Photo by Russ Hopcroft, University of Alaska, Fairbanks. - NOAA: A pelagic pteropod collected during one of the net tows. Species probably Limacina helicina.

Overview: ‘Ocean Acidification’

By Rud Istvan

          Long time WUWT readers know that I stopped posting specific ‘Whack-a-Moles’ some time ago here and at Judith’s Climate Etc. My reason was simple. Does no good. The climate fight is now on a higher non-specific ‘belief’ plane.

          Recently Charles asked me for more technical posts. I was going to deconstruct GM’s new “HOPIUM” EV battery named (you cannot make this up) “Ultium”. But there is simply not enough yet available info to make a technical judgment about it. Yes, they are spending $2.3 billion on a new Ultrium pouch cell battery plant. Yes, it is supposed to use more nickel and less cobalt in the cathode alloy, so cheaper. All the critical rest (energy density, power density, cycle life) is still a nullity except in their current stock price….

          Yet ctm’s recent post on the ‘deficient’ shells of pteropods got me going again at the higher general climate science belief plane. So this possible guest post is scientifically general, broadly covering the ‘ocean acidification’ argument and its failures.  For those seeking detailed references, please see essay ‘Shell Games’ in ebook Blowing Smoke, or my recent comments on pteropod shells.

          So, ‘ocean acidification’ is a supposed second order global warming effect, per AR3. Except that was never true scientifically — let alone that ‘acidification’ is a deliberate alarmist misnomer—slightly less alkaline has nothing to do with acids (below pH 7). The AR3 estimate of ocean pH going from  ~8.2 to 7.8 with a doubling of atmospheric CO2 ignored the fact that ocean pH is highly buffered. Taking buffering into account, the max pH reduction from a doubling is 0.15-0.2 pH per the IPCC embarrassingly corrected AR4. This becomes a biological non-problem, since calcifying organisms (corals, pteropods, coccoliths) all regulate their internal calcifying pH to withstand natural ocean pH variances within their natural range. Else, they would not have survived. Yet they did.

          A further alarmist problem is that the natural biologically driven pH ocean range is greater than even the AR4 assertion. The observed range depends on the biological photic zone and seasonality of this ocean sub-segment. In the biologically barren northern Pacific, it is about 0.1. In Pacific estuaries, the seasonal range is about 1.0 or greater. In the extreme of Florida Bay from the Everglades estuary to Key West  (a max of 90 miles) it is from 5.8 in the mangrove fringes in winter to 9.6 near Key West in summer. These extreme differences are driven by rainfall (less in winter), Thallasia seagrass photosynthesis (greater in summer), and evaporation increased salinity (greater in summer.)  Yet the humble yet delicious conch snail thrives in Florida Bay year around all over the Bay. Try ‘farm raised’ Florida Keys conch fritters. Yum.

          This ‘ocean acidification’ misnomer was contrived by warmunists from several distinct parts, all of which were false.

  • Part one was the scary appellation ‘ocean acidification’. Slightly less alkaline is still not nearly acidic, as any high school chemistry class should teach.
  •  Part two was the fundamental physical chemistry buffering error in AR3.
  • Part three was the corals bleaching false death implication, explained by Jim Steele previously here and by his saga of symbiotic Zooxanthellae.

          Parts four and five were the arguably ‘scientific misconduct’ papers promoted by the Seattle Times concerning Papau New Guinea coral reefs and Pacific Northwest Miyagi oyster spawn. Both explained with footnotes in essay “Shell Games’ in ebook Blowing Smoke. The first misconduct was lethal H2S in one of three volcanic seeps, the second misconduct was lethal spat upwelling water pH in a hatchery bay not also managed as a seasonal estuary.

And then there is this new pteropod nonsense, deliberately ignoring the large difference that sea water temperature makes to their metabolism and hence shell formation. Even though the issue was discussed (then ignored) in the paper.

Ocean ‘acidification’ danger is a canard to be fought at the highest levels. Oceans will never truly acidify. Organisms evolved for its varying seasonal pH variations continue to thrive everywhere.

As just one final example of ‘acidification’ nonsense, the coccolithophorids (calcium exoskeleton algae, (the White Cliffs of Dover), have observationally increased almost 30 fold in the North Atlantic in the past 30 years, despite warming ‘acidification’. Coccoliths thrive. Alarmist ‘acidification’ memes do not.

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Brian Pratt
January 23, 2021 2:28 pm

As I mentioned the other day, there are credible pteropod papers out there that argue that not every minute pit or scrape on the test is due to dissolution. There is so much science, especially in biological and toxicological fields that employ the latest high-tech analytical wizardry which makes their work seem so cutting-edge and publication-worthy, that fundamental questions are not asked and tests for validity are not done. The situation is made worse by the fact that the people doing the research are students, the senior people are invested in the subject, and careers need to be made.

Reply to  Brian Pratt
January 23, 2021 2:44 pm

I’ve seen the science of wishful thinking over and over again. Most people do what they think they are paid to do and students are of course seeking good grades. Narratives are told and being searched for and amazingly every experiment leads to the same story or is buried if it doesn’t.

Reply to  Brian Pratt
January 24, 2021 4:10 am

Yep,.. And most examples of dissolution-related pitting are from polar regions and/or upwelling zones with naturally low pH and diminished argonitte/calcite saturation states.

John Tillman
January 23, 2021 2:42 pm

Coccolithophores evolved in the Late Triassic, more than 200 Ma, so have seen it all, ie much hotter and colder than now. The most common species alone, E. huxleyi, is happy in tropical, subtropical and temperate seas.

They so thrived during the hottest portion of the past 250 million years, the mid-Cretaceous, that their “shells” (casts) make up most of The Chalk, of which, as you note, the White Cliffs of Dover compose a part. Their remains give the Cretaceous (“Chalky”) Period its name.

John Tillman
Reply to  John Tillman
January 23, 2021 2:52 pm

Balmyness during the PETM and Eocene peak early in our own Cenozoic Era might have equalled mid-Cretaceous heat, but coccolithophores thrived then, too.

They are photosynthetic eukaryotic unicells, but whether they technically count as phylogenetic algae is dubious. The classification of their larger clade is still controversial.

John Tillman
Reply to  John Tillman
January 23, 2021 3:06 pm

Similarly, pteropods (sea snails and slugs under a centimeter in length) are found in all major oceans at all latitudes, as was no doubt pointed out in the prior post, usually close to the surface. Pteropods occupy depths lower than ten meters, but in less biomass. Their adaptability to differing temperatures and pH regimes is shown by the fact that pteropods from tropical areas are more common at greater depths.

Reply to  John Tillman
January 23, 2021 11:26 pm

200 Ma ago CO2 peaked at over 5000ppm.

I guess coccolithophores evolved to profit from it. Maybe the ate it all.

January 23, 2021 2:57 pm

Great post Rud!

Here’s a review of coccolithophores by Fanny Monteiro showing they prospered best near the end of the Cretaceous. Current conditions are too cold and too low-CO2 for their liking.

Last edited 2 years ago by Phil Salmon
Phil Rae
Reply to  Phil Salmon
January 23, 2021 3:16 pm

Indeed, a good post, Rud….

It won’t stop the alarmists whose understanding of chemistry is sadly deficient. But hopefully it might encourage a few of them to do some reading on topics like pH and buffering so they understand how ridiculous their “acidification” claims actually are.

Clyde Spencer
Reply to  Phil Rae
January 23, 2021 3:23 pm

Tell that to Nick Stokes.

Reply to  Clyde Spencer
January 24, 2021 3:22 am

Astoundingly, The Great Stokes still believes that a reduction in alkalinity counts as acidification.

PS: Next time you hear an Alarmist imbecile pontificating about the imminent dissolution of shelled molluscs, simply point out that snails don’t dissolve in rainwater, despite its pH of 5.5.

January 23, 2021 3:06 pm

Since the term “ ocean acidification” was coined about 2003, it has been clear to anyone who examined the matter that it is a confected non-issue.
As Steve Goreham and others pointed out years ago,measured in the open ocean, sea water is basic with a pH of about 8.2.
The oceans will never be acidic.
What is being discussed is a fear of impacts from a reduction in alkalinity.
According to computer models,doubling of atmospheric CO2 would decrease ocean pH to about 7.9,still basic but less so.
The latest CSIRO Report in Australia says alkalinity has dropped from 8.18 pH to 8.08 pH in the last century,as an example.
The largest concern is that such a change would destroy coral reefs of the world.
Put simply the fear in this regard is hugely overstated.
It is as difficult to to develop a global average of ocean alkalinity as it is to develop a global average of surface temperature.
The pH of the ocean varies by depth,becoming less basic as one goes deeper.
It varies by latitude as one moves from the equator to the poles.
It varies by location,such as open ocean,coral reef,or kelp bed.
Scientists still know little about the alkalinity of today’s ocean or the oceans of past centuries.
In December 2011,a study by scientists at the Scripps Institution of Oceanography,( Hoffman 2011),found large variations in ocean pH by month,week,and even time of day.
Dr.Gretchen Hoffman led a team that measured pH at 15 locations in the Atlantic,Pacific and Antarctic Oceans.
They found that pH changes were large, from 0.1 to 1.4 units over a 30-day period.They also found that pH changed by as much as 0.35 units over a course of days.
The study concluded that “ climatology-based forecasts consistently under estimate natural variability” and that ocean residents are already experiencing pH regimes that are not predicted until 2100 by the climate models.”
(h/t “The Mad,Mad,Mad world of Climatism” by Steve Goreham.)

Robert MacLellan
Reply to  Herbert
January 23, 2021 3:45 pm

pH also changes (drops) as temperature rises which is why pH readings need to be done following a consistant protocol, either recording the temperature at time of reading, measuring at a standard temperature, or some combination of those.

Reply to  Herbert
January 23, 2021 7:08 pm

The latest CSIRO Report in Australia says alkalinity has dropped from 8.18 pH to 8.08 pH in the last century,as an example.

Please provide a reference. The 0.1 pH drop in the last hundred years is a canard. There are NO pH measurements from 100 years ago. The first pH meters weren’t built until around 1935, IIRC. Before that pH needed to be measured chemically using titration (IIRC), something time consuming and impractical in the open ocean. Even today there isn’t enough seasonal or spatial coverage in the ocean pH data to be able to calculate a global average ocean pH. In other words, both numbers (8.18 AND 8.08) are made up.

Please try to convince me otherwise. I would not be offended.

Reply to  Phil
January 23, 2021 9:54 pm

I agree. I think claiming there is ANY long term trend in pH is made up.

Reply to  Phil
January 24, 2021 4:18 am

They base this largely on CO2 estimates. CO2 is one of about a dozen things related to related to pH. 0.1 is probably a reasonable guesstimate… But it’s not much more than a guess.

Furthermore, pH isn’t what really matters. The saturation states of aragonite and calcite are what matter; and they’re quite a bit more complicated than pH.

Bill Rocks
Reply to  Herbert
January 24, 2021 8:20 am


“The study concluded that “ climatology-based forecasts consistently under estimate natural variability” and that ocean residents are already experiencing pH regimes that are not predicted until 2100 by the climate models.””

Can we call this scientific blunder The Great Ocean Acidification Catastrophe That Never Happened? [With credit to Dr. Susan Crockford and her polar bear book!]

Mike Dubrasich
January 23, 2021 4:19 pm

The climate fight is now on a higher non-specific ‘belief’ plane.

How true! But that doesn’t obviate the need for posts like this one. Thank you, Mr. Istvan.

The common or mass belief system has been manipulated with some degree of success by political forces and culture parasites, but the truth is not completely hidden. Average non-scientific people are not necessarily swayed by the alarmist hype. My casual querying of just plain folks suggests to me that most people recognize when they are being conned.

Joseph Zorzin
Reply to  Mike Dubrasich
January 24, 2021 4:23 am

“Average non-scientific people are not necessarily swayed by the alarmist hype.” They may not understand the science but when they see the revolutionary and expensive changes in our civilization to become “clean and green” with a less dependable electric power industry- all in the coming decades, they know they’re being screwed.

Reply to  Mike Dubrasich
January 24, 2021 4:23 am

A few years of this sort of schist may refocus people’s minds.

Renewed dependence on Saudi Arabia, Iran and Russia for oil, coupled with a doubling or tripling of gasoline prices might just downgrade the climate”emergency” on voters’ priorities lists.

Keith Peregrine
January 23, 2021 4:36 pm

One issue rarely if ever mentioned in any ocean chemistry article is the serpentinization process. Overall, basalt/peridotite is serpentinized as ocean water seeps into oceanic crust. This process is overall alkaline. The mid-ocean ridge extends approximately 65,000 km. Hence, serpentinization occurs along this vast distance. Yet, it is ignored when ocean acidification, actually ocean alkaline reduction, is discussed.

Reply to  Keith Peregrine
January 24, 2021 2:35 pm

Yet, it is ignored when ocean acidification, actually ocean alkaline reduction

I am having a problem with that. If you had entered the word “claimed” ahead of alkaline reduction, I would have no problem with it.

Acidification, the addition of CO2 to ocean water to produce H2CO3 -> HCO3- (bicarbonate) and CO3– (carbonate)

Amounts to adding alkaline products to our oceans, of which 90% adds to the ocean’s vast bicarbonate buffer AND with a pH the same as the ocean, 8.1 (OK, I can accept 8.2).

Else, “acidification” in our oceans would require the removal of proton receptors (removal of alkalinity products).

Except for some of us understand that the process is reversed by warming up the ocean (CO3– and HCO3- turns back to H2CO3 and CO2+ocean water), ref to Henry, Dalton….

Adding bicarbonate to a bicarbonate buffer can NOT reduce pH of a bicarbonate buffer.


Charles HIgley
January 23, 2021 7:09 pm

Let’s see, where to start. First off, seawater in bays and estuaries can rise above pH 10 on a sunny day, as photosynthesis is an alkalizing process. The organisms in these waters do just fine because they have a power, a superpower that life has, physiological power. They can control their internal pH despite the surrounding water. They have control over their shell pH. During the night, normal aerobic metabolism, which is an acidifying process as it produces organic acids, lowers the pH back to normal, around 8.1–8.4 pH.

Oceanic seawater flows through coral reefs, bringing in the microflora and fauna the corals filter and ingest. The 8.3 seawater enters the reef, but it leaves with a lower pH due to the acidic metabolic processes of the living reef. In other words, life is an acidifying process.
We do have to be careful when talking about seawater, because 8.0 pH is still far from acidic. The “acidification” descriptor is misused as it suggests the oceans are becoming more acidic when, in fact they might be becoming slightly less alkaline in a still clearly basic environment. (Coral Reefs, Temperature and Ocean pH; []
Nothing regarding temperature and CO2 concentrations has anything really to do with life in the ocean other than the best, most favorable places for each species to live. Over the eons, they move around as needed and allowed by the climate. To tell the truth, the coral reefs and, for that matter, the rainforests are the most stable ecosystems on the planet. It is the less temperate zones that are in danger of changes in climate. There is always a tropic zone.

Reply to  Charles HIgley
January 25, 2021 8:12 am

“…..control over their shell pH” – do you mean the shell-building tissue ? The shell is solid, not a solution.

“normal aerobic metabolism, which is an acidifying process as it produces organic acids” – Which acids ? Mainly CO2 as carbonic acid.

“life is an acidifying process” – Well, when you are willing to disregard photosynthesis : “….. an alkalizing process.” Photosynthesis and respiration are complements. Respiration can only consume what photosynthesis has built up (the carbon cycle), CO2 is consumed and produced. Carbonates are removed from the cycle as skeletons and dead shells for a long time, certainly not an acidifying process.

Steve Case
January 23, 2021 7:31 pm

Ocean acidification is a misnomer. It’s really a lowering of the pH. There’s lots of this in the popular press. We call them buffalos but they are in scientific terms Bison. Did you ever run into some pedantic snowflake who corrected you on that one?. We know that the polar ice caps are losing ice because the snow that fell decades ago is less than what’s calving into the sea is icebergs today. But it’s easier to say the ice caps are melting isn’t it?

It becomes bullshit when the popular press starts to illustrate Santa’s North pole melting away and shell fish unable to maintain their shells because the ocean is acid.

It’s a soundbite world and the truth is a loser.

The old joke:
“Why is a roll of toilet paper like TV’s Star Ship Enterprise?
They both sail around your anus and wipe out Klingons”
Except that today we are told the planet is really pronounced Urine-us.
Here’s a link about that”

From ‘Your-Anus’ to ‘Urine-us’: The Rebranding of Uranus

The bullshit from the so called mainstream press is suffocating.

Alan Reed
Reply to  Steve Case
January 24, 2021 1:25 am


Joel O'Bryan
January 23, 2021 8:29 pm

The ignored ocean rift zone basalts and continental margin carbonate (chalk) buffering is the big fly-in-the-ointment for the OA rent seekers. Those buffering reservoirs are vast and for the next million years or so, inexhaustible.

Reply to  Joel O'Bryan
January 23, 2021 9:57 pm


January 23, 2021 9:41 pm

I don’t know if this is relevant but in my textbook on soils, the following…
”Adding sulphur to a soil ( to lower pH through it’s conversion to sulphuric acid) will NOT alter it’s pH until all of the solid calcium carbonate in it has been dissolved”
I cannot see how it would be any different in the ocean. The pH changes – if they are even there – are probably only temporary/transitory.
Remember too that the Amazon river ALONE dumps 6000 cubic kilometers of water with a pH of 6.5 into the sea each year with no effect on it’s pH

January 23, 2021 10:16 pm

Thank you the article.
“The climate fight is now on a higher non-specific ‘belief’ plane.” Is so true.

I believe you could provide some valuable advice/techniques to assist us ( the average WUWT reader ) in engaging in the climate fight.

How have alarmists message mapped ocean acidification?
How should we counter this message mapping?

January 23, 2021 11:09 pm

coccolithophorids (calcium exoskeleton algae, (the White Cliffs of Dover), have observationally increased almost 30 fold in the North Atlantic in the past 30 years, despite warming ‘acidification’. Coccoliths thrive.

Calcium is an alkaline earth metal, they have metal exoskeletons?
Maybe coccolithophorids need carbonate for their calcium carbonate shells. Guess where that comes from: coccolithophorid fertiliser.

Thanks Rud.

Last edited 2 years ago by Greg
January 24, 2021 12:34 am

Coccoliths thrive

The link doesn’t work and I can’t find it on the Wayback machine

Danny Lemieux
January 24, 2021 4:54 am

There is an easy way to determine whether CO2-generated ocean acidification is even a factor: check the pH susceptibility of non-buffered fresh water ponds. Frankly, I doubt that there is really any way to accurately measure the pH of large bodies of water. For one, I would want to know the within- and between-sample coefficients of variation for such measurements before any conclusions could be reached. Without that, all is speculation.

Climate believer
January 24, 2021 7:03 am

There’s a lot of alarmist lies spread all over the web on the subject of “ocean acidification”, some examples:

Nanowerk: About one fourth of the CO2 produced by humans each day is being taken up by the oceans, resulting in a chemical reaction leading to a higher acid content in the water. In the long run, this can threaten marine life forms such as corals or shellfish as the acidification reduces the shell and skeleton production. This would affect biodiversity and the intricately interwoven food webs. Thus the CO2 uptake by the oceans is a danger for marine life.

The Seattle Times:  It didn’t take long for researchers examining the tiny sea snails to see something amiss. The surface of some of their thin outer shells looked as if they had been etched by a solvent. Others were deeply pitted and pocked. These translucent sea butterflies known as pteropods, which provide food for salmon, herring and other fish, hadn’t been burned in some horrific lab accident. They were being eaten away by the Pacific Ocean.

PBS: More carbon dioxide increases the water’s acidity and decreases it’s pH, making it harder for organisms like pteropods to create healthy calcium carbonate shells. Scientists liken it to osteoporosis, the bone-thinning disease, in humans.

Wiki: Limacina helicina was used to test the sensitivity to decreasing pH. This species of pteropod is potentially vulnerable to the corrosive waters associated with ocean acidification due to their calcium carbonate shell.

NOAA : For good reason, ocean acidification is often called “climate change’s evil twin.” The overload of carbon dioxide (CO2) in our oceans is literally causing a sea change, threatening fragile, finite marine life and, in turn, food security, livelihoods and local to global economies.

……it’s all highly emotive and low on science…. global warming™

Tim Anderson
January 25, 2021 2:14 am

pH is a logarithmic scale so a reduction of pH from 8.1 to 7.9 represents a 150% percent increase in the concentration of hydrogen ions and, yes that is a very big deal for marine calcifiers. Your belief (i.e. grossly unsupported claim) that because marine calcifiers can regulate their ‘internal calcifying’ (intracellular) pH to variable ocean carbonate chemistry means they could just across the board handle a ‘little’ drop in average pH by .1 is such a lazy and layman assumption, but it in no way implies that, you know, ability to respond to some environmental fluctuations in pH just makes, %150 percent increase in average acidity, totally chill for all calcifiers across the board.

The future ocean carbonate chemistry projects are reporting averages which means pH will continue to vary in the future and could easily reach less than 7.9 for certain durations. Obviously, that’s what moving the center of a distribution does. You also fail to acknowledge a fundamental component of ocean acidification, which is that seawater not only becomes less basic less by the freed hydrogen atoms from carbon dioxide, but that carbonic acid increases, effectively ‘stealing’ carbonate ions from the water that would have been available to form calcium carbonate. Essentially calium carbonate not only disolves easier but, less carbonate can be found by calcifiers.

Thousands of experiments have demonstrated or strongly indicated the negative effects of long-term reduced pH stress, particularly those combined with thermal and other stressors, which I encourage you to look into deeper. If you remove the blinders of ideology (i.e. pretend you know nothing about the subject, which shouldn’t be too hard for you) and actually give serious consideration of the body of OA literature, you would quickly discover this. Of course, that might not appeal to much of your audience, eagerly awaiting for you to validate their baseless opinions with amateur jargon and swiss cheese kinds of reasoning.


Rud Istvan
Reply to  Tim Anderson
January 25, 2021 9:41 pm

You know not of which you speak. There are thousands of ‘tank’ experiments disproving your assertion. References cites in essay Shell Games. You claim I am an ignorant amateur— check my references.
You are the ignorant amateur. Bad try, factually ignorant comment loser.

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