Monday
Dec072015
by 
Bishop Hill
Bishop Hill The same old story
Dec 7, 2015 Climate: MWP ;)
Update on Dec 8, 2015 by
Bishop Hill
Bishop Hill
In the comments ATTP says that the Christiansen reconstruction is a 2000 year one. I therefore provide this updated figure to give the comparison he wants.
;)
Reader Comments (92)
Phil Clarke again
It's interesting to note the difference in what Mann says about Mann 08 and what Ljungqvist says about it. I think the difference is probably just the effect of tacking the instrumental record onto the end.
In my view there is little value in this - if you can't see the unprecedentedness in the proxies then it's flawed.
If we are all agreed that the best evidence is that there is nothing in the proxy record to suggest current temperatures are unprecedented then this thread may have run its course.
I am quite happy to defend my own statements, not sure I am willing to do the same with things I never asserted nor agreed with. I've not read the MR responses, seems to be blocked from my current location.
Are you going to publish my earlier post? If not, I have far more enjoyable ways to spend my time ...
1. The 'bad stats' did not materially affect the conclusions
2. Mann noted that there were issues with the Tiljander lake sediments in the paper and showed that excluding them, and others with potential data quality issues did not have a huge impact on the conclusion.
3. See 2.
4. Mann 2009 is not obscure.
5. Not really, naturally if you throw out a large chunk of your proxies, you cannot validate as far back, that's just how it is. The no-dendro, no-lake reconstruction validates to 1500AD @ 95% or 1100 at 90%, but what is the case for throwing out the tree-ring data? The L+C paper, which is apparently fine, uses tree rings extensively, if you discount Mann et al cos you don't like tree rings, , you must do the same for L+C
6 -9. Examples needed
I seem to have an earlier comment stuck in moderation, if this also disappears I'm off to spend my valuable time more enjoyably.
SimonW, global warmists have yet to prove CO2 does cause noticeable warming. Global warmists have yet to prove anything, other than telling scary stories does start to scare people into taking irrational action.
Mann's Hockey Stick scared the world into believing something needed to be done. It fooled me, I admit it. I was fooled by the resounding endorsement it received from the United Nations experts known as the IPCC, and I did not know any better.
I do not claim to understand the physics of nuclear power or weapons, but I accept the actual evidence that they work. If the physics of global warming is so settled, why hasn't it warmed as predicted? Why are people again looking at climate sensitivity, and wondering about some of the assumptions?
The idea of Phil Clarke's time being of any value at all justifies this thread by itself.
Diogenes, Mann's Hockey Stick has earned self proclaimed experts lots of money. Some of them have a vested interest in maintaining the status quo.
In my view there is little value in this - if you can't see the unprecedentedness in the proxies then it's flawed.
Sorry, I've read that sentence three times and I still cannot make any sense of it.
L+C (2012) used a 50yr smooth, so could not tell us much about modern (recent decades) temperature comparisons. However it built on Ljungqvist's 210 paper, in which he wrote
Our temperature reconstruction agrees well with the reconstructions by Moberg et al. (2005) and Mann et al. (2008) with regard to the amplitude of the variability as well as the timing of warm and cold periods, except for the period c. AD 300–800, despite significant differences in both data coverage and methodology.
And
Since AD 1990, though, average temperatures in the extra-tropical Northern Hemisphere exceed those of any other warm decades the last two millennia, even the peak of the Medieval Warm Period
Sounds unprecedented to me.
Ref http://agbjarn.blog.is/users/fa/agbjarn/files/ljungquist-temp-reconstruction-2000-years.pdf
Off work again, Ken?
"Mann 1999, says 'Northern Hemisphere' in the title. Am I missing something?" Yes it's called "Teleconnections", not sure of the mechanism, but the NH somehow teleconnected with the SH so though the graph used only NH proxies it represents the globe. I think that's the gist of it.
Why, do you want to send me another rude email?
Phil
1. Wrong. Better stats reintroduces the MWP in the handle and lowers the uptick at the end. Truly proper stats would be able to avoid data mining in the first place so that a single proxy cannot be overweighted in the result. Here's a tip - if none of your inputs bar 1 show a HS but the output shows a HS then you have merely performed biased data-mining.
2. Mann noticed diddly squat! Steve McIntyre noticed it (as did Tiljander) and wrote a comment to PNAS. Mann initially squealed that the sign didn't matter and then put the corrected version in the SI where nobody would look.
3/4. See 2.
5. Ever heard of sensitivity analysis? Most tree rings were ok but the data mining of the bristlecones created the HS. Without bristlecones and upside down proxies but with other tree-rings the corrected Mann08 (in the SI) shows an MWP as high as today. So yes we all agree here that all correctly done recons show an MWP and that the HS should be dead! Congrats on agreeing with skeptics!
6./9 Educate yourself! Click on the link to hockey-stick illusion book or head off to the Steve McIntyre blog rather than SKS to get some perspective. Of course if all you want is your daily dose of alarmism then objectivity is not a priority.
Oooh that's right, I forgot all about "Teleconnections"...
Hahahaha, isn't climate science wonderfull?
Hey hokeyguys, tell us more about teleconnections please. But first give me a minute though, I am bleeding myself a little to get rid of this nasty cold I've been having.
I am all ears right after my phlebotomy!
JG Ever heard of sensitivity analysis? Most tree rings were ok but the data mining of the bristlecones created the HS. Without bristlecones and upside down proxies but with other tree-rings the corrected Mann08 (in the SI) shows an MWP as high as today.
As with most of your points, that is simply not the case. Even McIntyre only claims that you cannot make such a comparison
Once the Tilj proxies are unpeeled, Mann once again doesn’t have a “validated” reconstruction prior to AD1500 or so, and thus cannot make a modern-medieval comparison with the claimed statistical confidence.
Pasted from <http://climateaudit.org/2010/08/07/mann-and-his-bristlecones/>
In his opinion, of course)
Geronimo
Wrong. There is only a northern hemisphere recon. There is not enough data for the Southern hemisphere. Eli was wrong. No excuse for that except a brain fart. Teleconnections is just another brain fart, this time from Mann. In reality they should all calibrate proxies to local temps as in the Loehle recon. This stuff is so simple that it makes me wonder how you get a paleo degree. Can they even tie their shoelaces in the morning? Do they even know that the original paper with the bristlecone data said that the anomalous hockey stick (ie not in tune with local temps or even other trees) was due to CO2 enrichment? Of course that was likely bafflegab too but it should have meant the proxy was rejected a priori by a competent, honest researcher. Alas...
JG Ever heard of sensitivity analysis? Most tree rings were ok but the data mining of the bristlecones created the HS. Without bristlecones and upside down proxies but with other tree-rings the corrected Mann08 (in the SI) shows an MWP as high as today.
As with most of your points, that is simply not the case. Even McIntyre only claims that you cannot make such a comparison
Once the Tilj proxies are unpeeled, Mann once again doesn’t have a “validated” reconstruction prior to AD1500 or so, and thus cannot make a modern-medieval comparison with the claimed statistical confidence.
Pasted from <http://climateaudit.org/2010/08/07/mann-and-his-bristlecones/>
In his opinion, of course)
Me >>Mann noted that there were issues with the Tiljander lake sediments in the paper
>>JamesG Mann noticed diddly squat! Steve McIntyre noticed it
From the paper : we also examined whether or not potential problems noted for several records (see Dataset S1 for details) might compromise the reconstructions. These records include the four Tijander et al. (12) series used (see Fig. S9) for which the original authors note that human effects over the past few centuries unrelated to climate might impact records (the original paper states ‘‘Natural variability in the sediment record was disrupted by increased human impact in the catchment area at A.D. 1720.’’ and later, ‘‘In the case of Lake Korttajarvi it is a demanding task to calibrate the physical varve data we have collected against meteorological data, because human impacts have distorted the natural signal to varying extents’’)
Exactly as I said. Presumably why they did a sensitivity study.
We therefore performed additional analyses as in Fig. S7, but instead compaired the reconstructions both with and without the above seven potentially problematic series, as shown in Fig. S8.
Yawn.
Phil
a. you didn't refute any point I made you just parroted SKS and,
b. I don't think you can assert anything from the sparse data either. So we both agree with McIntyre. It is not me expecting good recons from sparse data but it is done all the time in this field - and especially so with the sea surface data. I feel exactly the same about the Loehle graph. However we have around 4 recons that say the same thing now plus a wealth of MWP data on the Idso site. If you want to describe them all as inadequate then I'd agree but they are all far better than MBH98.
Incidentally the IPCC are still using the old HS in their FAQ's about climate change in France at least.
Phil
He didn't notice it was upside down that's the point! Tiljander told him and he still didn't acknowledge it. As for the sensitivity analyses; one included the HS of bristlecones and the other included the upside down proxy. Since both created a large uptick at the end the proper sensitivity study is to exclude both. Which was done later after goading and put in the SI. That's the only recon that matters.
Casual readers are seeing your lack of knowledge - do you really think you are doing your side a favour here?
Email? Well you seemed very proud that you had one from me. I'll sign it if you like and you can frame it
JamesG
People can see that you disagreed with me saying that Mann noted quality problems with Tiljander in the paper- until I provided the evidence.
And all you've done is parrot Climate Audit, a blog. I can understand why you wouldn't like SkS, but at least they base their arguments on the literature. Criticism of McIntyre seems to be censored here.
According to the algorithm, Tiljander had to go in the way it did or not at all, Mann replies to the criticism and shows the results of his sensitivity studies here
http://www.meteo.psu.edu/holocene/public_html/supplements/MultiproxyMeans07/
My last word. PAGES 2K makes all this stuff moot.
Your reverence
I note Phil's earlier comment "I seem to have an earlier comment stuck in moderation, if this also disappears I'm off to spend my valuable time more enjoyably." He then continues in another five posts giving us the benefit of his wisdom.
Please hold one of his comments up. He has become even more tedious than normal.
ChrisM - "normal"? That's quite a stretch. I think you mean "usual".
I'm fascinated by this post that seems to bring together father and son, Phil and Ken (remarkable similarity in their comment styles and put downs), but what gets me is that they argue as if they were the only ones who got their hands on Mann's data and code. In fact, they must be, because I've heard of no-one else who has ever managed to get hold of Mann's original data and code as they are soooo sure of their 'opinions' (I think Phil called it).
That old canard?
The data is here ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/mann1999/
You're far better off developing your own code to reproduce the results, in fact the NSF ruled that there is no obligation to release proprietary code. Certainly Wahl and Amman had no problem writing independent code that demonstrated the robustness of the groundbreaking studies.
http://www.ucar.edu/news/releases/2005/ammann.shtml
Nearly missed this from you, Phil:
That's funny. Considering how it has been shown that Mann's code was so shonky, with some routines never even heard of. Of course, having said that one should develop ones own code you'd be fully supportive of the code that McIntyre did, in the end, have to develop.Harry Passfield, Phil Clarke's evidence can be dismissed as being anecdotal, or apocryphal in relation to Mann's Hockey Stick, unless he can explain where his evidence has been hiding for so long.
I've heard of no-one else who has ever managed to get hold of Mann's original data and code
Must get tiring, moving those goalposts all the time ...
Anyhow, history of science notwithstanding, even Molehill Mountain McIntyre concedes that the disclosure for Mann 2008 was acceptable, and the PAGES 2K project renders these historical meanderings moot.
"Since AD 1990, though, average temperatures in the extra-tropical Northern Hemisphere exceed those of any other warm decades the last two millennia, even the peak of the Medieval Warm Period. Sounds unprecedented to me."
They are definitely not unprecedented in periods earlier than the last two millennia when anthropogenic CO2 emissions of any significance could only have resulted from intentional forest firing - and even then would likely have been only a very small fraction of current levels of anthropogenic emissions.
Temperatures in the extra tropical northern hemisphere were almost certainly 1-3 ºC higher than they have been since AD1990 at the climax of the Bolling Interstadial 14,500YBP and for about four thousand of the of the five thousand four hundred years between 9700 and 4300 YBP as recorded in the NORTHGRIP ice core( Members 2004 and World Data Center for Paleoclimatology). During all these periods atmospheric CO2 concentrations as recorded in the Vostok ice core were likely between 180 and 280 ppmv ( Members 2004, Petit et al 1999)
Justice4Rinka,
Fair enough. I believe the question was "Is this a circle?". Perhaps you're right and the adjacent drawing was a red herring. The answer is still no; "this" is a demonstrative pronoun.
My main point was the fatuousness of mapping a person's views onto a simple liberal/illiberal line. It's actually worse than that. The headline said that the answer, a yes/no answer, "could reveal a lot". That the researchers appear to believe everyone can be trivially clustered in two groups of "outlooks" does reveal something -- about the researchers.
Phil Clarke, rather than waste your energy moving goalposts, could you get Mann to adjust his Hockey Stick to show the pause? Planet earth has given up trying to comply with Mann's ambition.
PAGES2k is the palaeo-climate version of a carry-on film...which way round do we put the proxies....let's try this way...no, this way...in, out, shake it all about....shove it here...PAGES is a car-crash that has already happened.
The answer...defund all climate science courses.
Nice attempt Phil C. referring to ClimateAudit in one sentence and PAGES2K in the other. Somehow, you forgot to mention that Steve M has been on to PAGES2K for a long time:
http://climateaudit.org/?s=Pages2k
and it does not look for the PAGES2K...
Not exactly substantive criticisms though. More of the same inconsequential nitpicks, like the centred PCA fiasco, or flagrant data mining - like the hockey sticks from red noise embarassment.
Yeah inconsequential nitpicks like the Gergis paper being retracted for errors that reversed the actual trend from down to up yet still appearing in PAGES2K.
http://climateaudit.org/2014/11/07/gergis-and-the-pages2k-regional-average/
Or like the Kauffman PAGES2K recon using upside down data. Well at least his proxies could magically be used the correct way round and when used correctly the uptick at the end reduced and a MWP increased to the same height; "The interpreted temperature relation of the series from Hvítárvatn was corrected from positive to negative" they wrote. And all because an amateur had to do an audit because the pro's cannot apparently tell up from down or cope with even basic stats. How nitpicky and inconsequential can you get?
http://climateaudit.org/2014/10/01/revisions-to-pages2k-arctic/
Lord it's so laughable the notion that you have to use a proxy upside-down so that it fits the algorithm. That's actually worse than mere data-mining (which just rejects data that doesn't fit the forced result)! It's what anyone in any other field would call gross incompetence or malpractice. Not to the true believers though where truth is also inconsequential because only the message is important. Quite why they are averse to the truth only they know but it's nothing whatsoever to do with the underlying science which says nothing much is happening anywhere of any consequence as a result of this mild, probably beneficial warming which has happened before and was apparently beneficial then too.
It’s a nitpick if putting it right has a negligible effect on the conclusions of the study.
All nitpicks, then.
http://www.nature.com/ngeo/journal/v8/n12/full/ngeo2566.html
Phil
a. Reporting an error is never a nitpick;
b. Since all these errors had the effect of lowering the MWP and heightening the modern warm period then it is important for the consideration of CO2 sensitivity and very important for the consideration of the existence of manmade warming in the first place. If a plot is a hockey-stick then it leads to press releases with the word 'unprecedented' in the title which then directs policy. The numbers themselves may be minor but the effect is major. The reality is that the recons when done correctly show nothing is unprecedented and that is hugely significant.
I'm well aware that climate science tries to downplay these serious errors. It always seems to 'matter' when something is unprecedented but it never seems to matter when errors are revealed that show nothing unusual is happening. This is not science - it is PR! Such an attitude breeds even more scepticism amongst those who prefer their science unvarnished by dogma.
That's all! Thanks for the discussion.
The reality is that the recons when done correctly show nothing is unprecedented and that is hugely significant.
Please provide some evidence of that. It is not actually the case is it? Errors such as the proxy orientation - in one proxy, in one region - have been fixed and the resulting graph still looks remarkably like Mann's curve from 15 years ago.
I do not share your blind faith in McIntyre, his constant and offensive insinuations of malpractice and bad faith turn me, and I suspect a lot of people, off. ('Get a stick, get a stick', talk of scientists using certain proxies 'like crack cocaine' have no place is a reasonable discourse). Plus he's been caught out too many times getting it wrong, data mining and quote mining to be taken with anything other than a huge amount of scepticism. [I would provide links but last time I did that the post never appeared, I suspect linking to certain sites trigger moderation here]
Plus, of course, it’s a fallacy to assert that naturally-forced warming in the past rules out man made warming now, in fact we seem to be warming at a faster rate than anything in the record, in fact the warmer the MWP, and the cooler the LIA, the more sensitive is the planet to forcings, whether natural or manmade.
Phil Clarke? Yawn.
Why aren't your chosen experts at Skeptical Science providing witness evidence in court to support Mann? Then you could obtain some clarity.
The real fun will start in next ten years when we have global cooling, watch how the scientists will maintain this is what they meant all along
Phil Clarke,
If the handle of the hockey stick is sloping downwards and your much mentioned pages 2k graph indicates the same, and this time period does not involve mans burning of fossil fuel, why would an upturn in temps be down to CO2 etc if the previous downturn was not?
Phil Clarke,
Here's a fallacy for you: swapping the null and alternative hypotheses. Nobody "rules out" man made warming. Nor do we rule out showers of superheated ions from Klingon warp drives. Or fairy farts. The onus is on the scientists to show that our emissions of greenhouse gases explain much of the observed warming (or lack thereof). Given the observations of the last couple of decades, an honest scientist (Prof. Curry springs to mind) would say "Hmmm -- must be more complicated than I thought. Will go on looking".
As to the faster rate, rate of change depends on Δt. Extrapolation is fraught. If you measure temperature second to second, hour to hour, -- or day, month year, decade, century -- the smallest Δts will give the fastest rates of change. Would a trend over a few samples in one category tell you anything about the trend in the next category? The temperature record just doesn't have the resolution in time, location or temperature to say much about today's trends vs past centuries. "Unprecedented" loses a lot of its impact when it turns out it's "unprecedented in the whole age of television".