Guest Post by Willis Eschenbach
I’m a long-time ocean devotee. I’ve spent a good chunk of my life on and under the ocean as a commercial and sport fisherman, a surfer, a blue-water sailor, and a commercial and sport diver. So I’m concerned that the new poster-boy of alarmism these days is sea-water “acidification” from CO2 dissolving into the ocean. Heck, even the name “acidification” is alarmist, because sea water is not acid, nor will it every be. What we are seeing is a slight reduction in how alkaline the sea water is.
There is a recent and interesting study in GRL by Byrne et al., entitled “Direct observations of basin-wide acidification of the North Pacific Ocean“. This study reports on the change in ocean alkalinity over a 15 year period (1991-2006) along a transect of the North Pacific from Hawaii to Alaska. (A “transect” is a path along which one measures some variable or variables.) Here is the path of the transect:
Figure 1. Path (transect) used for the measurement of the change in oceanic alkalinity.
I love researching climate, because there’s always so much to learn. Here’s what I learned from the Byrne et al. paper.
The first thing that I learned is that when you go from the tropics (Hawaii) to the North Pacific (Alaska), the water becomes less and less alkaline. Who knew? So even without any CO2, if you want to experience “acidification” of the ocean water, just go from Hawaii to Alaska … you didn’t notice the change from the “acidification”? You didn’t have your toenails dissolved by the increased acidity?
Well, the sea creatures didn’t notice either. They flourish in both the more alkaline Hawaiian waters and the less alkaline Alaskan waters. So let’s take a look at how large the change is along the transect.
Changes in alkalinity/acidity are measured in units called “pH”. A neutral solution has a pH of 7.0. Above a pH of 7.0, the solution is alkaline. A solution with a pH less than 7.0 is acidic. pH is a logarithmic scale, so a solution with a pH of 9.0 is ten times as alkaline as a solution with a pH of 8.0.
Figure 2 shows the measured pH along the transect. The full size graphic is here.
Figure 2. Measured ocean pH from the surface down to the ocean bottom along the transect shown in Figure 1.
The second thing I learned from the study is that the pH of the ocean is very different in different locations. As one goes from Hawaii to Alaska the pH slowly decreases along the transect, dropping from 8.05 all the way down to 7.65. This is a change in pH of almost half a unit. And everywhere along the transect, the water at depth is much less alkaline, with a minimum value of about 7.25.
The third thing I learned from the study is how little humans have changed the pH of the ocean. Figure 3 shows their graph of the anthropogenic pH changes along the transect. The full-sized graphic is here:
Figure 3. Anthropogenic changes in the pH, from the surface to 1,000 metres depth, over 15 years (1991-2006)
The area of the greatest anthropogenic change over the fifteen years of the study, as one might imagine, is at the surface. The maximum anthropogenic change over the entire transect was -0.03 pH in fifteen years. The average anthropogenic change over the top 150 metre depth was -0.023. From there down to 800 metres the average anthropogenic change was -0.011 in fifteen years.
This means that for the top 800 metres of the ocean, where the majority of the oceanic life exists, the human induced change in pH was -0.013 over 15 years. This was also about the amount of pH change in the waters around Hawaii.
Now, remember that the difference in pH between the surface water in Hawaii and Alaskan is 0.50 pH units. That means that at the current rate of change, the surface water in Hawaii will be as alkaline as the current Alaskan surface water in … well … um … lessee, divide by eleventeen, carry the quadratic residual … I get a figure of 566 years.
But of course, that is assuming that there would not be any mixing of the water during that half-millennium. The ocean is a huge place, containing a vast amount of carbon. The atmosphere contains about 750 gigatonnes of carbon in the form of CO2. The ocean contains about fifty times that amount. It is slowly mixed by wind, wave, and currents. As a result, the human carbon contribution will not stay in the upper layers as shown in the graphs above. It will be mixed into the deeper layers. Some will go into the sediments. Some will precipitate out of solution. So even in 500 years, Hawaiian waters are very unlikely to have the alkalinity of Alaskan waters.
The final thing I learned from this study is that creatures in the ocean live happily in a wide range of alkalinities, from a high of over 8.0 down to almost neutral. As a result, the idea that a slight change in alkalinity will somehow knock the ocean dead doesn’t make any sense. By geological standards, the CO2 concentration in the atmosphere is currently quite low. It has been several times higher in the past, with the inevitable changes in the oceanic pH … and despite that, the life in the ocean continued to flourish.
My conclusion? To mis-quote Mark Twain, “The reports of the ocean’s death have been greatly exaggerated.”
[UPDATE] Several people have asked how I know that their method for separating the amount of anthropogenic warming from the total warming is correct. I do not know if it is correct. I have assumed it is for the purposes of this discussion, to show that even if they are correct, the amount is so small and the effect would be so slow as to be meaningless.
[UPDATE] WUWT regular Smokey pointed us to a very interesting dataset. It shows the monthly changes in pH at the inlet pipe to the world famous Monterey Bay Aquarium in central California. I used to fish commercially for squid just offshore of the aquarium, it is a lovely sight at night. Figure 4 shows the pH record for the inlet water.
Figure 4. pH measurements at the inlet pipe to the Monterey Bay Aquarium. Inlet depth is 50′ (15 metres). Light yellow lines show standard error of each month’s measurements, indicating a wide spread of pH values in each month. Red interval at the top right shows the theoretical pH change which the Byrne et al. paper says would have occurred over the time period of the dataset. Photo shows kids at the Aquarium looking at the fish. Photo source.
There are several conclusions from this. First, the sea creatures in the Monterey Bay can easily withstand a change in pH of 0.5 in the course of a single month. Second, the Byrne estimate of the theoretical change from anthropogenic CO2 over the period (red interval, upper right corner) is so tiny as to be totally lost in the noise.
This ability to withstand changes in the pH is also visible in the coral atolls. It is not widely recognized that the pH of the sea water is affected by the net production of carbon by the life processes of the coral reefs. This makes the water on the reef less alkaline (more acidic) than the surrounding ocean water. Obviously, all of the lagoon life thrives in that more acidic water.
In addition, because of the combination of the production of carbon by the reef and the changes in the amount of water entering the lagoon with the tides, the pH of the water can change quite rapidly. For example, in a study done in Shiraho Reef, the pH of the water inside the reef changes in 12 hours by one full pH unit (7.8 to 8.8). This represents about a thousand years worth of the theoretical anthropogenic change estimated from the Byrne et al. paper …
The sea is a complex, buffered environment in which the pH is changing constantly. The life there is able to live and thrive despite rapidly large variations in pH. I’m sorry, but I see no reason to be concerned about possible theoretical damage from a possible theoretical change in oceanic pH from increasing CO2.
[UPDATE] I got to thinking about the “deep scattering layer”. This is a layer of marine life that during the day is at a depth of about a thousand meters. But every night, in the largest migration by mass on the planet, they rise up to about 300 meters, feed at night, and descend with the dawn back to the depths.
Looking at Figure 1, this means they are experiencing a change in pH of about 0.4 pH units in a single day … and alarmists want us to be terrified of a change of 0.002 pH units in a year. Get real.
Smokey says:
June 21, 2010 at 7:05 am
Where did that 3% figure come from and on the basis of what?
As for Neptunes location? Have a guess and belatedly, he’s taken to antacid tablets.
CO2,
All CO2 is natural. By convention I’m using ‘natural’ to differentiate non-human emitted CO2. But you knew that.
CO2 has been much higher in the geologic past, and life flourished to a greater extent when CO2 levels were much higher. It is simple cherry-picking to select an arbitrary time span like 10,000 years.
As you can see here, the human component of CO2 is ridiculously small. That is where the ≈3% figure came from. And since plants respond to more available fertilizer, any excess will eventually be consumed over time.
Further, there is nothing to worry about because we’re talking about the tiny human addition to a tiny trace gas. Water vapor has about 1,000 times the effect of CO2 as a so-called greenhouse gas. But it is much more difficult to tax water vapor.
Since a rise in CO2 always follows a rise in temperature, at all time scales, the current rise in CO2 must be due to prior temperature increases, and not vice-versa. CO2 does not cause measurable warming; warming causes more CO2.
Since CO2 is a function of temperature, it is clear that the current rise in CO2 is due primarily to ocean outgassing. If CO2 caused warmer temperatures, then there would be much greater correlation.
To summarize: CO2 is entirely beneficial. It does not cause any but the most minor, insignificant warming, which is too small to measure; otherwise, the climate sensitivity number would be agreed by everyone. The current rise in CO2 is primarily the result of the rise in temperature since the LIA, and is only coincidental with the industrial revolution.
Rising CO2 can not cause runaway global warming. The incessant drumbeat of “carbon” is based on the big lie, repeated until the scientifically illiterate general public gradually accepts the premise that something “must be done.”
That ‘something’ is to sharply raise taxes, by adding a hidden “carbon” tax to all goods and services across the board. It is an insidious and regressive tax that will hit the poor the hardest, and it will certainly cause starvation among the world’s one billion people who live on less than one dollar a day.
But the government propagandists pushing the CO2=CAGW lie simply do not care about the resulting starvation. To them, causing death by demonizing and taxing a harmless and beneficial trace gas is a small price to pay for money, power and control. That is the real problem.
tallbloke says:
June 20, 2010 at 5:01 am
1) if the ocean is not acidic to begin with (it isn’t) , then it can’t become “more acidic”, only less alkaline. It can undergo a process of acidification however, as Chris said.
what’s the difference between ‘a process of acidification’ and more acid?
One is correct the other (yours) is wrong.
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Oh dear, they mean the same so how can one be wrong?
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Oh dear. Trying to hide your error with extra complication and further errors doesn’t change the incorrectness of your original statement. How is the warming of oceans going to increase the disolved(sic) co2 level, CO2?
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Because it is only an initiation of the process over a relatively short period. CO2 disolves into the ocean (solubility pump) and the biomass (biological pump) sequesters CO2. Phytoplankton act in two ways; they fix CO2 as organic carbon during photosynthesis and form shells from calcium carbonate. Marine snow carries both of these forms of carbon away from the atmosphere and surface waters to reservoirs in the deep oceans and ocean sediments.
Warming of the ocean causes stratification which inhibits upwelling of the particles, necessary for the plankton to feed on. When this happens the declining phytoplankton will sequester less Co2; if they simply become extinct, no CO2 at all. The moment this sequestration falls below the balance point which has existed for the present interglacial has severe consequences. Given that the rate of atmospheric CO2 increase is going up rapidly and the rate of phytoplankton sequestration will decline, more and more CO2 will remain in the ocean, increasing the acidity. A total loss of phytoplankton will disrupt the entire oceanic food chain.
This is the process of acidification, more acid if you like.
Excellent post Smokey. I understand that it was directed at another, but it effectively answers my question too.
CO2 says:
June 22, 2010 at 5:56 am
what’s the difference between ‘a process of acidification’ and more acid?
One is correct the other (yours) is wrong.
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Oh dear, they mean the same so how can one be wrong?
No they don’t mean the same. If the alkaline ocean undergoes acidification it will become less alkaline, until it gets below 7ph at which point it becomes acidic. If it drops further below 7 in ph value, then and only then can you correctly say “The ocean is becoming more acidic.”
I’ve done with this. If you still don’t get it, tough cookies, stop blabbing on at me about it.
Phytoplankton act in two ways; they fix CO2 as organic carbon during photosynthesis and form shells from calcium carbonate. Marine snow carries both of these forms of carbon away from the atmosphere and surface waters to reservoirs in the deep oceans and ocean sediments.
And this makes the ocean “more acidic” how? Sedimented carbonates are pretty chemically stable are they not?
John M says:
June 21, 2010 at 6:23 pm
Phil. says:
June 20, 2010 at 8:26 pm
“you do know what precision is, don’t you?”
Certainly. But if my financial guy came to me telling me my net worth to +/-$0.01, but with an “adjustment” from 5 years ago of -$26,237.56, I don’t know about you, but I’d be asking questions.
Quite possibly but it’s hardly comparable, a better analogy would be to make a measurement of a 10.00V source and get a result of 10.03 with a precision of ±0.01.
But more to the point, the stated precision requires taking into account both the precision of the today’s measurements and the precision of the correction made for the impure indicator compound used in the past. I guess that assumes that the level of impurity was always the same. You’re not a synthetic chemist I take it.
Which would have no effect on the precision! Also no reason to suppose that it was a different batch of indicator.
I’m asking what I think is a reasonable question. The recent paper we are discussing has few experimental details on errors and uncertainty. They cite references from the late 80s/early 90s as their basic technique. I am citing a paper from 2004 that shows greater levels of uncertainty for the technique.
Your paper from 2004 quotes the same references from “the late 80s/early 90s” and describes a modification to the technique to use a CCD detector (a cheaper, quicker method) rather than use a scanning spectrophotometer. The paper shows that they were able to get similar precision (long term ±0.0032, short term ±0.0012) with their modification of the technique.
Your inherent supposition appears to be that ‘newer = more precise’, whereas it’s clear that the authors of the 2004 paper were prepared to sacrifice some precision for a cheaper, quicker variation of the technique.
re Smokey: June 22, 2010 at 5:56 am
I would (sadly) add the following to your commentary:
Given the many individuals who have been, and still are, involved in various hot/cold/other scares going back to the 70’s or earlier, and who have been active in the “eugenics/over-population” issue, the starvation is hardly an accidental byproduct of the alarmism. For many of them, it is the ultimate purpose.
/dr.bill
Willis Eschenbach says:
June 22, 2010 at 12:31 am
“This to me is one of the biggest tragedies of the onslaught of global warming alarmism. Global warming has stolen all of the spotlight away from what are very real environmental issues.”
They do more damage than simply stealing the spotlight -they make impossible demands that force all resource problems and remediation to fit their ideological paradigm. Pac. Salmon problems as an example must always have dams as the cause. Yet the most stressed salmon stocks are Oregon coastal coho which have neither dam nor habitat issues. (The problem is the phase of the PDO, mixed stock harvest and the cascade effect from not allowing sufficient escapement – marine derived nutrients- to enter the freshwater system.) For the Atlantics its a decline in pH which disrupts smoltification caused by the decline in agriculture, regrowth in forest and disruption in fire cycle. Again the greens champion dam removal- even though there are no salmon in rivers without dams. And actively oppose a liming project to remedy this problem.
They don’t just steal the spotlight- they sacrifice the environment on the altar of their ideology.
Keep up the good fight.
Pat
Smokey says:
June 22, 2010 at 5:56 am
CO2,
All CO2 is natural. By convention I’m using ‘natural’ to differentiate non-human emitted CO2. But you knew that.
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By what convention? I wasn’t talking about the CO2 molecule. So what’s the point, if all CO2 is natural, what’s your differentiation about?
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CO2 has been much higher in the geologic past, and life flourished to a greater extent when CO2 levels were much higher. It is simple cherry-picking to select an arbitrary time span like 10,000 years.
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The time span is not arbitrary, it refers to an interglacial period. Okay, so I will give you 20 million years and cite you a figure of 280ppm for interglacials and 170ppm for glacials.
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As you can see here, the human component of CO2 is ridiculously small. That is where the ≈3% figure came from. And since plants respond to more available fertilizer, any excess will eventually be consumed over time.
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Your link provides information about the sources of CO2 , NOT the percentage of CO2 in the atmosphere. It shows an increase of 11.7 Gtonnes of CO2 per year in the 1990’s.
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Further, there is nothing to worry about because we’re talking about the tiny human addition to a tiny trace gas. Water vapor has about 1,000 times the effect of CO2 as a so-called greenhouse gas. But it is much more difficult to tax water vapor.
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A stupid argument, science is well aware of the fact that water vapour has the largest warming effect. However, water vapour is not a gas, it is suspended H2O and has a cycle of hours or days. If the original “tiny trace of gas” of 280ppm has kept the earth’s temperature to what we have had since 200 years ago, and a reduction to 180ppm causes a glacial period, then an increase of 114ppm is leading us into uncharted territory.
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Since a rise in CO2 always follows a rise in temperature, at all time scales, the current rise in CO2 must be due to prior temperature increases, and not vice-versa. CO2 does not cause measurable warming; warming causes more CO2.
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Okay, keep repeating this fallacy, and some will believe it I guess.
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Since CO2 is a function of temperature, it is clear that the current rise in CO2 is due primarily to ocean outgassing. If CO2 caused warmer temperatures, then there would be much greater correlation.
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Since the premise is false, the conclusion is too. The graph you link to doesn’t tell me anything. Point me to reputable science that claims that CO2 always follows temperature rise. It is possible under certain circumstances, but presently the opposite is beyond dispute. Please don’t say that short term there is cooling while CO2 is rising and that this proves that CO2 follows temperature. Do some more reading beyond the simplistic.
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To summarize: CO2 is entirely beneficial. It does not cause any but the most minor, insignificant warming, which is too small to measure; otherwise, the climate sensitivity number would be agreed by everyone. The current rise in CO2 is primarily the result of the rise in temperature since the LIA, and is only coincidental with the industrial revolution.
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Cause and effect, so what caused the rise in temperature?
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Rising CO2 can not cause runaway global warming. The incessant drumbeat of “carbon” is based on the big lie, repeated until the scientifically illiterate general public gradually accepts the premise that something “must be done.”
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Can you quote the science rather than the rhetoric?
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That ‘something’ is to sharply raise taxes, by adding a hidden “carbon” tax to all goods and services across the board. It is an insidious and regressive tax that will hit the poor the hardest, and it will certainly cause starvation among the world’s one billion people who live on less than one dollar a day.
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Hello, Lord Christopher Monckton.
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But the government propagandists pushing the CO2=CAGW lie simply do not care about the resulting starvation. To them, causing death by demonizing and taxing a harmless and beneficial trace gas is a small price to pay for money, power and control. That is the real problem.
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Indeed, such nasty creatures these propagandists, determined to kill innocent people. Demonising CO2 the beneficial plant food, this harmless gas of which we should have as much as possible. Apologies for the sarcasm.
dr.bill says:
June 22, 2010 at 8:24 am
“….the starvation is hardly an accidental byproduct of the alarmism. For many of them, it is the ultimate purpose.”
Demeaningly cynical.
CO2,
You may think that nitpicking everything said shows that you are intelligent and up to speed on the subject, but all it shows is insecurity covered up by ad hominem attacks [Monckton, etc].
Arbitrarily changing your original 10,000 year assertion to 20 million years is still cherry-picking. Using the time scale of the biosphere’s use of CO2 does away with the cherry-picking. I can provide you with charts similar to the one I provided up-thread, going back 4.6 billion years if it helps. They show that CO2 has been almost twenty times higher than today, in both hothouse and icehouse epochs, and during times when life thrived in much higher CO2 concentrations — without any runaway global warming.
I stand by every statement I made, and while you demand citations [which I routinely gave], you provided none yourself, but only off the cuff opinions based on your scientific flawed assumptions.
For one example of many, you stated that: “…water vapour is not a gas, it is suspended H2O and has a cycle of hours or days.”
In fact, water vapor is a gas. Since your level of understanding is so rudimentary and filled with misconceptions, I suggest you read the WUWT archives from the beginning, so you can have an intelligent conversation without making such basic scientific errors.
Oh dear, 200+ posts and no one commented on the title? Love the reference to “The Electric Kool-Aid Acid Test”–haven’t thought of it in a long while, but it’s one of my favorite books. Thanks again, Willis.
CO2 says:
June 22, 2010 at 9:38 am
Paul Erlich wants a much much lower human population. Given that Gordon Brown and other leaders said there was only months left until we reached the famous tipping point, and that they obvously wants to reduce the population of the world to avoid it, I would very much like to see how they would reduce it?
Mass murder? Mass starvation? Mass sterilisation? What society do they want? How will they achieve it?
My suspicion is that they like Pol Pots solution.
I hope you dont wear glases, CO2. I hope you dont know any foreign language.
Dont raise your hand in class.
Bill S says:
June 22, 2010 at 11:23 am
“Oh dear, 200+ posts and no one commented on the title? Love the reference to “The Electric Kool-Aid Acid Test”–haven’t thought of it in a long while, but it’s one of my favorite books. Thanks again, Willis”
And with the new PNAS “blacklist” paper it sure seems clear now “that either your on the bus or off the bus.”
This means that for the top 800 metres of the ocean, where the majority of the oceanic life exists, the human induced change in pH was -0.013 over 15 years. This was also about the amount of pH change in the waters around Hawaii.
Now, remember that the difference in pH between the surface water in Hawaii and Alaskan is 0.50 pH units. That means that at the current rate of change, the surface water in Hawaii will be as alkaline as the current Alaskan surface water in … well … um … lessee, divide by eleventeen, carry the quadratic resdual … I get a figure of 566 years.
You didn’t just divide one into the other did you? It’s a log scale, and that just doesn’t work that well.
Besides when dividing one into the other I get 577.
Caleb says:
June 20, 2010 at 2:07 am
Ed,
I can’t supply a link, but I recall reading about scientists studying the life thriving around a deep-sea vent. While studying some giant clams they noted a strange liquid oozing front a crack near the vent. Upon investigation, it turned out to be CO2, which is liquid under the extreme pressures of deep sea environments (as it is under the pressure inside a CO2 fire extinguisher.)
Apparently the liquid CO2 did not form puddles on the sea bottom, but rapidly dissolved into the water. It had no apparent effect on the nearby deep-sea vent life forms. I have no idea what the Ph of the water was.
Does anyone know more about this subject?
Sounds like the CO2 was under sufficient temperature and pressure to become a supercritical fluid http://en.wikipedia.org/wiki/Supercritical_fluid – which are noted for being excellent solvents and are used industrially as such.
CO2 says:
June 22, 2010 at 9:38 am
dr.bill says:
June 22, 2010 at 8:24 am
“….the starvation is hardly an accidental byproduct of the alarmism. For many of them, it is the ultimate purpose.”
Demeaningly cynical.
Unfortunately in this world, cynicism on the megaton scale does not stop you from being right.
Z says:
June 22, 2010 at 1:35 pm
Sounds like the CO2 was under sufficient temperature and pressure to become a supercritical fluid http://en.wikipedia.org/wiki/Supercritical_fluid – which are noted for being excellent solvents and are used industrially as such.
Pressure obviously supercritical, the temperature of the CO2 would have to be over 31ºC to be a supercritical fluid.
You may think so, CO2, but I am not at all cynical. I am simply saddened by the inhumanity of some of my con-specifics. You need go no further than to read the publications of the Club of Rome and its members and hangers-on in order to see the reality of this. For example:
For reasons that baffle me, they have publicly produced many such plans and pronouncements over the years, but few people remember them, or perhaps they don’t want to believe that people could have such base motivations.
Here’s a list of verbatim quotes that was posted by commenter Jason on WUWT about a month ago: “In Their Own Words”. Make yourself aware of reality, and perhaps get your social standing checked out, or even have a DNA profile done. You might not be on the ‘good list’.
/dr.bill
Since you’re citing and interpreting Monterey Bay Aquarium data, I contacted one of our water quality researchers. Here’s what they have to say:
If you add a basic trendline to the data set, it actually shows that there is a longterm decrease in the pH of our intake water. The slope of the line is −4.1283e−006. They can use the data, but it actually does more to reinforce ocean acidification using it at face value.
Ken Peterson, Communications Director, Monterey Bay Aquarium
The authors of this paper are definitely overstating the certainty of their data. The spectrophotometric procedure may have an internal precision of around 0.001 absorption units, but the total reportable uncertainty must be determined by propagation of the error throughout all calculations performed. Their calculations rely on the relative amounts of the two ionization states of m-cresol purple. These ionization states are related to the dissociation constant associated with loss of a proton from the phenolic group. Ultimately, this pKa value will have been determined using a method that measures the concentrations of the acidic and basic species as a function of pH. The accepted pKa (from the Handbook of Acid-Base Indicators) for the HL = H + L equilibrium of m-cresol purple is 8.32 (indicating an uncertainty of no less than ±0.01). The spectrophotometric method for measurement of the pH of a solution containing m-cresol purple must have been determined from the rearrangement of the equilibrium constant relation K = H*A/HA combined with the mass balance equation HA(total) = HA + A. Thus, propagation of the error in the calculated pH value cannot be less than the uncertainty of the measured pKa used in the calculation.
I took a look at the references to the author’s method to better understand the basis of their claims. The article referenced an earlier paper that claims the spectrophotometric method is precise to within ±0.005 pH units. The derived equation utilizes a calculated pKa value from an equation expressing the pKa as a function of both the ionic strength and temperature. This equation provides an accurate description of the behavior of the pKa against these external influences. However, the authors use the calculated pKa value without noting its uncertainty, which implies that they consider it to be considerably less than the error in the absorbance readings. This is simply not possible; no reported pKa value has ever been determined with an uncertainty less than ±0.001. Furthermore, nearly all of the highest quality pKa values, measured at a single temperature and ionic strength condition and determined using acceptable methodologies, have reported errors of ±0.01 to ±0.05.
The experimental pKa determinations of m-cresol purple must have been made against a calibrated pH meter using a technique relating species concentration to proton activity as described by Albert and Serjeant (1984). The precision of the primary pH standards (traceable calibration buffer solutions adhering to IUPAC standards) have uncertainties of ±0.01 pH units (2-sigma). Therefore, in accordance with IUPAC specifications, a properly calibrated pH meter has a minimum uncertainty of ±0.01 to ±0.03 pH units. Hence, each pKa value obtained and subsequently used in the multiple regression equation, pKa = f(T, I), will have an uncertainty of at least ±0.01 to 0.03. The calculated best-fit coefficients will have additional standard errors from the regression. Hence, the pKa value used in the pH determination cannot have an uncertainty small enough to ignore it in the final reported pH uncertainty.
It is obvious that the spectrophotometric pH measurement technique is no more certain than any other accepted pH measurement technique used by chemists worldwide. A reasonable lower bound for the pH error of seawater is ±0.01 – 0.05 (approximately two to ten times greater than the author’s claimed max error). A reasonable upper bound for the error associated with a high-precision pH measurement of seawater by this technique, considering the likely magnitude of the errors associated with temperature, ionic strength, spectral purity and total concentration of the dye, is probably around ±0.10. As others have pointed out, the true uncertainty in the pH measurement far exceeds any changes associated with observed pH values of seawater. The peer-review process of this paper has completely failed to ensure that these authors critically evaluate the uncertainty of their measurements.
dr.bill says:
June 22, 2010 at 2:25 pm
I had a commenter at http://www.scientificamerican.com/article.cfm?id=experts-warn-climate-change-disrupts-agriculture tell me this about my comment lauding Norman Borlaug for feeding a starving world.
“Borlaug did more to increase the human population than whatever, and in so doing, he increased the suffering. If the gains in production had gone to increasing wealth and the education of girls so as to not increase population, you would have a point, but they didn’t. Borlaug just made the ultimate catastrophe worse.”
So Borlaug by feeding a starving people made the problem worse. You see Ehrlich and Holdren weren’t wrong— Borlaug just prolonged the suffering. Perhaps that is why Borlaug passed recently with little note and Holdren is our Science adviser.
It seems that some are so angry that the apocalypse didn’t happen that they are now trying to create it.
There is a word for this – misanthropy.
Phil. says:
June 22, 2010 at 8:07 am
“Also no reason to suppose that it was a different batch of indicator.”
What a wonderfully faith-based asumption. So the same batch of indicator was used in 1991 as in 2006?
If a correction was applied, isn’t the total precision uncertainty the uncertainty of the measurement itself plus the uncertainty of the correction (part of the propagation of error issue mentioned by ZP)?
Anyway, here’s the abstract for Yao 2007, which is the reference for making the correction.
http://discover-decouvrir.cisti-icist.nrc-cnrc.gc.ca/dcvr/ctrl?action=shwart&aix=7&aid=7160664
Since Byrne is a co-author, one might suppose they saved the indicator…for the 2006 cruise. How does one correct for the 1991 cruise?
You also say:
“The paper shows that they were able to get similar precision (long term ±0.0032, short term ±0.0012) with their modification of the technique.”
My point all along is that both technique should give “similar precision”. The problem is that +/-0.0032 is based on 1 sigma (lots of details shown) and +/-0.001 is…what? (no details shown.)
And finally, perhaps you’re right about my financial analyst analogy. A more apt analogy would be if my financial advisor comes to me and says “OMG! Your net worth last quarter fell by $0.03 +/-$0.01! What’s more, I have a financial model that says this will accelerate in the future! You and your family must change your lifestyles NOW and you have to give me more money to so I can stay on top of this and so that I can study it further. No question allowed!”
Always like to have the right analogy.
ZP- nice job. I too am concerned with this method. In fact there may be no more important issue with respect to ocean acidification than the uncertainty associated with this method. You simply cannot make any claims using hard data with respect to ocean pH as a result of anthro-CO2 unless you accept Byrne’s analytical assertions. I would add one more thing to your comment– what one is able to achieve under best practices in a lab is always better than what can be achieved in the field – especially an insitu devise.
Byrne holds patents on both the instrument and method– not sure of (or if) the financial incentives to him and or the university if pH spectrphotometers become a “must have” piece of equipment.
re Pat Moffitt: June 22, 2010 at 6:33 pm
Hi Pat. There is an element of truth in the statement made by your commenter. Simply feeding the starving is fine as a temporary measure, but if all you are doing is creating more mouths, and are not able to support them indefinitely (which will eventually be the case), then you may well just be creating more deaths.
The only long term solution, always, is for societies and groups to have the means to support and develop themselves. People will generally find a way to accomplish that if not interfered with, but the current demonization of carbon has the direct effect of interfering with such efforts in a massive way.
What is insidiously effective in making basic energy prohibitively expensive, from the point of view of a eugenicist, is that you don’t have to ‘target the undesirables’ or actively become involved with them in any way. You just make it hard for them to survive, and they will eventually not be there.
I have friends who feel that this indicates cynicism on my part. They just cannot believe that other human beings would have such motives, nor actually attempt to carry them out. I understand their reluctance to believe this, but all you have to do is take the eugenicists at their word, and they have issued such statements of intent often enough, and publicly enough, to be believed.
/dr.bill