IQ Test: Which of these is not upside down?

This is a simple IQ test anyone should be able to complete easily. Here are four images, which one of the images has elements that are not upside down? You have 5 seconds. Go.

Having trouble deciding? - Click for a larger image

Having trouble deciding? - Click for a larger image

Answer below.

Chances are, if you are not Dr. Michael Mann of Penn State University, you’d answer: “It’s a trick question, all of them are upside down”.

And you’d be right.

If you are Dr. Michael Mann, and continue to insist that data in the image (from Mann et al 2008 ) in the lower right is not upside down, please contact me about some real estate in Brooklyn I’d like to sell you at a bargain price.

As WUWT and Climate Audit readers know, Mann made some blatantly obvious mistakes in his use of proxy data in Mann et al 2008, where he claims to be able to make a present day “hockey stick” of climate without the use of Bristlecone Pines that he used in his flawed 1998 study which produced the original Hockey Stick. Mann inverted data, upside down if you will, notably the Tiljander sediment as pointed out by Steve McIntyre.

Steve writes:

Mann didn’t just use one Tiljander series upside down; he used all four of them upside down, a point illustrated in the graphic below from a Japanese language article that rather appealed to me.

This isn’t an opinion. McIntyre personally verified this data inversion with the researcher, Tiljander, who collected the original proxy data. Yet Mann still denies it, probably because using the data right side up doesn’t produce the desired results.

Here is a figure from Tiljander et al showing the density graphic, rotated so that up corresponds to warm periods.

Figure 1. Excerpt from Tiljander et al, rotated from vertical in original graphic to show interpreted warm periods as up.

Here is the corresponding Mann data inverted from the Mann orientation:

Even if Mike Mann doesn’t, the Japanese know this:

Mann didn’t just use one Tiljander series upside down; he used all four of them upside down, a point illustrated in the graphic below from a Japanese language article that rather appealed to me.

Figure 3. Excerpt from Itoh graphic identifying upside down Tiljander proxies.

In a more mundane version, the figures below (from CA in fall 2008) show the Xray density series shown above in the upside down Mann orientation together with another upside down Tiljander series.

Figure 2. Two of 4 versions used in Mann et al 2008

The huge HS blade is, as noted above, attributed by Tiljander to “intensive cultivation in the late 20th century… peat ditching and forest clearance … the rebuilding of the bridge.

The SI to Mann et al 2008 conceded that there were problems with the recent portion of the Tiljander proxies (without mentioning that they were using them upside down from the interpretation of Tiljander and Finnish paleolimnologists), but argued that they could still “get ” a Stick without the Tiljander sediments. However, as I observed at the time, this case required the Graybill bristlecone chronology (where they failed to mention or cite Ababneh’s inability to replicate Graybill’s Sheep Mt results, even though Malcolm Hughes, a member of Ababneh’s thesis panel was a coauthor of Mann et al 2008). Thus their “robustness” analysis used either upside down Tiljander sediments or Graybill bristlecones.

Even though there is no doubt whatever that Mann used the Tiljander proxies upside down, in their reply to our comment, Mann et al flat out denied that they had used them upside down. Mann:

The claim that ‘‘upside down’’ data were used is bizarre. Multivariate regression methods are insensitive to the sign of predictors. Screening, when used, employed one-sided tests only when a definite sign could be a priori reasoned on physical grounds. Potential nonclimatic influences on the Tiljander and other proxies were discussed in the SI, which showed that none of our central conclusions relied on their use.

These comments are either unresponsive to the observation that the Tiljander sediments were used upside down or untrue. Multivariate methods are indeed insensitive to the sign of the predictors. However, if there is a spurious correlation between temperature and sediment from bridge building and cultivation, then Mannomatic methods will seize on this spurious relationship and interpret the Tiljander sediments upside down, as we observed. The fact that they can “get” a Stick using Graybill bristlecones is well known, but even the NAS panel said that bristlecones should be “avoided” in temperature reconstructions – and that was before Ababneh’s bombshell about Sheep Mt bristlecones. The claim that upside down data was used may indeed be “bizarre”, but it is true.

This wasn’t the only proxy used upside down in Mann et al 2008. In our discussion of Trouet et al 2009 in the spring, Andy Baker commented at CA and it turned out that Mann had used one of Baker’s series upside down – as discussed here.

Mann’s failure to concede that they had used the Tiljander proxies upside down resulted in Kaufman et al 2009 also using them upside down. Kaufman said that he was unaware of our comment on this point, but was sufficiently attuned to the controversy that he truncated the data at 1800. As a result, the big HS blade isn’t used, but the Little Ice Age and MWP are flipped over, a point made at CA here Kaufman and Upside Down Mann. Two other Finnish paleolimnology series also appear to have been used upside down by Kaufman.

Atte Korhola, a prominent Finnish paleolimnologist, familiar with the Tiljander and other sediments, recently commented on the upside down use of Finnish proxy data, as follows (Jean S’s translation) (Google translation here):

data collected from Finland in the past by my own colleagues has even been turned upside down such that the warm periods become cold and vice versa.

And yet at realclimate, Mann and others not only deny the undeniable, but accuse anyone saying otherwise of being “dishonest”.

Chris Dudley in comment #651 says:

Over at Dot Earth, McIntyre is taking another shot at Mann et al. 2008. community.nytimes.com/comments/dotearth.blogs.nytimes.com/2009/10/05/climate-auditor-challenged-to-do-climate-science/?permid=302#comment302

He seems to still be worried about inverted data despite Mann et al. publishing a formal reply to this. At this point bizarre is not the word any more.

A few posts later #665, JM says:

He seems to still be worried about inverted data despite Mann et al. publishing a formal reply to this. At this point bizarre is not the word any more.

The word we’re all groping for is “dishonest.” I’m sure everyone is as shocked as I am.

At #673, Benjamin asked:

Could someone point me to where this “inverted data” issue is addressed by Mann or someone else who knows? I’ve so far been unable to debunk McIntyre’s claims that there was an error there. Thanks!

To which, Mann referred to the PNAS Reply referred to above:

[Response: The original commenter appears to be referring to: Mann, M.E., Bradley, R.S., Hughes, M.K., Reply to McIntyre and McKitrick: Proxy-based temperature reconstructions are robust, Proc. Natl. Acad. Sci., 106, E11, 2009. – mike]

Yeah right-o buddy,  robusto crappo.

In other words, Mann’s study is falsified, yet he’s not Mann enough to admit it.

Here’s an interesting use of upside down graphs followed by a consensus insistence that the orientation of the data is correct:

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rbateman

So that’s what happened to the MWP.
I would highly advise him not to drive on any one-way streets… like the freeway.

…even though Malcolm Hughes, a member of Ababneh’s thesis panel was a coauthor of Mann et al 2008)

That would be “…coauthor of Mann et al 1998” not 2008.

Paging Joel Shore, paging Joel Shore –
I need some high-level dissembling as lately my lying eyes are telling me one thing while ‘the Team” unabashedly ‘says’ another …
Paging Joel Shore, paging Joel Shore …
.
.
.

Steve Hempell

Actually Anthony, my wife has one of those tomato things which I hung for her. She says it is meant to be hung that way – so it isn’t really upside down.
REPLY: I knew this from the start, while the container is oriented correctly, but by nature’s orientation, the plant is upside down as plants never grow “root above fruit”. And since we are talking about tree rings and other similar proxies, it seemed an apt visual. – Anthony

Steve Hempell

Anthony:
That is far far too convoluted (almost Mannian!!) for a simpleton like me to have thought of. :]

Evan Jones

It’s easy to see how Mann made the mistake: The numbering from 60 to 160 has an “opposite” meaning, that is to say 60 x-ray density is warm and 160 x-ray density is cool.
What is impossible to see is why he doesn’t Mann up and admit he made a mistake. It’s also a cogent indictment of the sufficiency of peer review–the peers waffle even after St. Mac pointed it out! When your peers are looking only to affirm and not to disprove, such things slip by (QED).
Therefore, as I (and many others here) have said, only Independent review will do, and any refusal to divulge data and methods automatically invalidates the conclusions.

mr.artday

evanmjones: Mann is not likely to admit what he really did: Created a fraudulent graph. He knew exactly what he was doing. And it didn’t “slip by” the peer reviewers, they are on the “Team”. These people used up all their slack with the first hockey stick. A swindle (largest in history) is a swindle, it’s long past time to be polite about such a crime.

John Wright

Got this in my mailbox yesterday:
http://www.clintonfoundation.org/testyourglobaliq
I was just wondering how to respond and without losing a good friend until I saw this post.
Thanks Anthony.

gtrip

I still do not know why that this:…
http://www.quadrant.org.au/magazine/issue/2009/10/climate-modelling-nonsense
…was deleted along with my comments. Not snipped like the birther comments were…but deleted completely. It is an important commentary by a physicist concerning our obsession with climate change. Maybe there is something in the article that would make this blog obsolete. If that is the case, then I can understand the deletions and the attempt to make a persons thoughts unavailabe. You can’t sell umbrellas if it never rains eh?

REPLY:
Comments with links often end up in the spam filter automatically, we get hundreds of pieces of spam a day for penis enlargement, Viagra, Nigeria etc. and bulk deletion is often employed since it is a lot of work to wade through all the dreck. Simply submit it again or flag a moderator. I will say that a very recent comment of yours was deleted because it was not only personally a direct insult to me, but suggested I broke the law. I don’t tolerate such things, even in jest, so your comment was deleted. – Anthony

“Top Climate Scientist Caught Out Lying Through his Teeth About Key IPCC Science” – isn’t that about it?

D. King

Maybe Mann suffers from uplexia. Similar to dyslexia,
uplexia causes one to flip all graphs showing upward
trends.

Keith Minto

In the paragraph beginning ” As WUWT and Climate Audit readers know,…….”,of Bristlecone instead of us Bristlecone.

Evan Jones

I doubt it was intentional. But now it’s out, he needs to own up and correct.

Caleb

Often I get the feeling Mann and others use a lot of jargon which laymen have trouble understanding. You might get hit by a statement such as, “The graphs don’t match up because the first data set was adjusted using Besancon corridor methods while the second employed RCS standardization.” (I use that as an example because I recently spent up a lot of my few remaining brain cells attempting to comprehend “Besancon corridor methods” as opposed to “RCS Standardization.”)
Now it looks like I’ll have to do it again to understand Mann’s statement, “Multivariate regression methods are insensitive to the sign of predictors. Screening, when used, employed one-sided tests only when a definite sign could be a priori reasoned on physical grounds. Potential nonclimatic influences on the Tiljander and other proxies were discussed in the SI, which showed that none of our central conclusions relied on their use.”
If someone could translate this into simple English for me it would save me a lot of time, and also arm me for duels with Alarmists.
Back in high school I was pretty good at coming up with excuses for undone homework, and also for incorrect answers. However I wish I had Mann’s skill. How I would have loved to see the look on my Geometry teacher’s face when he told me a graph was upside down, and I answered, “Multivariate regression methods are insensitive to the sign of predictors. Screening, when used, employed one-sided tests only when a definite sign could be a priori reasoned on physical grounds. Potential nonclimatic influences on the Tiljander and other proxies were discussed in the SI, which showed that none of our central conclusions relied on their use.”

gtrip

I will say that a very recent comment of yours was deleted because it was not only personally a direct insult to me, but suggested I broke the law. I don’t tolerate such things, even in jest, so your comment was deleted. – Anthony
I can honestly say that I have never accused you of breaking any law. To “delete” and then accuse is far beyond the person I have come to know on this website. I have always admired you for your tolerance of all opinions on the subjects discussed.
I would think that the link to the story would have piqued your interest. Or maybe the person that wrote it is on your short list. Either way, truth always wins at the end. Maybe that is why Marc Moreno gets the scorn of so many.
Anyway, I have enjoyed your site and especially you commenters. Y;ou have the wisest followers that I have ever seen on a blog. And that should be a complement to you.
But like all initiatives; One needs to know ones limits. As MS was diminished with the help of Jerry and the March of Dimes, it is unfortunate that the campaign is still going on.
As there is no AGW, to continue posting lame studies that show that there is no AGW just ends up making this site…..well…stupid. Over at CP big Joe try’s to get people on board by posting leftist political observations. And it may be working.
It is time to stop arguing the science and start attacking the oppressors. (unless of course you get income from it).

REPLY:
You suggested that I was keeping a stash of marijuana, that’s an accusation that I’m breaking the law. If you don’t like the deletion when you step over such lines of decorum, tough noogies. – Anthony

Matthew W

WOW !!!!
Mann is still taken seriously ??

Evan Jones

I will add that it is in no way established there is no global warming. I would suggest that it is most probably mild, mostly natural, and not subject to harsh feedbacks.
And it is never time to “attack the oppressors” in the sense you mean. We must wage a debate using facts and probabilities as we can best interpret them.
We must also entertain the notion, however unlikely, that we are just plain wrong. Yes, it’s more than the other side of the debate usually does (or they make a false appeal to Pascal), but that does not let us off the hook.

C Colenaty

Anthony,
I don’t know about “root above the fruit”, but on reading that statement I recalledseeing a photo (fifty or sixty years ago) of an orchid with some of its roots stuck up over the blossom. So I just now emtered “orchid root” into Google and the first entry read, “Orchid roots often creep over the edge of the pot before the body of the plant makes it to the edge of the pot. This is not necessarily an …” If memory serves, in tropical areas some orchid roots get most of their water from the air. But that is a memory from a long time ago.

gtrip

REPLY: You suggested that I was keeping a stash of marijuana, that’s an accusation that I’m breaking the law. If you don’t like the deletion when you step over such lines of decorum, tough noogies. – Anthony
Oh my. Are you that “serious”? I didn’t suggest that you were “keeping a stash of marijuana”. I said that you must have “come across a stash” of MJ that you may have hid years ago (you did grow up in the seventies didn’t you?). And yes it was a joke. It had to do with your writing about nonsense. The fact that you have such a thin skin and still put yourself out there with a blog completely blows my mind.
Credibility lost is hard to regain….ya know?
[REPLY – For heaven’s sake, please drop it. You have no idea what Anthony gets put through. If anyone got the notion he ever broke the law, they’d be all over him like a pack of hyenas. So, no, he can’t afford to let ANY such implication pass, be it in jest or no. He’s deleted me more than once. You should be glad there’s someone out there willing to carry a heavy burden for the good of us all. ~ Evan]

Gacooke

gtrip: you’ll still find your post with that link at (09:29:13) over on the “Searching the Paleoclimate Record” How many times did you post it?

gtrip

I did laugh at “tough noogies”!!! I am probably as far from you as your elbow is.
[In reply to your probably-to-be-deleted post (currently in spam queue). I did not delete you, I put you in spam for later review. Please be reasonable. ~ Evan]

nk

It’s a trick question, none of them are upside down.

Patrick Davis

The 5 stages which could indicate Mann-made global warming is likely based on shonky data, methods and practices;
1. Denial. 2. Anger. 3. Bargaining. 4. Depression. 5. Acceptance.
We have a way to go yet.

gtrip

You deleted me again………what can I say? I guess “goodbye” is all you want to hear. Just like “Climate Progress” and “Real Climate”….Silencing the people is addictive…it give one control. I don’t like what you have to say so,,,PRESS DELETE KEY…and it is gone.

Don S.

@evanjones: Sir or Madam, it would make no difference what any scientist believed if that belief had not been devolved into an economic factor. Scientists are free, indeed must, refrain from making “decisions” about what they know. It is understood in the lay community that scientists are a drain on the economy which much be sustained lest they sometimes discover something that might be useful in improving the lives of the population. This relationship has been the norm for many centuries, from the seers to the age of the enlightenment. Now, we are confronted with in-your-face “science” which seeks to drive agendas which will beggar the planet, and you come to us and say “We must entertain the notion…..”. Sir, or Madam, tell me where I can FedEx you a clue. Scientific courtesy is not required when frauds are about, and it is high time you learned what’s a fraud and what’s not.

AnonyMoose

Caleb –

Back in high school I was pretty good at coming up with excuses for undone homework, and also for incorrect answers. However I wish I had Mann’s skill. How I would have loved to see the look on my Geometry teacher’s face when he told me a graph was upside down…

Nice excuse, Caleb, now show your work.

gtrip

I think that I have been “ROMMed

Retired Engineer

evanmjones (17:45:12) :
“We must also entertain the notion, however unlikely, that we are just plain wrong. ”
We are certainly changing the climate. Everything has an effect. The question is by how much and what should we do about it. If we are warming it up a bit, that may not be a bad thing. Another LIA would not help anyone. Unfortunately, alarmists, by definition, need a crisis they can solve and save the world. That’s the real problem. Is the solution worse than the problem? Answering that could take time, more than just ramming a ‘budget resolution’ through Congress.
Or, like the Maldives cabinet, we could don SCUBA gear and meet underwater.
[REPLY – Yes, quite. ~ Evan]

George M

I thought of Mann yesterday when the news reported record early snowfall for State College, PA. I guess he is still there. Another example of the Gore effect, teleported or whatever it is they use for far-fetched correlations. You’d think a first rate university,—- well, let’s not go there.

Evan Jones

Don S.: Definitely not madam.
Yes, I know. I wrote a guest post on that very subject:
http://wattsupwiththat.com/2008/03/08/who-decides/
Nonetheless, one must entertain the notion because falsifiability is an indispensable keystone of science. If one does not entertain the notion one may be wrong, whatever one is doing isn’t science.

Jim Steele

evanmjones (17:17:41) :
I doubt it was intentional.
A few years ago I would have assumed it was unintentional. But after experiencing several timesthe way the RealCimate “scientists” manipulate their blog by selectively deleting posts, I firmly believe they have no integrity whatsoever. It’s simple street rules, never admit you were wrong, even when caught in the act.
[REPLY – Well, not assume. Say rather, we must “presume”. Besides, Mann’s subsequent denials hoist him. And regardless of how the opposition behaves, I don’t think we can win this one via street rules. ~ Evan]

Mike Blackadder

Caleb, Mann said:
“Multivariate regression methods are insensitive to the sign of predictors. Screening, when used, employed one-sided tests only when a definite sign could be a priori reasoned on physical grounds.”
I’m not sure, but it sounds like Mann is saying that he accepts the Tiljander sediment in the reconstruction without regard to the sign of the relationship (as though he has no expectation of whether higher temperatures will lead to higher or lower sediment density). McIntyre’s statement that the sediment data was used ‘upside-down’ infers that we would normally expect higher sediment density for higher temperatures (someone please correct me if I’m wrong).
My interpretation is that he admits to what Anthony has indicated “However, if there is a spurious correlation between temperature and sediment from bridge building and cultivation, then Mannomatic methods will seize on this spurious relationship and interpret the Tiljander sediments upside down, as we observed.”
So does Mann not attempt to justify his use of proxies in reconstructions on any physical grounds? Obviously he doesn’t, or he would care about the sign of the predictors. Or in his words he would employ “one-sided tests”. And when they admit that there were “problems with the recent portion of the Tiljander proxies” (where a HS blade has occurred due to non-climatic factors) do they provide any explanation for why they used the data anyway?

tokyoboy

I have been, to my mortification, unaware of the “Japanese article”. Could anyone identify the source? (I was unable to find it on the McIntyre page.)
Thanx.

J.Hansford

LoL…. ah, those chimps crack me up everytime. They just fit right in with the dendroclimatologists and their work.

Pete M.

Mann helped Al Gore win the Nobel Prize with these lies. I say Gore must give back the million dollars that came with the prize. Or is there no justice after all?

gtrip

[In reply to your probably-to-be-deleted post (currently in spam queue). I did not delete you, I put you in spam for later review. Please be reasonable. ~ Evan]
Just remember folks….be reasonable…..Or God will punish you…[snip].
[Reply – Or you will be snipped. Or deleted. And I’m the guy who hardly ever deletes anyone. (At any rate, that post seems to have been approved, regardless.) At the risk of repeating myself, please be reasonable. ~ Evan]

INGSOC

I love how some folks will make an escalating series of ridiculous and slanderous comments, then beak off about censorship when their garbage is snipped or deleted.
Twits.
Nice article BTW.

Caleb (17:27:59) :
Back in high school I was pretty good at coming up with excuses for undone homework, and also for incorrect answers. However I wish I had Mann’s skill. How I would have loved to see the look on my Geometry teacher’s face when he told me a graph was upside down, and I answered, “Multivariate regression methods are insensitive to the sign of predictors.
Made my day!
Thanks for that

Raven

Mike Blackadder,
The problem with Mann is he correct when he says the statistical algorithm he used does not care if the signs are reversed, however, steve’s point is statistical algorithm also does not care about the physical meaning of the proxies and that it makes no sense to a proxy that goes up with temperatures and treat it as if it was a proxy that goes down with temperatures.

gtrip

[snip – racial epithets – final warning sent via email]

gtrip

Caleb (17:27:59) :
How does one actually get the name :Caleb???

J. D. Lindskog

To pick a knit…
That portion of the test question graph corresponding to the MWP does not appear to be inverted. Is it just the red portion of the plot that is inverted?
How deep does this apparent data manipulation go?

Reed Coray

Down is up.
Up is down.
Mann flip flops.
Like a clown.

pyromancer76

Mann dishonest? Hmmmm. Mann’s “research” fraudulent? A little closer to the mark. Lucy Skywalker (16:49;13) sees it the way I see it. “Top Climate Scientist Caught Out Lying Through his Teeth About Key IPCC Science” – isn’t that about it?
I hope he and his followers are prosecuted for fraud.
I like an upside down “Laugh In” line. “Sock it to ’em, Anthony.”
[REPLY – I would hate to see anyone prosecuted, except in the court of public opinion. Besides, that sword cuts both ways. ~ Evan]

I love how some folks will make an escalating series of ridiculous and slanderous comments, then beak off about censorship when their garbage is snipped or deleted

Dave Wendt

I have a plan. Suppose we have a collection drive to gather up as many copies of Mr. Mann’s work that have made it into print as we can in the next few weeks. Then we run the collected material through a paper cutter to make nice neat squares and ship it all to Copenhagen where it can be placed in receptacles in all the restroom stalls in the conference facility where the UN will be gathering for their Rape and Pillage of the Western World Climate Conference, to replace all that fluffy three ply that’s destroying the climate. It’d be a perfect kill two birds with one stone opportunity. The gathered dignitaries would be able to demonstrate their dedication to recycling and Mr. Mann’s work would finally be able to fulfill the one function for which it always been most perfectly suited.

crosspatch

This certainly explains why they hold their data and methods so close. When it comes to science, when one hides their data, it can raise suspicion. But the subject of climate change is not your typical scientific food fight. In this case people are being asked to sacrifice real money in the causing of “fighting” global warming. We are being asked to do with less, change our lifestyle, pay more for the basics of life. Californians are even being asked to give up their big screen TV’s all in the name of a cause that is based on mistake after mistake after mistake.
When someone tells you “the science is settled” that should cause alarm bells to ring. If it was all that “settled”, one wouldn’t need to sell it as “settled”.
But this is outright robbery. Average people are being harmed by this and the people lowest on the economy ladder are harmed the most. Urban poor don’t have a bus to take and they can’t afford a new car every time the government changes the standards. They might have to drive 60 miles to a doctor or 40 miles to a grocery store. It is cruel to burden these people with such a hoax. Everyone has been afraid of using the “fraud” word but when all of these “mistakes” are taken in sum, what else could it possibly be? You have the same “scientists” reviewing each others work. Time after time their “research” has been shown to be nothing more than an arrival at a predetermined outcome.
You hear cries of Antarctic warming and learn that the very study that supposedly documents that shows cooling since 1980. Weasel words, careful use of semantics to say things in a way that are true but misleading become business as usual. It is just shameful and so very cynical at a very basic human level. The people who can least afford it would be impacted most by “climate change” legislation. How is an elderly retired couple expected to pay to heat their home when they are on a fixed income and energy costs triple, not due to market conditions but due to artificially inflated costs due to government regulation.
It is the largest scam ever perpetrated on the population of the world.

Evan Jones

Multivariate regression methods are insensitive to the sign of predictors.
Well, you have to admit he is a man whose values are absolute.

Mr Lynn

gtrip (16:31:48) :
I still do not know why that this:…
http://www.quadrant.org.au/magazine/issue/2009/10/climate-modelling-nonsense
…was deleted along with my comments. . .

I don’t know what all the fuss is about, but the essay by John Reid that ‘gtip’ cites is really quite good, and I hope gets wider circulation. Send it to all your friends, and to public officials, like the egregious Senator Lindsay Graham, for instance (don’t bother with Sen. Kerry—he’s a hopeless, vain nitwit).
/Mr Lynn

davidc

Caleb:
“Multivariate regression methods [asume temperature can be expressed in the form t=m1.x1+m2.x2+…where x1,x2… are variables and m1,m2… are (constant) coefficients which are estimated in the regression] are insensitive to the sign [see below]of predictors [=variables which are retained and used to predict values of T which were not directly measured]. Screening, when used, employed one-sided tests [95% of observations either less than or greater than a particular value; two sided, between an upper and lower limit] only when a definite sign could be a priori reasoned on physical grounds [such as a tree ring is always wider with higher T, never lower]. Potential nonclimatic influences on the Tiljander and other proxies were discussed in the SI, which showed that none of our central conclusions relied on their use. [in climate science, when errors are pointed out, they”don’t matter”]”
[sign: An increase in a variable, say x1, could indicate a positive increase in T; in this case the coefficient m1 would be positive. But it is also possible for a variable, say x2, to indicate an increase in T when the variable decreases (eg istope ratios which can be expressed as the inverse); in this case m2 would be negative, which would emerge automatically from the regression. In the Mann paper a negative m2 was included when there were “physical grounds” for assuming it was positive – and grounds for excluding it as an artifact]