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Why climatologists used the tree-ring data ‘trick’

39 points by MikeCapone 17y ago

hga 17y ago
Because otherwise people would have realized much earlier that their tree-ring data is not a useful proxy for temperature?
- bjelkeman-again 17y ago
  Do you have a good peer-reviewed article that shows that tree-ring data as a proxy for temperature is a poor fit. I'd be interested in reading it.
  - hga 17y ago
    a) One of the worst aspects of ClimateGate is how that group was keeping people less fervent than them out of the peer-reviewed literature. b) All you have to do is look at how their tree-ring data (MXD to be precise) diverges from recorded temperatures starting in 1960, it declines, to be precise, to know why they felt they had to "hide the decline". Heck, look at the chart where they cut off the green line that represents this data just as it's starting to fall and conveniently where it's in a thicket of other lines so that you won't easily notice the cutoff.
  - robotrout 17y ago
    I don't have one. That's sort of the problem, though, isn't it? With the climatologists interfering so strongly in the way this is supposed to work, by selecting which peers do their reviews, and by applying political pressure to the journals, the whole "look it up in the established body of work" approach has been sabotaged. EDIT: I forgot an important one. The collusion aspect that the emails revealed. We're not going to put this result in our paper, even though we believe it, because it messes up Scientist B's premise.
    - thaumaturgy 17y ago
      You're kidding, right? Evidence of absence is not proof. Imagine if this argument were used in other contexts: "there are no papers published in peer-reviewed journals about intelligent design. This proves that there's a conspiracy in the biological community!" In fact: there are a few published papers which challenge popular climatological measurements and papers, and they are cited as often as possible by ... I don't want to call them denialists, but I'm not sure what else to call them. So, wrong on both counts.
      - robotrout 17y ago
        Reread my post. I didn't say that the absence of papers proved anything. I said that the scientific process has been sabotaged in this instance, making things more unclear than they should be. You are slick though! EDIT: Perhaps you're honestly confused. I'm a bit doubtful on that, but in case you are. We know that the process has been sabotaged. Not because there are no papers, but because many of the details of the sabotage were revealed in the ClimateGate emails.
- thaumaturgy 17y ago
  You seem to be another carrier of the recent disease infecting HN, where users are commenting on articles that they didn't bother reading.
  - hga 17y ago
    Pray tell, how do you know I didn't read it? (In all fairness, I read some, skimmed the rest.)
    - thaumaturgy 17y ago
      Thanks (sincerely) for being honest about that, at least. There were two clues: one, your comment timestamp was not far removed from the time that the article was posted. I read pretty quickly, but it still took me some time to fully read and digest the entire article. Second, there was your statement: "their tree-ring data is not a useful proxy for temperature". The article specifically mentioned that tree-ring data correlated with other proxies for temperature measurements, as well as going into other details (like the difference between measuring ring thickness and ring density, and the fact that there has only somewhat recently been a divergence between the measurements). Basically, the article answered your statement, I think.
      - hga 17y ago
        No, it doesn't answer why they felt they had to "hide the decline" instead of discussing and justifying how the recent divergence is congruent with their claims of its usefulness as a proxy when there were no (accurate) temperature readings. These are not the actions of honest men.
        ugh 17y ago
        Well, they discussed it. In public. In peer reviewed journals. You know, this mail is not the only place where climate scientists talked about tree rings.
        17y ago
nice1 17y ago
Another thing worth remembering in this context is that once people get used to lying with a straight face it is a hell of a job to stop.
- MikeCapone 17y ago
  Indeed. But at least that's more discouraged in scientific circles than in think tanks and PR/astroturfing campaigns financed by those who want to discredit science for financial gain.
  - cwan 17y ago
    And you don't think that the billions of dollars at stake in carbon trading don't result in proponents attempting to discredit critics?
    - thaumaturgy 17y ago
      The current views in climatology were developed long before there were "billions at stake". Meanwhile, if there are "billions at stake" in the "green" industry, there are trillions at stake in those industries that would like to not have to install complicated and expensive filters for their manufacturing exhaust, and for the automotive industry which would surely love not to have to meet quite so stringent air quality standards. Can we at least agree that arguing about monetary motivation is problematic at best, and probably stupid, and stick to the actual science here?
      - cwan 17y ago
        Sure (though the millions at stake in academic research particularly given the political climate as the leaked emails illustrate are also of significance) - but let's first separate the conversation to understanding that (1) what's the problem and (2) what we should do about it are two separate issues. Let's also understand that much of the western world like the US are about to show significant declines in carbon emissions irrespective of what Fox news or any other polemics - pro or con say. (ref: http://www.guardian.co.uk/environment/2009/oct/15/us-decline-carbon-emissions http://www.guardian.co.uk/environment/2009/oct/15/us-decline...)
cwan 17y ago
This is how science is supposed to work. Sure there are a few straw men/ad hominem attacks peppered in the article but the proper response to criticism isn't calling the other side "denialists" and feigning offense but to respond with data and counter arguments. The problem that many of these scientists have themselves compounded is the shroud of secrecy they've put over their "normalized" and "value added" data and methodologies. Painting Armageddon like scenarios and then obstructing freedom of information act requests when people ask about how they came about their conclusions is at best bizarre. Meanwhile we have a myriad of rationalizations from their defenders that we should instead trust their peer review which at the very least, the CRU/UEA emails show are suspect at least in this field. Instead we are bombarded by these scientists/politicians who are anything but impartial who seem to present us with a binary choice that either we radically change our way of life which has serious risks in making us and the rest of the world significantly economically poorer or armageddon... and then they're surprised at the resistance? (This also ignores the myriad of policy responses like carbon trading being mired in corruption and leakages that are being advocated by these very same people) It would seem to me that there are two parts to the problem - first understanding conclusively what has been happening and what will happen and second deciding what the appropriate policy response will be. Personally, I think AGW is likely but I also think that we are on the cusp of a massive transition towards clean burning (and more importantly, cheap) natural gas and alternative energies which makes at least the emissions as generated by much of the Western world moot.
- jacoblyles 17y ago
  It still doesn't give a scientific reason why it is okay to truncate the tree ring temperature graph at 1960 and paste the real thermometer temperature graphs on top of them, except for the fact that it makes one hell of a picture. That's the "hiding the decline" that most people are concerned about. This article completely dances around that.
lionhearted 17y ago
I was going to comment that this borders on ad hominem: > FoxNews.com tells us that we finally have a 'smoking gun'--proof that scientists are manufacturing a global warming crisis so that they can… they can… You know, calling out political theater instead of acknowledging that reasonable people are concerned when they see scientific misconduct. I was going to explain that this sort of Fox News reference is not so good for the discussion - let the points stand, noting that one critic of yours is abrasive does not make the criticisms invalid. But, then I came upon this a little lower, which is a bit less subtle about it: > It's interesting stuff ... not interesting in the way that the rabid anti-science fuckhead (pardon me!) reality-denying luddite denialsphere types are saying, though. Why might the science be wrong? Because it's moved from science to an identity issue. Us vs. them. This guy isn't helping.
- rauljara 17y ago
  Not to disagree with you that ad hominem attacks aren't helpful, but the article laid out a lot of interesting data based arguments which you yourself completely ignored. Intentionally or not, you instead preceded to cast "the science" into doubt in an ad hominem fashion. Ad hominem attacks are besides the point, and degrade conversion, but just because people use them doesn't make everything they say wrong.
- thaumaturgy 17y ago
  This argument was framed in an "us vs. them" context a long time ago; that indeed has been one of the primary tactics and successes of the media engine of the right wing. It was obvious in Rush Limbaugh's earliest shows, and it's obvious in Fox News today. I don't think it's altogether wrong for some people to be getting frustrated by this.
- slyn 17y ago
  "Why might the science be wrong? Because it's moved from science to an identity issue. Us vs. them. This guy isn't helping." This is exactly why I choose to avoid the whole global warming climate debate thing. It is so hard to find any sort of unbiased information because everyone who talks about it has an agenda and forces it in your face. An Inconvenient Truth was actually gag worthy, an hour and fifteen minutes of Al Gore masturbating his ego over his crusade, five minutes of ridiculous cartoons, and maybe fifteen minutes of actual statistics. Obviously a station like Fox News or a talking head like Sean Hannity is going to push a right wing viewpoint to the death, so there is really no point bringing them up in any serious debate about basically anything. Even this posting, I just have a hard time taking this particular blog seriously given the "Evolution, development, and random biological ejaculations from a godless liberal", as the description, whether it is intended to be humorous or not. The whole global warming debate is not as clear cut (if you can call it that) as something like stem cell research where the issue was basically science vs morality/religion. Both sides have their own statistics, both sides try their hardest to refute the other sides' science, and even the people who actually agree with each other that there is global warming often have different opinions on what can actually be done (if anything) to fix the problem. When something like the climate-gate situation becomes public, it makes it even harder to actually take any of the science seriously, because one can only assume that the studies, experiments, and modeling is being done with the intention of proving one side right or wrong, which will undoubtedly lead to all sorts of unintended cognitive bias.
thaumaturgy 17y ago
If anything, I would expect the relatively recent divergence of correlation between tree-ring measurements and other climate measurements to bolster claims of an unstable climate, rather than suggest cooling. Here we have a situation where plant behavior closely follows other measurements of the climate for a very long time, and then recently ... they don't. The most likely explanation here -- still being studied, mind you -- is that there has been a significant change in the interaction between trees and environment in certain areas.
- deleted 17y ago
  [deleted]
- robotrout 17y ago
  Which "other measurements of the climate" are you referring to exactly? CO2 level is not a measurement of climate, of course. It seems to be correlated, but it's unknown if its phase is leading or lagging. So, what measurements are you referring to?
  - thaumaturgy 17y ago
    > CO2 level is not a measurement of climate, of course. LOL. Well, that's it. I'm done. Have a nice weekend, folks.
    - robotrout 17y ago
      If you honestly think that CO2 is the one and only cause of climate, ignoring solar cycles, and other effects, and furthermore, if you believe with certainty, that the CO2 cycle is phase shifted ahead in time, compared to temperature, when it's just as likely that it's lagging, than you're right, we really have no point in talking. Also based on your response, I think we now know what "other climate measurements" you were referring to.
- InclinedPlane 17y ago
  More accurately, it draws into question the accuracy of tree-ring measurements as a proxy for temperature. We do not have a situation "where plant behavior closely follows other measurements of the climate for a very long time". Instead we have a situation where one of the principle components of a small subset of tree-ring data generally follows other measurements of the climate for a very short time. And where even with all of that we still have "divergence" problems. These problems draw into question the validity of such measurements as a proxy for historical climate. If they do not track global temperature even a little accurately today how can we have any confidence that they do so in times long past when we don't have temperature records to check their accuracy? The answer is that we don't. And every indication seems to be that many of these proxy reconstructions from the CRU are wholly inaccurate representations of historical climate.
DanielBMarkham 17y ago
I have spent some hundreds of hours listening to arguments for global warming, er Catastrophic Anthropogenic Climate Change or AGW or ACC (or whatever the PC acronym is this week) The problem that I keep getting back to is best phrased like this: archaeological climate record extrapolation is nowhere near as sure-fire as supporters make it out to be. I have many more problems, but this one addresses the current article. I understand these are honest, hard-working scientists, and they know a heckuva lot more than I do about their particular area, but as an intelligent person I can make fairly informed guesses based on the standards of proof required and the types of phrases being used. There a lot of "it appears" and "it seems" in there, phrases that mean that while consensus has been achieved (we'll take that as a given for this comment) it's nowhere near a slam-dunk. There's also quite a bit of ad-hominem character assassination going on, even in this piece. I find that folks who have to result to labeling and name-calling usually are insecure about their position. Especially troubling is the way the current divergence is addressed. The argument looks to me like "we can use this data as a proxy for all periods except those where we have direct measurements to verify correlation" I find that weak at best. To me, the layman, tree-ring data is going to show you how well a certain tree grew in a certain place over time. That might or might not have implications for the larger area or the entire planet. Like so many other pieces of this argument, it depends on having a control group and repeatable experiments -- none of which are doable. So it boils down to speculation. Speculation by great, intelligent people, perhaps, but speculation nonetheless. I know some folks will say "no matter what the proof you're never going to believe" I don't know how to respond to that, except to point out that I've always been more interested in the character of the debate around GW and the political implications of letting scientific consensus drive public policy more than I have the actual facts on the ground. I have no more emotion invested in whether the planet is cooling or warming than I do variations of the gravitational constant around the time of the big bang. Whichever way the facts lead will not change my underlying concern. So I really don't have a dog in this fight as far as the science goes, at least not to the degree that some others do.
- algorias 17y ago
  This bothers me too. I don't know how tree-ring data is interpreted, but it's safe to assume that it's not a simple size of rings -> temperature mapping. How are the myriad of factors that contribute to tree growth accounted for?
fauigerzigerk 17y ago
It's interesting and important to read the comments below that article. What this shows is that seeing a smoking gun in the "nature trick" email alone is misplaced, but also that the interpretation of what's going on with those tree rings is not nearly as clear or uncontroversial as the global warming alarmists want us to believe.
w00pla 17y ago
Is anyone a little disturbed about that website? From the title "Evolution, development, and random biological ejaculations from a godless liberal". On the sidebar: "The Rise of Atheism, Global Atheist Convention". This guy is some type of Atheist cult member.
- albemuth 17y ago
  > "Atheist cult" That's quite an oxymoron don't you think?
  - btilly 17y ago
    Not at all. Atheism is without God or gods. This is not the same as without religion. As an example some Buddhist sects are both atheistic and cults.
jellicle 17y ago
Watching Hacker News argue about climate change is like watching the blind argue about colors. Please stop. In general you have no idea what you are talking about. Again and again and again and again there are comments along the lines of, "I did five minutes of Googling about this issue and I've come up with a fatal flaw in climate science!" Do you really think that the tens of thousands of scientists who do their life's work in this area are all fucking idiots? Every last one of them? You are late to the party. How greenhouse gases work has been thoroughly explored. The science of whether we'll get a substantial human-caused climate change from increasing the amount of atmospheric CO2 by 35% is done. It's over. The science now is in determining/predicting just how much it will be, and in predicting the effects. Every thread about climate science on Hacker News is one giant facepalm. Every thread. Please stop.
- pg 17y ago
  Your comment has even less evidence or analysis than the comments you're complaining about. It's just an angry assertion. It's ok for people to who are not experts in a subject to explore it. If you feel they're on the wrong track, help them by giving them information.
  - antonovka2 17y ago
    There's an over-abundance of information. All that's left for HN is angry, emotional quibbling by those who lack the basic qualifications to evaluate the data and science, even if they were interested in actually doing so.
    - Panoramix 17y ago
      The comments I've read so far present interesting POV's backed up by data and observations. I don't see how that qualifies as "angry emotional quibbling". I don't see the problem with discussing science either. Newton's law of gravitation has been around fot 322 years, and it has been shown to be just a very good approximation (like everything else in science). Also, it is still an open question (AFAIK) whether it holds at very small distances. Climate research is not physics. The number of variables and the complexity of the system is of such magnitude that I am pretty sure there will plenty of room for scientific discussion for years and years to come.
CamperBob 17y ago
FTA: The main cause seems to be increasing atmospheric carbon dioxide. Call me when you're sure. Extraordinary calls to action require extraordinary proof.
brc 17y ago
I've read through the article, and what it all says to me is that there are more questions on answers, and a lot of speculation as to the divergence problem. While there are some sound suggestions as to why, it would seem to me that these are all enough to discount tree rings as a useful proxy until they are better understood. To me, the use of statistical methods to blend out the divergence from a specific date seems like a real fudge.
sown 17y ago
I love HN. Everyone here is an expert on anything.
- vikram 17y ago
  Does one need to be an expert to follow the argument and form an opinion about it? If that was the case then why don't we let the experts make decisions, not just provide information.
rms 17y ago
If AGW is a vast scientific left-wing conspiracy, I think it's diabolically brilliant. Surely everyone thinks reducing pollution and fossil fuel dependency is important, right?
- hga 17y ago
  How important? Look at the arguments of Bjørn Lomborg, "The Skeptical Environmentalist". He says e.g. there are far better ways to spend the world's money to improve lives than e.g. what's being proposed WRT to AGW/CC.
  - rms 17y ago
    http://news.ycombinator.com/item?id=1005924 http://news.ycombinator.com/item?id=1005924

39 points by MikeCapone 17y ago

hga 17y ago

Because otherwise people would have realized much earlier that their tree-ring data is not a useful proxy for temperature?

bjelkeman-again 17y ago
Do you have a good peer-reviewed article that shows that tree-ring data as a proxy for temperature is a poor fit. I'd be interested in reading it.
- hga 17y ago
  a) One of the worst aspects of ClimateGate is how that group was keeping people less fervent than them out of the peer-reviewed literature. b) All you have to do is look at how their tree-ring data (MXD to be precise) diverges from recorded temperatures starting in 1960, it declines, to be precise, to know why they felt they had to "hide the decline". Heck, look at the chart where they cut off the green line that represents this data just as it's starting to fall and conveniently where it's in a thicket of other lines so that you won't easily notice the cutoff.
- robotrout 17y ago
  I don't have one. That's sort of the problem, though, isn't it? With the climatologists interfering so strongly in the way this is supposed to work, by selecting which peers do their reviews, and by applying political pressure to the journals, the whole "look it up in the established body of work" approach has been sabotaged. EDIT: I forgot an important one. The collusion aspect that the emails revealed. We're not going to put this result in our paper, even though we believe it, because it messes up Scientist B's premise.
  - thaumaturgy 17y ago
    You're kidding, right? Evidence of absence is not proof. Imagine if this argument were used in other contexts: "there are no papers published in peer-reviewed journals about intelligent design. This proves that there's a conspiracy in the biological community!" In fact: there are a few published papers which challenge popular climatological measurements and papers, and they are cited as often as possible by ... I don't want to call them denialists, but I'm not sure what else to call them. So, wrong on both counts.
    - robotrout 17y ago
      Reread my post. I didn't say that the absence of papers proved anything. I said that the scientific process has been sabotaged in this instance, making things more unclear than they should be. You are slick though! EDIT: Perhaps you're honestly confused. I'm a bit doubtful on that, but in case you are. We know that the process has been sabotaged. Not because there are no papers, but because many of the details of the sabotage were revealed in the ClimateGate emails.
thaumaturgy 17y ago
You seem to be another carrier of the recent disease infecting HN, where users are commenting on articles that they didn't bother reading.
- hga 17y ago
  Pray tell, how do you know I didn't read it? (In all fairness, I read some, skimmed the rest.)
  - thaumaturgy 17y ago
    Thanks (sincerely) for being honest about that, at least. There were two clues: one, your comment timestamp was not far removed from the time that the article was posted. I read pretty quickly, but it still took me some time to fully read and digest the entire article. Second, there was your statement: "their tree-ring data is not a useful proxy for temperature". The article specifically mentioned that tree-ring data correlated with other proxies for temperature measurements, as well as going into other details (like the difference between measuring ring thickness and ring density, and the fact that there has only somewhat recently been a divergence between the measurements). Basically, the article answered your statement, I think.
    - hga 17y ago
      No, it doesn't answer why they felt they had to "hide the decline" instead of discussing and justifying how the recent divergence is congruent with their claims of its usefulness as a proxy when there were no (accurate) temperature readings. These are not the actions of honest men.
      - ugh 17y ago
        Well, they discussed it. In public. In peer reviewed journals. You know, this mail is not the only place where climate scientists talked about tree rings.
        17y ago

nice1 17y ago

Another thing worth remembering in this context is that once people get used to lying with a straight face it is a hell of a job to stop.

MikeCapone 17y ago
Indeed. But at least that's more discouraged in scientific circles than in think tanks and PR/astroturfing campaigns financed by those who want to discredit science for financial gain.
- cwan 17y ago
  And you don't think that the billions of dollars at stake in carbon trading don't result in proponents attempting to discredit critics?
  - thaumaturgy 17y ago
    The current views in climatology were developed long before there were "billions at stake". Meanwhile, if there are "billions at stake" in the "green" industry, there are trillions at stake in those industries that would like to not have to install complicated and expensive filters for their manufacturing exhaust, and for the automotive industry which would surely love not to have to meet quite so stringent air quality standards. Can we at least agree that arguing about monetary motivation is problematic at best, and probably stupid, and stick to the actual science here?
    - cwan 17y ago
      Sure (though the millions at stake in academic research particularly given the political climate as the leaked emails illustrate are also of significance) - but let's first separate the conversation to understanding that (1) what's the problem and (2) what we should do about it are two separate issues. Let's also understand that much of the western world like the US are about to show significant declines in carbon emissions irrespective of what Fox news or any other polemics - pro or con say. (ref: http://www.guardian.co.uk/environment/2009/oct/15/us-decline-carbon-emissions http://www.guardian.co.uk/environment/2009/oct/15/us-decline...)

cwan 17y ago

This is how science is supposed to work. Sure there are a few straw men/ad hominem attacks peppered in the article but the proper response to criticism isn't calling the other side "denialists" and feigning offense but to respond with data and counter arguments. The problem that many of these scientists have themselves compounded is the shroud of secrecy they've put over their "normalized" and "value added" data and methodologies. Painting Armageddon like scenarios and then obstructing freedom of information act requests when people ask about how they came about their conclusions is at best bizarre. Meanwhile we have a myriad of rationalizations from their defenders that we should instead trust their peer review which at the very least, the CRU/UEA emails show are suspect at least in this field. Instead we are bombarded by these scientists/politicians who are anything but impartial who seem to present us with a binary choice that either we radically change our way of life which has serious risks in making us and the rest of the world significantly economically poorer or armageddon... and then they're surprised at the resistance? (This also ignores the myriad of policy responses like carbon trading being mired in corruption and leakages that are being advocated by these very same people) It would seem to me that there are two parts to the problem - first understanding conclusively what has been happening and what will happen and second deciding what the appropriate policy response will be. Personally, I think AGW is likely but I also think that we are on the cusp of a massive transition towards clean burning (and more importantly, cheap) natural gas and alternative energies which makes at least the emissions as generated by much of the Western world moot.

jacoblyles 17y ago
It still doesn't give a scientific reason why it is okay to truncate the tree ring temperature graph at 1960 and paste the real thermometer temperature graphs on top of them, except for the fact that it makes one hell of a picture. That's the "hiding the decline" that most people are concerned about. This article completely dances around that.

lionhearted 17y ago

I was going to comment that this borders on ad hominem: > FoxNews.com tells us that we finally have a 'smoking gun'--proof that scientists are manufacturing a global warming crisis so that they can… they can… You know, calling out political theater instead of acknowledging that reasonable people are concerned when they see scientific misconduct. I was going to explain that this sort of Fox News reference is not so good for the discussion - let the points stand, noting that one critic of yours is abrasive does not make the criticisms invalid. But, then I came upon this a little lower, which is a bit less subtle about it: > It's interesting stuff ... not interesting in the way that the rabid anti-science fuckhead (pardon me!) reality-denying luddite denialsphere types are saying, though. Why might the science be wrong? Because it's moved from science to an identity issue. Us vs. them. This guy isn't helping.

rauljara 17y ago
Not to disagree with you that ad hominem attacks aren't helpful, but the article laid out a lot of interesting data based arguments which you yourself completely ignored. Intentionally or not, you instead preceded to cast "the science" into doubt in an ad hominem fashion. Ad hominem attacks are besides the point, and degrade conversion, but just because people use them doesn't make everything they say wrong.
thaumaturgy 17y ago
This argument was framed in an "us vs. them" context a long time ago; that indeed has been one of the primary tactics and successes of the media engine of the right wing. It was obvious in Rush Limbaugh's earliest shows, and it's obvious in Fox News today. I don't think it's altogether wrong for some people to be getting frustrated by this.
slyn 17y ago
"Why might the science be wrong? Because it's moved from science to an identity issue. Us vs. them. This guy isn't helping." This is exactly why I choose to avoid the whole global warming climate debate thing. It is so hard to find any sort of unbiased information because everyone who talks about it has an agenda and forces it in your face. An Inconvenient Truth was actually gag worthy, an hour and fifteen minutes of Al Gore masturbating his ego over his crusade, five minutes of ridiculous cartoons, and maybe fifteen minutes of actual statistics. Obviously a station like Fox News or a talking head like Sean Hannity is going to push a right wing viewpoint to the death, so there is really no point bringing them up in any serious debate about basically anything. Even this posting, I just have a hard time taking this particular blog seriously given the "Evolution, development, and random biological ejaculations from a godless liberal", as the description, whether it is intended to be humorous or not. The whole global warming debate is not as clear cut (if you can call it that) as something like stem cell research where the issue was basically science vs morality/religion. Both sides have their own statistics, both sides try their hardest to refute the other sides' science, and even the people who actually agree with each other that there is global warming often have different opinions on what can actually be done (if anything) to fix the problem. When something like the climate-gate situation becomes public, it makes it even harder to actually take any of the science seriously, because one can only assume that the studies, experiments, and modeling is being done with the intention of proving one side right or wrong, which will undoubtedly lead to all sorts of unintended cognitive bias.

thaumaturgy 17y ago

If anything, I would expect the relatively recent divergence of correlation between tree-ring measurements and other climate measurements to bolster claims of an unstable climate, rather than suggest cooling. Here we have a situation where plant behavior closely follows other measurements of the climate for a very long time, and then recently ... they don't. The most likely explanation here -- still being studied, mind you -- is that there has been a significant change in the interaction between trees and environment in certain areas.

deleted 17y ago
[deleted]
robotrout 17y ago
Which "other measurements of the climate" are you referring to exactly? CO2 level is not a measurement of climate, of course. It seems to be correlated, but it's unknown if its phase is leading or lagging. So, what measurements are you referring to?
- thaumaturgy 17y ago
  > CO2 level is not a measurement of climate, of course. LOL. Well, that's it. I'm done. Have a nice weekend, folks.
  - robotrout 17y ago
    If you honestly think that CO2 is the one and only cause of climate, ignoring solar cycles, and other effects, and furthermore, if you believe with certainty, that the CO2 cycle is phase shifted ahead in time, compared to temperature, when it's just as likely that it's lagging, than you're right, we really have no point in talking. Also based on your response, I think we now know what "other climate measurements" you were referring to.
InclinedPlane 17y ago
More accurately, it draws into question the accuracy of tree-ring measurements as a proxy for temperature. We do not have a situation "where plant behavior closely follows other measurements of the climate for a very long time". Instead we have a situation where one of the principle components of a small subset of tree-ring data generally follows other measurements of the climate for a very short time. And where even with all of that we still have "divergence" problems. These problems draw into question the validity of such measurements as a proxy for historical climate. If they do not track global temperature even a little accurately today how can we have any confidence that they do so in times long past when we don't have temperature records to check their accuracy? The answer is that we don't. And every indication seems to be that many of these proxy reconstructions from the CRU are wholly inaccurate representations of historical climate.

DanielBMarkham 17y ago

I have spent some hundreds of hours listening to arguments for global warming, er Catastrophic Anthropogenic Climate Change or AGW or ACC (or whatever the PC acronym is this week) The problem that I keep getting back to is best phrased like this: archaeological climate record extrapolation is nowhere near as sure-fire as supporters make it out to be. I have many more problems, but this one addresses the current article. I understand these are honest, hard-working scientists, and they know a heckuva lot more than I do about their particular area, but as an intelligent person I can make fairly informed guesses based on the standards of proof required and the types of phrases being used. There a lot of "it appears" and "it seems" in there, phrases that mean that while consensus has been achieved (we'll take that as a given for this comment) it's nowhere near a slam-dunk. There's also quite a bit of ad-hominem character assassination going on, even in this piece. I find that folks who have to result to labeling and name-calling usually are insecure about their position. Especially troubling is the way the current divergence is addressed. The argument looks to me like "we can use this data as a proxy for all periods except those where we have direct measurements to verify correlation" I find that weak at best. To me, the layman, tree-ring data is going to show you how well a certain tree grew in a certain place over time. That might or might not have implications for the larger area or the entire planet. Like so many other pieces of this argument, it depends on having a control group and repeatable experiments -- none of which are doable. So it boils down to speculation. Speculation by great, intelligent people, perhaps, but speculation nonetheless. I know some folks will say "no matter what the proof you're never going to believe" I don't know how to respond to that, except to point out that I've always been more interested in the character of the debate around GW and the political implications of letting scientific consensus drive public policy more than I have the actual facts on the ground. I have no more emotion invested in whether the planet is cooling or warming than I do variations of the gravitational constant around the time of the big bang. Whichever way the facts lead will not change my underlying concern. So I really don't have a dog in this fight as far as the science goes, at least not to the degree that some others do.

algorias 17y ago
This bothers me too. I don't know how tree-ring data is interpreted, but it's safe to assume that it's not a simple size of rings -> temperature mapping. How are the myriad of factors that contribute to tree growth accounted for?

fauigerzigerk 17y ago

It's interesting and important to read the comments below that article. What this shows is that seeing a smoking gun in the "nature trick" email alone is misplaced, but also that the interpretation of what's going on with those tree rings is not nearly as clear or uncontroversial as the global warming alarmists want us to believe.

w00pla 17y ago

Is anyone a little disturbed about that website? From the title "Evolution, development, and random biological ejaculations from a godless liberal". On the sidebar: "The Rise of Atheism, Global Atheist Convention". This guy is some type of Atheist cult member.

albemuth 17y ago
> "Atheist cult" That's quite an oxymoron don't you think?
- btilly 17y ago
  Not at all. Atheism is without God or gods. This is not the same as without religion. As an example some Buddhist sects are both atheistic and cults.

jellicle 17y ago

Watching Hacker News argue about climate change is like watching the blind argue about colors. Please stop. In general you have no idea what you are talking about. Again and again and again and again there are comments along the lines of, "I did five minutes of Googling about this issue and I've come up with a fatal flaw in climate science!" Do you really think that the tens of thousands of scientists who do their life's work in this area are all fucking idiots? Every last one of them? You are late to the party. How greenhouse gases work has been thoroughly explored. The science of whether we'll get a substantial human-caused climate change from increasing the amount of atmospheric CO2 by 35% is done. It's over. The science now is in determining/predicting just how much it will be, and in predicting the effects. Every thread about climate science on Hacker News is one giant facepalm. Every thread. Please stop.

pg 17y ago
Your comment has even less evidence or analysis than the comments you're complaining about. It's just an angry assertion. It's ok for people to who are not experts in a subject to explore it. If you feel they're on the wrong track, help them by giving them information.
- antonovka2 17y ago
  There's an over-abundance of information. All that's left for HN is angry, emotional quibbling by those who lack the basic qualifications to evaluate the data and science, even if they were interested in actually doing so.
  - Panoramix 17y ago
    The comments I've read so far present interesting POV's backed up by data and observations. I don't see how that qualifies as "angry emotional quibbling". I don't see the problem with discussing science either. Newton's law of gravitation has been around fot 322 years, and it has been shown to be just a very good approximation (like everything else in science). Also, it is still an open question (AFAIK) whether it holds at very small distances. Climate research is not physics. The number of variables and the complexity of the system is of such magnitude that I am pretty sure there will plenty of room for scientific discussion for years and years to come.

CamperBob 17y ago

FTA: The main cause seems to be increasing atmospheric carbon dioxide. Call me when you're sure. Extraordinary calls to action require extraordinary proof.

brc 17y ago

I've read through the article, and what it all says to me is that there are more questions on answers, and a lot of speculation as to the divergence problem. While there are some sound suggestions as to why, it would seem to me that these are all enough to discount tree rings as a useful proxy until they are better understood. To me, the use of statistical methods to blend out the divergence from a specific date seems like a real fudge.

sown 17y ago

I love HN. Everyone here is an expert on anything.

vikram 17y ago
Does one need to be an expert to follow the argument and form an opinion about it? If that was the case then why don't we let the experts make decisions, not just provide information.

rms 17y ago

If AGW is a vast scientific left-wing conspiracy, I think it's diabolically brilliant. Surely everyone thinks reducing pollution and fossil fuel dependency is important, right?

hga 17y ago
How important? Look at the arguments of Bjørn Lomborg, "The Skeptical Environmentalist". He says e.g. there are far better ways to spend the world's money to improve lives than e.g. what's being proposed WRT to AGW/CC.
- rms 17y ago
  http://news.ycombinator.com/item?id=1005924 http://news.ycombinator.com/item?id=1005924