Horrible new threat from global warming – fewer pearl necklaces (or not)

From the CO2 solubility curve and the Captain Obvious department comes this press release that leaves us wondering if this isn’t just lip service to justify a grant:

How ocean acidification and warming could affect the culturing of pearls


Pearls have adorned the necklines of women throughout history, but some evidence suggests that the gems’ future could be uncertain. Increasingly acidic seawater causes oyster shells to weaken, which doesn’t bode well for the pearls forming within. But, as scientists report in ACS’ journal Environmental Science & Technology, the mollusks might be more resilient to changing conditions than previously thought.

Pearl aquaculture is big business, particularly in Asia and Australia. But much of it takes place in oceans, which are susceptible to the increasing amounts of carbon dioxide human activity releases into the atmosphere. CO2 from the air gets absorbed by the oceans, which become more acidic as a result. Research has found that pearl oysters produce weaker shells under these conditions, and this could hurt their chances of survival. But in addition to acidity, rising water temperature could also play a role in oyster health. Rongqing Zhang, Liping Xie and colleagues wanted to see how combining acidity and water temperature would affect pearl oysters.

The researchers tested oysters for two months under varying water temperature and pH conditions, including those predicted for oceans in 2100. Their results confirmed previous work that had found boosting acidity led to weaker shells, but that effect didn’t occur when the water temperature was also higher. The researchers concluded that warmer oceans could buffer these valuable marine animals from increasingly acidic seawater.


The authors acknowledge funding from the National Natural Science Foundation of China and the China Postdoctoral Science Foundation.

127 thoughts on “Horrible new threat from global warming – fewer pearl necklaces (or not)

  1. How are we getting along with the predicted shrinking no. of islands?
    Does anybody know of a count of the total number of islands globally?
    Surely with the assistance of the Chinese, we are seeing an overall increase.
    That’s the Chinese miracle, in summary; Burn coal, expand economy, build islands.
    The irony is not lost on me!!!

  2. Pearl aquaculture is big business, particularly in Asia and Australia. But much of it takes place in oceans
    I prefer desert pearls myself. Who writes this stuff and do they read it after it is written?

    • I think the point of that statement is that the pearls are grown (farmed) in the natural ocean environment rather than farmed in a controlled environment (salt water tanks) where such factors could be controlled.
      The natural environment is susceptible to changing factors. (and always has been) It is good to see though that the temperature factor is the perfect natural buffer to the acidity factor.

    • I know, I saw that. Prairie pearls versus mountain pearls, who’s to say which is best. Mojave pearls are probably the best, you’re probably right.

    • I can’t see the problem myself.
      These are ……cultured…… pearls.
      Which means the oysters are artificially inseminated with grit to breed a pearl, so it is not a natural process.
      So just artificially adjust the water Temperature and alkalinity or acidity if you want of your oyster pond, and quit carping about it.

      • The point of “Growing/farming” pearls in Ocean Oysters is so that you don’t have the expense of needing to feed them or trouble of managing the water temperature or other factors.

      • So if you are a cheapskate pearl farmer and don’t want to bother keeping your pearl ranch free of weeds; don’t blame the naturally preferred state of your farm for the poor crop yields.
        PS The New Zealand green shell mussels are ” farmed ” in open water; but that open water abuts the Tasman sea on the West, and the Pacific ocean on the East at the Cook Straight, so it sloshes back and forth through that gap twice a day, flushing out any possible contamination that might harm the process. They don’t bother to seed them to try and make green pearls.

  3. “CO2 from the air gets absorbed by the oceans, which become more acidic as a result.”
    Same old propaganda, midirection & misinformation. The oceans are becoming less alkaline, not the same thing at all!

      • It’s the terminlogy I am commenting on, not the specific science. UNIPCC scientists claim this to be the case, & “my” scientists tell me that the alkalinity varies on a daily basis globally.

      • becoming less alkaline
        Yes, the oceans are alkaline. Blood is alkaline, which suggests that the oceans have been alkaline for hundreds of millions of years, when the primitive ancestors of mammals first left the oceans for the land.
        The oceans are heavily salt buffered, which means you could add acid to them in vast quantities and still not make them acidic. What would happen is simply that more limestone and other rocks would form on the ocean bottom.
        The White Cliffs of Dover are fossilized CO2.
        The notion that more CO2 would be harmful to ocean life is not supported by the paleo evidence. CO2 is the basic building block of the shells of marine life. CaCO3 is the basic material of shell, and this is made from CO2, calcium and oxygen dissolved in the ocean. Adding more of the basic building block of shells will not weaken shells. The fossil record contains trillions upon trillions of shells from millions of years ago when CO2 levels were much higher as proof of this.

      • I think you are seeing sinister motives where none exist. Acidification means reducing the pH. Look up soil acidification. It is referred to as acidification whether or not the soil starts off acid or alkali. We do not say it is soil alkali reduction from 14 to 7, then soil acidification from 7 to 0. It is all called acidification.
        I recognise that language can be used to convey differences in meaning beyond strict definitions, but this is not one of those cases. Ocean de-alkalisation is just clumsy. Ocean neutralisation could be used, but “neutralisation” implies an intention to stop at pH 7, and that would be arguably more misleading as there is no target. It is not used for sinister reasons, but because acidification is a widely used term.
        Incidentally, on the buffering you mention: “Seawater is naturally ‘buffered’ against these pH changes, but the buffering process consumes carbonate ions. Carbonate ion is an essential ingredient in the creation of calcium carbonate shells and skeletons produced by a large number of marine organisms… Thus, ocean acidification not only reduces surface ocean pH, but also reduces the availability of carbonate ion.”
        (from NOAA – you may not trust them, but this is basic chemistry)

      • seaice1 “Ocean de-alkalisation is just clumsy.”
        It may be clumsy but it’s not “just” clumsy; it’s an attempt to address the emotive power of the inaccurate term “acidification”.
        If you add a base to an acid, you neutralize to a pH, which may well be below 7. You don’t de-acidify or basify or alkalize.
        I think, also, that ‘basic chemistry’ might not be sufficient to describe the complexity of shell formation. Afaik, organisms actually use bicarbonate, not carbonate, to form calcium carbonate. They eject H with proton pumps. I will not suggest that that is merely “basic biology”

      • seaice says:
        “Acidification means reducing the pH.”
        Iin this case the correct term is neutralization. But that’s not scary, so the propagandists use ‘acidification’.
        Could you at least try to be a little more honest? It would begin to repair your credibility, which is currently near zero.

    • If the the hydrogen ion concentration (pH) increases, it is quite normal to say the solution has become more acidic. If you start off at pH10 and go to pH9 you may well say the solution has become more acidic, even though both are alkali.
      We could say the solution has become less alkali but it would be exactly the same thing, not a completely different thing.

      • The correct term for adding an acid to a buffered base is “neutralization”.
        rain water is acidic. would you call rain falling on the ground “acidification of the ground”? The same thing applies in the ocean. it is a corruption of the English language for political ends.

      • seaice1 January 21, 2016 at 6:32 am
        “it would be exactly the same”

        It may be “exactly the same” in the technical sense but I assure you it is not “exactly the same” to a layman. Since this is a technical blog I understand and expect that the comments would be technical. The press release will, however, be picked up by media and read by laymen, who will not understand the distinction.

      • We could say that; but it still would not be true.
        And who cares in a cultured pearl reactor.

      • pmhinsc
        January 21, 2016 at 7:36 am

        seaice1 January 21, 2016 at 6:32 am
        “it would be exactly the same”

        It may be “exactly the same” in the technical sense but I assure you it is not “exactly the same” to a layman.

        Instead of “more acidic”, why not “less caustic”? Doesn’t give the desired impression?

      • Because caustic means “1.able to burn or corrode organic tissue by chemical action”. It would be inappropriate to use it in this context.

      • From here http://www.kuntze.com/en/parameter/ph-value.html

        The pH value is an intrinsic value of all aqueous solutions: Each aqueous solution has a pH value. At 25°C pure water contains H+ and OH- ions in equal amounts.This state is called neutral with a pH value of 7. The pH scale covers values between 0 and 14. Acids have pH values towards 0, caustic solutions have pH values towards 14.

        To say “less caustic” would be technically correct.

      • seaice1 said: ” it is quite normal to say the solution has become more acidic.” It may seem normal to you, but the term was not used in oceanographic literature prior to about a decade ago. If “less alkali (sic)” is equivalent in your mind, why not say “less alkaline,” which makes it clear the direction the pH is moving in an alkaline solution. “More acidic” only conveys clearly the direction the pH is moving, and because of the careless use of the term, leaves it ambiguous whether the solution is currently alkaline or acidic. Less information is conveyed in your preferred usage. What is really critical is the ratio of hydronium ion to hydroxyl ion because acidic solutions have different properties from alkaline solutions.

    • More CO2 gets absorbed by the ocean as the atmospheric concentration rises. CO2 also leaves the ocean as the temperature rises even if the concentration in the air has increased. So…where is the balance point? How much warmer must we allow it to become in order to completely prevent the pearl oysters from having thinner shells (or not)?

    • how you choose to label the effect has no bearing on its consequence, which is the point of the article. The text easily makes reasonable sense and is understood properly by any reader. I dont see why the specifics of the word matter so much, given the purpose of the paper is to describe the consequence.

    • “The researchers tested oysters for two months under varying water temperature and pH conditions, including those predicted for oceans in 2100. Their results confirmed previous work that had found boosting acidity led to weaker shells, but that effect didn’t occur when the water temperature was also higher didn’t affect the flavor.”

    • “the administration’s efforts to make the space agency a tool of international diplomacy”
      Words fail me!

      • They have to justify their jobs SOMEhow . . . it’s not like anyone’s been to the Moon lately, after all. And even back then half of what they did was for propaganda value.

    • The best way for Infidels to make Muslims happy is to convert or die. The Koran permits no freedom of worship. A tax (Jizya or jizyah) must be paid by the Infidels to Muslims for letting them live. Muslims that wish to convert to other religions face the death penalty.
      Most western nations take freedom of religion for granted. However, this freedom was not given freely. It was won by our ancestors and paid for in the blood of millions. Our politicians would trade this away willingly in return for the Muslim vote, blissfully unaware of the dangers to freedom.

      • One of my uncles often said that blood was the price of freedom.
        He always followed that up with saying “Make sure it is your enemy’s blood.”

      • I believe it was Patton who said that patriotism is not dying for your country, it’s making sure that the other poor b@stard die for his.

  4. First off, oysters have no problem maintaining their shells with slightly lower pH, particularly as there is no evidence of any OA happening anywhere and carbonic acid is a weak acid and seawater is a complex buffer, which will resist its effects, if any.
    Anyhow, pearls are formed inside the oyster and is formed by the oyster actively increasing the calcium carbonate concentration in the stomach.
    Sean Acidification is a non-issue unless one is dumping large quantities of a true, strong acid, such as hydrochloric, into a bay.

    • such as hydrochloric
      the original studies on ocean pH were conducted with hydrochloric, which is chemically nothing like CO2. Since these studies delivered the wanted alarmist results, they breezed through peer review. It is amazing what gets published when money changes hands.

    • “First off, oysters have no problem maintaining their shells with slightly lower pH ” Not what the paper says- and they actually did the measurements. This is why actual experiments are useful – you can test things instead of relying on conjecture.
      Carbonic acid being a weak acid is irrelavent. Acetic acid is a weak acid but it will strip your skin off.

      • Acetic acid is a weak acid but it will strip your skin off.
        Vinegar is acetic acid. People eat it all the time. Ketchup, pickles. By your reasoning they should be dropping dead in the streets.
        number 1 fruit and vegetable consumed in the US? Ketchup and fries.

      • @seaice1: Re: “Carbonic acid being a weak acid is irrelevant. Acetic acid is a weak acid but it will strip your skin off.”
        Don’t be silly. I regularly eat acetic acid with my potato chips and it never did me any harm.

      • ferdberple and mrpeteraustin, You are refering to dilute acetic acid. Pure acetic acid will take your skin off, although it remains a weak acid. Do not confuse the term “weak” in this context with inability to cause powerful effects. The fact that carbonic acid is a weak acid says nothing about how it may affect oysters.

      • My father was a chemist. He told me a story about how, on hot days (no AC in those days) they would create their own refreshing drink from 500ml of water in a beaker, to which they would add two or three drops of concentrated sulfuric acid. Tasted like lemonade.
        One day, there was a builder working outside on a very hot day. He came over to the window to ask if he could have a glass of water. They made up some “lemonade” for him. He really enjoyed it. He came back later for another, and then another.
        Next day, when he didn’t turn up, they got very worried.
        Turns out his boss had another job he wanted him on.

      • ferdberple
        January 21, 2016 at 7:03 am
        Acetic acid is a weak acid but it will strip your skin off.
        Vinegar is acetic acid. People eat it all the time. Ketchup, pickles. By your reasoning they should be dropping dead in the streets.
        Don’t forget though, those all too important science experiments using Vinegar to strip away the Eggshell

      • How many generations did wait to see if the clams are able to adjust?
        Did they test to see if clams reacted differently to changes in alkalinity caused by more carbonic acid vs. more sulfuric acid?
        Did the limit their tests to alkalinity changes that are actually possible in the free ocean?
        Your eagerness to accept any “test” results that support your religion does you no credit.

      • “Carbonic acid being a weak acid is irrelavent. Acetic acid is a weak acid but it will strip your skin off.”
        Note how seaice1 blithely ignores the differences in ph between acetic and carbonic acids. It is as if he is saying that all “weak acids” (a technical term with a precise meaning) are equivalently acidic. But they are not–see http://www.aqion.de/site/191. Not to mention that he is also ignoring concentration levels.
        Seltzer water is dilute carbonic acid, and beer and soft drinks contain carbonic acid too. Will any of them strip your skin off?

  5. Thank you for some sanity higley7.
    Here’s some more – aside from the fact that the “changes” in ocean pH are forecasts, not facts, the pH swings “expected” are well within the natural bounds as exhibited in different areas of each ocean by purely natural factors all of the time. So, talking about “acidification” affecting these creatures is akin to claiming that animals can’t cope with a temperature change over decades that amounts to considerably less than the changes seen every 12 hours or so of their lives.
    Proper science please.

  6. A quick search found “The oldest known fossil pearls date from 230-210 million years ago”
    Triassic period? Warmer then, wasn’t it?

  7. What a load of old cobblers. The manufacturers of the largest and most beautiful silver pearls in the world, Pinctada maxima, is harvested in waters off Broome that vary from 16C to 32C. When cultured in tanks, the warmer water is preferred to grow hatchlings and the best farms are in tidal inlets where a ten metre tidal difference twice a day is normal. Found naturally in the strongest tidal and monsoonal supplied rivers, and off the 80 mile beach, the pH must vary an enormous amount over one year of 6 seasons.

  8. China is the biggest producer of Cultured Pearls in the world
    Create a scare to keep the price up because of over production

  9. OK, I realize that I am only a lowly engineer, so I know I get confused very easily.
    So today my confusion has to do with this business of the oceans absorbing all this CO2, while at the same time warming up.
    I vaguely remember being taught in about grade 11 that as a liquid warms up, its capacity for dissolved gas goes down.
    Could somebody please explain to me how global warming and the evil CO2 are going to make the oceans more acidic?
    Do I need to revisit grade 11; or should I just accept the new science of “climate science”?
    Need answer fast.

    • CO2 is on a direct correlation with CO2 absorbed in water in accordance with Henry’s Law. Thus, if you double CO2 you will double the absorbed CO2, causing a significant increase in H2CO3. The increase in CO2 dominates the trivial change in solubility over less than two degrees of warming.
      Of course, there are all the chemical and biological buffers in ocean water, but that’s a different story. The solubility change due to temperature is insignificant. The data for Henry’s law is widely available

    • Just because an engineer should know better, I went and did it.
      The Henry’s constant for CO2 value at 25C is 0.034 mol/L*atm
      The constant at 30C is 0.030 mol/L*atm
      So even under ludicrous warming, you’d have a 15%drop in solubility alongside a tripling or so of partial pressure of CO2.

      • benofhouston
        Thanks for that. I asked about that issue up the page. So how high would the concentration of CO2 have to be to maintain the 0.034 level if the water warmed 1 degree C? That is the key question.
        As it is going to be pretty much impossible for humans to drive the concentration above 540 ppm, a compensating warming number can be calculated to hold the ocean pH constant.

      • Going from 298 to 299, you get to a solubility of 0.0333 (the formula’s in the link).
        Let’s presume Victorian era. To have a constant amount of CO2 absorbed in the water,
        0.34*260 ppm = 0.0333 * X
        X= 266 ppm
        You can go to any degree you like or say it any way you like, but the conclusion is still the same. The change in CO2 concentration in the air massively overpowers the small change in solubility due to temperature. The amount of CO2 dissolved in the oceans IS increasing.
        The correct response is to show how it’s not a meaningful or important change, not to try and say that it doesn’t exist.

      • To those checking I had a typo and accidentally typed 0.34 instead of 0.034, and all solubility units are mol/L*atm.

      • The Henry’s constant for CO2 value at 25C is 0.034 mol/L*atm
        The constant at 30C is 0.030 mol/L*atm

        The odd thing about this climate “science” is that they haven’t even begun to collect the evidence to prove their point, yet there is a consensus on the confidence. Someone needs to create a chart that shows the increase in atmospheric CO2 in ppm for an increase in temperature of the oceans. The oceans have been warming according to the climate alarmists, I accept that, but if the oceans are warming, so should the atmospheric CO2. I’ve never seen a chart that claims to adjust the atmospheric CO2 for the additional CO2 due to ocean warming. The oceans have warmed 0.9°C over the past 100 years. How much of the CO2 increase is due to that warming, warming that is due to visible light, and totally unrelated to CO2.

    • …explain to me how global warming and the evil CO2…
      Blabbedy-blab buzzword buzzword, den*er, gobbledy-gook bafflegab gibberish bureaucratese insult. Does that answer your question?

      • PiperPaul. Actually there are some very good and accurate explanations for the effect posted shortly before yours. From yours it appears that you think there is no good explanation, but alarmists would nevertheless make noises to try to make it seem reasonable. Now you can see that there is a very good and simple explanation you can revise you opinion.

  10. So we “SAVE THE WORLD!” so pearl production isn’t impaired, but by then the economies of the world will be so dilapidated that no one will be able to afford pearls … oh the irony of it all

  11. I handled industrial CO2 for years. Low temps hold CO2 in water and high temps squirt it away. That’s why your coke can fizzes much harder when you shake it warm. How do you get the high temps and high CO2 to coincide?
    Or did they just sour the water with any old stuff? Never mind. Give ’em a shared Nobel (one of those cheap Peace ones) or an Emmy or whatever.
    Next publication!

    • At saturation with significant temperature changes, yes. However, we are talking at low pressure where the limiting factor is the CO2 in the atmosphere and the temperature change is tiny.
      I did the math a few posts up, but going from 25C to 30C (far more than any reasonable person expects) drops solubility of CO2 in water by ~15%. This change is dominated by the fact that the partial pressure of CO2 is greatly increasing.
      Be careful, using the wrong experience can lead you to the wrong conclusion.

      • Ben – but going from 25C to 30C (far more than any reasonable person expects) drops solubility of CO2 in water by ~15%.
        ERSST.v4 Trend = +0.089 Deg C/Decade [ that’s the trend based on imaginary numbers ]
        5 C / .089 C/10 years = 560 years or until you hit Willis’ 30 C ocean temp limit.
        “Houston, we have someone not living in the real world.”

      • DD, I’m sorry, but what are you objecting to? The conclusion holds even more-so for smaller temperature rises.

    • hello gary,
      I can’t tell, you seem to be lampooning yourself here – what you’ve written above is exactly what I would expect someone to say when they attempt to portray your claims as being part of a global conspiracy, kicked into the public domain by threatening pearls.
      I’m also unclear why you regard people who bother to read the literature as “elitist” – could you elaborate? is it just that people can read (presumably well), you describe them as such?

  12. And here I though this was going to be about ZZ Top albums melting if the temperature of the globe hit +2C over the long term average. Whew!

  13. When it rains, I often refer to the process as “land oceanification”, since that is the direction it is going.

  14. I have to admit that I have nothing constructive to add to this discussion.
    I also have to admit that I thought of a certain ZZ Top song when I first read the title.

  15. I don’t think much of this study. Pearl oyster species are estuarine. That is why pearls can be cultured. (OK, pacific black pearls from giant clams are an atoll species.) Estuary pH and water temperatures vary greatly with the seasons owning to biological activity and fresh water input. And estuaries are highly buffered by the shallow sea bottoms, even more than the open oceans. None of that gets reflected in a lab tank.

  16. Were I not happily married I would gallantly volunteer to greatly increase the world supply of pearl necklaces just as I did when I was a bachelor.

  17. Wow, is this one helluva long publicly funded train that everybody everywhere wants to hop onto before it really picks up speed. It’s already left the station. It’s gonna’ be real dog eat dog as each and every single economic interest jockeys for position as it tries to protect itself by hopping aboard before being rammed and splattered by this stupid train. And, once aboard each and every single economic interest is gonna’ see if they can capitalize on this speeding train. Unfortunately, for all these simpletons, they don’t realize that speeding trains turn into runaway trains when the brakes begin to fail.

  18. Why is it that the 4% of CO2 that we bad humans put into the atmosphere is the only CO2 that is bad for pearls (and everything else that is wrong with the World)?
    Are they able to discriminate and NOT use the 96% naturally occurring CO2?

  19. Does adding the (“projected”) demise of pearls to yet another “C” in the “CAGW” hype now make pearls of great vice?

  20. Just think about how many better uses for those tax dollars there are. There clearly needs to be a comprehensive review of how and why projects are funded. This Government Funded Research Industry has clearly gone off track, and is now more welfare for professors.This video of Eisenhower proves we’ve been warned, and the outcome was obvious.

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