This idea that releasing data will result in a copier, UK universities have plenty of measures in place to ensure that data is handled properly and that plagiarism does not occur.

Unfortunately it is often the case that the consensus view is wrong. If you want a really controversial one – haemophiliacs started dying from AIDS in large numbers from 1987 onwards – there really is a hockey stick in the stats there. But was it AIDS that killed them? 1987 was the year that haemophiliacs began to be prescribed AZT as a preventative……and before the deaths started occurring.

George E. Smith (14:18:34) :

I think you’re kinda touching on my point that the core bores are irreproducible.

DaveE. “”"

Kind of shocking isn’t it DaveE ? We all understand the conservational concept of core boring trees; but that one crossection shown in this essay points to the flaw in that methodology. And as I mentioned trees have a height variable as well, so what would another section of this same tree show if taken at a height say two metres different in height from this one.

When you read any article on paleontology or archeology and the like; it is always intriguing to see just how ingenious are practitioners in all these sciences at prying “information” out of seemingly nothing samples or data. They gladly reconstruct a whole dinosaur incuding the color of its eyes from a broken chip off one tooth.

While one can applaud the attempt to gain information from scarce evidence; this simple tree ring problem; demonstrates that as a source for quantitative information it is sadly lacking.

Plant growth depends on a lot more factors than just temperature, water supply, CO2 levels, soil mineral content, etc etc; so it is a wild leap of faith to use any of this information for climate proxies.

The story of the bristlecone pines recalibration of the C14 dating scale, is well known.

The one reasonably dependable thing about tree rings seems to be that they do grow a new ring each year. So dating trees by counting rings is reasonably safe even with core boring.

It used to be assumed that the rate of production of C14 in the upper atmosphere by cosmic rays and the like was absolutely constant. This led to the dating of ahses from ancient kilns that were used to date pottery fragments, and make assumptions about the spread of technology. That process had certain advanced pottery techniques spreading out of Mesopotamia into southern Europe (Spain). But with a bristlecone pine core, you can actually radiocarbon date each individual ring of the core; whose real age you are fairly sure of.
When this was done, it was found that the radiocarbon production rate was anything but constant; and when the tree ring ages were used to calibrate the caron age scale, it was found that the European pottery artifacts were in fact older than the ones from the middle east; showing that the technology actually propagated the opposite direction from accepted history.

But you see; none of that saga relied on making any climate assumptions about any of those tree rings; they were simply dated by two methods; one of which was rather rock solid; depending only on our ordinary methods of counting years.

I suspect that corals, and oceanic mud cores all have the very same hazards, as does the tree ring method. Apart from the link between ring properies and climate being somewhat uncertain; the core boring method of sampleing clearly violates the Sampling theorem; so the results are a crap shoot.

George

The fact that you believe the taxpayer should pay for the identical services repeatedly, makes me wish I were a plumber when your pipes break. If the job were to be completed in 10 days, I could extend that time indefinitely by assessing the jobsite (acquiring the raw data) at the beginning of each work day. I could easily quadruple the cost to you to finish the job.

The taxpayer can choose: live in a stable stagnating society, the way the chinese society lasted for thousands of years, or nurture scientific creativity to continue the rapid technological advance ( rather than the usual plumbing) that we have lived through the past century. There is a cost, you get what you pays for.

Thanks much for pointing out the Nature blog on this. I have posted a comment there.

The fact that you believe the taxpayer should pay for the identical services repeatedly, makes me wish I were a plumber when your pipes break. If the job were to be completed in 10 days, I could extend that time indefinitely by assessing the jobsite (acquiring the raw data) at the beginning of each work day. I could easily quadruple the cost to you to finish the job.

timetochooseagain,
I believe your are mistakenly equating presumption and assumption. We have very good meteorological data for the last 50 or 60 years. If we can identify the conditions that led to growth in trees of that time and can identify similar growth in historic trees, there is a presumption of correlation rather than an assumption of same.

I think you’re kinda touching on my point that the core bores are irreproducible.

DaveE.

I take a dim view of people shoing pictures like that tree ring section above, and then describing the rings as “concentric”.

A few minutes studying just these “Concnetric” tree rings will reveal that they are anything but concentric. And the growth conditions if that is what determines the ring thickness, evidently vary from radial to radial and over the years.

So on to anna v’s observation that tree ring data on long lived trees are normally obtained by core boring, rather than by slaughtering the entire tree.

So pick your favorite radial angle to core bore the ring sample above; what sort of scientific balderdash are you going to discover by core boring this tree. Might I suggest that the tree ring core boring community buy a good text book on the general theory of sampled data systems; and READ it.

Of course you are all familiar with the sad story (as detailed by National Geographic some years ago) of the recent graduate in Botany from some southern California University; (with a Masters Degree no less). So he decides to make his fame and fortune by finding an old tree; specifically a bristle cone pine in the White Mountains of the Nevada/California border.
So this new genius heads up the white mountaint to look for old looking bristlecone pines. He finally settles on a candidate, and proceeds to cut it down; and cut a section out of it, to lug all the way back down to SoCal, to the lab so he can count the rings. It was somewhere in the 4500 to 5000 years old; much older than anyone thought trees got to be.
So he proudly announced his new famous discovery to his colleagues; some of whom are horrified, and ask the chap if he has ever heard of core boring to sample the age of a tree, instead of murdering the tree.

So our hero hies back to the white mountains armed now with a core borer, and a blighted ego. He core bores bristle cone pines till he is blue in the face, and takes them back for study,

He never ever found another tree that came within 500 years of the age of the oldest tree on earth that he had cut down. The Nat Geo article had a picture of the forlorn stump of that old tree left as a monument to the stupidity of some people who call themselves scientists.

Yeah; tree rings are a great way to develop a proxy for temperature; if you kill enough of them; but how are you properly going to dsample them with the boring tool, without killing the tree or violating the Nyquist criterion.

Remember that trees have a height variable, as well as a radial angle variable; you’d have to bore more holes than a whole forest full of woodpeckers; just to sample one tree.

George

http://blogs.nature.com/news/thegreatbeyond/2009/08/climate_researcher_vs_foi_part.html

I tend to agree except for one point.

The tree ring data can never be exactly reproduced.

On long lived trees, rarely are the tree ring data taken by cutting down the tree, but from bores from the tree. This apparently came out when they took new bores from trees used in the original hockey stick. The new results were completely different, though I cannot recall where I read that.

In this kind of instance, where the original experiment may not be reproducible and the data was part of the paid for experiment; the data belongs to the paymaster.

DaveE.

Look carefully. The “cross-section” is a cartoon, an artist’s rendering, a symbology rather than anything real. Whatever climate history it implies is strickly an artifact of art, not reality.

Which is telling. Reading tree rings for climate history is like reading tea leaves or chicken bones for foretelling the future. It is a misuse of the word “reading”. It is closer to ouija than science.