One of the great things about WUWT is that people from all walks of life frequent here. We have PhD’s right down to Average Joe that read and post comments here. Everyone has something to contribute.
A general truism that I’ve noticed through life is that the people that actually work “hands on” with the things they study often know far more about them than the people that study them from afar. As in the case of the surface stations project, top scientists missed the fact that many of the climate monitoring stations are poorly sited because they never bothered to visit them to check the measurement environment. Yet the people in the field knew. Some scientists simply accepted the data the stations produced at face value and study its patterns, coaxing out details statistically. Such is the case with Briffa and Yamal tree rings apparently, since the tree ring data was gathered by others, field researchers Hantemirov and Shiyatov.
American Indians have been said to be far more in tune with the patterns of the earth than modern man. They had to be, survival depended on it. They weren’t insulated by technology as we are. Likewise somebody who works in the forest whose daily livelihood is connected to trees might know a bit more about their growth than somebody sitting behind a desk.
WUWT commenter “Caleb”, who has worked with trees for 50 years, wrote this extraordinary essay on Briffa’s lone tree core known as YAD061, which has a pronounced 8 sigma effect on the set of 10 tree cores Briffa used in his study. Caleb’s essay is in comments here, which I’m elevating to a full post. While we may never know the true growth driver for YAD06, this is one possible explanation.
Guest comment by Caleb Shaw:
I’ve worked outside since I was a small boy in the 1950’s, and have cut down hundreds of trees. I always check out the rings, for every tree has its own story.
I’ve seen some rather neat tricks pulled off by trees, especially concerning how far they can reach with their roots to find fertilizer or moisture. For example, sugar maple roots will reach, in some cases, well over a hundred feet, and grow a swift net of roots in the peat moss surrounding a lady’s azalea’s root ball, so that the azalea withers, for the maple steals all its water.
I’ve also seen tired old maples perk right up, when a pile of manure is heaped out in a pasture a hundred feet away, and later have seen the tree’s rings, when it was cut down, show its growth surged while that manure was available.
After fifty years you learn a thing or two, even if you don’t take any science classes or major in climatology, and I’ve had a hunch many of the tree-ring theories were bunkum, right from the start.
The bristlecone records seemed a lousy proxy, because at the altitude where they grow it is below freezing nearly every night, and daytime temperatures are only above freezing for something like 10% of the year. They live on the borderline of existence, for trees, because trees go dormant when water freezes. (As soon as it drops below freezing the sap stops dripping into the sugar maple buckets.) Therefore the bristlecone pines were dormant 90% of all days and 99% of all nights, in a sense failing to collect temperature data all that time, yet they were supposedly a very important proxy for the entire planet. To that I just muttered “bunkum.”
But there were other trees in other places. I was skeptical about the data, but until I saw so much was based on a single tree, YAD061, I couldn’t be sure I could just say “bunkum.”
YAD061 looks very much like a tree that grew up in the shade of its elders, and therefore grew slowly, until age or ice-storms or insects removed the elders and the shade. Then, with sunshine and the rotting remains of its elders to feed it, the tree could take off.
I have seen growth patterns much like YAD061 in the rings of many stumps in New Hampshire, and not once have I thought it showed a sign of global warming, or of increased levels of CO2 in the air. Rather the cause is far more simple: A childhood in the under-story, followed by a tree’s “day in the sun.”
Dr. Briffa should spend less time gazing at computer screens, and actually get out and associate with trees more. At the very least, it might be good for his health.
wsbriggs (13:55:54) :
Trees with 90% down time – sheesh! Sounds like some Government employees I’ve seen.
ROFLMAO
One problem with the collection of tree growth data not often mentioned: the researchers aren’t botanists. They make assumptions that aren’t necessarily true. When they fail to collect and/or archive metadata, the numbers they get might as well be invented.
Super post Caleb. While the areas from where these trees came were population sparse, there was still a randomness to the distribution, and so a tree could very well grow up in the shade of another. What didn’t occur to me was that the slow spreading of the roots could also send some of them to new sources of nutrients. Also, if the direction of waterflow down a hillside changed very slightly, a tree that wasn’t getting enough water might suddenly get much more. It seems to me that since these trees lived on the border of the northern tree line, the little ice age could have killed many of them off. Then, as we came out of the little ice age, the caracasses of the dead served as food for the living. I don’t have your experience Caleb, but it seems to me that the growth pattern on a tree could have inumerable explanations. Then, when you take evaluation methods for the data that amplify the differences because it’s considered “signal”, you can end up with virtually meaningless reconstructions; or reconstructions that are dominated by just a few trees. I’ll go back to Leif’s quote and say that I’m not sure that tree ring proxies can be trusted to tell us much of anything. A look at the spagetti graphs and the huge variations between the individual proxies also drives that home.
Roger:
“I agree with your general assessment, but the fact is that we don’t know what the local environment was for the tree in question. It may have been part of a sparse grove, or it may have been a young tree inside of an older cluster. ”
This is one of the reasons that a large sample size is important, so that an outlier or two won’t effect your data to such a large extent. And it’s why Briffa’s tiny sample size is such a travesty. He’s suppose to be a professional, and he’s suppose to know this. Of course maybe he does know it, but he didn’t care because the series gave the result that he was looking for.
I this proves that we need a process more than peer review. It needs to also reviewed by thoughtful intelligent people as well.
Caleb,
I have seen growth patterns much like YAD061 in the rings of many stumps in New Hampshire.The Team has millions in grant money. You might be able to make some serious dough by producing tree-ring series with those stumps
Good explanation of just while tree ring data can be indicative of climate, it can never produce an accurate historic temperature even when well calibrated.
Common sense is a vital to the scientific process. Once people get too close to a problem it is all too easy for them to stop seeing the wood for the trees.
There are errors on both extremes. People are often more willing to believe what a PhD says merely because they have the degree but there are also lots of instances of people claiming to be equally or even better able to pontificate on a topic they have no education about because academia is seen as some form of elitism. Just look at politicians who decide to set the official value of pi at an even three because they want it to be that. Look at all the folk who have a “scientific” theory about something when they don’t know what a theory is. The belief that experts know nothing is at least as prevelant and damaging as the belief that experts know nothing. Unfortunately, this entire issue of climate science and the hockey stick debacle in particular will be a kick in the teeth to real scientists who are confronted with pseudoscience for generations to come. Creationists still harp about the Piltdown man, even though it didn’t fool nearly as many people as was portrayed. A hundred years from now astrologers will be telling astronomers that the sphere of fixed stars is a perfectly valid model and they only disagree because they are closed minded egg heads who don’t know anything about stars and make up all their data. “Remember global warming?” they will snear. That will be enough to convince the PTA to put horoscopes 101 onto the curriculum.
Thanks for a real down to earth post based on hands on experience. This clearly answers the questions asked over at RC about “Communicating Science: Not just Talking the Talk” – in one simple work “bunkum”.
It seems to me that the only thing tree rings can tell us is: During this time the tree did poorly and during that time the tree did well. Didn’t the whole dendro thing get started as dendrochronology? I think the papers that claimed to prove that any other information could be extracted from tree ring studies need to be looked at for evidence of good old boy review.
Surely there is payola here somewhere from the maple syrup industry! 🙂
Thanks Caleb. Nice post.
Caleb rocks. And Anthony rocks for giving Caleb the mike. And the commenters rock for adding depth, nuance, pressure-testing, other ideas and follow-on ideas.
People, this is us working a problem well. Thanks.
As for substance, I grew up in Yukon Territory where the forests were pretty much as depicted in the photo at top of thread. Not much competition for light. Semi-arid (15″ rainfall a year?). Cold as hell a lot of the time. And billions of trees sorting out their individual and collective fates. BILLIONS. And no two the same.
For me, that’s the key. If Briffa and his ilk ever thought about the tree-ring proxy concept, and ever got out of their basements to gain a sense of the environment in which the data is generated by those “living thermometers,” they would never have dared to think, let alone sell, a model that rested on a trivial sample set of 1 tree, or 12, or even hundreds. Here and in other WUWT threads I’ve seen statistically-savvy commenters suggest that a randomized set of geographical coordinates should have been used to pick nearest tree; with that would have come a precise (and regularly checked/calibrated) system of taking samples from those trees and reading them; plus of course “chain of title” to ensure data integrity. And then (pre-set) rules for what can be discarded. Double-blind the thing. Run it like a clinical trial for a new drug. Basic scientific hygiene. Because the biggest risk in science is fooling yourself.
That’s what Briffa and his friends seem to want to do. Sad. And once you start to do it, you start to think you’re pretty damned smart, and so you keep on doing it. The “Enron” mindset of being “the smartest guys in the room” is not just for energy derivative traders. It’s a mindset that almost always leads to the Enron outcome, however. Which is where Briffa and Co. may now be.
It’s about humility and letting the world talk to you. Caleb probably gets more real truth from the forest in an afternoon that Briffa will get in his entire lifetime. I wouldn’t mind that, except Briffa wants to sell me a trillion-dollar pig in a poke.
Enough. Again, Caleb, super job. And the post may generate some excellent follow-on for empirical testing/comment of how trees grow, and what they’re really telling us.
Dare I say it, but, sometimes (particularly in technical or scientific fields):
You can’t see the wood for the trees.
I am going to name this tree “Andre” in respect to “Andre The Giant”. This single tree is much akin to having Andre in a room full of “normal” sized people. Sure, Andre will change the overall averages of height, weight etc, but he is not a trend or at all representative of the overall group. I can not accuse Dr. Briffa of cherry picking (but it sure looks like it from here.)
Much of the science of the AGW believers theories can settled IF they release their data and source code.
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Doug in Seattle (14:07:03) :
I do agree though with the general point you make though. Too many folks in climate science seem to do all their work in front of computers and do not consider field conditions when they make their analyses or conclusion. This may not be related to why Briffa’s data archive was missing the metadata, but I have to wonder.
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The Twelve Disciples set of cores back up what Caleb said. The other Eleven Disciples tell us that the Twelfth is an outliar. (Yep, I mean outLIAR! – an out and out liar 🙂 There was something different about the tree, probably something about its environment, just as Caleb said.
(Ugh, I guess that’s outlasted it’s welcome…)
RE: Alan S. Blue (13:41:02) :
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“Therefore the bristlecone pines were dormant 90% of all days and 99% of all nights, in a sense failing to collect temperature data all that time,”
That’s actually why they’re useful. In a ‘hot year’, those same numbers would be, say, 85% and 99%. Versus the cold year of 95% and 99%.
A three-fold change in the time spent growing is a dramatic effect.
On the other hand, picture the tree outside my house in Seattle. In a cold year, it might freeze solid enough to stop growth for, say, 21 nights. That is:
You’d be trying to measure the difference in growth based on 365 days of growth versus 355 days of growth. And the ‘hot’ years would be identical to a normal year. So there is very little “swing” in the size of the rings (based on temperature alone) if the trees are unstressed.
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If the bristlecone pines reflected temperatures, they should show a growth spurt in the 1930’s to match Mann’s hockey stick.
Wow, nail… head. Good strike. My view (I don’t have a dog in this race by the way in terms of AGW) is that the dissemination of pseudo-science is growing, precisely because people are losing confidence in the Scientific method. I’ve seen it, particularly on the web and more so in the mainstream media. This is almost inevitable in a culture where Science is done by press-release and politicians pick up and run with popular sentiment. There’s a kind-of destructive feedback between Scientists, the media and politicians. It’s a circle I can see no way of breaking, except of course through blogs such as this and legislation to put the ship back on an even keel.
We are in culturally dangerous territory, as I think most people here can appreciate.
Can I make a bonsai by lowering the temperature?
Nice post, thanks Caleb and Anthony.
First day of my first climatology class; prof’s main point “Don’t forecast with your back to the window.” Seems to fit here somehow.
In dryer & warmer areas, it is often annual precipitation AND how it is redistributed in the landscape that affects tree growth and thus ring widths. For example, at the hillslope scale trees grow better in hollows (topographic concentration of surface and subsurface water flow) than they do on noses (topographic areas of dispersion of flow). Likewise, a very small dike or temporary interruption of subsurface and surface flow such as a few rocks or a dead tree can slow the flow of water and make it more available to plants.
So, variations in annual precipitation and spatial variations in water flow paths both contribute to large variations in tree ring widths when temperature is not the limiting factor. One must consider a myriad of other limiting factors depending upon the site specific ecosystem properties.
Some places it is temperature, others precipitation, others nutrients, and others the degree of insect infestation, etc.; and at a single place, all of these things can be important from year to year.
Horse manure=AGW priceless.
One feed the other…..
LOL
mr.artday (15:42:48) : “It seems to me that the only thing tree rings can tell us is: During this time [this part of] the tree did poorly and during that time [this part of] the tree did well. Didn’t the whole dendro thing get started as dendrochronology? I think the papers that claimed to prove that any other information could be extracted from tree ring studies need to be looked at for evidence of good old boy review.”
Amen. When they went from dendrochronology to dendrophrenology, that’s when the coprolites hit the impeller.
Good job, Caleb.
For a tree that has evolved to take full advantage of scarce sunlight, the Siberian Larch did exactly what nature programmed it to do…take off. I was thinking a wound healed or two trees joining.
So, where is the documentary evidence of this tree ring cut? Drawing? Photo? I would think that the in-field researches would have done that. And, like archaeologists, the surrounding environment might be also documented.
Preserved cut specimen or borehole core?
Does anybody know if photos of tree ring cuts/cores are a common practice?
Very interesting post.
Just to add my 2 pence with a personal experience. 25 years ago the local authority planted about 25 trees, one outside each house in our street. Unfortunately for the trees the following two years had very dry summers. Some of us watered “our” tree, and some didn’t for those summers. Now over twenty years later the watered trees are still out growing the unwatered trees.
Probably on no scientific value but interesting none the less.
The Reverent Expert says, …….
…-
“The exhortation to defer to experts is underpinned by the premise that their specialist knowledge entitles them to a higher moral status to the rest of us.”
“Specialist pleading
ONE of the most influential contemporary cultural myths is that our era is characterised by the end of deference.
Commentators interpret the declining influence of traditional authority and institutions as proof that people have become less deferential and possess more critical attitudes than in the past. However, it is less frequently noted that deference to traditional authority has given way to the reverence of expertise.
Western culture assumes that a responsible individual will defer to the opinion of an expert. Politicians frequently remind us that their policies are “evidence based”, which usually means informed by expert advice. Experts have the last word on topics of public interest and increasingly on matters to do with people’s private affairs. We are advised to seek and heed to advice of a bewildering chorus of personal experts — parenting specialists, life coaches, relationship gurus, super-nannies and sex therapists, to name a few — who apparently possess the authority to tell us how to live our lives.
The exhortation to defer to experts is underpinned by the premise that their specialist knowledge entitles them to a higher moral status to the rest of us. For example, …”
http://www.theaustralian.news.com.au/story/0,25197,25979808-25132,00.html