Errors Adding Up

David Appell writes in Scientific American of a number of recent errors in climate science data identified by bloggers, and how, though largely trivial, they are undermining the faith in AGW.

While any error in science is important, and those identified should be swiftly corrected, my concern has always been non-trivial errors of statistics. My beef is that large tranches of AGW orthodoxy are supported by claims that do not pass standard tests of significance. Why is significance important? Wikipedia states that a result is called statistically significant if it is unlikely to have occurred by chance. Therefore many of the claims may be simple change occurrences that scientists are being fooled into believing by their own prejudices. For example:

  1. I called Rahmstorf on the claim that ‘the climate is more sensitive than we thought’, based on his untested, mangled and misunderstood methodology before he subsequently recanted.
  2. I have forthcoming submissions showing that sea level is not accelerating – its not, the models are non-significant in the acceleration terms, and based on the most recent satellite altimetry, sea level is significantly decelerating.
  3. I have shown that claim that current temperature levels are ‘unprecedented in the last 1000 years’, is based on faulty calculation of confidence limits that fails to account for selection bias in the proxies.
  4. I have submitted an article showing that water vapour feedback is strongly positive is based on a statistical methodology with an infinite variance, that is, it has no inherent confidence.
  5. The claim that droughts are going to increase enormously is based on projections of unvalidated climate models at variance with actual recorded significant decreases in droughts in the last 100 years.

The list goes on.

What possesses usually rational people to believe in things that fly in the face of standard testing of claims they learn in under-graduate school (one hopes)? To some extent the answer is; the claims are consistent with expectations based on the projections of the climate models. But the climate models are largely used without validation, even though it is acknowledged they have large errors in many areas, particularly precipitation. Either because the phenomenon is so subtle that it can’t be seen yet, or the models are wrong, there is a troubling disagreement between the models and reality across a range of phenomena.

And for one reason or another, climate scientists choose to believe their models, and forgo basic testing against reality. Many global warming papers do not report significance tests because if they did, they would show that there is no statistical significance to the phenomena they report on.

The general public are easily able to appreciate trivial errors in data, but less able to appreciate significant errors in statistics. Nevertheless, the errors in the data draw attention to the fact that climate science is not the squeaky clean paragon of science it is claimed to be.

I don’t expect everyone to be perfect. But if a paper contains no statistical tests to show the result is not a chance event, I assume it is a chance event and reject it. And every so-called scientist should do the same.

Read on in the Wiki article and find that tests of statistical significance are not perfect, but they are much more preferable to no tests at all, which seems to be the norm in climate science.

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0 thoughts on “Errors Adding Up

  1. Speaking of statistical significance…I think it is important to discuss what reasonable null hypotheses are in various situations.

    I was recently admonished for noting that, at face value of the OLS trend, the lower tropospheric data hasn’t warmed in slightly over twelve years. I apparently don’t know the meaning of “statistical significance”-okay, sure, I never quite made it through my high school stats class, but what a ridiculous statement! Not “statistically significant” implies that the result is not distinguishable statistically from a certain null hypothesis. I’m sure that the uncertainty in the trend over the last twelve years can encompass warming-but it would be more interesting to ask whether the models have a greater than 2.5% chance of not showing any warming over a twelve year period in the lower troposphere under realistic emissions scenarios over the next few decades. Frankly, I have to doubt whether any model shows that, let alone a small number on the low tail of the distribution.

    “In the Climate of Extremes, we don’t even do the simplest tests. Climate models are nothing but hypotheses-hypotheses must be subject to falsification, and if they fail tests they must be modified or abandoned. Try and find a real test of the climate models in the literature. You WON’T! But we could do it right here if you wanted.”~Patrick J. Michaels, Heartland Institutes 3rd International Conference on Climate Change

    Look here:
    http://www.worldclimatereport.com/index.php/2009/02/13/committee-on-energy-and-environment-testimony/
    And remember that the LT trend should be even greater than the surface trend. The twelve year trend is outside the confidence limits from the climate models-sounds like a hypothesis in the process of failing. See also:
    http://icecap.us/images/uploads/EPA_ChristyJR_Response_2.pdf

    David-I’m glad to see someone with statistics background looking into the “hypotheses” of AGW. The way I see it, the death of this “Vampire” can only be achieved by driving a hard stake of detailed analysis right into it’s heart.

    • Thanks Andrew. Sure there is going to be ‘argy-bargy’ over the form of the tests. PatM is also concerned that tests are not being done at all. All climate models are equal and believable, according to IPCC.

      I try to use the simplest most stock-standard tests. This is not of great academic interest, as it seems complicated novel methods get published all the time. But to me, its the most reliable source of information. You want to believe 100 speculative papers, or one paper that proves them wrong with a simple test? Take your pick.

  2. Speaking of statistical significance…I think it is important to discuss what reasonable null hypotheses are in various situations.I was recently admonished for noting that, at face value of the OLS trend, the lower tropospheric data hasn't warmed in slightly over twelve years. I apparently don't know the meaning of “statistical significance”-okay, sure, I never quite made it through my high school stats class, but what a ridiculous statement! Not “statistically significant” implies that the result is not distinguishable statistically from a certain null hypothesis. I'm sure that the uncertainty in the trend over the last twelve years can encompass warming-but it would be more interesting to ask whether the models have a greater than 2.5% chance of not showing any warming over a twelve year period in the lower troposphere under realistic emissions scenarios over the next few decades. Frankly, I have to doubt whether any model shows that, let alone a small number on the low tail of the distribution.”In the Climate of Extremes, we don't even do the simplest tests. Climate models are nothing but hypotheses-hypotheses must be subject to falsification, and if they fail tests they must be modified or abandoned. Try and find a real test of the climate models in the literature. You WON'T! But we could do it right here if you wanted.”~Patrick J. Michaels, Heartland Institutes 3rd International Conference on Climate ChangeLook here:http://www.worldclimatereport.com/index.php/200…And remember that the LT trend should be even greater than the surface trend. The twelve year trend is outside the confidence limits from the climate models-sounds like a hypothesis in the process of failing. See also:http://icecap.us/images/uploads/EPA_ChristyJR_R…David-I'm glad to see someone with statistics background looking into the “hypotheses” of AGW. The way I see it, the death of this “Vampire” can only be achieved by driving a hard stake of detailed analysis right into it's heart.

  3. Thanks Andrew. Sure there is going to be 'argy-bargy' over the form of the tests. PatM is also concerned that tests are not being done at all. All climate models are equal and believable, according to IPCC.I try to use the simplest most stock-standard tests. This is not of great academic interest, as it seems complicated novel methods get published all the time. But to me, its the most reliable source of information. You want to believe 100 speculative papers, or one paper that proves them wrong with a simple test? Take your pick.

  4. Thank you for continuing the thankless battle against the (religious left?, morons?, psuedoscientists?, money-hungry scientists?, environmental-extremobastards?, idiots?, ????). Some people really appreciate your brilliant thoughts!

    • Thanks jae, I hope that more of their colleagues start to check their work more closely, and there are promising signs of that too.

  5. Thank you for continuing the thankless battle against the (religious left?, morons?, psuedoscientists?, money-hungry scientists?, environmental-extremobastards?, idiots?, ????). Some people really appreciate your brilliant thoughts!

  6. Thanks jae, I hope that more of their colleagues start to check their work more closely, and there are promising signs of that too.

  7. Quite a lot of people disagree that statistical significance tests are preferable to no test at all and some are mentioned in that Wikipedia entry. A bad test can easily be worse than no test at all because it misleads via false confidence. I mentioned this to Wm Briggs on his blog and he also agreed that Statistics and Science in general would be better off if the idea of statistical significance completely disappeared. Armstrong mentions better methods in his texts “Significance Tests Harm Progress in Forecasting,” and “Statistical Significance Tests are Unnecessary Even When Properly Done” both mentioned in that Wikipedia entry.

    This is why it’s so easy for learned people to argue the toss about which test is relevant. Since none of them are truly relevant, for one reason or another, then the loudest voice will win. Whenever statistics is being used in science it is far too tempting for agenda-led scientists to misuse it. Climate science is only one of several soft sciences guilty of this; the only difference being that climate scientists like to use their own ad-hoc methods with little or no justification.

    • Briggs is probably an advocate of Bayesian expectations. I personally only quote p values so I don’t usually use significance tests either. What I should have said was ‘some extimate of uncertainty’, but then there are bad ones too.

      • I don’t think he would. Bayes just isn’t appropriate in climate science because too many people are just guessing. Though I’ve seen a few papers now where accumulating a bunch of guesses are assumed to somehow adequately replace real expertise (Annan and Hargreaves for example). An expert for Bayesian analysis has to be someone with a good track record of being correct: Somewhat in short supply among climateers.

        Briggs has his own quite interesting methods though: Less mathematical and more logical.

  8. Quite a lot of people disagree that statistical significance tests are preferable to no test at all and some are mentioned in that Wikipedia entry. A bad test can easily be worse than no test at all because it misleads via false confidence. I mentioned this to Wm Briggs on his blog and he also agreed that Statistics and Science in general would be better off if the idea of statistical significance completely disappeared. Armstrong mentions better methods in his texts “Significance Tests Harm Progress in Forecasting,” and “Statistical Significance Tests are Unnecessary Even When Properly Done” both mentioned in that Wikipedia entry.This is why it's so easy for learned people to argue the toss about which test is relevant. Since none of them are truly relevant, for one reason or another, then the loudest voice will win. Whenever statistics is being used in science it is far too tempting for agenda-led scientists to misuse it. Climate science is only one of several soft sciences guilty of this; the only difference being that climate scientists like to use their own ad-hoc methods with little or no justification.

  9. Briggs is probably an advocate of Bayesian expectations. I personally only quote p values so I don't usually use significance tests either. What I should have said was 'some extimate of uncertainty', but then there are bad ones too.

  10. Just to add another datapoint (and I’ll try to minimize editorial comment). As a chemist, I’ve been following claims of extraordinary accuracy in measuring ocean pH. So I was interested to read this:

    http://www.sciencedaily.com/releases/2009/08/090806112609.htm

    As it turns out, I’ve been following the “real time” data at the Hawaii web site, so much so that I made a point of downloading and saving this image in May.

    So when I read the sciencdaily article from the same group, I went back and viewed the graph, and, lo and behold:

    As you can see, the “observed” is in much better agreement with the “calculated”.

    One of my interests in this field deals with the uncertainties involved in “calculating” ocean pH based on measurements of CO2, carbonate, and bicarbonate, and then using “known” equilibrium constants to calculate the pH. The problem is that I’ve seen references to the fact that “synthetic” sea water has different equilibrium constants for this reaction than “real” ocean water, implying to me that there is some unknown buffering mechanism in “real” ocean water. Hence, when I see “observed” pH values (typically measured spectrophotometrically and requiring extreme care and calibration) differing from “calculated” pH values (also requiring extreme care and calibration), I pay attention.

    But somehow, the difference has now disappeared.

    What’s it mean? Who knows. All I know is that there is no explanation other than a generic warning that all data beyond 2007 is preliminary.

    • John M, its observations like these that pique your curiosity and get one
      started on an audit. I don’t know much about pH in the ocean, but suspect
      there is a lot more there than meets the eye, regarding the concentration of
      Aragonite, etc.
      Thanks

    • I’ll reply to myself to avoid the column narrowing that amused TCO so on another thread.

      ecoeng, my comments regarding uncertainty of pH measurements were related to buffering species present in seawater, not salinity. While it’s gratifying that so many smart fellers with fancy ‘puters can “model” this stuff, I was referring to the actual measurement of pH and how precise and accurate it might be. In this regard, I agree with Nick Stokes.

      For those interested in my precise point, I refer you to the first full paragraph on the left column of p. 135 of this paper

      http://aslo.org/lomethods/free/2004/0126.pdf

      and page 6 of this paper

      http://www.jodc.go.jp/info/ioc_doc/Experts/120608eo.pdf#8

      (second one is a slow download)

      I grant you that the unexplained discrepencies in the citations above are much less than in the graphs I originally linked to. I also grant that the state of the art may have advanced since 1999 or 2004, but concrete references rather than insults would have been helpful. Note that I’d be more impressed by experimental measurements than “models” (despite the title of this blog :)).

      But to get back to the premise of this post by David, why would publically available ocean pH data that showed mismatches between “calculated” and “observed” values going back almost 20 years suddenly fall into lock-step with no explanation?

      It’s too bad that “ocean acidification” has been latched onto as a headline-grabbing sound bite, since pH measurements are indeed open to so much question.

  11. Just to add another datapoint (and I'll try to minimize editorial comment). As a chemist, I've been following claims of extraordinary accuracy in measuring ocean pH. So I was interested to read this:http://www.sciencedaily.com/releases/2009/08/09…As it turns out, I've been following the “real time” data at the Hawaii web site, so much so that I made a point of downloading and saving this image in May.http://img197.imageshack.us/img197/4697/haph.jpgSo when I read the sciencdaily article from the same group, I went back and viewed the graph, and, lo and behold:http://img269.imageshack.us/img269/1092/haphnew…As you can see, the “observed” is in much better agreement with the “calculated”. One of my interests in this field deals with the uncertainties involved in “calculating” ocean pH based on measurements of CO2, carbonate, and bicarbonate, and then using “known” equilibrium constants to calculate the pH. The problem is that I've seen references to the fact that “synthetic” sea water has different equilibrium constants for this reaction than “real” ocean water, implying to me that there is some unknown buffering mechanism in “real” ocean water. Hence, when I see “observed” pH values (typically measured spectrophotometrically and requiring extreme care and calibration) differing from “calculated” pH values (also requiring extreme care and calibration), I pay attention. But somehow, the difference has now disappeared.What's it mean? Who knows. All I know is that there is no explanation other than a generic warning that all data beyond 2007 is preliminary.

  12. John M, its observations like these that pique your curiosity and get onestarted on an audit. I don't know much about pH in the ocean, but suspectthere is a lot more there than meets the eye, regarding the concentration ofAragonite, etc.Thanks

  13. I don't think he would. Bayes just isn't appropriate in climate science because too many people are just guessing. Though I've seen a few papers now where accumulating a bunch of guesses are assumed to somehow adequately replace real expertise (Annan and Hargreaves for example). An expert for Bayesian analysis has to be someone with a good track record of being correct: Somewhat in short supply among climateers.Briggs has his own quite interesting methods though: Less mathematical and more logical.

  14. Re John M on pH of oceans.

    About 1970 I did a draft of a Masters Thesis on electrode measurement of water extracts from agricultural soils. We used the best gear we could get, from Orion research, Mass., and we used several electrodes as well as pH. Maybe instrumentation has improved, but I have seen no evidence.

    We were unable to replicate readings to 0.1 pH, especially on dilute, unbuffered solutions and on solutions with high ionic strength (and seawater is in the latter category). Remember, pH is defined as the negative logarithm of the hydrogen ion activity, and activity is not the same as concentration.

    A year or so ago I wrote to IPCC author R Feeley from Oak Ridge, asking if they had done a simple titration of seawater with CO2. He did not answer.

    His papers are seemingly more dependent on stability diagrams, which I have also used. One of their characteristics is that the end result is very dependent on the accuracy of the coefficients used and on the relationship style, be it linear, log, exponential etc. Also, they are very dependent on the inclusion of all possible influences, which can be difficult in natural systems. Like the place of aragonite. Complex systems also depend on reaching equilibration and sometimes on correction for exothermic/endothermic reactions if measurements are done at other than STP or soon after a mixing.

    It is also important that the pH scale is a log scale and it needs conversion to linear before the application of a number of distribution/confidence tests. But you know this.

    So, ref the graphs you provide, having owned a moderately large laboratory, I can say that analytical chemists, like golfers, often have an inflated view of their ability. I used to. These days I usually disregard any pH stated to better than +/-0.5 pH in complex systems at about the pH of ocean water. I also wonder why a linear regression (as seen by eyeball) is applied to a log unit on the graphs you show. Maybe because the range is so small?

    • Understanding of the chemistry of aqueous (and even mixed aqueous/non-aqueous) systems is highly advanced – right up to the fused salts limit. The issue of the effect of the (modestly) increased ionic strength of seawater on pH is not a problem. These days, prediction of pH, Eh, osmotic pressure, viscosity etc in a whole host of such systems over a wide range of temperatures is not problematical – the science is well understood there are numerous comprehensive models/databases to do it with.

      The above comments by John M and Sherro are all naively incorrect I’m sorry to say.

      Just so happens aqueous/mixed aqueous non-aqueous chemothermodynamics is my field i.e. I actuaally do it every day for a living.

      This is not to say that the issue of declining pH of seawater is a significant problem – its significant has been vastly overstated by the AGW lobby. Just look at how many 100s of milions of years corals, nautiluses etc have been around!

      • But ecoeng, do you think the methods used in climate science are appropriate and state-of-art, or flawed?

      • IMHO, while the chemistry is well known, the assessment of the acidity-generating impacts of increased pCO2 on marine biota is complex.

        I would say many of the alarmist papers are deeply flawed.

        For short term effects they ignore the enormous resilience of aragonite- and calcite-secreting organisms – well demonstrated over many Ma. Recent state-of-the-art papers are clearly demonstrating this resilience.

        Why have the oysters retaken Chesapeake Bay so well you may well ask.

        Secondly, in respect of longer term effects there is manifest ignorance of the countervailing effects e.g. increased pCO2 increases continental plant and methanogenic bacterial activity. This in turn increase weathering rates, increasing the concentrations of Ca and Mg in runoff and groundwaters passing to the continental shelves (where the major of biogenic CaCO3-formers occur).

        Bottom line is we even have coral taxa which have continued to diversify right through past eras where pCO2 was as high as 1500 – 1700 ppmv.

        So it goes.

      • It was to be hoped that improvements have happened in pH and associated measurement as discussed. This is pleasing. I still find it difficult to accept a 0.1 pH unit change able to be reproduced, unless unknown to me there has been a breakthrough in electrode design. Or unless other non-electrode methods are used.

        My comments on the use of phase diagrams could have stressed, in hindsight, the need to accept
        uniformitarianism. While one can sample ocean water right now, would the changes to water chemistry caused by a major volcanic eruption be both predicted and modelled with accuracy? When so many chemical variables are needed to reach the final solution (so to speak) the accululation of model errors from phase digrams can be large, especially when one goes beyong first- and second-order interactions as can be envisaged.

        BTW, what does happen to the pH when you titrate seawater with CO2?

      • pH is hard to measure and doesn’t really matter. What you want to know is to what extent, if any, extra CO2 will cause the various kinds of CaCO3 to dissolve. That is determined by the concentrations of various COx species (and their equilibria), which are more abundant and easy to measure than H+.

      • “BTW, what does happen to the pH when you titrate seawater with CO2?”

        It decreases.

        “pH is hard to measure and doesn’t really matter.”

        pH is easy to measure (many methods) and matters much. Can you deny the power of that hydrated proton?

        The Saturation Indices (SIs) of calcite and aragonite are the key. Equilibrium thermodynamics is the constraining framework. Biogenically manipulated kinetics and surface free energy effects (phosphate, organics etc) form the cream on the coffee. Think Ostwald step rule.

        Always so much hard stuff to learn, thus always so much (sl)easy obscurantism begging to be indulged.

      • This is all very, very silly. pH is the negative logarithm of hydrogen ion activity. As such, it is a thermodynamic equilibrium parameter subject only to minimization of the Gibbs free energy of the overall system. The science of aqueous equilibrium thermodynamics is a very long developed (200 years plus) and very well known field! If the major cation (Na. K, Ca, Mg) and anion (Cl, SO4, Total Alkalinity) inventory of any particular sample of seawater (and they vary from location to location – especially on the continental shelves due to river inputs etc) has been measured it is relatively simple to calculate the pH (for any partial pressure of CO2) with high precision. This can be done manually on a few sheets of paper by solving about 20 simultaneous equations or it can be done with any competent aqueous speciation model e.g PHREEQC etc. The models are simply labor-saving devices which set up a Jacobian matrix to solve that suite of simultaneous equations. If one then measures the pH accurately it will be within 0.01 pH units of the calculated (model) value.

        To suggest that modern equilibrium chemothermodynamic models for e.g. seawater etc suffer from the same propensity for dodgy assumptions and hence lack of authority and precision as climate models is to have absolutely no understanding of the modern science and practice of equilibrium chemothermodynamics – one of the most sound fields of modern science.

        Last year I did a contract for the South Australian Water Corporation for the proposed City of Adelaide Reverse Osmosis (RO) Desalination Plant. The contract required me to predict theoretically pHs, chemical additive requirements for scaling control and osmotic pressures across RO membranes. The outcomes were simply state-of-the-art modelled values which can (and were) easily verified against real world plant performance parameters at many locations the world over.

        There is no point whatsoever trying to establish a sceptical ‘scientific’ position if the science of that position is simply technically illiterate, abysmally wrong-headed, and thus sub-standard.

        Isn’t this the sort of ‘science’ which we have been accusing, in my opinion quite rightly in many cases, the AGW bandwagon of promulgating?

        If you want to discuss more complex issues such as kinetic and other non-equilibrium thermodynamic issues of e.g. biogenic carbonate formation inside membranes then fine, lets do so. This is where it does get to be cutting edge (and good stuff), but let’s not descend into the irrelevant abyss of ‘combat’ between one lot of simplistic BS with more simplistic BS.

      • “This is all very silly.”

        It needn’t be. Perhaps if you would actually post some citations to help us all out rather than bragging about how many simultaneous equations you can solve it might help.

        “pH is the negative logarithm of hydrogen ion activity. ”

        Thanks. I understand a nucleus is made up of protons and neutrons too (most of the time).

        Look, I’m sure there’s a lot of smart people working on this. But I’m still looking for whether all of the buffering species in sea water are known and accounted for. It may very well be that cranking 20 simultaneous equations through a computer program (or maybe you solve those in a night at the bar) will solve for the equilbrium constants, but how well do those agree with constants determined independently? You can model all you want, but if you don’t know all the buffering species, the predictive value of your model over multiple decades of increasing CO2 is going to be in question, since you don’t have a mechanistic understanding of what you’re modeling.

        Maybe you do, but in the past when people have bragged to me about how “easy” it is to measure the pH of sea water and how well understood all the equilibria are, they haven’t provided me with any useful references. I’ve shown you mine…

        And BTW, about those original pH plots I linked to…

  15. Re John M on pH of oceans.About 1970 I did a draft of a Masters Thesis on electrode measurement of water extracts from agricultural soils. We used the best gear we could get, from Orion research, Mass., and we used several electrodes as well as pH. Maybe instrumentation has improved, but I have seen no evidence.We were unable to replicate readings to 0.1 pH, especially on dilute, unbuffered solutions and on solutions with high ionic strength (and seawater is in the latter category). Remember, pH is defined as the negative logarithm of the hydrogen ion activity, and activity is not the same as concentration.A year or so ago I wrote to IPCC author R Feeley from Oak Ridge, asking if they had done a simple titration of seawater with CO2. He did not answer.His papers are seemingly more dependent on stability diagrams, which I have also used. One of their characteristics is that the end result is very dependent on the accuracy of the coefficients used and on the relationship style, be it linear, log, exponential etc. Also, they are very dependent on the inclusion of all possible influences, which can be difficult in natural systems. Like the place of aragonite. Complex systems also depend on reaching equilibration and sometimes on correction for exothermic/endothermic reactions if measurements are done at other than STP or soon after a mixing.It is also important that the pH scale is a log scale and it needs conversion to linear before the application of a number of distribution/confidence tests. But you know this.So, ref the graphs you provide, having owned a moderately large laboratory, I can say that analytical chemists, like golfers, often have an inflated view of their ability. I used to. These days I usually disregard any pH stated to better than +/-0.5 pH in complex systems at about the pH of ocean water. I also wonder why a linear regression (as seen by eyeball) is applied to a log unit on the graphs you show. Maybe because the range is so small?

  16. Understanding of the chemistry of aqueous (and even mixed aqueous/non-aqueous) systems is highly advanced – right up to the fused salts limit. The issue of the effect of the (modestly) increased ionic strength of seawater on pH is not a problem. These days, prediction of pH, Eh, osmotic pressure, viscosity etc in a whole host of such systems over a wide range of temperatures is not problematical – the science is well understood there are numerous comprehensive models/databases to do it with. The above comments by John M and Sherro are all naively incorrect I'm sorry to say. Just so happens aqueous/mixed aqueous non-aqueous chemothermodynamics is my field i.e. I actuaally do it every day for a living.This is not to say that the issue of declining pH of seawater is a significant problem – its significant has been vastly overstated by the AGW lobby. Just look at how many 100s of milions of years corals, nautiluses etc have been around!

  17. IMHO, while the chemistry is well known, the assessment of the acidity-generating impacts of increased pCO2 on marine biota is complex. I would say many of the alarmist papers are deeply flawed. For short term effects they ignore the enormous resilience of aragonite- and calcite-secreting organisms – well demonstrated over many Ma. Recent state-of-the-art papers are clearly demonstrating this resilience.Why have the oysters retaken Chesapeake Bay so well you may well ask.Secondly, in respect of longer term effects there is manifest ignorance of the countervailing effects e.g. increased pCO2 increases continental plant and methanogenic bacterial activity. This in turn increase weathering rates, increasing the concentrations of Ca and Mg in runoff and groundwaters passing to the continental shelves (where the major of biogenic CaCO3-formers occur).Bottom line is we even have coral taxa which have continued to diversify right through past eras where pCO2 was as high as 1500 – 1700 ppmv.So it goes.

  18. It was to be hoped that improvements have happened in pH and associated measurement as discussed. This is pleasing. I still find it difficult to accept a 0.1 pH unit change able to be reproduced, unless unknown to me there has been a breakthrough in electrode design. Or unless other non-electrode methods are used.My comments on the use of phase diagrams could have stressed, in hindsight, the need to acceptuniformitarianism. While one can sample ocean water right now, would the changes to water chemistry caused by a major volcanic eruption be both predicted and modelled with accuracy? When so many chemical variables are needed to reach the final solution (so to speak) the accululation of model errors from phase digrams can be large, especially when one goes beyong first- and second-order interactions as can be envisaged.BTW, what does happen to the pH when you titrate seawater with CO2?

  19. pH is hard to measure and doesn't really matter. What you want to know is to what extent, if any, extra CO2 will cause the various kinds of CaCO3 to dissolve. That is determined by the concentrations of various COx species (and their equilibria), which are more abundant and easy to measure than H+.

  20. I'll reply to myself to avoid the column narrowing that amused TCO so on another thread.ecoeng, my comments regarding uncertainty of pH measurements were related to buffering species present in seawater, not salinity. While it's gratifying that so many smart fellers with fancy 'puters can “model” this stuff, I was referring to the actual measurement of pH and how precise and accurate it might be. In this regard, I agree with Nick Stokes. For those interested in my precise point, I refer you to the first full paragraph on the left column of p. 135 of this paper http://aslo.org/lomethods/free/2004/0126.pdfand page 6 of this paperhttp://www.jodc.go.jp/info/ioc_doc/Experts/1206…(second one is a slow download)I grant you that the unexplained discrepencies in the citations above are much less than in the graphs I originally linked to. I also grant that the state of the art may have advanced since 1999 or 2004, but concrete references rather than insults would have been helpful. Note that I'd be more impressed by experimental measurements than “models” (despite the title of this blog :)).But to get back to the premise of this post by David, why would publically available ocean pH data that showed mismatches between “calculated” and “observed” values going back almost 20 years suddenly fall into lock-step with no explanation?It's too bad that “ocean acidification” has been latched onto as a headline-grabbing sound bite, since pH measurements are indeed open to so much question.

  21. “BTW, what does happen to the pH when you titrate seawater with CO2?”It decreases.”pH is hard to measure and doesn't really matter.”pH is easy to measure (many methods) and matters much. Can you deny the power of that hydrated proton?The Saturation Indices (SIs) of calcite and aragonite are the key. Equilibrium thermodynamics is the constraining framework. Biogenically manipulated kinetics and surface free energy effects (phosphate, organics etc) form the cream on the coffee. Think Ostwald step rule.Always so much hard stuff to learn, thus always so much (sl)easy obscurantism begging to be indulged.

  22. Re ecoeng and Nick,

    Thanks for the responses. I agree with Nick that pH is hard to measure. However, without measuring it, you have an unknown in the solutions to stability diagrams, ecoeng.

    That’s a bit of a trite comment about titrating ocean water with CO2. It was a serious quantitative question and I no longer have the lab appartus to do it. Everyone I have asked has dodged the quantitative answer.

    The question has importance because one of the dogmas seen too often is that “The pH of the oceans is going acidic from man-made CO2 and new seashells will be deprived of carbonate. We’re all going to die”. As the great dictators of history knew so well, simple messages that children fear have enormous impact and can take years to place in context. Of course the titration will trend towards acidic, but by the expected amount and at the expected pace, without complex feedbacks, side reactions, etc?

    My questioning is along the lines of why people set up elaborate models when a simple sealing wax and string experiment can cast so much light.

    • And BTW, about those original pH plots I linked to…

      (1) (p135, Limnol. & Oceanogr. 2004)

      “The pH error arising
      from our TCO2 and TA accuracy is of the order ±0.005 units. Therefore errors in the constants seem the most probable
      cause. The outlier values of the surface samples in Fig. 8b
      cannot be explained easily but could be due to the sampling
      technique that may provide inexact salinity values. A more
      speculative explanation for the discrepancy could be acid-base
      systems not reflected in the alkalinity calculation but perhaps
      present in surface waters.”

      It is noted that this paper ignores the well known fact that dissolved methane is present in oceanic surface waters at levels far higher than would be expected for equilibrium with the atmospheric pCH4. This is due to the net fluxes from submarine seeps. Thus the high in situ (microbial) rate of conversion of CH4(aq) to CO2(aq) in near-surface seawater has not been taken into account in this study. As well as other issues such as the (high) level of precision with which the pK1&2 of carbonic acid is known (see below) this is another possible problem with this field study.

      (2) (p6, Joint IOC-JGOFS CO2 Advisory Panel Meeting, 1999)

      “Andrew Dickson led the discussion on this topic which focused on the discrepancies resulting
      from employing different sets of dissociation constants when calculating pC0, from measurements of
      total dissolved inorganic carbon, CT, and of the total alkalinity, AT, of a water sample. He illustrated
      the dimensions of the problem with the use of several plots of calculated pC0, over a range of
      temperatures and pressures using different sets of constants and fingered the subtle but important
      uncertainties that can arise with current practice.”

      Well this is simply all very good science! As Annex III shows, what they are discussing here are errors in the theoretical estimation of oceanic pH of <0.005 (!), which are possibly related to minor errors (<0.01) in the known values of pK1 (6.36) and pK2 (3.60). It is a principle of good science that fundamental constants are always be considered subject to a continuous process of checking and revision.

      A couple of points:

      (1) These are not, by a very long shot, errors at a level likely to lead, in themselves, to serious disputation about the degree of near-surface oceanic acidification due to rises in pCO2 of the order of 10s to 100s of ppmv.

      (2) Secondly, and even more importantly, near-surface seawater is NOT A STATIC MEDIUM. For example, it contains the nano-cyanobacterium Prochlorococcus at levels of ~100,000 cells/mL as well as the cyanobacterium Synechococcus at levels of the order of 10,000 cells/mL, each conducting photosynthesis (= absorption of CO2 and emission of O2) not to mention many other aerobic microbes. The surface also frequently has a monofilm on it of various lipids which can also interfere with water-air chemical equilibration. As I have noted above, the water also contains CH4 at levels higher than expected for equilibrium with atmospheric CH4. There is a lot going biogeochemically even in open ocean seawater (it gets even more complex closer to the continents) and many of these effects has the propensity to cause (VERY) minor variations in pH!

      In a nutshell, what John M and Sherro are on about here is called 'making a mountain out of a mole hill'.

      I strongly agree that much of what the AGW lobby is now on about is clearly a corruption of the (ever ongoing) processes and standards of good science.

      But that doesn't mean that I have to feel at all comfortable with armchair sceptics who want to nitpick good, hard, transparent science with antediluvian and lightweight inferences that somehow even the fundamentals of our science are deeply suspect, replacing that science with their own brand of medieval dogma.

      Neil Armstrong did not 'do it' in the back lot at Warner Brothers and we are a long, long, long way beyond the sealing wax and string stage here.

      • “But that doesn’t mean that I have to feel at all comfortable with armchair sceptics who want to nitpick good, hard, transparent science with antediluvian and lightweight inferences that somehow even the fundamentals of our science are deeply suspect, replacing that science with their own brand of medieval dogma.

        Neil Armstrong did not ‘do it’ in the back lot at Warner Brothers and we are a long, long, long way beyond the sealing wax and string stage here.”

        Well I guess your really are a climate scientist. You’ve perfected the “ridicule = persuasion” technique.

        Anyway, the “original images” I was referring to were these:

        For a measurement that you originally claimed was “easy”, it seems odd that the first figure above was publically presented for so long and then corrected to the second figure. And I really encourage folks to read the citations I linked to if they have any question as to whether pH determinations of seawater are “easy”, or is someone who questions the precision of such measurements is “naive”.

        While it may very well be that the “state of the art” gives the ability to measure pH to a precision of 0.01 units, this needs to be considered in the context that the purported rate of change is 0.02/decade. This is a rate extracted from data that not only includes the instrumental error measurement for the pH, but natural variations that are on the order of multiple 10ths of pH units.

        For further perspective, here is Figure 5.9 from AR4

        The text of the report says the trend is 0.02 pH units per decade. I’ll give you those +/- 0.01 error bars and I’ll leave it to others to speculate on whatever other errors and natural variability might be inherent in the data. Note that the “ESTOC” curve is the only one that is “experimental” pH measurements.

        The purported trend does indeed make a mole hill look like a mountain.

      • “While it may very well be that the “state of the art” gives the ability to measure pH to a precision of 0.01 units, this needs to be considered in the context that the purported rate of change is 0.02/decade. This is a rate extracted from data that not only includes the instrumental error measurement for the pH, but natural variations that are on the order of multiple 10ths of pH units.”

        Agreed.

        But my point is that this is all an utterly useless consideration because any such trends are not linear or even an easy non-linear function to discern simply because the whole system is so complex.

        The ‘problem’ (?) with precisely measuring (and hence understanding implications of) of oceanic pH (given that we know it is different everywhere in place and time) is not at all logically the same as simply measuring the level of, and trends in atmospheric CO2.

        I’m probably the only one here who has actually measured (diurnally!) pHs in the middle of open ocean cyanobacterial blooms or way out in the deltas of major rivers such as the Fly River.

        Oceanic inorganic carbon system complexity is easily discernible even now on a gross scale as I showed in my article on the 25-year scale behaviour of atmospheric pCO2 over the Great Southern Ocean on Niche Modeling earlier. Such mass action effects will become even more and more apparent as the decades of this century (and beyond) roll on.

        We need to clearly keep in mind that:

        (1) Increasing pCO2 is being increasingly adapted-to by the world’s ‘standing crop’ of marine cyanobacteria. This comprises about 45% of the world’s living biomass! This increases the rate of abstraction of DIC from surface waters and its conversion into TOC. This effect is also very dependent on the availability of critical nutrient such as iron, silicon and available nitrogen. Hence it is also affected by the anthropogenic flux of nitrogen into the continental shelves – a flux also rising with increasing population and one greater that the anthropogenic flux of CO2 into the atmosphere!

        (2) At the same time, the world’s standing crop of continental plants is also increasing due to CO2 fertilization. This is now proven. These comprise about 55% of the world’s living biomass. This, plus increased tillage with increasing population is in turn increasing the rate of soil and rock weathering which in turns increases the rate of export of Ca, Mg, Al, Si, Fe, Mn etc out of the worlds rivers and groundwaters into the continental shelves.

        All this is right now, and will in the future, affecting the sea aqueous concentrations of CO2 (CO2(aq)) and bicarbonate (HCO3-) and hey presto, as Nick points out, it all naturally shifts accordingly – including pH.

        In this context, it would be a very foolhardy person indeed who claimed to be able to understand the fundamental mathematical structure of fine trends in pH at any particular location in the world’s oceans, much less make some sort of meaning out it.

        On top of all this we have the equally important effect of adaptation (please see my other post).

        My simple question is this:

        Given all this, why get so hung up about issues of precision or indeed trends or (even worse) perceived ‘conspiracies of data massaging’ right down at the 0.01 pH unit level?

        This lovely planet is a big and highly complex system (fortunately for us).

        Let’s concentrate on getting a very good grip on the ‘big picture’.

      • ecoeng,

        The “hang up” and “conspiracies” were figments of you imagination. Please reread my original comment, in which (consistent with the theme of David’s original post) I merely pointed out the “now you see it, now you don’t” differences shown in publically available pH data. I then pointed out my interest in the technique and problems I perceived in its use.

        As it turns out, we now seem to be in agreement with regard to the overstating and over-reporting of ocean pH change. It certainly is true that the pH will drop with increasing CO2 levels, I’m just not convinced the quantitative ability to measure the current rate of change and forecast the future change is as advertised.

        At this point, I will yield to your expertise, particularly with regard to oceanic carbon chemistry.

      • You said:

        “But to get back to the premise of this post by David, why would publically available ocean pH data that showed mismatches between “calculated” and “observed” values going back almost 20 years suddenly fall into lock-step with no explanation?”

        Figment of what?

      • I’m open to an explanation.

        I think the point of the post is that climate scientists have to get used to public scrutiny of their data. After all, it is they who are wearing out a path to the media and clamoring for a policy role.

        When no explanations are given, it’s fair to ask why. ‘Tis even worse when honest questions are greeted with derision.

      • All true and agreed.

        I suggest the discussions at the Joint IOC-JGOFS CO2 Advisory Panel Meeting in 1999 (which you referenced) were a genuine attempt to grapple at a technical level with the observed minor discrepancies (between theory and measurement) and the correction of those mismatches resulted from resolution (post-1999) of the maters which Andrew Dickson and others had raised and discussed.

        In respect of the general issue of ocean acidification, it is becoming clear that there are plenty of overblown arguments being put by partisan scientists who want the general public to ignore both the deep complexity of the system and the well-referenced body of evidence for a complex array of trending forces and a high degree of past and present natural biological adaptation.

        The modern ‘green movement’ which has also co-opted much the scientific world (especially the younger generation who may have not got quite as rigorous an education as their elders) there is a strong tendency to believe that the global biogeosphere is a static, fixed thing for which any small perturbation somehow has to be, by definition, for the worse.

        This view is not only hopelessly naive but it is also dead wrong.

    • Sherro, you don’t have to measure pH. You have a set of well-understood equilibria. because of the limited symbols here, I’ll write ~ for equilibrium arrows:
      CO2 + H2O ~ H2CO3
      H2CO3 ~ HCO3- + H+
      HCO3- ~ CO3– + H+
      There’s another, Ca++ + CO3– ~ CaCO3, which is important, but I’ll leave it out here because it often isn’t actually in equilibrium. So we have 3 equilibrium relations and 5 concentrations (CO2, H2CO3, HCO3- CO3– and H+). So you only need two measurements. They usually use
      total inorganic C ([CO2]+[H2CO3]+[HCO3-]+[CO3–])
      total alkalinity ([HCO3-]+2[CO3–])
      Then you can algebraically get everything else, including pH.

      To get TA you titrate with strong acid to a pH of about 4.5. To get TIC you just acidify further and measure CO2 evolved.
      And OK, Steve will tell us it’s all much more complicated. But that’s the idea.

  23. Re ecoeng and Nick,Thanks for the responses. I agree with Nick that pH is hard to measure. However, without measuring it, you have an unknown in the solutions to stability diagrams, ecoeng.That's a bit of a trite comment about titrating ocean water with CO2. It was a serious quantitative question and I no longer have the lab appartus to do it. Everyone I have asked has dodged the quantitative answer.The question has importance because one of the dogmas seen too often is that “The pH of the oceans is going acidic from man-made CO2 and new seashells will be deprived of carbonate. We're all going to die”. As the great dictators of history knew so well, simple messages that children fear have enormous impact and can take years to place in context. Of course the titration will trend towards acidic, but by the expected amount and at the expected pace, without complex feedbacks, side reactions, etc?My questioning is along the lines of why people set up elaborate models when a simple sealing wax and string experiment can cast so much light.

  24. This is all very, very silly. pH is the negative logarithm of hydrogen ion activity. As such, it is a thermodynamic equilibrium parameter subject only to minimization of the Gibbs free energy of the overall system. The science of aqueous equilibrium thermodynamics is a very long developed (200 years plus) and very well known field! If the major cation (Na. K, Ca, Mg) and anion (Cl, SO4, Total Alkalinity) inventory of any particular sample of seawater (and they vary from location to location – especially on the continental shelves due to river inputs etc) has been measured it is relatively simple to calculate the pH (for any partial pressure of CO2) with high precision. This can be done manually on a few sheets of paper by solving about 20 simultaneous equations or it can be done with any competent aqueous speciation model e.g PHREEQC etc. The models are simply labor-saving devices which set up a Jacobian matrix to solve that suite of simultaneous equations. If one then measures the pH accurately it will be within 0.01 pH units of the calculated (model) value.To suggest that modern equilibrium chemothermodynamic models for e.g. seawater etc suffer from the same propensity for dodgy assumptions and hence lack of authority and precision as climate models is to have absolutely no understanding of the modern science and practice of equilibrium chemothermodynamics – one of the most sound fields of modern science.Last year I did a contract for the South Australian Water Corporation for the proposed City of Adelaide Reverse Osmosis (RO) Desalination Plant. The contract required me to predict theoretically pHs, chemical additive requirements for scaling control and osmotic pressures across RO membranes. The outcomes were simply state-of-the-art modelled values which can (and were) easily verified against real world plant performance parameters at many locations the world over.There is no point whatsoever trying to establish a sceptical 'scientific' position if the science of that position is simply technically illiterate, abysmally wrong-headed, and thus sub-standard. Isn't this the sort of 'science' which we have been accusing, in my opinion quite rightly in many cases, the AGW bandwagon of promulgating?If you want to discuss more complex issues such as kinetic and other non-equilibrium thermodynamic issues of e.g. biogenic carbonate formation inside membranes then fine, lets do so. This is where it does get to be cutting edge (and good stuff), but let's not descend into the irrelevant abyss of 'combat' between one lot of simplistic BS with more simplistic BS.

  25. “This is all very silly.”It needn't be. Perhaps if you would actually post some citations to help us all out rather than bragging about how many simultaneous equations you can solve it might help.”pH is the negative logarithm of hydrogen ion activity. “Thanks. I understand a nucleus is made up of protons and neutrons too (most of the time).Look, I'm sure there's a lot of smart people working on this. But I'm still looking for whether all of the buffering species in sea water are known and accounted for. It may very well be that cranking 20 simultaneous equations through a computer program (or maybe you solve those in a night at the bar) will solve for the equilbrium constants, but how well do those agree with constants determined independently? You can model all you want, but if you don't know all the buffering species, the predictive value of your model over multiple decades of increasing CO2 is going to be in question, since you don't have a mechanistic understanding of what you're modeling.Maybe you do, but in the past when people have bragged to me about how “easy” it is to measure the pH of sea water and how well understood all the equilibria are, they haven't provided me with any useful references. I've shown you mine…And BTW, about those original pH plots I linked to…

  26. And BTW, about those original pH plots I linked to…(1) (p135, Limnol. & Oceanogr. 2004)”The pH error arisingfrom our TCO2 and TA accuracy is of the order ±0.005 units. Therefore errors in the constants seem the most probablecause. The outlier values of the surface samples in Fig. 8bcannot be explained easily but could be due to the samplingtechnique that may provide inexact salinity values. A morespeculative explanation for the discrepancy could be acid-basesystems not reflected in the alkalinity calculation but perhapspresent in surface waters.”It is noted that this paper ignores the well known fact that dissolved methane is present in oceanic surface waters at levels far higher than would be expected for equilibrium with the atmospheric pCH4. This is due to the net fluxes from submarine seeps. Thus the high in situ (microbial) rate of conversion of CH4(aq) to CO2(aq) in near-surface seawater has not been taken into account in this study. As well as other issues such as the (high) level of precision with which the pK1&2 of carbonic acid is known (see below) this is another possible problem with this field study.(2) (p6, Joint IOC-JGOFS CO2 Advisory Panel Meeting, 1999)”Andrew Dickson led the discussion on this topic which focused on the discrepancies resultingfrom employing different sets of dissociation constants when calculating pC0, from measurements oftotal dissolved inorganic carbon, CT, and of the total alkalinity, AT, of a water sample. He illustratedthe dimensions of the problem with the use of several plots of calculated pC0, over a range oftemperatures and pressures using different sets of constants and fingered the subtle but importantuncertainties that can arise with current practice.”Well this is simply all very good science! As Annex III shows, what they are discussing here are errors in the theoretical estimation of oceanic pH of <0.005 (!), which are possibly related to minor errors (<0.01) in the known values of pK1 (6.36) and pK2 (3.60). It is a principle of good science that fundamental constants are always be considered subject to a continuous process of checking and revision. A couple of points:(1) These are not, by a very long shot, errors at a level likely to lead, in themselves, to serious disputation about the degree of near-surface oceanic acidification due to rises in pCO2 of the order of 10s to 100s of ppmv.(2) Secondly, and even more importantly, near-surface seawater is NOT A STATIC MEDIUM. For example, it contains the nano-cyanobacterium Prochlorococcus at levels of ~100,000 cells/mL as well as the cyanobacterium Synechococcus at levels of the order of 10,000 cells/mL, each conducting photosynthesis (= absorption of CO2 and emission of O2) not to mention many other aerobic microbes. The surface also frequently has a monofilm on it of various lipids which can also interfere with water-air chemical equilibration. As I have noted above, the water also contains CH4 at levels higher than expected for equilibrium with atmospheric CH4. There is a lot going biogeochemically even in open ocean seawater (it gets even more complex closer to the continents) and many of these effects has the propensity to cause (VERY) minor variations in pH! In a nutshell, what John M and Sherro are on about here is called 'making a mountain out of a mole hill'.I strongly agree that much of what the AGW lobby is now on about is clearly a corruption of the (ever ongoing) processes and standards of good science. But that doesn't mean that I have to feel at all comfortable with armchair sceptics who want to nitpick good, hard, transparent science with antediluvian and lightweight inferences that somehow even the fundamentals of our science are deeply suspect, replacing that science with their own brand of medieval dogma.Neil Armstrong did not 'do it' in the back lot at Warner Brothers and we are a long, long, long way beyond the sealing wax and string stage here.

  27. Sherro, you don't have to measure pH. You have a set of well-understood equilibria. because of the limited symbols here, I'll write ~ for equilibrium arrows:CO2 + H2O ~ H2CO3H2CO3 ~ HCO3- + H+HCO3- ~ CO3– + H+There's another, Ca++ + CO3– ~ CaCO3, which is important, but I'll leave it out here because it often isn't actually in equilibrium. So we have 3 equilibrium relations and 5 concentrations (CO2, H2CO3, HCO3- CO3– and H+). So you only need two measurements. They usually use total inorganic C ([CO2]+[H2CO3]+[HCO3-]+[CO3–])total alkalinity ([HCO3-]+2[CO3–])Then you can algebraically get everything else, including pH.To get TA you titrate with strong acid to a pH of about 4.5. To get TIC you just acidify further and measure CO2 evolved.And OK, Steve will tell us it's all much more complicated. But that's the idea.

  28. Making a mountain out of a molehill.

    In a loose sense, I am drawing a parallel between GCM deficiencies, overconfidence and lack of ability to verify. Here are some of the CSIRO results from a famous GCM comparison.
    Australia’s results are remarkably close to the mean. Starting from lowest altitude and going upwards in altitude, with results in millidegrees centigrade per decade, Australia VS multi-model mean is

    163 156
    213 198
    174 166
    181 177
    199 191
    204 203
    226 227
    271 272
    Then the figures start to diverge a little more.
    307 314
    200 320
    255 307
    166 268
    53 78

    The last digit in these columns is one part in a million of a degree C/decade.

    You are at liberty to chose the explanation of the extraordinary accuracy of these results. I caution care.

    Back to ocean pH. Suppose you want to give me a numerical answer to the change in pH of typical ocean water as it is titrated stepwise with CO2. Some questions arise.

    1. Do you filter the water first?

    2. If so, to exclude particles of which size?

    3. Do you make the test biologically sterile (eg killing bacteria, etc beforehand)

    4. Do you make an allowance for the methane seep you mentioned? How?

    5. How do you define a “typical” ocean water?

    6. Do you perform the titration at standard temperature or at simulated ocean temperature?

    7. How do you simulate the temperature, which varies enormously for many reasons, globally?

    8. Do you add your CO2 as a pure gas, or do you add it in a simulated above-ocean air? What is the composition of your simulated air?

    I could go on, but you can see that there is a disconnect from the realm of theory and nature.

    ecoeng, when you write “(1) These are not, by a very long shot, errors at a level likely to lead, in themselves, to serious disputation about the degree of near-surface oceanic acidification due to rises in pCO2 of the order of 10s to 100s of ppmv.”, please remember that I’m seeking numbers that show the pH to change as those pCO2s change.

    My contention is that the potential for error in the points I quoted is very likely to disallow sweeping comments that the “pH of the global oveans has changed by 0.1 pH unit as a result of the greenhouse gases made by mankind” or however a siilar statement might be worded.

    I dn’t like that word “antedeluvian”. I don’t like the word “revisionist” either. I happen to think, with years more of experience than you show, that talking of pH changes of 0.001 is about as open to criticism as claiming that the Antarctic is warming, in a paper where the author’s choice of mathematical method made or broke the paper. It was broke.

    • “I happen to think, with years more of experience than you show, that talking of pH changes of 0.001 is about as open to criticism as claiming that the Antarctic is warming,…”

      At age 60, with a doctorate in geochemistry, a few hundred papers and books chapters, and a mere 35 years in the field I’m well weathered enough to cop this sort of baloney (;-)

      Getting back to the real issue of ocean acidification.

      Rather than nitpicking about how many angels can fit onto the head of a pH 0.001 ‘pin’ we should be considering whether the likely changes in Saturation Indices (SIs) or Saturation Ratios (Omega) of calcite and aragonite induced by anthropogenic changes in pCO2 while the world’s fossil fuel resources are consumed are going to cause changes which significantly exceed the bounds within which such biogenic CaCO3-secreting organism have adapted over many Ma.

      This is the real issue.

      There is a great deal of paleological proxy evidence to suggest that the capacity of marine organisms to adapt to wide ranges in pCO2 and hence to SIs right down to near zero levels is very impressive indeed.

      For example, one only has to look at the longevity of the Nautilus which has survived, even exhibiting greater genetic diversity and greater geographic spread than the present day, through periods of significantly higher pCO2 than today.

      These observations raise very important issues surrounding the biogeochemical powers of natural evolution – specifically the durability of biological membranes e.g. on molluscs the periostracum , and the overall adaptability of biochemical controls on CaCO3 secretional kinetics within the enclosure of such membranes.

      Recently, there was a very interesting paper (Tunnicliffe et al. Nature Geoscience Vol. 2 May 2009, 344 -348) descibing the incidence of the submarine vent mussel Bathymodiolus brevior on the northwest Eifoku volcano, Mariana arc where liquid carbon dioxide (!) and hydrogen sulfide emerge in a submarine hydrothermal setting, to survive under natural conditions of pH values between 5.36 and 7.29.

      The authors remark on how..” where chemosynthetic symbiosis provides an energetic benefit to living in in a corrosive, low pH environment, (this) attests to the extent to which long-term adaptation can develop tolerance to extreme conditions. Thus, in a future scenario of a low-pH ocean, some species may adapt but the metabolic cost will be high’.

      Clearly, these authors have not considered the well-established longevity and diversity of, for example, even just the Caribbean coral gene pool over ranges of pCO2 exceeding 1000 ppmv.

      As happens so often in real science this is not an open and shut case that can be reduced to simplistic memories of e.g. high school chemistry.

  29. Making a mountain out of a molehill.In a loose sense, I am drawing a parallel between GCM deficiencies, overconfidence and lack of ability to verify. Here are some of the CSIRO results from a famous GCM comparison.Australia's results are remarkably close to the mean. Starting from lowest altitude and going upwards in altitude, with results in millidegrees centigrade per decade, Australia VS multi-model mean is163 156213 198174 166181 177199 191204 203226 227271 272Then the figures start to diverge a little more.307 314200 320255 307166 26853 78The last digit in these columns is one part in a million of a degree C/decade.You are at liberty to chose the explanation of the extraordinary accuracy of these results. I caution care.Back to ocean pH. Suppose you want to give me a numerical answer to the change in pH of typical ocean water as it is titrated stepwise with CO2. Some questions arise. 1. Do you filter the water first?2. If so, to exclude particles of which size?3. Do you make the test biologically sterile (eg killing bacteria, etc beforehand)4. Do you make an allowance for the methane seep you mentioned? How?5. How do you define a “typical” ocean water?6. Do you perform the titration at standard temperature or at simulated ocean temperature?7. How do you simulate the temperature, which varies enormously for many reasons, globally?8. Do you add your CO2 as a pure gas, or do you add it in a simulated above-ocean air? What is the composition of your simulated air?I could go on, but you can see that there is a disconnect from the realm of theory and nature.ecoeng, when you write “(1) These are not, by a very long shot, errors at a level likely to lead, in themselves, to serious disputation about the degree of near-surface oceanic acidification due to rises in pCO2 of the order of 10s to 100s of ppmv.”, please remember that I'm seeking numbers that show the pH to change as those pCO2s change.My contention is that the potential for error in the points I quoted is very likely to disallow sweeping comments that the “pH of the global oveans has changed by 0.1 pH unit as a result of the greenhouse gases made by mankind” or however a siilar statement might be worded.I dn't like that word “antedeluvian”. I don't like the word “revisionist” either. I happen to think, with years more of experience than you show, that talking of pH changes of 0.001 is about as open to criticism as claiming that the Antarctic is warming, in a paper where the author's choice of mathematical method made or broke the paper. It was broke.

  30. Nick, Thaks for the lecture in elementary inorganic chemistry, but it's the same as I learned in the 60s.I was also taught about Arrhenius, but that does not make GCMs perform better.Over the years I have noticed a tendency for errors to be estimated on constrained datasets rather than on all-embracing ones. On belief in the authority of the computer printout as opposed to the actual measurement. You know in your heart what I mean.

  31. Nick, Thaks for the lecture in elementary inorganic chemistry, but it’s the same as I learned in the 60s.

    I was also taught about Arrhenius, but that does not make GCMs perform better.

    Over the years I have noticed a tendency for errors to be estimated on constrained datasets rather than on all-embracing ones. On belief in the authority of the computer printout as opposed to the actual measurement. You know in your heart what I mean.

  32. “I happen to think, with years more of experience than you show, that talking of pH changes of 0.001 is about as open to criticism as claiming that the Antarctic is warming,…”At age 60, with a doctorate in geochemistry, a few hundred papers and books chapters, and a mere 35 years in the field I'm well weathered enough to cop this sort of baloney (;-)Getting back to the real issue of ocean acidification. Rather than nitpicking about how many angels can fit onto the head of a pH 0.001 'pin' we should be considering whether the likely changes in Saturation Indices (SIs) or Saturation Ratios (Omega) of calcite and aragonite induced by anthropogenic changes in pCO2 while the world's fossil fuel resources are consumed are going to cause changes which significantly exceed the bounds within which such biogenic CaCO3-secreting organism have adapted over many Ma.This is the real issue.There is a great deal of paleological proxy evidence to suggest that the capacity of marine organisms to adapt to wide ranges in pCO2 and hence to SIs right down to near zero levels is very impressive indeed. For example, one only has to look at the longevity of the Nautilus which has survived, even exhibiting greater genetic diversity and greater geographic spread than the present day, through periods of significantly higher pCO2 than today.These observations raise very important issues surrounding the biogeochemical powers of natural evolution – specifically the durability of biological membranes e.g. on molluscs the periostracum , and the overall adaptability of biochemical controls on CaCO3 secretional kinetics within the enclosure of such membranes.Recently, there was a very interesting paper (Tunnicliffe et al. Nature Geoscience Vol. 2 May 2009, 344 -348) descibing the incidence of the submarine vent mussel Bathymodiolus brevior on the northwest Eifoku volcano, Mariana arc where liquid carbon dioxide (!) and hydrogen sulfide emerge in a submarine hydrothermal setting, to survive under natural conditions of pH values between 5.36 and 7.29. The authors remark on how..” where chemosynthetic symbiosis provides an energetic benefit to living in in a corrosive, low pH environment, (this) attests to the extent to which long-term adaptation can develop tolerance to extreme conditions. Thus, in a future scenario of a low-pH ocean, some species may adapt but the metabolic cost will be high'.Clearly, these authors have not considered the well-established longevity and diversity of, for example, even just the Caribbean coral gene pool over ranges of pCO2 exceeding 1000 ppmv.As happens so often in real science this is not an open and shut case that can be reduced to simplistic memories of e.g. high school chemistry.

  33. “But that doesn't mean that I have to feel at all comfortable with armchair sceptics who want to nitpick good, hard, transparent science with antediluvian and lightweight inferences that somehow even the fundamentals of our science are deeply suspect, replacing that science with their own brand of medieval dogma.Neil Armstrong did not 'do it' in the back lot at Warner Brothers and we are a long, long, long way beyond the sealing wax and string stage here.”Well I guess your really are a climate scientist. You've perfected the “ridicule = persuasion” technique.Anyway, the “original images” I was referring to were these:http://img197.imageshack.us/img197/4697/haph.jpghttp://img269.imageshack.us/img269/1092/haphnew…For a measurement that you originally claimed was “easy”, it seems odd that the first figure above was publically presented for so long and then corrected to the second figure. And I really encourage folks to read the citations I linked to if they have any question as to whether pH determinations of seawater are “easy”, or is someone who questions the precision of such measurements is “naive”.While it may very well be that the “state of the art” gives the ability to measure pH to a precision of 0.01 units, this needs to be considered in the context that the purported rate of change is 0.02/decade. This is a rate extracted from data that not only includes the instrumental error measurement for the pH, but natural variations that are on the order of multiple 10ths of pH units.For further perspective, here is Figure 5.9 from AR4http://img269.imageshack.us/img269/3162/fig59.pngThe text of the report says the trend is 0.02 pH units per decade. I'll give you those +/- 0.01 error bars and I'll leave it to others to speculate on whatever other errors and natural variability might be inherent in the data. Note that the “ESTOC” curve is the only one that is “experimental” pH measurements.The purported trend does indeed make a mole hill look like a mountain.

  34. “While it may very well be that the “state of the art” gives the ability to measure pH to a precision of 0.01 units, this needs to be considered in the context that the purported rate of change is 0.02/decade. This is a rate extracted from data that not only includes the instrumental error measurement for the pH, but natural variations that are on the order of multiple 10ths of pH units.”Agreed.But my point is that this is all an utterly useless consideration because any such trends are not linear or even an easy non-linear function to discern simply because the whole system is so complex. The 'problem' (?) with precisely measuring (and hence understanding implications of) of oceanic pH (given that we know it is different everywhere in place and time) is not at all logically the same as simply measuring the level of, and trends in atmospheric CO2. I'm probably the only one here who has actually measured (diurnally!) pHs in the middle of open ocean cyanobacterial blooms or way out in the deltas of major rivers such as the Fly River.Oceanic inorganic carbon system complexity is easily discernible even now on a gross scale as I showed in my article on the 25-year scale behaviour of atmospheric pCO2 over the Great Southern Ocean on Niche Modeling earlier. Such mass action effects will become even more and more apparent as the decades of this century (and beyond) roll on.We need to clearly keep in mind that:(1) Increasing pCO2 is being increasingly adapted-to by the world's 'standing crop' of marine cyanobacteria. This comprises about 45% of the world's living biomass! This increases the rate of abstraction of DIC from surface waters and its conversion into TOC. This effect is also very dependent on the availability of critical nutrient such as iron, silicon and available nitrogen. Hence it is also affected by the anthropogenic flux of nitrogen into the continental shelves – a flux also rising with increasing population and one greater that the anthropogenic flux of CO2 into the atmosphere!(2) At the same time, the world's standing crop of continental plants is also increasing due to CO2 fertilization. This is now proven. These comprise about 55% of the world's living biomass. This, plus increased tillage with increasing population is in turn increasing the rate of soil and rock weathering which in turns increases the rate of export of Ca, Mg, Al, Si, Fe, Mn etc out of the worlds rivers and groundwaters into the continental shelves.All this is right now, and will in the future, affecting the sea aqueous concentrations of CO2 (CO2(aq)) and bicarbonate (HCO3-) and hey presto, as Nick points out, it all naturally shifts accordingly – including pH. In this context, it would be a very foolhardy person indeed who claimed to be able to understand the fundamental mathematical structure of fine trends in pH at any particular location in the world's oceans, much less make some sort of meaning out it. On top of all this we have the equally important effect of adaptation (please see my other post).My simple question is this:Given all this, why get so hung up about issues of precision or indeed trends or (even worse) perceived 'conspiracies of data massaging' right down at the 0.01 pH unit level?This lovely planet is a big and highly complex system (fortunately for us). Let's concentrate on getting a very good grip on the 'big picture'.

  35. ecoeng,The “hang up” and “conspiracies” were figments of you imagination. Please reread my original comment, in which (consistent with the theme of David's original post) I merely pointed out the “now you see it, now you don't” differences shown in publically available pH data. I then pointed out my interest in the technique and problems I perceived in its use.As it turns out, we now seem to be in agreement with regard to the overstating and over-reporting of ocean pH change. It certainly is true that the pH will drop with increasing CO2 levels, I'm just not convinced the quantitative ability to measure the current rate of change and forecast the future change is as advertised. At this point, I will yield to your expertise, particularly with regard to oceanic carbon chemistry.

  36. You said:”But to get back to the premise of this post by David, why would publically available ocean pH data that showed mismatches between “calculated” and “observed” values going back almost 20 years suddenly fall into lock-step with no explanation?”Figment of what?

  37. I'm open to an explanation.I think the point of the post is that climate scientists have to get used to public scrutiny of their data. After all, it is they who are wearing out a path to the media and clamoring for a policy role.When no explanations are given, it's fair to ask why. 'Tis even worse when honest questions are greeted with derision.

  38. All true and agreed. I suggest the discussions at the Joint IOC-JGOFS CO2 Advisory Panel Meeting in 1999 (which you referenced) were a genuine attempt to grapple at a technical level with the observed minor discrepancies (between theory and measurement) and the correction of those mismatches resulted from resolution (post-1999) of the maters which Andrew Dickson and others had raised and discussed.In respect of the general issue of ocean acidification, it is becoming clear that there are plenty of overblown arguments being put by partisan scientists who want the general public to ignore both the deep complexity of the system and the well-referenced body of evidence for a complex array of trending forces and a high degree of past and present natural biological adaptation.The modern 'green movement' which has also co-opted much the scientific world (especially the younger generation who may have not got quite as rigorous an education as their elders) there is a strong tendency to believe that the global biogeosphere is a static, fixed thing for which any small perturbation somehow has to be, by definition, for the worse.This view is not only hopelessly naive but it is also dead wrong.

  39. ecoeng,

    I’m happy to stop the old bull/young bull type discussion.

    Out of side interest, with your experience in the observation of numerical data, would you see the CSIRO GCM results as worth another look, or consider them just coincidence? That’s a philosophical question, not a computational one. Do I see trouble where I need not?

    One of the recurrent themes in climate science is that claims cannot be fully substantiated by performance. That is really why Climate Audit continues to grow. It shows that there is value in diligence when examining results. That is why some of us feel that climate science has some maturing to do before it can start to be accepted as a discipline able to stand on it feet with only occasional support by specialists from other branches of science.

    Now to oceanic pH. The area where I am weak and have refrained from comment is the interface between inorganic chemistry and life processes. I have done no particular studies looking at the rates of growth, repopulation, modification etc of marine species. However, I have done a modest amount on the growth of plants and I have to borrow some points from that field to progress further here.

    In a nutshell, plants grow in a wide variety of soil pH conditions, with some evidence of a broad preferred pH. The pH that I find of most interest is not that of the soil moisture in contact with minerals, or some extract of it, but the pH inside cells such as those at root tips where liquids form and some exudates are produced. The structural skeleton of plants is vastly different to that of shells, so the analogy can be taken only so far.

    Calcium and magnesium are well-known among the required plant nutrients. Calcium ions, for example, are released by the impact of certain tiny, heavy balls inside some root cells. Calcium ions alter the effect of auxins that control growth rates and cause the roots to generally point downwards (gravitropism). So if the roots are disturbed, the little balls roll around, release calcium ions, alter the auxin activity and slow the growth rates of cells at the base of the root tips.

    Now, in the sense that we do not start to see plant roots growing skywards outside certain soil pH ranges, one might infer that this calcium mechanism, if pH dependent, is controlled by a biological pH rather than an inorganic one.

    I’ll stop here beacuse I have not studied whether related concepts have been researched in depth in marine biology. In particular, I do not know if certain genera are at threat because they lack the ability to generate an approriate biological pH despite small fluctuations in water pH.

    Yes, I realise this is rather OT with calcite/aragonite/dolomite etc solubility. But, I wonder at which point the sea pH question is most important. Is it during nucleation and growth of marine organisms, or during their mature life, or in decay? Or all over the place, depending on the organism? So I reserve doubts about dogmatic statements that ocean acidification by 0.1 pH will greatly alter the population of marine biota. I just do not know.

    • “One of the recurrent themes in climate science is that claims cannot
      be fully substantiated by performance. That is really why Climate
      Audit continues to grow. It shows that there is value in diligence
      when examining results. That is why some of us feel that climate
      science has some maturing to do before it can start to be accepted as
      a discipline able to stand on it feet with only occasional support by
      specialists from other branches of science.”

      Nicely said too.

      • Exactly. Like any other science it was always meant to be simply a developing process, not some sort of a post-modernist (bowel) movement for lightweight 70s, 80s graduates….

        For example, apropos of Hockey Sticks, Medieval Warm Period, etc we now have, and much closer to the home of ENSO/PDO etc:

        A new 2,000-year-long reconstruction of sea surface temperatures (SST) from the Indo-Pacific warm pool (IPWP) suggests that temperatures in the region may have been as warm during the Medieval Warm Period as they are today.

        http://www.newswise.com/articles/view/555646/?sc=dwhn

  40. ecoeng,I'm happy to stop the old bull/young bull type discussion.Out of side interest, with your experience in the observation of numerical data, would you see the CSIRO GCM results as worth another look, or consider them just coincidence? That's a philosophical question, not a computational one. Do I see trouble where I need not?One of the recurrent themes in climate science is that claims cannot be fully substantiated by performance. That is really why Climate Audit continues to grow. It shows that there is value in diligence when examining results. That is why some of us feel that climate science has some maturing to do before it can start to be accepted as a discipline able to stand on it feet with only occasional support by specialists from other branches of science.Now to oceanic pH. The area where I am weak and have refrained from comment is the interface between inorganic chemistry and life processes. I have done no particular studies looking at the rates of growth, repopulation, modification etc of marine species. However, I have done a modest amount on the growth of plants and I have to borrow some points from that field to progress further here.In a nutshell, plants grow in a wide variety of soil pH conditions, with some evidence of a broad preferred pH. The pH that I find of most interest is not that of the soil moisture in contact with minerals, or some extract of it, but the pH inside cells such as those at root tips where liquids form and some exudates are produced. The structural skeleton of plants is vastly different to that of shells, so the analogy can be taken only so far.Calcium and magnesium are well-known among the required plant nutrients. Calcium ions, for example, are released by the impact of certain tiny, heavy balls inside some root cells. Calcium ions alter the effect of auxins that control growth rates and cause the roots to generally point downwards (gravitropism). So if the roots are disturbed, the little balls roll around, release calcium ions, alter the auxin activity and slow the growth rates of cells at the base of the root tips.Now, in the sense that we do not start to see plant roots growing skywards outside certain soil pH ranges, one might infer that this calcium mechanism, if pH dependent, is controlled by a biological pH rather than an inorganic one.I'll stop here beacuse I have not studied whether related concepts have been researched in depth in marine biology. In particular, I do not know if certain genera are at threat because they lack the ability to generate an approriate biological pH despite small fluctuations in water pH.Yes, I realise this is rather OT with calcite/aragonite/dolomite etc solubility. But, I wonder at which point the sea pH question is most important. Is it during nucleation and growth of marine organisms, or during their mature life, or in decay? Or all over the place, depending on the organism? So I reserve doubts about dogmatic statements that ocean acidification by 0.1 pH will greatly alter the population of marine biota. I just do not know.

  41. “One of the recurrent themes in climate science is that claims cannotbe fully substantiated by performance. That is really why ClimateAudit continues to grow. It shows that there is value in diligencewhen examining results. That is why some of us feel that climatescience has some maturing to do before it can start to be accepted asa discipline able to stand on it feet with only occasional support byspecialists from other branches of science.”Nicely said too.

  42. Exactly. Like any other science it was always meant to be simply a developing process, not some sort of a post-modernist (bowel) movement for lightweight 70s, 80s graduates….For example, apropos of Hockey Sticks, Medieval Warm Period, etc we now have, and much closer to the home of ENSO/PDO etc:A new 2,000-year-long reconstruction of sea surface temperatures (SST) from the Indo-Pacific warm pool (IPWP) suggests that temperatures in the region may have been as warm during the Medieval Warm Period as they are today.http://www.newswise.com/articles/view/555646/?s

  43. Exactly. Like any other science it was always meant to be simply a developing process, not some sort of a post-modernist (bowel) movement for lightweight 70s, 80s graduates….For example, apropos of Hockey Sticks, Medieval Warm Period, etc we now have, and much closer to the home of ENSO/PDO etc:A new 2,000-year-long reconstruction of sea surface temperatures (SST) from the Indo-Pacific warm pool (IPWP) suggests that temperatures in the region may have been as warm during the Medieval Warm Period as they are today.http://www.newswise.com/articles/view/555646/?s

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