),
More material for the Mannomatic ver 20.08.
It goes without saying that “bringing the proxies up to date” would be far more important than adding a number of proxies that are generally not “up to date.”
Because this region is teleconnected to global average temperature?
Incidently, what are the statistical ramifications of having far more samples associated with certain areas? Isn’t some type of weighted average called for?
This time they used a forest; hoping no one would notice some of the trees they put in and some they left out. It’s like a left-over Hollywood set from the Nineties. Some of the trees are real, some are fake.
Mann is over emphasizing North America for the same reason Hansen does in GISS. There are not large numbers of sample sets or proxies available from other regions. It seems to be an American fascination to quantify temperature everywhere, and it is spreading around the globe. But we and the British were doing it first, so we have a head start of everyone else, and therefore, more data to contribute. It also suggests that they heavily weight those proxies from other regions to counteract any signal that might be regional for North America. This suggests another bias. If a series that precludes the MWP or LIA is weighted 50 times that of a series that shows it, even though each is as reliable as the other, then you are not going to see the MWP or the LIA.
I’m glad they did add all this data. It makes it really easy to demonstrate the holes in the CPS technique. I have been digging through these proxies for weeks plotting individuals and groups together and really can’t pick out any trend, –except for the infilled end data.
Last weekend I did a post matching all kinds of shapes to the non-infilled data, what is interesting is that I accidentally got higher correlation to a negative linear slope than M08 did to temperature with infilled data. Also, it’s got enough uncorrelated red noise from one proxy to another that any pattern at all can be extracted.
You can actually see the de-magnification of historic trends with higher proxy correlation numbers. The same effect I saw with red noise.
I bet a large percentage of regular CA readers already know this (I’m still a newbie) but from the lack of a trend in the proxies I feel certain that when the software is reproduced, a very few series are responsible for the historic MWP and LIA in the final plots. The bigger starting data set just required a higher degree of sorting.
Jeff Id, I am amazed that the peer reviewers did not require Mann to reveal the proxy weights that were in the final reconstruction.
Re: wkkruse (#10),
Did anyone politely ask him for them?
As I understand it, the CPS and EIV weightings are not the total amplification per series. After calibration I believe additional weighting is performed based on geographic area (I haven’t verified this myself in the code). It would make the final result pretty easy to adjust just by the addition or elimination of one series in a sparsely populated proxy area.
This will be interesting to investigate using the original 1357 data series which were pared down to 1209 after the software is running.
#11
You’re right. So I need to join in and add mine.
Thanks Steve for encouraging climate scientists to produce their data and for making it more accessible. Without your efforts I would personally have been stuck reading Real Climate, Watts Up, Open Mind and other sites trying to balance the reasoning to form some kind of conclusion. Accessibility to the data and math used made the truth much clearer.
Now two of the three above sites won’t accept my posts, oh well.
JEff, that’s been a long-time theme at this site. What makes it more bizarre is that these few series (bristlecones, Yamal, Tornetrask) are repeated in supposedly “independent” studies; that replication attempts of some important series has called the Mann versions into question (the Ababneh thesis, Grudd, Polar URals update) and that obsolete versions are used without apology.
AndyL, How would I know if anyone POLITELY asked him? No one should have to. Clearly, it’s important to talk about the methodology as Mann does, but ultimately the credibility of the reconstruction comes down to what proxy’s were used, how were they calibrated, and what weights were given to them. A peer reviewer should want the answers to these questions.
wkkruse
I wasn’t asking you specifically – just responding to your point
In the past, Mann apparently hasn’t been responsive to requests for data, but he hasn’t previously posted data and code either. Now he has changed his approach, perhaps he might answer a polite request. I wonder if anyone has tried?
Re: AndyL (#16),
Probably nobody has tried. I’m not too certain it would be worth it. I mean, why waste time answering people that just want to find things wrong with the work?
What happens if you feed the mannomatic stock market data? How does it compare to the reality of it?
(Lightly) Who was the lucky girl? And I KNOW I make lots of hypos myself.
If someone decides to ask Mann politely for the weighting remember to ask for proxy area weighting also. If I am understanding correctly it isn’t just the EIV or CPS coefficient but also the area the proxy covers.
I used GISS temp data and CPS to make positive and negative hockey sticks all over the proxy time series. I’m basically done with this demo now but it really cleared up the distortions of the math for me.
In MBH98 there were no where near this many proxies to check with so this kind of analysis had to happen using matched red noise or other random patterns to get enough series. This left the AGW guys an opening to say there was some problem with the modeled red noise proxies the math was fine. The large number of proxies in M08 made the demonstration of the flaws easier.
I owe a big thanks to Mann for “accidentally” posting the 1357 non-infilled original original proxy series. It really sped things along.
How to get a journal to publish what is essentially old, much criticised data, which has already been rehashed multiple times over the past decade?
Why, just add in some previously disgarded/ignored datasets and all that was old, is new again. Voila!
“..It seems to be an American fascination to quantify temperature everywhere, and it is spreading around the globe. But we and the British were doing it first, so we have a head start of everyone else, and therefore, more data to contribute…”
More of a British fascination, I think? It was part of the experimental approach to science being pushed in the 1620s, which reached its peak with the establishment of the Royal Society in 1660. Early papers are full of rural parsons’ lists of all conceivable natural phenomena, such as migration times. No hypotheses or understanding – just data. I assume that the British (mainly English) colonists took the habit with them everywhere they went, so we might find early data in Africa and India as well?
Re: Dodgy Geezer (#22),
Well, the Japanese have been at it since the early 1700s, too.
“What happens if you feed the mannomatic stock market data? How does it compare to the reality of it?”
You get a prediction for the Super Bowl winner. Or vice versa. See http://www.snopes.com/business/bank/superbowl.asp
Re: #22
I doubt you’ll find any early data in India from British colonists. Unlike Australasia & America, there was no effort to settle India with white British people – it was simply a trade venture by the East India Company. Up until 1948 when independence occurred the pattern was for British people to psend their working career in India as (say) a policeman or administrator & then return to Blighty on retirement. (O/T but I hope interesting.)
Gavin’s statement appears to be sloppy. Really, really sloppy.
Casey Stengel (it is alleged) once got so frustrated with the Amazin’ Mets in their inaugural season in 1962 (record number of losses) that he asked, “Can’t anybody here play this game?” As I read Steve’s posts about the team, I sense he must get the same feeling that Stengel once had. Science doesn’t have to be this way. Shouldn’t be this way.
Studies ought to be straightforward. Data and code readily available. Made up, bizarre new statistics are not necessary to establish correlation. We already have a raft of legitimate statistical tools to determine that.
With all the money flooding into climate research, why can’t we get basic, competent science in return? Heck, we can’t even get the temperature taken competently!
Steve, I admire your persistence and your tolerance.
Is it possible that Mann, Gavin, et.al., write what they write for a different audience? Could it be that back in 1998 [and certainly since], members of the “Team” recognized that their main audience is the MSM and the environmental writers/reporters graduating then as now from Universities and not the scientific community. they write for people with little understanding of the science and statistics behind it all but, highly motivated toward a political agenda. The “science” jounalists have far more direct contact with the average american than CA, WCR, Junkscience, etc. will ever have. So, why should they care about you? It appears to me, that with each passing year the Team reaches new heights in arrogance because the MSM can and does ignore you all.
sorry
Re: dougw (#27),
[snip – too muh policy]
Lastly, I don’t think that the objective of this and other blogs is to be mainstream, but critical. Yet, this blog has reached Real Climate’s internet share this year, which means that we are probably reaching some kind of a “tipping point”, but not one that catastrophists would expect.
Re: dougw (#27),
Ah, but doug, we now know that climate scientists think that the popular media are “irrelevant”.
Why would such smart fellas waste their time running to the media all the time if what the media print isn’t to be taken seriously?
My background is in chemistry, and in that science, which has been around for a while, it is absolutely unthinkable that any paper could be published without total disclosure of data and methods–in short, everything one would need to reproduce the work or falsify the result, and I do mean EVERYTHING. Really, it is that which was most responsible for elevating chemistry to a real science from its benighted beginnings as alchemy. Sometimes I wonder if modern-day climate science ought instead to be called “alclimate science”. The many legitimate investigators in the field ought to INSIST, for themselves and for their cohorts, that the most rigorous standards of reportage be observed–this at a very minimum.
Bill Larson:
October 15th, 2008 at 1:13 pm
My background is in chemistry, and in that science, which has been around for a while, it is absolutely unthinkable that any paper could be published without total disclosure of data and methods–in short, everything one would need to reproduce the work or falsify the result.
What amazes me is how gullible the majority of the Realclimate readership must be, they obviously have total belief in their leader, any leader, they do not need proof, these are true believers of the team religion, how sad.
I understand why you snipped me, mr Steve, but I was only responding to the political questions that dougw posed, not exactly the policy questions… I don’t think it’s too OT to his question (but definitely on the post though) to say who is getting the most attention right now and why, without any resort to cynicism, con theories, etc.
I’m the same chemistry background as Bill and, like him, just appalled at the awful politicisation and disgraceful anti-scientific behaviour of the AGW climatologists.
Global warming isn’t something you believe in. It is something you measure as carefully and objectively as possible and then try to understand without making extravagant and unjustified claims. Consensus has nothing to do with science, everything to do with politics.
I defy any real scientist to read RealClimate for more than a few hours without feeling totally sickened at the degradation of science and scientists that it represents.
I read CA with enjoyment and appreciation because it represents the kind of careful, open and objective science I believe in and respect.
Re: Alan Wilkinson (#33),
(Steve, please don’t snip this. If I ever refer to politics of some kind is only as a observer of social phenomenon in the most objective way that I can write, as a recognition its ideological power underneath this discussion and its consequences, but with the most toning down that was possible to me)
snip- sorry, Luis. You broke a red-letter rule in one of the examples you raised. I do not edit or snip posts that break this particular rule. Usually they are automatic deletes.
Re: Steve McIntyre (#34),
Got it.
Re: Alan Wilkinson (#33),
Add me to the list of chemists with the same views.
“..I doubt you’ll find any early data in India from British colonists. Unlike Australasia & America, there was no effort to settle India with white British people..”
Of course, there was no ‘free’ land there! But the British mania for collecting natural data (and I think it was a peculiarly British eccentricity – you can trace individual records of natural occurences which are associated with festivals or religious rites back to 2000BC or earlier in Egypt and other old civilisations, but you don’t get them recording ‘weather’) is often associated with the Church. I would be very surprised if missionaries, or, indeed, administrators generally did not record weather somewhere. They didn’t have to be ‘settled’ in the country to do so – in fact, one might think they were MORE likely to record the weather of a strange land, which might hold more surprises than home. Monsoon onset is surely something you want to predict?
Of course, such ‘pointless’ activity would be unlikely to be saved for posterity, but I wonder if the Foreign Office or the CofE archives hold anything interesting which has not been weeded out and thrown…
#29, #33, #37, et al,
Similar list for engineers started…
The British were excellent collectors of data. In their former colonies they even established such Star Wars-sounding positions like Imperial (in India) or Dominial Mycologist (in Canada), whose task was to describe in an yearly report new fungi, especially those with pathogenic potential. In general, old taxonomy was the best in lands where the Brits or the Germans were doing the collection and description job (Germans were very active in South America).