"the consensus, based on tree ring and coral calibration" - Means What?

Assorted retorts from yahoo boards and elsewhere : Answering HolyKoolaid on Babel, part I · Creation vs. Evolution : "the consensus, based on tree ring and coral calibration" - Means What? · What Would Carbon Buildup, from Scratch, Normal Speed, Look Like? · How Long is a Halflife, Then?

What exactly is involved in the following claim? Here:

Ok, interesting claim. Do you have any evidence for your assumption that the radio carbon dates are too old, or are you just starting from your conclusion of how old the things should be, and trying to force the evidence to support that? Are you aware that the consensus, based on tree ring and coral calibration, is, that the radiocarbon dates measured are a bit too young, not ten times too old.

More specifically, as I have given my evidence for my view elsewhere, this part:

Are you aware that the consensus, based on tree ring and coral calibration, is, that the radiocarbon dates measured are a bit too young, not ten times too old.

More specifically, and contrary to title, I am going to omit the coral part - leaving it to CMI - and stick to the "tree ring calibration" of ¹⁴C method.

Back when tree rings and ¹⁴C method were being tested, there was a place in Arizona where both were tested and used to double check each other. The range of carbon dates for a certain late pre-Columbian habitation matched perfectly. Both methods were validated.

I agree they were both very well validated for 1300 - 1500 AD. But that is the key. Tree rings from the area were available sufficiently abundantly to bridge the gap between earliest samples and either modern or at least early post-Columbian historically dated samples. This is a very pristine state of tree rings. You cannot find tree rings from any area going back from historically dated times to 1300 or 1500 BC. Not such a restricted area.

Also, both tree rings and texts become scarcer as we go back in time. You cannot observe the minds via the writings for 19th C BC Near East as you can for 19th C AD Europe or America. Why? Because, put all that is preserved in writing from 19th C. BC beside all we have or even a fairly large sample we have (like Congress Library in US) left from the 19th C. AD, it is like a drop to a sea. The thing applies to both texts on any support (papyrus, vellum or baked mud) and to objects made out of or even random samples of non-processed wood. We have too few of them as we get back that early.

"Wait a minute, don't we have trees that have lived since 5000 years and are still alive?"

On a LXX or even non-standard LXX reading like that of Roman martyrology for 25th of December, this tree ring count doesn't reach back to the Flood even. Or for Roman martyrology, just barely. A very young pre-Flood tree was uprooted and replanted in what is now California. It was and still is a redwood pine. But we can't use that to calibrate carbon dates. Each layer of wood from inside to outside certainly is alive at exactly one year, through exactly the carbon dioxide available in that time, with its exact carbon level. But in an object like wood, or even harder ones, the oldest carbon levels will be contaminated from younger ones. Not totally, but I presume at least partially.

To see what carbon level a tree ring series had, you need to get to much more limited samples, like a tree that lived 50 years before it was felled to make a coffin or a chair or whatever else.

And precisely these limited pieces of wood have become too scarce back in 19th C. BC to provide a safe tree ring date by which to calibrate the carbon dates associated with it.

I will give you the context for the quote as well, it is in a debate on this post, with Valkea Kirahvi (it's Finnish for White Giraffe - I suppose that is some kind of drink):

Assorted retorts from yahoo boards and elsewhere : Answering HolyKoolaid on Babel, part I
https://assortedretorts.blogspot.com/2020/11/answering-holykoolaid-on-babel-part-i.html

The main format is, time signatures for the video are bold and what follows refers to what "Holy Koolaid" said at that time in the video. under some of my comments, someone else commented, and that is then "indented" after handle of the one so commenting - or rather like pushed inside whole paragraphs, with only his and my names reaching out to normal margin. My debate with Valkea Kirahvi came after my comment at 3:05.

Hans Georg Lundahl
Paris
St. Josaphat of Polotsk
14.XI.2020

Sancti Josaphat, e sancti Basilii Ordine, Episcopi Polocensis et Martyris, cujus dies natalis recensetur pridie Idus Novembris.

Note that the following speaks of a bishop called Hypatius who was martyred by Novatians.