Something completely unknown is making tree rings too small after 1960. And if you correlate your tree ring data to post-1960 temperatures it makes historical temperature look way too high.
Bizarro-Briffa sent a similar letter to Bizarro-Nature warning of an unknown divergence problem and saying not to correlate tree rings to pre-1960 temperatures because it makes historical temperature look way too low.
I don't know what you're trying to argue. Tree rings underestimate current, not historical, temperatures. This means that, yes, if you calibrate to current temperature, the past will look comparatively hotter. This is a causal relationship.
At what other periods to tree rings not correctly correlate to temperature? How do we know the last 50 years is the only time this has happened?
Since we do not know why the temperature has not correctly correlated over the last 50s years, we can't really know when else that has been the case, can we?
So why do we rely on tree rings for any period?
They are proven to be unreliable over a signifcant period, and we don't know if or how often that's also true of the past.
You can cross-check historical reconstructions to assess their accuracy for given periods. I don't know how often this has been done and if other significant, unexplained, and unaccounted for divergences have been found. I haven't heard of any, but I'm not an expert. For complete answers to your questions, I'm afraid you may have to review the literature.
If you're not an expert, please don't claim that it's feasible to cross-check this data against historical reconstructions -- you clearly do not know whether it is or not.
How can you support that claim without having any relevant knowledge? I don't see that a general knowledge of statistics is particularly relevant here -- we're all well aware that things can, in general, be correlated.
Scientists don't rely solely on tree ring data for historical temperatures, it's one of many methods used. Thus the tree ring data can be correlated against other measurements to know it's accurate for past time periods. This should be obvious.
Thus, either (a) it has already been done, or (b) it is more difficult than you would expect for non-obvious reasons. So what is your point? Have you even bothered to find out if anyone has done it or not?
Fallacy of bringing absolutely nothing to the debate and asserting to the point of ad homonim that scientists would have skipped basic statistics on their data. Please see the post immediately above yours and go demonstrate that the method is flaw before continuing this debate.
The standard of evidence to show fault is yours. Assuming that papers published in freaking NATURE have sound statistics is a reasonable thing for a layman to do.
>Fallacy of bringing absolutely nothing to the debate and asserting to the point of ad homonim that scientists would have skipped basic statistics on their data.
I thought that's what you were asserting. My assumption is that scientists have correlated tree ring data with other sources and found it to be unreliable. But of course, neither my nor your assumptions about what's possible and impossible in this area are worth a damn, because we __don't know what we're talking about__. That is my point.
Also, all this talk about fallacies, ad homonim, etc. etc., is very "internet". Especially since you only seem to have a vague grasp of what these words actually mean. Do you think we could maybe leave all that stuff out and have a serious discussion?
Can you direct me to papers correlating tree ring data to temperature data outside of the 100 year range from the mid 19th to the mid 20th cenutry? You indicate it's obvious, but I'd like to see the actual papers.
If you're really this interested in it and really suspect an entire scientific field has engaged in completely terrible statistics, it's basic statistics and I suggest you publish a paper yourself.
That or you go look for the papers or the reason the papers have not been written.
This game is old. The standard of proof to demonstrate the method is flawed based on poor correlations is on your side. The method to do the correlation is public knowledge. The data to correlate is public knowledge. R is open source. Go forth and correlate.
>If you're really this interested in it and really suspect an entire scientific field has engaged in completely terrible statistics
You're confused about something: the post you're replying to clearly wasn't accusing an entire scientific field of engaging in "completely terrible" statistics. The poster was just questioning whether the comparison you were suggesting was feasible given our current (rather imperfect) knowledge of temperature changes over the last few hundred years. It may not be a matter of just getting two sets of figures and comparing them.
I honestly don't understand what you mean. But if you think these discussions are games in which the aim is to score points (as your analogy would suggest) please do sod off back to reddit.
You wouldn't. Moving the goalpost is a fallacy, though given your complete inability to do original research I doubt you could ever find that out on your own. This thread started because you asked for unreasonable evidence in response to a post that said "They are proven to be unreliable over a signifcant period, and we don't know if or how often that's also true of the past." (emphasis mine).
This is a clear claim that climate science researchers have not done basic statistics when presenting new models. This claim has been substantiated by nothing except you requesting more and more detailed analysis from non-experts, which you discount every time we provide it because you assert that you would only listen to an expert.
Ironically, you are actually failing to respect the authority of experts, because the discussion is fundamentally an accusation that experts are failing to do basic statistics. You are accusing us of not being experts so you can't listen to us in the defense of the experts you're attacking by proxy.
I seriously fucking doubt you understood any of this. But it doesn't matter, I won't return. I have no tolerance for people who argue by asking questions and petulantly demanding unreasonable proof while providing absolutely nothing of their own.
My problem here is that I'm not sure which metaphorical goalposts you are referring to. By the way, constantly talking in terms of "fallacies" (especially these informal ones, as opposed to actual fallacies of propositional or predicate logic) just makes you sound like a petulant 15 year old. (Ad hominem -- I'll do that one for you.) Don't refer me to a Wikipedia page on the informal fallacy of the month; address what I'm saying instead. Otherwise, you may be guilty of the fallacy of Missing the Goddamn Point Because You're Looking For Fallacies Instead of Reading What the Other Guy has Written.
Getting back to the issue at hand, I can only suggest that you (a) reread the thread and (b) calm down. I am not accusing any scientists of failing to do basic statistics, and neither was anyone else. I am merely expressing my awesome ignorance of all things related to climate science, and suggesting that perhaps some of the other posters here are about as ignorant of these issues as I am, but lacking a suitable degree of caution in their statements.
Good luck with leaving HN. Sadly, I very much doubt that you will find any discussion sites worthy of your superior intellect.
I think you are confusing politics and science here. Apparently some scientists study the correlation between tree ring growth and temperature. This is a perfectly valid research area. It is OK to publish articles about, to announce to the world that at some time the correlation went away.
Climate research is research. It is not some know-it alls claiming one thing or another. It is making up theories and testing and aligning them with available data. It is trying to get new sources for data. And so on. It is an ongoing process.
Science never KNOWS anything. It only assigns weights and likelihoods.
We don't know if all history of earth is just an illusion, because we could just be a computer simulation that started 10 seconds ago.
So we will never KNOW if tree ring data at all times before 1960 correlated with temperature. All we can do is to collect evidence, make up theories and compare them with reality.
Something completely unknown is making tree rings too small after 1960. And if you correlate your tree ring data to post-1960 temperatures it makes historical temperature look way too high.
Bizarro-Briffa sent a similar letter to Bizarro-Nature warning of an unknown divergence problem and saying not to correlate tree rings to pre-1960 temperatures because it makes historical temperature look way too low.