Temperature Dependence of Ocean pH shows CO2 may not be only driver of 'ocean acidification'

Guest essay by James R. Barrante, Ph.D.

Emeritus Professor of Physical Chemistry, Southern Connecticut State University, New Haven, CT

It is well-known that ocean pH has decreased from approximately 8.2 pH units to 8.1 pH units in the last 150 years. One explanation is that the increase in atmospheric carbon dioxide from the burning of fossil fuels is responsible. This is based on a law of physical chemistry, known as Henry’s Law, that states: if the partial pressure of a gas over a solution is increased, the concentration of the dissolved gas in the solution will increase. Since dissolved CO2 is a weak acid, one would expect the pH of the oceans to decrease.

Describing Henry’s Law in this simple manner, however, is a very narrow interpretation of the boundaries of the system. For example, the above statement of Henry’s Law is only valid, if the temperature of the solution is constant. Moreover, using pH to describe the acidity or alkalinity of a solution can be misleading. The pH of a pure water solution (neither acidic nor alkaline) is 7.00 at 298.2 K. Increase the temperature of the water and the pH will drop to below 7.00. Does this mean that simply raising the temperature of water will cause water to become “acidic?” That would be a ridiculous interpretation of pH.

Thermodynamic equilibrium constants are a sensitive function of temperature. We know that if the temperature of an aqueous solution of a gas increases, the solubility of that gas has to decrease, not increase. Moreover, if the ionic strength of the solution is high, describing equilibrium constant equations in terms of concentration will produce, at best, only approximate results. Activities must be used. Ocean chemistry is complex, involving a number of important equilibria, that include the dissociation of carbonic acid (dissolved CO2), the buffering equilibria due to the presents of dissolved salts of bicarbonate and carbonate, the solubility of the sparingly soluble salt CaCO3, and the equilibrium between dissolved CO2 and the partial pressure of carbon dioxide in the atmosphere. Luckily, the temperature dependence of these equilibrium constants has been highly studied. A typical example of each is given below.

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Ksp (weighted average for calcite and aragonite) clip_image020; clip_image022

The pH of seawater (ionic strength of approximately 0.7) can be determined at any temperature a modified form of the Henderson-Hasselbalch equation for buffer systems (derived in my blog: climaterx.wordpress.com., post OAII). For reasons described in the post, the activity of calcium ion in the oceans is assumed to be constant.

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To test this equation, consider the following:

Preindustrial pH: PCO2 = 0.000280 atm

aCa++ = 0.00123 (described in blog)

T = 288.2 K

pK1 = 6.4149; pK2 = 10.4202

kH = 22.24 atm/C

Ksp = 6.05 x 10-9 (average calcite/aragonite)

pH = 8.214 (very close to published value)

Post-industrial pH: PCO2 = 0.000380 atm

aCa++ = 0.00123 (described in blog)

T = 290.2 K

pK1 = 6.4105; pK2 = 10.4063

kH = 23.56 atm/C

Ksp = 5.718 x 10-9 (average calcite/aragonite)

pH = 8.138 (very close to published value)

We find from similar calculations that a 2-degree C increase in temperature can lower ocean pH by approximately 0.05 pH units. The temperature range taken in this study was ocean SST at the Equator, approximately 305 K, to ocean SST at the poles, approximately 273 K. This alone with play havoc with pH measurements. Moreover, ocean temperature ranges in bands containing water of different surface areas and land masses running parallel to the Equator. Simply recording ocean temperature at various points over the ocean and averaging them to get a number has no useful scientific meaning, no more than the average diameter of a football tells us anything about the shape of a football. At best, a weighted average must be used. In fact, if the measurement of ocean pH were not so complicated, and we had that data for the last 150 years, I would bet that we could show exactly that the increase in atmospheric CO2 from 280 ppmv to 380 ppmv in the last 150 years is an ocean temperature effect and not at all related to burning fossil fuels.

The graph below is a three-dimensional representation of P-pH-T data, similar to PVT graphs. The two-dimensional dependence of pH on either CO2 pressure or ocean surface temperature can be followed by looking at various isotherms or isobars; however, be sure to follow the graphs back to their original axes. For convenience, pH values at the intersection of these curves are given. It is obvious that to assume the drop in alkalinity of such a highly buffered system as our oceans is due to an uptake of atmospheric CO2 without taking the increase in ocean temperature, particularly in the Northern Hemisphere, into account is a very narrow interpretation of the science.

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Temperature and Pressure Behavior of Ocean pH

Note: the word “only” was added to the title for clarity – Anthony

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Alex
March 21, 2016 5:20 am

Is it really well-known that pH has decreased from 8.2 to 8.1?

Don K
Reply to  Alex
March 21, 2016 7:41 am

Seems like everyone “knows” it. Exactly what evidence (if any) the statement is based on doesn’t seem to be clear at all. Check out this post http://wattsupwiththat.com/2015/01/02/a-neutral-view-of-oceanic-ph/ by Willis Eschenbach and see how likely such a measurement seems.

James Barrante
Reply to  Don K
March 21, 2016 12:02 pm

Look up any post or article on the web that deals with ocean “acidification,” and you will find it stated without any scientific proof that since the industrial revolution, ocean pH has decreased from 8.2 to 8.1 (their claim, not mine). I just assume this is another consensus between 97% of climate scientists, requiring no scientific proof. Just be quiet and accept it. It has as much scientific force as the statement, “everyone knows that atmospheric CO2 has increased from 280 ppmv to 380 ppmv from burning fossil fuels.”

RWturner
Reply to  Don K
March 21, 2016 12:54 pm

“For reasons described in the post, the activity of calcium ion in the oceans is assumed to be constant”
That’s another false assumption that the OA industry relies upon. There is no fixed amount of salts in the ocean, they enter solution via fresh water and dissolution of marine sediments.
We have a 500+ million year record showing that ocean chemistry is controlled by ion ratios dictated by tectonic spreading rates, not partial pressure of CO2 in the atmosphere.
http://openearthsystems.org/data/readings/FridaySeminars/2012-02-10-Linda-Carbonates/StanleyandHardie1998-Secular%20oscillations%20in%20the%20carbonate%20mineralogy%20of%20reef-building%20and%20sediment-producing%20organisms%20driven%20by%20tectonically%20forced%20shifts%20in%20seawater%20chemistry.pdf
http://www.whoi.edu/science/GG/geodynamics/2005/images2005/lowenstein01_SCI.pdf

pd2413
Reply to  Don K
March 22, 2016 6:30 am

On the timescale of 100-200 years, the activity of calcium is constant in the ocean. You are citing papers and studies that deal with changes over tens of millions of years, in which case long-term geologic processes become much more important.

RWturner
Reply to  Don K
March 22, 2016 9:47 am

No, the chemistry involved does not take millions of years, it’s taking place as I type this. The links were just a general overview on marine chemistry and make no mistake that the current tectonic activity on the ocean floor dictates the Aragonite Seas on Earth today. There is no instance in the geologic record where CO2 controls marine chemistry.
Trillions of liters of marine waters are currently moving through alkaline marine sediments worldwide, either moving landward into sediments or seaward out of sediments due to the tidal pump and advection. These processes work on timescales of minutes, not hundreds of years.
http://www.biogeosciences.net/10/2467/2013/bg-10-2467-2013.pdf

pd2413
Reply to  Don K
March 22, 2016 12:00 pm

That paper studied a small scale fringing coral reef and discusses the importance of the alkalinity flux solely in a lagoon and reef setting. In addition, even on a small scale those reactions have very little effect on Ca concentrations in the free water column. When you are discussing full ocean basins, the activity changes very little on short time scales and changes in carbonate ion activity are much more important.

RWturner
Reply to  Don K
March 22, 2016 2:16 pm

So let’s put it all together, what happens when CaCO3 sediment dissolves and enters the water collumn? What happens to buffering capacity as TA increases?
The overall ion flux in the shallow marine environment is magnitudes larger than the CO2 dissolving into the oceans. I don’t think the OA scare has much to do with the open ocean, everything I’ve read is all about the shelf environment where most of the productivity and chemistry takes place.
The last time I checked the surface waters of the oceans are still super saturated with respect to CaCO3 (specifically aragonite), despite the speculated decrease of pH from 8.2 to 8.1. You’d think that much change would result in observable affects. You can still see spontaneously precipitate aragonite in the form of oolite shoals in NW Australia and the Bahamas. Whitings (the spontaneous precipitation of acicular aragonite) are still occurring every day in the Caribbean Sea. Why haven’t we seen any observable changes if the chemistry of marine waters are significantly changing, specifically the surface waters becoming less saturated with CaCO3?

Reply to  Alex
March 21, 2016 8:38 am

I welcome the post, enjoyed reading it and agree that the temperature dependance of pH measurements are crucial. It is also worth noting that pH reduces rapidly with depth (To 500m) and this effect also differs markedly from ocean to ocean.
However, as far as I’m concerned, Ocean Acidification (OA) is the deliberately obtuse invention of the maniacal.
The patent absurdity of OA isn’t hard to visualise. The composition of seawater is well defined and it is dominated (96.5%) by H2O. The remaining 3.5% are salts and of that, just 0.7% make up the acid-base chemistry, the so-called reacting species of the OA scare.
So, whatever else it is they are talking about, it is less than an ocean’s* worth!
It is extremely difficult to measure ocean pH and anybody who says that that have measured any long term change is a barefaced liar!
All this OA mongering is a massive and astonishingly stupid beat-up.
*OA is depth dependant ultimately.

billw1984
Reply to  Alex
March 21, 2016 9:15 am

Took the words right out of my mouth (so to speak, err, ummm, I mean so to write).
Trying to assign a single pH to the ocean is even more ridiculous than trying to assign
a single global temperature to the planet. Even if you come up with some kind of a definition for either one, the error bars should be so large (if one is to take care to make it meaningful for the entire planet) as to make it less than useful. And given, that for both temp. and pH, the farther back in time you go, the the fewer and the less accurate the measurements become, it makes it difficult to make a meaningful comparison with the recent (100 years say) past and impossible once you go beyond that.

Richard
Reply to  Alex
March 21, 2016 9:25 am

Canadian marine authority,-
The seas are between 7.5 and 8.5.

John Harmsworth
Reply to  Richard
March 21, 2016 6:51 pm

Exactly! Way to much variation worldwide to say there has been a global reduction from 8.2 to 8.1. I’ve checked a few spots and I say it’s gone up from 8.1 to 8.2!

oeman50
Reply to  Alex
March 21, 2016 10:37 am

Sure. They used a model to calculate it…..oh, no.

Clyde Spencer
Reply to  Alex
March 21, 2016 6:23 pm

I think that this claim can be traced back to a paper by Caldeira and Wickett (2003). Abstract: http://www.nature.com/nature/journal/v425/n6956/abs/425365a.html
If I remember correctly, they used a computer model to hindcast the pre-industrial pH. However, there was a graph showing dissolved CO2 and pH that just looked ‘too good” and too simple, considering that the diagram relating pH to carbonate and bi-carbonate is not as simple.

johnmarshall
Reply to  Alex
March 22, 2016 4:31 am

Ocean pH given is an average. Texts give it as 7.4-8.6 as measured round the globe but no mention is made of temperature. The above post makes things clear.

Antti Naali
March 21, 2016 5:22 am

“It is well-known that ocean pH has decreased from approximately 8.2 pH units to 8.1 pH units in the last 150 years.”
Sorry folks but I have to ask. What was the accuracy 150 years ago? What is it now?

Alex
Reply to  Antti Naali
March 21, 2016 5:32 am

Perhaps the wording should be ‘it is claimed’

Doubting Rich
Reply to  Antti Naali
March 21, 2016 5:43 am

I was going to query the same statement. pH of the ocean cannot be measured to that precision, as it varies too much by location and time, and there are too few measurements. 150 years ago? Not a chance.

skeohane
Reply to  Antti Naali
March 21, 2016 6:03 am

Isn’t a change from 8.2 to 8.1 actually an order of magnitude difference? It’s not really small.

Reply to  skeohane
March 21, 2016 8:12 am

He’s a physical chemist, he should know better. ‘Alkalinity’ is not what he’s talking about and does not change as a result of the addition of CO2, [H+] is what he’s talking about and that does change with the addition of CO2, as he himself has shown. As a professional in the field he has a responsibility to use the correct terminology and not further confuse things.

Reply to  skeohane
March 21, 2016 8:24 am

No, a change from 8.2 to 7.2 is an order of magnitude change, 8.2 to 8.1 is a ~25% change.

BFL
Reply to  skeohane
March 21, 2016 8:42 am

It does but it’s still hard to do accurately
“Realistic accuracy of your pH values:
Laboratory: ± 0.05 pH
Online: ± 0.2 pH”
http://www.all-about-ph.com/ph-test.html
Then there’s what Doubting Rich said:
I was going to query the same statement. pH of the ocean cannot be measured to that precision, as it varies too much by location and time, and there are too few measurements. 150 years ago? Not a chance.

billw1984
Reply to  skeohane
March 21, 2016 9:27 am

Yes, about a 25% increase. From a very tiny [H3O+] of 6.3 x 10^-9 to 7.9 x 10^-9 From 6.3 nano molar to 7.9 nano molar.

Reply to  skeohane
March 21, 2016 9:54 am

billw1984 March 21, 2016 at 9:27 am
Yes, about a 25% increase. From a very tiny [H3O+] of 6.3 x 10^-9 to 7.9 x 10^-9 From 6.3 nano molar to 7.9 nano molar.

Yes as I pointed out earlier. A similar very tiny change in your blood pH would likely kill you, so it all depends on the context.

Paul of Alexandria
Reply to  skeohane
March 21, 2016 12:08 pm

Don’t forget that pH is a logarithmic scale! https://en.m.wikipedia.org/wiki/PH

mrmethane
Reply to  skeohane
March 21, 2016 1:28 pm

about 25% change in Hydrogen ion concentration, not a n order of magnitude. Um more like a decrease in OH (basic, not acidic) ion concentration. If it were true. If it could actually be measured. To any meaninful accuracy. Over that long period of time. Without menaingful instrumentation. Scary, indeed.. How many microns on my slide rule?

Reply to  Antti Naali
March 21, 2016 8:38 am

There were no pH measurements 150 years ago. The pH scale was invented in 1909. There are estimates of pH. The current measured ocean pH is based on estimates and indicated in the article.

Reply to  Bob Greene
March 21, 2016 8:40 am

Phil, any change of about 0.1 su is a ~25% change, hence the claims (rounded) of 30% more acidic for a minor change.

Reply to  Bob Greene
March 21, 2016 9:26 am

Yes I know, isn’t that what I posted?

Bill Illis
March 21, 2016 5:34 am

Just did some quick calculations. The oceans hold about 40,000 billion tons of Carbon (dissolved, biota etc.). 90 billion tons per year is released back to atmosphere each year and 92 billion tons is absorbed back into the oceans. They are a Carbon sink.
If the oceans were responsible for 50% of the total that is removed each year through natural sinks, since 1750, the oceans have absorbed a net 96 billion tons. [Of our emissions since 1750, about half has been absorbed by plants oceans and soils. I have the actual numbers and the total is 193 billion tons Carbon.]
The Carbon store held in the oceans, therefore, has only increased by 0.2% or 96 billion tons on top of the original store of 40,000 billion tons. Now someone can do the math for how this has affected the pH. I doubt it changed it from 8.2 to 8.1 pH units.

Reply to  Bill Illis
March 21, 2016 5:53 am

The change may refer to near surface waters? I don’t think abyssal waters have been told that CO2 has increased.

michael hart
Reply to  Fernando Leanme
March 21, 2016 8:30 am

Yes. Apparently Trenberth’s heat can go AWOL in the abyss but CO2 isn’t allowed to. It’s not logical, captain.

Editor
Reply to  Bill Illis
March 21, 2016 12:58 pm

Bil Illis – There is another factor that you have not taken into account which adds to your argument: The ocean floor is another carbon sink; it takes carbon from the ocean. Oilfields are a manifestation of the process (but not all such carbon forms oilfields).

GeoChemist
March 21, 2016 5:39 am

Thank you for the first comprehensive description of the acid-base chemistry of seawater I have seen on climate blogs. It is exactly what I have been telling people who think you can simply apply Henry’s Law to the ocean. Introductory geochemistry material. It is even far more complicated when one takes into account the biogeochemical effects on pH.

TomRude
Reply to  GeoChemist
March 21, 2016 9:32 am

Hear, hear I second this motion!

seaice1
March 21, 2016 6:00 am

I am a little confudsed. Are you trying to explain atmospheric CO2 levels due to warming oceans, or pH reduction due to warming oceans?
From the graph, we can go from pH 8.2 to pH of 8.1 by going from from 293K to 303K with atmospheric CO2 constant at 300ppm. A 10K rise in ocean temperature is not remotely feasible to explain pH change. Or we could do it by going from 200 to 300ppm CO2 at 303K. This seems a reasonable explanation.
You say “I would bet that we could show exactly that the increase in atmospheric CO2 from 280 ppmv to 380 ppmv in the last 150 years is an ocean temperature effect and not at all related to burning fossil fuels.”
Are you saying that the atmospheric CO2 has come out of the oceans becasue they are warming up? Why are they warming up at all?
It may be too complicated to model the ocean fully, but surely a simple model would tell us if this was at all likely. What would be a simple model that would explain both the increase in CO2 concentration and the decrease in pH?

Marcus
Reply to  seaice1
March 21, 2016 6:10 am

..Oh boy, more models !! LOL

TonyL
Reply to  seaice1
March 21, 2016 8:14 am

My takeaway is that is is a sampling problem. Consider how the sampling distribution changes over time. If early samples were taken in the cold waters of northern Europe and northeastern US, you would get one reading. As your program expands to more tropical locations, you would see a consistent change in the measured values.
Consider my own research plan. Initial sampling must be done locally to get started. My range extends from Newport, Rhode Island in the south, through Boston, and along coastal Maine. After I make sufficient noise about CAGW, I get my funding and I can expand my sampling. So I add the Caribbean (Virgin Is., Martinique, Barbados), the South Pacific (Tahiti, Bora-Bora), and the Indian Ocean (Maldives, Seychelles Is.). All for Science, of course. As sampling proceeds, I record a consistent drop in measurement readings, and confirm other researcher’s fears. So everybody is happy and I get my funding renewed.
As far as simple models go, that has been done to death. They just do not work. As soon as you start playing with them, they diverge from reality. There is nothing “simple” about seawater. Where I went to graduate school, the ocean was within walking distance to campus. Grabbing a bucket of seawater and carting it back to the lab was an everyday chore for quite a few of us. So reality checks were the order of the day and you could not hide from them.
New grad student proposes to model seawater for whatever:
“Hope you like solving simultaneous equations”
“You can’t use simplifying assumptions”
“I am getting my ‘Told You So’s lined up”
“Been there, done that, painful”
“Seawater HATES chemists”

seaice1
Reply to  TonyL
March 22, 2016 3:31 am

What is the claim here? We have the title “Temperature Dependence of Ocean pH shows CO2 may not be only driver of ‘ocean acidification’” This suggests that it is temperature that is driving reduced pH, not CO2. From the chart given in the post this would require a 10k change in temperature. It is totally unrealistic to suggest the ocean has warmed by 10°C. This is a simple model – there are many complications, but there are none significant enough to allow us to explain the pH change purely as a temperature rise.
Then we have the statement “I would bet that we could show exactly that the increase in atmospheric CO2 from 280 ppmv to 380 ppmv in the last 150 years is an ocean temperature effect and not at all related to burning fossil fuels.”
This suggests that the claim is not about ocean acidification, but about the source of the atmospheric rise in CO2. This would also require a large change in temperature. A simple model would indicate if this is a likely physical explanation for the rise in CO2. How much would the temperature need to rise to produce that much CO2?
“As far as simple models go, that has been done to death. They just do not work. As soon as you start playing with them, they diverge from reality.” Yes, but how much would it have to diverge to produce the effect? This is how science is done. If the model must be divergent to such an extent that we cannot get anywhere near to explaining the divergence, then we probably have the wrong answer. The simple model of changing ocean temperature to cause the pH change from 8.2 to 8.1 shows us that this is an extremely unlikely explanation.
If this is the explanation for the increase in CO2 there is then the huge question of why the oceans are warming to such an extent.

Bill Treuren
Reply to  seaice1
March 21, 2016 2:06 pm

There is also the Fe depletion issue relating to modern industrial fishing.
How much Fe would reduce the dissolved CO2 to balance this purported problem and even deplete the atmosphere of its CO2 somewhat.
The downside would be great fishing just a minute mixed up again.

Geoff
March 21, 2016 6:05 am

Since land plants are benefiting from CO2 is it not the same for the oceanic plant life ? Most plant inhale during daylight hours and exhale at night. Depending on the buffering it can swing wildly on a pH scale.

PRD
Reply to  Geoff
March 21, 2016 12:10 pm

In another life I worked at a drinking water plant. We turned the muddy, nutrient rich Brazos River into pretty good drinking water. Taking pH measurements of the raw water, clarified water, and filtered water 6 times/24 hours (two shifts) provided a very good example of what you refer to above. During the day the planktonic as well as sessile (photosythesizing) algal species would be sucking up the CO2 from the water and we would observe increases in pH up until sunset, then slow decreases through the night. During the summer months, the clarifiers would get a decent growth of streaming algae. Before copper got an MCL we’d use copper sulfate to kill it, then started using chlorine dioxide. Niether was a permanent fix, but would slow it down somewhat.
We’d also see an uptick in clarify turbidity, which would become evident once the sample was placed under a microscope. The algae would be releasing its reproductive units into the water.

March 21, 2016 6:20 am

Simply recording ocean temperature at various points over the ocean and averaging them to get a number has no useful scientific meaning, no more than the average diameter of a football tells us anything about the shape of a football.

This analogy confused me, until I realised you meant a rugby ball.

JohnWho
Reply to  MCourtney
March 21, 2016 6:23 am

Or American Football.

A. Zeeman
March 21, 2016 6:20 am

“Simply recording ocean temperature at various points over the ocean and averaging them to get a number has no useful scientific meaning, no more than the average diameter of a football tells us anything about the shape of a football.”
Obviously not a climatologist since he doesn’t know that the laws of physics don’t apply to climatology.

JohnWho
March 21, 2016 6:22 am

The more we learn, the more we learn that there is more to learn.

PRD
Reply to  JohnWho
March 21, 2016 12:13 pm

“The larger the island of knowledge, the longer the shoreline of wonder.”
– Ralph W. Sockman

March 21, 2016 6:22 am

All of climate change ‘science’ is represented by a single statement:
The application of simple linear equations to a system which is complex and/or non-linear
Why?
Because simple linear equations are all ‘climate scientists’ can do…

Marcus
Reply to  Leo Smith
March 21, 2016 6:31 am

..That’s not rue..Climate scientists are also very good at adjusting perfectly good raw data to make it fit to their beliefs of what the data should be !!

Reply to  Leo Smith
March 21, 2016 2:19 pm

The adjustments to satellite data are non linear. Are you saying Roy Spencer isnt a climate scientist?

Retired Engineer John
March 21, 2016 6:25 am

There is a cycling of Calcium dissolved by carbonic acid in rainwater reacting with limestone and flowing through the world’s rivers into the world’s oceans. This should have a large impact on the ocean’s pH. I don’t see this being mentioned.

Reply to  Retired Engineer John
March 21, 2016 10:40 am

Because it’s trivial, total runoff = 44,000 km^3/yr vs ocean volume of 1,388,000,000 km^3
In any case the ocean concentration of Ca is about 30x greater than the average river concentration.

RWturner
Reply to  Phil.
March 21, 2016 1:18 pm

Trivial? Dissolved salts from carbonate sedimentary rocks and basic igneous rocks is one of two primary sources of salts in the ocean. It’s trivial in the same sense that my body contains many more calories than what I ate today, so what I ate today is trivial…

Phil.
Reply to  Phil.
March 23, 2016 10:17 am

Yes trivial, the annual influx of Ca from rivers is about one millionth of the amount already present in the oceans. To continue your analogy that’s the same proportion as the number of calories you consumed in the last second has to your total caloric intake for the last year.

Don K
March 21, 2016 6:34 am

“This alone with play havoc with pH measurements.” typo almost certainly. Probably meant to say ” This alone will play havoc with pH measurements.”

Michael Maddocks
March 21, 2016 7:40 am

Isn’t the relationship between the solubility of CO2 and temperature so close to linear at normal Earth sea temperatures that you can average the temperature without significant error in the average solubility?

Scott Scarborough
March 21, 2016 7:44 am

The concept of PH was only invented about 100 years ago. So how do they know what the PH was to 0.01 50 years before the concept was invented? Also, I thought that to measure PH the temperature had to be carefully measured and removed from consideration… all PH measuring equipment has thermocouples as an integral part of the equipment.

Marcus
Reply to  Scott Scarborough
March 21, 2016 7:51 am

..Silly, they use Foxy Proxies !!

Reply to  Scott Scarborough
March 21, 2016 7:59 am

pH is just the negative log of [H+], if you have a measurement of [H+] from 100 years ago it’s trivial to calculate pH from it. Back then all you’d need to do was take a sample of seawater and titrate at 25ºC, without exposure to the atmosphere.

Scott Scarborough
Reply to  Phil.
March 21, 2016 8:59 am

Yes, and how many times was that done? Consider that the PH changes daily and sometimes hourly in many locations. It would have to be done many times in many different locations to be able to say for sure that PH has changed in 150 years.

Reply to  Phil.
March 21, 2016 9:34 am

That’s a different argument, the fact that pH wasn’t defined back than has no bearing on whether the measurements of [H+] could be made which was your original argument.

Reply to  Scott Scarborough
March 21, 2016 11:06 am

The measurement of ocean pH is usually made colorimetrically not using pH-meters.
pmel.noaa.gov/co2/story/Quality+of+pH+Measurements+in+the+NODC+Data+Archives
http://pmel.noaa.gov/co2/files/co2_time_series_through_april2012_v5_nomap_w_no_equations_w_credits.jpg

RWturner
Reply to  Phil.
March 21, 2016 1:33 pm

So the pH was not measured, it was modeled by measuring CO2 and making assumptions. Seems consistent with Climate Inc., science.

Duster
Reply to  Phil.
March 21, 2016 7:15 pm

“Measured colorimetrically” is not “modeled.” Its a chemical dye method that uses several dyes. I have not employed it in many years, but I do not recall that it could be pushed to accuracies of 1/100th of a pH unit. The alternative method is electrometric.

Phil.
Reply to  Phil.
March 22, 2016 9:35 am

Had you read what I posted carefully and went to the link I cited you would have seen that the pH was accurately measured, not modeled.
The colorimetric methods I mentioned are referred to here:
http://www.sciencedirect.com/science/article/pii/0198014989901520
Abstract
Observations of sulfonephthalein absorbance ratios provide the basis for very precise measurements of seawater pH. Our analyses, using cresol red, indicate that meaningful pH comparisons at sea can be obtained at the level of ±0.001 pH units or better. Comparison of replicate seawater samples obtained from different Niskin bottles exhibited, in most instances, agreement within 0.0005 pH units. The procedures involved in multiwavelength pH measurements are quite simple relative to the required methodology in single wavelength observations.

March 21, 2016 7:48 am

“I would bet that we could show exactly that the increase in atmospheric CO2 from 280 ppmv to 380 ppmv in the last 150 years is an ocean temperature effect and not at all related to burning fossil fuels.”
Since we have had a positive increment in pCO2 every year since 1959 I’d bet that this is not solely an ocean temperature effect, particularly when in each of those years the emission of CO2 from fossil fuels has approximately doubled the growth in PCO2.
It is obvious that to assume the drop in alkalinity of such a highly buffered system as our oceans is due to an uptake of atmospheric CO2 without taking the increase in ocean temperature, particularly in the Northern Hemisphere, into account is a very narrow interpretation of the science.
Firstly it’s confusing to incorrectly use the term of ‘alkalinity’ here, alkalinity of seawater is defined as the ‘excess base’ (sum of excess proton acceptors) and remains constant even when CO2 is added to the ocean. If the author wishes to be politically correct and not use the correct term ‘acidity’ he’d be better to refer to the increase in [H+].
I’m not aware of anyone who understands the physical chemistry who does not realize that temperature also has an effect that he mentions, however as his graph shows, that to have the same effect as an increase in pCO2 from 280-400 at T=303K would require about a 10K temperature increase.
In fact using pH for this plot with a 30K range of temperature is not appropriate since the implication is that pH7 is neutral, that is only true at 298.15K. At 273K neutrality is 7.47, at 303K it’s 6.92, that’s a change in [H+] from 0.34×10^-7 to 1.21×10^-7 (mol/L), I’d suggest the ratio of [H+]/[H+]neut as a clearer axis.

Marcus
Reply to  Phil.
March 21, 2016 7:54 am

..” If the author wishes to be politically correct and not use the correct term ‘acidity’ ” ??? WTF ?? LOL

Reply to  Marcus
March 21, 2016 8:14 am

He’s a physical chemist, he should know better. ‘Alkalinity’ is not what he’s talking about and does not change as a result of the addition of CO2, [H+] is what he’s talking about and that does change with the addition of CO2, as he himself has shown. As a professional in the field he has a responsibility to use the correct terminology and not further confuse things.
(Incorrectly linked further up the thread).

Marcus
Reply to  Marcus
March 21, 2016 8:28 am

..Phil. ” acidity ” is the ” politically correct ” term !

Reply to  Marcus
March 21, 2016 9:19 am

Not on here it isn’t!

Marcus
Reply to  Marcus
March 21, 2016 1:06 pm

..Uh Phil, WUWT is NOT politically correct !

RWturner
Reply to  Marcus
March 21, 2016 1:46 pm

Acid and base are qualitative terms. If you increase the H+ concentration of an alkaline solution it does not become more acidic. The solution doesn’t exhibit any more properties of an acidic solution, it exhibits less properties of an alkaline solution.

Samuel C Cogar
Reply to  Phil.
March 21, 2016 10:00 am

Phil said:

“I would bet that we could show exactly that the increase in atmospheric CO2 from 280 ppmv to 380 ppmv in the last 150 years is an ocean temperature effect and not at all related to burning fossil fuels.”

Since we have had a positive increment in pCO2 every year since 1959 I’d bet that this is not solely an ocean temperature effect, particularly when in each of those years the emission of CO2 from fossil fuels has approximately doubled the growth in PCO2

Phil, you would have a better chance of being correct if you were betting on the Flying Spaghetti Monster.
Why didn’t you just reply to DR. Barrante’s statement by proclaiming it “Rubbish!” ….. the same as you replied to my claim about ocean water temperature and the bi-yearly cycling of pCO2? In case you forgot, to wit: http://wattsupwiththat.com/2016/03/17/greens-declare-victory-over-co2/comment-page-1/#comment-2169566
And Phil, you have no verifiable evidence to support your above claim about CO2 emissions from fossil fuels during the past 57 years.

Reply to  Samuel C Cogar
March 21, 2016 10:18 am

Samuel C Cogar March 21, 2016 at 10:00 am
Why didn’t you just reply to DR. Barrante’s statement by proclaiming it “Rubbish!” ….. the same as you replied to my claim about ocean water temperature and the bi-yearly cycling of pCO2? In case you forgot, to wit: http://wattsupwiththat.com/2016/03/17/greens-declare-victory-over-co2/comment-page-1/#comment-2169566

Because his post is mostly correct except for a minor error. Yours on the other hand was nonsense!

Samuel C Cogar
Reply to  Samuel C Cogar
March 22, 2016 4:04 am

Phil said:

Because his post is mostly correct except for a minor error. Yours on the other hand was nonsense!

Phil,
Shur nuff, and you have the facts and evidence that proves my commentary was nonsense, ….. RIGHT, ……. but you are not going to tell anyone what those facts and evidence are because it is secret info that the CAGW’ers do not want the public to know.
I don’t blame you one bit, Phil, …. I wouldn’t tell anyone either iffen I were you.

Phil.
Reply to  Samuel C Cogar
March 22, 2016 9:25 am

Samuel C Cogar March 22, 2016 at 4:04 am
Phil,
Shur nuff, and you have the facts and evidence that proves my commentary was nonsense, ….. RIGHT, ……. but you are not going to tell anyone what those facts and evidence are because it is secret info that the CAGW’ers do not want the public to know.
I don’t blame you one bit, Phil, …. I wouldn’t tell anyone either iffen I were you.

Since I had already pointed out the error with supporting evidence I assumed that you wouldn’t want to be further embarrassed. Clearly I was mistaken, you are a glutton for punishment!
You claimed:
“And the cause of said “bi-yearly CO2 cycling” is NOT the near-land temperatures in the Northern Hemisphere, ….. but IS in fact the ocean water temperatures in the Southern Hemisphere. The ocean surface area in the SH is far greater than the land surface area in the NH …. and therefore the temperature of the SH ocean waters is the “DRIVER” of the bi-yearly cycling of CO2.”
I pointed out that you were wrong because there is no significant cycling of pCO2 above the SH oceans, and showed, inter alia, the following data in support:
http://cdiac.ornl.gov/trends/co2/graphics/Baring_Head_NZ_CO2.jpg
Baring Head is an isolated headland in NZ where the air being sampled has flowed over thousands of miles of pristine ocean, if your hypothesis of the SH temperature variation was the source of the global variation it would be visible there.
https://www.niwa.co.nz/atmosphere/facilities/baring-head
Similar data was presented from the Kermadec islands, isolated uninhabited islands, located many miles away from habitation.
In contrast to the NH:
http://cdiac.ornl.gov/trends/co2/graphics/SIOMLOINSITUTHRU2008.JPG
It is clear from the station data that the seasonal variation has its origin in the NH, thereby falsifying your hypothesis.
The OCO-2 satellite data shows the same effect.

I notice in your more recent post you have quietly eliminated the claim of SH ocean involvement:
“The same as the bi-yearly seasonal cycling of atmospheric CO2 is also an ocean temperature effect and not at all related to burning fossil fuels or related to the growth of “green” biomass in the NH”.
A bit sneaky I would say, why not just man-up and admit you were wrong?

Samuel C Cogar
Reply to  Samuel C Cogar
March 23, 2016 5:26 am

Phil said:

I pointed out that you were wrong because there is no significant cycling of pCO2 above the SH oceans, and showed, inter alia, the following data in support:

Phil, ….. quit talking trash. Your posted Baring Head, NZ, CO2 ppm graph explicitly shows the “yearly” increase in CO2 ppm from 332 in 1977 to 382 in 2008 (avg 1.6 ppm/year)…… which was the direct result of the LONG TERM increase in the temperature of the ocean water which has been slowly warming up ever since the LIA ended.
And Phil, quit blowing smoke in hopes of confusing me. Please take note of the “squiggly” red line on your posted Baring Head, NZ, CO2 ppm graph, …. which is definite proof of the SHORT TERM bi-yearly cycling of atmospheric CO2 ppm which is the direct result of the seasonal temperature change of the near-surface volume of ocean water.
And because of the constant fluctuation of the NEAR-SURFACE high humidity (H2O vapor) in all sub-tropical and tropical locales it is impossible to get an accurate measurement of OCO-2 ….. simply because, ….. when the H2O vapor (humidity) ppm increases …. the CO2 ppm decreases. (And that’s the reason Charles Keeling moved his lab to the top of Mauna Loa, HI)
We know for a fact that for the past 58 years there has been a “steady & consistent” bi-yearly cycling of atmospheric CO2 (as defined by your ML graph above) …. and the only possible explanation is the “steady & consistent” bi-yearly cycling of the equinoxes (seasons). DUH, human CO2 emitting activities have never been, nor will ever be, … “steady & consistent” for multiple sequential years, be it daily, monthly, bi-yearly or whatever.
Phil also said:

I notice in your more recent post you have quietly eliminated the claim of SH ocean involvement:

Are you going delusional on me ….. or was that just a reading comprehension problem manifesting itself?

Phil.
Reply to  Samuel C Cogar
March 23, 2016 8:09 am

Samuel C Cogar March 23, 2016 at 5:26 am
Phil said:
“I pointed out that you were wrong because there is no significant cycling of pCO2 above the SH oceans, and showed, inter alia, the following data in support:”
And Phil, quit blowing smoke in hopes of confusing me. Please take note of the “squiggly” red line on your posted Baring Head, NZ, CO2 ppm graph, …. which is definite proof of the SHORT TERM bi-yearly cycling of atmospheric CO2 ppm which is the direct result of the seasonal temperature change of the near-surface volume of ocean water.

Here’s the monthly data from Baring Head for 2007:
379.11 379.33 379.59 379.71 380.05 380.57 380.95 381.27 381.27 381.03 381.09 381.21
Where’s the proof of a short term bi-yearly cycling? There isn’t any, so how can that drive the observed cycling in the NH (e.g. ML 2007)?
382.45 383.68 384.23 386.26 386.39 385.87 384.39 381.78 380.73 380.81 382.33 383.69
Phil also said:
“I notice in your more recent post you have quietly eliminated the claim of SH ocean involvement:”
Are you going delusional on me ….. or was that just a reading comprehension problem manifesting itself?

I replied to your comment:
“And the cause of said “bi-yearly CO2 cycling” is NOT the near-land temperatures in the Northern Hemisphere, ….. but IS in fact the ocean water temperatures in the Southern Hemisphere. The ocean surface area in the SH is far greater than the land surface area in the NH …. and therefore the temperature of the SH ocean waters is the “DRIVER” of the bi-yearly cycling of CO2.”
In contrast your latest claim is:
“The same as the bi-yearly seasonal cycling of atmospheric CO2 is also an ocean temperature effect and not at all related to burning fossil fuels or related to the growth of “green” biomass in the NH”.
The explicit link to “SH ocean waters” has gone, understandable really since I demonstrated that it’s not supported by the data.

Ferdinand Engelbeen
Reply to  Samuel C Cogar
March 23, 2016 9:26 am

Samuel,
The CO2 levels are increasing in the NH first and the 13C/12C ratio is dropping in the NH first. It takes 1-2 years to get the same levels of CO2 in the SH as at Barrow. Thus the increase is from a low-13C source in the NH.
That excludes the oceans, as these have a high 13C/12C ratio and vegetation decay can’t be the cause either, as that is a net, growing sink: the earth is greening…
http://www.ferdinand-engelbeen.be/klimaat/klim_img/co2_trends_1995_2004.jpg

Samuel C Cogar
Reply to  Samuel C Cogar
March 24, 2016 6:44 am

Phil said: March 23, 2016 at 8:09 am

Here’s the monthly data from Baring Head for 2007:
379.11 379.33 379.59 379.71 380.05 380.57 380.95 381.27 381.27 381.03 381.09 381.21

Phil, and here’s the monthly data from Mauna Loa for 2007
2007 1 2007.042 382.93 382.93 382.74 23
2007 2 2007.125 383.81 383.81 382.95 21
2007 3 2007.208 384.56 384.56 382.92 31
2007 4 2007.292 386.40 386.40 383.58 28
2007 5 2007.375 386.58 386.58 383.34 31 (max CO2 in May)
2007 6 2007.458 386.05 386.05 383.77 30
2007 7 2007.542 384.49 384.49 383.99 31
2007 8 2007.625 382.00 382.00 383.69 30
2007 9 2007.708 380.90 380.90 384.25 25
2007 10 2007.792 381.14 381.14 384.48 30
2007 11 2007.875 382.42 382.42 384.64 30
2007 12 2007.958 383.89 383.89 384.81 28
Source: ftp://aftp.cmdl.noaa.gov/products/trends/co2/co2_mm_mlo.txt
DUH, the BH max CO2 for 2007 was 381.27 …… and the ML max was 386.58 …….. which is a difference of 5.31 ppm
Phil, I really don’t care what those Baring Head near-surface atmospheric CO2 ppm calculated estimations were for the year 2007.
Phil, PAY ATTENTION, my claim is based on or rooted in ….. the bi-yearly (seasonal) cycling of the temperature of the ocean water in respect to the ingassing-outgassing of CO2 as defined by Henry’s Law …… with said ingassing-outgassing of CO2 directly affecting the measured quantity of CO2 ppm as recorded at the Mauna Loa observatory.
Phil, it is easy to “observe” the bi-yearly cycling in the ocean water near Baring Head, Southern Hemisphere or atop Mauna Loa, Northern Hemisphere ….. and here is your Baring Head surface water data from 1997 to 2010, to wit:

Ocean surface carbon dioxide and temperature
CO2 and temperature of surface water near Dunedin, New Zealand . Red lines show examples of higher CO2 and cooler water, green lines show examples of lower CO2 and warmer water.
http://sciencelearn.org.nz/Contexts/The-Ocean-in-Action/Sci-Media/Images/Ocean-surface-carbon-dioxide-and-temperature

Phil, the above stated higher ocean surface CO2 and cooler water occurs during the Southern Hemisphere wintertime. The atmospheric CO2 ppm decreases because it is being absorbed by the cooling SH water (Henry’s Law) … and it matters not a twit what the Northern Hemisphere land surface is doing during its warming summertime.

Samuel C Cogar
Reply to  Samuel C Cogar
March 24, 2016 7:36 am

Phil said:

In contrast your latest claim is:

“The same as the bi-yearly seasonal cycling of atmospheric CO2 is also an ocean temperature effect and not at all related to burning fossil fuels or related to the growth of “green” biomass in the NH”.

The explicit link to “SH ocean waters” has gone, understandable really since I demonstrated that it’s not supported by the data.

Fer kerist sake, Phil, ….. can you not keep track of what you have read, … from one (1) paragraph to the next paragraph?
Phil, iffen you require “explicit links” from one (1) sentence to the next sentence ….. to remind you of what was previously said or written ….. then I truly fear your early nurturing was a complete disaster which you will never recover from.
T’is no wonder you have convinced yourself that you “demonstrated” something of importance.

March 21, 2016 7:56 am

Since the end of the Little-Ice-Age the Earth temperature has gone up ~1.5C. This not only stimulated emission from the oceans but similarly stimulated emission from all other natural sources (microbes, insects, frozen terrestrial, volcanic, forest fire and Mammalia).
However, the statement:
I would bet that we could show exactly that the increase in atmospheric CO2 from 280 ppmv to 380 ppmv in the last 150 years is an ocean temperature effect and not at all related to burning fossil fuels.
Is incorrect.
The move from 280ppm to 378ppm was entirely natural while the last bit, from 378ppm to 380ppm was anthropogeniclly produced by our 2% contribution to the CO2 flux.

Ferdinand Engelbeen
Reply to  Ron Voisin
March 23, 2016 9:36 am

Ron,
Wrong reasoning: if you have a fountain with a cycling flux of 1000 l/minute and someone forget to close the supply valve which gives 1 l/minute extra, the basin will overflow from that 1 l/minute, not from the huge cycle.
Further, even while Henry’s law is only applicable for gaseous CO2, the rest of the equlibria are fixed too, expressed as the Revelle factor, so that the total change with temperature is not more than 16 ppmv/°C in equilibrium with the atmosphere. Not over 100 ppmv…
Further. 1.5°C since the LOA seems quite high to me, the deepest temperatures (Moberg, Esper, Huang,…) were around -0.8°C compared to the MWP and today or good for ~10-15 ppmv of the ~110 ppmv increase in the atmosphere…

Crispin in Waterloo
March 21, 2016 8:00 am

First, thank you for bringing some actual chemistry to this question.
Second:
“Simply recording ocean temperature at various points over the ocean and averaging them to get a number has no useful scientific meaning, no more than the average diameter of a football tells us anything about the shape of a football. At best, a weighted average must be used.”
I view this as a case where a sum of values is needed to get a meaningful answer – if there is any meaning (at all) in the resulting number. You confirm there is no meaning in an unweighted ‘average’.
One of the more bizarre aspects of alarming pH claims is that an average of averages provides some valuable insight into some or other aspect of the global climate system. If we are going to report something about the state of the oceans we need a metric that is meaningful.
The average of values resulting from multiple calculations of a non-linear function tells us what exactly? It is just a number. If the pH of the great majority of the volume of the oceans is constant for any purpose, deduct that from the total. Then examine that portion which changes to see if there is anything interesting to learn. Because the pH of the ocean changes every few metres, claiming an average value means avoiding sampling errors. Good luck with that.
The only piece of information of value I can think of is whether or not the CO2 increase in the atmosphere is emerging from the oceans. If it is, we will just have to deal with the consequences because we are not capable of modifying the heat content of the oceans. It is not beyond our imaginations, but it is beyond our capabilities. As shown over the past two decades, a 30% increase in AG CO2 emissions has had no demonstrable effect on the atmospheric temperature which is rather obviously dominated by natural variation.

March 21, 2016 8:04 am
Reply to  Jamal Munshi
March 21, 2016 9:16 am

I don’t find the results convincing. You have, and noted, correlation coefficients approaching 0, charts showing increase in [CO2] over time and a chart showing a decrease in temperature over time. If that translates to ocean temperature, one would expect some increase in CO2 concentration.
If you briefly point out the differences, it would be helpful.

dikranmarsupial
Reply to  Jamal Munshi
March 21, 2016 9:26 am

The first line of the abstract is: “Detrended correlation analysis of annual fossil fuel emissions and mean annual changes in ocean CO2 concentration in the sample period 1958-2014 shows no evidence that the two series are causally related.”
If you detrend annual fossil fuel emissions, you are just looking at the very minor variation from year to year superimposed on the long term increasing trend. There is no good reason whatsoever to expect this to be correlated with ocean CO2 concentration. One would expect to see a correlation between cumulative fossil fuel emissions and ocean CO2 concentration, but if you detrend the observations this is eliminated.

March 21, 2016 9:23 am

Dr. Barrante’s excellent post covers well known, long known and well documented relationships. Much of the equilibria has been covered as examples in chem texts for at least 50 years. He does a very good job of pointing out the difficulties in finding real, small changes in ocean pH.

March 21, 2016 9:47 am

At last some rational thinking re the source of CO2 not being fossil fuels, it is an assumption after all, the keystone of the alarmist cause. I honestly think the Global Average Temperature nonsense is slight of hand, look at this, not at the fact we cant even prove where the CO2 is coming from.
Regional pH is and always was buffered, otherwise pH measurements would be entirely random, buffering = stability, something marine life depends on. There would be almost no life in oceans, or at least very different pH indifferent life, if pH levels were not stable. Average of regional levels gives you a rough guess of pH, not something you can then use to make a case of any certainty.
Averaging ocean pH, from top to bottom.. has there been a study that has sampled all depths and all regions, buffers effects and such, that’s if we forget for a moment how dynamic things can be with changes.
Oceanic minerals, I mean do we even have a clue as to what we have where and how it affects the water chemistry where a lot of water is filtered through the crust, changes in the crust can have impacts, each small but again another metric? Just thinking about how uninformed we are when talking OA
If it well within the boundary of reason, and logic, to suspect that geological changes are the main driver of oceanic CO2 levels along with water temperature, water movement, water pressure and temperature difference among other things, like alkaline buffer material, something I am sure there is plenty of in the oceans. Dead coral like pacific Atolls are also buffers, being coral islands n’all.
And lets not forget bio waste, terrestrial runoff and dumping, all play a part, especially when there is over 100 dead zones around the globe changed by pollution to the point of depleting oxygen where jellyfish thrive, never mind some small regional effect on pH.
I really do fail to see how we can claim to know ocean pH to any level of high certainty, I really do.
No doubt I am overlooking a billion other possible things that may effect ocean pH.
While I have only got interested in this climate issue recently due to the work of many showing there was actually another side of the debate, I have been controlling water chemistry for aquatic projects for nearly 2 decades. The only OA issues are regional geological issues.
Doesn’t take a genius to figure out that water loses gas retention potential and gains solid dissolving potential with temperature increase.
I must point out that with water, CO2 in the atmosphere will exchange with water at what 7ppm which ever way the potential swings, but if that water is in motion, anything in excess of the temperature driven retention will escape with water turnover.
So if you have a pH of 6.0 which is driven by CO2 injection, one fact is that first of all the CO2 must be fed in at a lower water column and it must be atomised, not to atom size but as small a bubble as you can get, which gets absorbed as the bubble rises.
Once you feed in more CO2 gas than the temperature dictates you can contain without pressure, you need pressure and no turnover to retain the excess gas. So as the ocean waters warm, the other two conditions are met for a net CO2 transfer to the atmosphere.
This is what we have been seeing since the 1800s. There is a lag, land temps change faster than ocean temps, so really it is not a lag at all. It’s right on queue, natural processes don’t know about this human concept of lag.

Gary Pearse
March 21, 2016 9:52 am

Good simple chemical treatise on the effect of CO2 and Temperature on pH of seawater. I commented on this affect about a year ago (without the fine details provided here). It is more complicated, depending on the pH level we are dealing with. At T=25C, a temperature increase with a starting pH of 7.0 to 14.00 (in the ocean range) the pH indeed does go down. It is interesting, however that with a pH of 7.0 at 25C, pH resists acidification remaining essentially neutral even to 50C. At a starting pH of 4.0 at 25C, increasing the temperature results in increasing pH (more alkaline – a counterintuitive effect say for highly acidified lake water). I don’t have a link but here is the title of a paper on calibrating pH meters – it aint easy!!
“The Effects of Temperature on pH Measurement”
Authors: John J. Barron Colin Ashton & Leo Geary – Technical Services Department, Reagecon Diagnostics Ltd, Shannon Free Zone, County Clare, Ireland
Another effect is that with increasing temperature of seawater, the solubility of CaCO3 also increases thereby increasing pH (making it more alkaline). As many of you know, I have hyped the Le Chatelier Principle as an under appreciated much broader actor in all things. Here, in addition to it’s appearance in Newton’s laws of motion, back EMF in a motor starting up, etc. etc., is another example of Le Chatelier’s resisting change. Ignoring the principle, climate scientists have exaggerated the effects of increased temperature (and increased “ocean acidification”) by its driver CO2. To not have anticipated that the effects of changing elements in climate are likely to be significantly less than “calculated” is a measure of the competence and scientific literacy of such climate scientists.

March 21, 2016 10:10 am

Re: Temperature Dependence of Ocean pH shows CO2 may not be driver of ‘ocean acidification’, 3/21/2016.
Professor Barrante writes,
… ocean pH has decreased from approximately 8.2 pH units to 8.1 pH units in the last 150 years. One explanation is that the increase in atmospheric carbon dioxide from the burning of fossil fuels is responsible. This is based on a law of physical chemistry, known as Henry’s Law, that states: if the partial pressure of a gas over a solution is increased, the concentration of the dissolved gas in the solution will increase. Since dissolved CO2 is a weak acid, one would expect the pH of the oceans to decrease. [¶] Describing Henry’s Law in this simple manner, however, is a very narrow interpretation of the boundaries of the system. For example, the above statement of Henry’s Law is only valid, if the temperature of the solution is constant.
This statement of Henry’s Law is about as weak a statement as possible, but nonetheless still valid. A stronger statement is that the concentration of a gas in a liquid is proportional to the partial pressure of the gas above the liquid, the proportionality being called Henry’s coefficient, which depends on the gas and liquid. But instead of Henry’s Law being “only valid[] if the temperature of the solution is constant”, Henry’s coefficient declines steadily with increasing temperature of the solution for most atmospheric gases in water, (N and H2 being exceptional). This behavior of Henry’s Law is what accounts for the ocean outgassing and absorption of CO2. This is what accounts for the natural carbon pump, driven by the inadequately named thermohaline circulation. IPCC calls the process both the solution pump and the solubility pump without ever mentioning Henry’s Law or its coupling into the THC. IPCC misses the massive carbon pump that regulates the concentration of atmospheric CO2 because it overwhelms all anthropogenic effects.
Henry’s coefficients are known to depend slightly on salinity of the liquid, but any dependence on pH is unknown. Prof. Barrante says imprecisely and ambiguously, Thermodynamic equilibrium constants are a sensitive function of temperature. This follows his introduction of the pH of the solution, suggesting he is not referring to Henry’s coefficients, but to the constants in his subsequent equations of marine carbon chemistry. See also IPCC, AR4, Box 7.3, Eqs. 7.1, 7.2, p. 529. Barrante can be applauded for introducing the phrase thermodynamic equilibrium, but in neither case, Henry’s Law nor carbonate chemistry, are these constants or coefficients properly called thermodynamic equilibrium constants. He then continues, saying
Ocean chemistry is complex, involving a number of important equilibria, that include the dissociation of carbonic acid (dissolved CO2), the buffering equilibria due to the presents of dissolved salts of bicarbonate and carbonate, the solubility of the sparingly soluble salt CaCO3, and the equilibrium between dissolved CO2 and the partial pressure of carbon dioxide in the atmosphere.
Thermodynamic equilibrium, which is defined as simultaneous thermal, mechanical, and chemical equilibrium, exists nowhere in the climate system, and that includes the hydrosphere. Thermodynamic equilibrium is the state of death and complete decay. Henry’s coefficients and the carbonate equations, including their constants, are only defined for thermodynamic equilibrium, a state that can only be approximated in laboratory experiments.
Acidification and the carbon pump are phenomena of the ocean surface layer, which IPCC, following the work of contributing author, computational oceanographer, Prof. David Archer, assumes to be in equilibrium. Imagine! The surface layer in equilibrium, when it is mixed with entrained air, churned by the wind, warmed by the Sun, cooled by IR radiation, and teaming with life to nominal depths between 100 and 300m, and far deeper at either pole where the THC plunges to the ocean bottom in winter!
By assuming some unnamed equilibrium exists at the surface of the ocean, IPCC manages to create a bottleneck to block dissolution of CO2 in the ocean. It even goes so far as restricting this bottleneck to anthropogenic CO2, ignoring the natural carbon cycle. Its misuse of carbonate equations causes ACO2 to remain in the atmosphere for about 30-35Kyrs (Archer (2005)) or many thousands of years (IPCC), waiting for CaCO3 precipitation to make room for new CO2. This bottleneck causes (anthropogenic) CO2 to accumulate in the atmosphere, essential to the story because man doesn’t emit enough CO2 to make even GCMs create alarming warming. This, in turn, is necessary to convert Keeling’s famous CO2 measurements at MLO from the effects of sitting in a seasonal wind-modulated branch of the plume of maximal outgassing at the outlet of ancient THC waters in the Eastern Equatorial Pacific into the contemporary master time series for determining the changing composition of the atmosphere in the story attributing CO2 and global warming to man. This equilibrium conjecture makes Henry’s Law newly dependent on the pH of the solvent with no experimental evidence. The consequence of acidification is merely a bonus bugaboo.
The atmosphere is not the imagined buffer reservoir for excess CO2, whether natural or anthropogenic. The mixed layer is the buffer, holding both aqueous and gaseous CO2, and allowing Henry’s Law to proceed apace, whatever the estimate might be for the effective coefficient for CO2.

RWturner
Reply to  Jeff Glassman
March 21, 2016 1:52 pm

Reading Archer papers is like watching a man kiss himself in the mirror.

Samuel C Cogar
March 21, 2016 10:20 am

Stated by James R. Barrante, Ph.D.
Emeritus Professor of Physical Chemistry, Southern Connecticut State University, New Haven, CT

In fact, if the measurement of ocean pH were not so complicated, and we had that data for the last 150 years, I would bet that we could show exactly that the increase in atmospheric CO2 from 280 ppmv to 380 ppmv in the last 150 years is an ocean temperature effect and not at all related to burning fossil fuels.

Dr. Barrante is absolutely correct. The ocean temperature has been slowly increasing from the cold temperature of the Little Ice Age.
The same as the bi-yearly seasonal cycling of atmospheric CO2 is also an ocean temperature effect and not at all related to burning fossil fuels or related to the growth of “green” biomass in the NH.

Windchaser
Reply to  Samuel C Cogar
March 21, 2016 11:27 am

Nonsense. The ocean can’t on net be both absorbing and emitting CO2. It’s either emitting as a whole, or absorbing as a whole.
We’ve emitted enough CO2 from fossil fuels to increase CO2 by twice the observed increase. Which means that the oceans and biosphere must be absorbing about half of it, while the other half goes into the atmosphere.
We see the ocean getting more acidic, so we know that some of the atmospheric CO2 is going there. Which makes perfect sense.
The oceans haven’t warmed anywhere close to enough to outgas enough CO2 to increase the atmospheric concentration, nor would that explain where all the CO2 from fossil fuels went. Easily the most logical explanation is that the carbon that we dug up and burned is going into the atmosphere, oceans, and biosphere. This also lines up with the isotopic evidence.
There’s really only one sensible explanation: if you dig up and burn sequestered carbon, it will increase CO2 in the air, oceans and biosphere. This is very simple. You have to strain to reject it.

Reply to  Windchaser
March 21, 2016 11:33 am

Except what you say defies physics and water chemistry.
Oceanic CO2 is of a larger order of magnitude and as such would regulate atmospheric CO2.
Besides I have worked on biotope projects and a lot of what you say is meaningless hyperbole

Reply to  Windchaser
March 21, 2016 11:45 am

Also, “we see the oceans get more acidic”. Can you tell me where these acidic oceans are?

Windchaser
Reply to  Windchaser
March 21, 2016 12:20 pm

“More acidic” == declining pH.
Oceanic CO2 is of a larger order of magnitude and as such would regulate atmospheric CO2.
So where does the CO2 from burning fossil fuels go, I wonder? And man, what an interesting coincidence it is that atmospheric CO2 is the highest it’s been in a million years, right when we started digging up and burning billions of tons of sequestered carbon. And funny that the atmospheric O2 is decreasing. And funny that the isotopes of carbon in the atmosphere meshes with that of the fossil fuels.
And again: if it didn’t go into the oceans, where did the CO2 from burning fossil fuels go?
The oceans aren’t warming anywhere close to enough to emit this much CO2, and they’re getting more acidic, which means they’re not even emitting CO2. They’re absorbing it.
Which makes perfect sense, as we are emitting it. This is a known fact.
It strains credulity to claim that ocean is responsible for the CO2 increase. It’s just completely backwards. You might as well be saying that the Earth is flat.

Bartemis
Reply to  Windchaser
March 21, 2016 1:52 pm

“The ocean can’t on net be both absorbing and emitting CO2.”
Actually, it can. It is doing both all the time. What is important is the net.
“We’ve emitted enough CO2 from fossil fuels to increase CO2 by twice the observed increase. Which means that the oceans and biosphere must be absorbing about half of it, while the other half goes into the atmosphere.”
Not so. The oceans and biosphere can be absorbing essentially all of it, with what is left over being the net natural contribution.
It is a dynamic feedback system, and it does not necessarily obey your rules. Your argument is the standard pseudo-mass balance argument, and it is naive in the extreme.

Windchaser
Reply to  Windchaser
March 21, 2016 3:52 pm

Actually, it can. It is doing both all the time.
No, it can’t. This is like saying that a number can be both greater than zero and less than zero. It’s either one or the other (or zero); it can’t be both.
Look, literally all the evidence points to mankind causing the increase in atmospheric CO2. The ocean hasn’t warmed enough, the isotopic evidence is that the source is fossil fuels, atmospheric oxygen levels are decreasing, all while we put out twice as much CO2 as ended up in the atmosphere.
You have to try really, really hard to reject the simplest explanation: that when you dig up and burn carbon, the atmospheric CO2 will increase.

Bartemis
Reply to  Windchaser
March 21, 2016 4:14 pm

Let me give you an example of a feedback system which illustrates the error in reasoning.
A(k+1) = A(k) – alpha*A(k) + B(k) + C(k)
representing some quantity “A” at time step k, with sources B(k) and C(k). Sink activity is represented by -alpha*A(k), where alpha is some parameter between zero and unity. This is how the CO2 sinks work – they are active in proportion to how much CO2 there is, and that produces a feedback signal which regulates the level of CO2.
An alpha near unity represents a short time constant, where A(k) rapidly approaches B(k) + C(k). An alpha near zero represents a long time constant, where A(k) asymptotically approaches (B(k)+C(k))/alpha. For alpha near zero, in the near term long before ultimate settling, A(k) approaches the cumulative sum of B(k) + C(k) (try it – select parameters and inputs, and run the recursion).
So, assume B(k) is constant, and C(k) is zero, and A(k) has settled out to approximately B(k)/alpha. Now, we add a C(k), and some years later note that A(k) has risen approximately as much as the cumulative sum of C(k). Does that mean that the rise in A(k) came from C(k)?
Only if the time constant is long, and alpha is near zero. Otherwise, if alpha is near unity, the contribution of C(k) to A(k) is approximately only one time step’s worth, so the rise has to be attributed, in that case, to a change in B(k).
The Earth’s CO2 regulatory system is more complex than this, so do not try overmuch to stretch the analogy. The important takeaway is that, where active feedback is involved, you cannot deduce the relative contribution of one component without knowing precisely what the feedback dynamics are.
And, that is why the pseudo-mass balance argument is jejune and facile. You should not trust the opinion of anyone who uses it on anything. They are mathematically illiterate and have no idea what they are talking about.

Windchaser
Reply to  Windchaser
March 21, 2016 4:56 pm

Sure, that’s a fine example and all, but in this case we know that C(k) – the human contribution – increased. Moreover, we know that B(k) — sources from the ocean — actually turned negative (going from being a source to being a sink)…. so it’s not hard to determine that C(k) is responsible. Otherwise, A would be dropping. And it’s not.
Your example contradicts itself by first assuming that B(k) is constant, and then that it’s changing. You can’t do that in math – your terms are either constant or variable / to be solved. You’ll end up with contradictions if you change the conditions of an equation while you’re trying to solve it.
Again, atmospheric CO2 is higher than it has been in a million years. It’s not a magic coincidence that that happened right when we started digging up and burning carbon.

Windchaser
Reply to  Windchaser
March 21, 2016 5:06 pm

Additionally, we know that if atmospheric CO2 increases, then with all else being equal, the oceans and biosphere will absorb more.
There’s no negative feedback that causes increasing atmospheric CO2 to make the oceans emit more CO2. It goes the other way: it’s a stabilizing mechanism. More atmospheric CO2 == more ocean absorption.
All else isn’t equal, of course. The temperatures went up, which naturally causes CO2 to leave the ocean. But then, the atmospheric CO2 went up way more than you’d expect from the ocean’s warming. And on top of that, when we look, we don’t see the oceans emitting more, but absorbing more CO2 on net.
This tells you that the oceans aren’t the source. It doesn’t make sense from Henry’s Law, and it doesn’t make sense from a mass balance perspective.
Just from that, we can deduce that there must be some other source causing CO2 to rise in both the atmosphere and oceans. Hmmm, whatever could that source be?
This is high school level physics, at most.
Sure, without nailing down the feedback dynamics we can’t nail down the exact contribution of humankind. Maybe in our absence, the atmospheric CO2 would have been 290 ppm, instead of its starting value of 280 ppm. Or maybe it would have been 270 ppm.
But we can certainly claim that the vast majority of the increase in CO2 is from burning fossil fuels. This is simple scientific, logical reasoning.

David Riser
Reply to  Windchaser
March 21, 2016 5:29 pm

Windchaser, the ocean is not a single body of water with a meaningful average anything. Any given location is not a constant from top to bottom. Most of your bottom water is cold, very cold, some surface waters are very warm. PH is vastly variable throughout the system. The multitude of them do sink CO2 and off gas CO2 simultaneously. The only question that is unknown is the net effect. In higher latitudes(N&S) the warm water from the tropics is cooled, absorbs CO2 to the level of CO2 in the atmosphere and sinks down below the surface to travel about for an estimated 1000 years. The surface waters near the equator and depending on the season off gas for quite a distance to NorS. The net effect is unknown, the meaning of an average is extremely difficult to calculate do to the very sparse observations compared to area. Just something to consider when you talk about something as the ocean system of the Earth.
v/r,
Dave

Windchaser
Reply to  Windchaser
March 21, 2016 6:29 pm

Sure, David.. in a given timespan, parts of the oceans emit, and parts of it absorb.
All of these have a negative feedback relationship with increasing atmospheric CO2. Meaning, if you increase atmospheric CO2, the parts of the ocean that were emitting will emit less, and the parts of the ocean that were absorbing will absorb more.
The same goes for the biosphere. If you put more CO2 into the atmosphere, the biosphere sinks will absorb more, and the sources will emit less. If the biosphere spontaneously decided to outgas a bunch of CO2, then the oceans would absorb it. If one part of the oceans outgassed, then other parts would absorb it, or the biosphere would.
All of these feedbacks are negative. And interlinked, via the well-mixed atmospheric CO2. If one part emits more, the others absorb more or emit less, by the laws of chemistry.
In other words, oceans and biosphere work to mitigate external sources and sinks. They dampen any external changes in the atmospheric CO2. As they are doing right now, too.
We can look at the ice cores to see how much the CO2 naturally changes as a result of external forcing (like the Earth warming). A normal amount is roughly 100 ppm as the Earth comes out of a glacial period – this is about how much atmospheric CO2 was increasing as the ice sheets covering N. America melted. About 100 ppm for roughly 6 degrees Celsius.
In other words, the outgassing from the oceans is relatively insensitive to the temperature. What has happened recently is that the oceans warmed much less – a tenth of a degree or two in the last 100 years, and yet atmospheric CO2 has increased already 120 ppm.
Again, this happened at the exact same time as we emitted enough CO2 to increase the atmospheric concentration by twice that much. But.. just a coincidence, I’m sure. There’s no way that our massive CO2 emissions directly into the atmosphere could have anything to do with atmospheric CO2 increasing.

Bartemis
Reply to  Windchaser
March 22, 2016 4:20 am

You are arguing in circles, and your reasoning is completely circular. Bottom line: the fact that the observed rise is less than the sum total of human inputs only tells us that they could be responsible for it, but it does not tell us they are. It is the difference between necessary and sufficient conditions.

Samuel C Cogar
Reply to  Windchaser
March 22, 2016 5:34 am

Windchaser – March 21, 2016 at 11:27 am

Nonsense. The ocean can’t on net be both absorbing and emitting CO2. It’s either emitting as a whole, or absorbing as a whole.

Sorry bout that, Windchaser, …. but the science of the natural world pretty much disagrees with most everything that you have stated in your several postings on this subject matter.
Mimicry of “things” that you have been miseducated on and/or know nothing about is damaging to your good name and credibility in the realm of factual science.

Windchaser
Reply to  Windchaser
March 22, 2016 9:31 am

Sorry bout that, Windchaser, …. but the science of the natural world pretty much disagrees with most everything that you have stated in your several postings on this subject matter.
Is that what you fall back on when you have no good arguments? Because you haven’t addressed mine. And I’m sorry, but your position is embarrassingly wrong.
You are arguing in circles, and your reasoning is completely circular.
Again, we’ve got isotopic evidence, oxygen levels falling, atmospheric CO2 is the highest it’s been in a million years, the biosphere and ocean are absorbing carbon, all while humans are digging up and burning carbon that’s been sequestered for millions of years. Much more carbon than was necessary to raise just the atmospheric CO2 by the observed amount.
Notice that none of those points are dependent on any other; it’s not circular in the slightest.
When we have a half-dozen lines of evidence that all point to the same conclusion, and no evidence that points against… you have to be crazy to reject it. This is consilience of evidence, like the evidence that points for the theory of evolution or an orbital model of celestial mechanics.
I know you’re very attached to the idea that nature is responsible for this.. but really, step back and ask yourself what the best explanation is.

Bartemis
Reply to  Windchaser
March 22, 2016 9:48 am

Every “evidence” you point to is merely consistent with the notion that we have significantly affected atmospheric CO2 levels, but not dispositive. It’s actually primitive thinking – the volcano rumbled and we have a drought, therefore the Gods are angry, and we need a human sacrifice.
The best explanation is actually that our inputs are negligible compared to the flows of nature, and CO2 is temperature dependent. This is clearly seen in the data where, over intervals comparable at least to the modern era since atmospheric CO2 began to be measured accurately, the rate of change of CO2 is proportional to appropriately baselined temperature anomaly. As you can see, both the variations and the trend match. The emissions rate also has a trend but, as the trend is already explained by the temperature relationship, there is little room for it to be having a significant impact.
I don’t expect you to agree, and don’t really care. The bottom line is, you have nothing to prove that humans are responsible, only an internal bias that makes you connect the dots in a particular way. In time, the truth will become known.

Windchaser
Reply to  Windchaser
March 22, 2016 11:51 am

The bottom line is, you have nothing to prove that humans are responsible,
Ayep… if you ignore all the evidence I presented, then there’s no evidence at all. Pretty convenient! =D
And really? “The volcano rumbled, so the gods are angry?”
This is incredibly straightforward: we pumped CO2 into the atmosphere, so atmospheric CO2 increased as a result.
It ain’t magic or religion. It’s literally as simple as science ever gets. Cause and effect, quiet directly.
With your type of argument, I could shoot someone in the head, and you’d say “wellllll… he could have died from something else. The gun and bullet aren’t necessarily related to his cause of death, even though his head exploded right after you pulled the trigger. Just a coincidence, I’m sure.”
I don’t have any dog in this fight. I just look at the evidence, and the evidence overwhelmingly points to fossil fuels as the source of the increase in CO2.

Bartemis
Reply to  Windchaser
March 22, 2016 4:12 pm

“It ain’t magic or religion. It’s literally as simple as science ever gets.”
Simple minded. Classic post hoc ergo propter hoc, with rationalization based on equivocal evidence.

Ferdinand Engelbeen
Reply to  Windchaser
March 23, 2016 9:59 am

Windchaser,
You are 100% right. Bart has an alternative theory (it’s all caused by temperature), which violates all observations, but that is just waved away. He has zero evidence for his theory, except an arbitrary match of two slopes: temperature and dCO2/dt.
The main problem for his theory is that human emissions increased a fourfold in the past 55 years and so did the average increase in the atmosphere and the net sink rate. If the natural carbon cycle was the real cause, dwarfing human emissions, it should have increased a fourfold too, or one violates the equality of the sinks for CO2 whatever the source…

Bartemis
Reply to  Windchaser
March 23, 2016 5:40 pm

Nonsense. It violates no observation.

Ferdinand Engelbeen
Reply to  Windchaser
March 24, 2016 3:00 am

Bart,
Do you have even one single observation which shows that temperature is the cause of the long-term slope in CO2 rate of change, besides your completely arbitrary match of two straight lines?

Clyde Spencer
Reply to  Samuel C Cogar
March 21, 2016 6:05 pm

Samuel,
If you haven’t already dons so, you should take a look at the 12-month animation of OCO-2 maps. You might change your mind about the role of biomass in the NH.

Samuel C Cogar
Reply to  Clyde Spencer
March 22, 2016 5:16 am

Clyde Spencer said:

Samuel,
If you haven’t already dons so, you should take a look at the 12-month animation of OCO-2 maps. You might change your mind about the role of biomass in the NH.

Clyde, I earned my AB Degree in the Biological and Physical Sciences many years ago and the biology of planet earth is still the same today as it was 50+ years ago.
And Clyde, you really should find out what those “12-month animation maps” are actually “animating” …… because it sure as hell isn’t the changing quantities (ppm) of atmospheric CO2 molecules.
And Clyde, me also thinks that you really should check out the role of biomass in your refrigerator-freezer ……. and after you figure out the reason you own/use a refrigerator-freezer then you should have a wee bit of an idea about the “seasonal” roles of both the dead and live NH biomass.
Ps, you do realize don’t you that the primary purpose of “refrigeration” is to prevent your stored “edible” dead biomass from microbial decomposition.

Clyde Spencer
Reply to  Clyde Spencer
March 22, 2016 9:42 am

Samuel,
While “the biology of planet earth is still the same today as it was 50+ years ago,” hopefully, we have learned a little more about it in that period of time.
It sounds like you think you have some special insight on just what the OCO-2 maps are showing. Perhaps you would be so bold as to share with everyone just what they are actually showing, if not CO2 concentration.
I use my refrigerator for an experiment on the spontaneous generation of life. Those things that grow on jelly and old pizza sauce may compete directly with the extant forms that think a 50-year old AB degree is the height of achievement.

Samuel C Cogar
Reply to  Clyde Spencer
March 23, 2016 3:24 am

Clyde Spencer,
You too could have a special insight on just what the OCO-2 maps are showing ……. iffen you would just take your head out of the sand long enough to educate yourself.
Here ya go Clyde, read the following, ….. and if you can’t figure it out ….. have your Mother explain it to you.

NASA Jet Propulsion Laboratory – Measurement Approach
The principal science objective of the OCO-2 mission is to retrieve a global geographic distribution of CO2 sources and sinks. The OCO-2 mission will not, however, directly measure CO2 sources and sinks. Instead, sophisticated computer-based data assimilation models that use column averaged dry air CO2 mole fraction (Xco2) data will infer the location of these sources and sinks.
To get the representative values of Xco2, or the amount of CO2 in the measured space, the OCO-2 instrument will measure at a given location, the intensity of reflected sunlight off the Earth’s surface at specific wavelengths. Gas molecules in the atmosphere absorb the sunlight at specific wavelengths. So when light passes through the Earth’s atmosphere, the gases that are present leave a distinguishing fingerprint that can be captured. The OCO-2 spectrometers, working like cameras, will detect these molecular fingerprints. Then the absorption levels shown in these spectra, like a captured image, will tell us how many molecules were in the region where the instrument measured. The OCO-2 measurement approach will concentrate on gathering data near the Earth’s surface, where almost all of the CO2 sources and sinks are located.
Read more @ http://oco.jpl.nasa.gov/science/MeasurementApproach/#

There now Clyde Spencer, if you don’t agree with what is stated above ….. then you call NASA on your I-phone and tell them their explanation is FUBAR because that is not how they determine atmospheric CO2 ppm.

Ian
March 21, 2016 11:02 am

“I love the smell of chemistry in the morning. It smells like… V.I.C.T.O.R.Y.”

James Barrante
March 21, 2016 12:18 pm

Look up any post or article online dealing with ocean “acidification” and you will find stated, generally without scientific proof, that since the industrial revolution ocean pH has dropped from 8.2 to 8.1. I just assumed that this is just another unproven claim made by a consensus of 97% of climate scientists. They regularly claim that everyone knows that atmospheric CO2 has increased from 280 ppmv to 380 ppmv because of burning fossil fuels.
To the question of “acidification” of the oceans, I am talking about the alkalinity (basicity) of the oceans and not the acidity. When pH drops from 8.2 to 8.1, oceans are not becoming more acidic, they are becoming less alkaline (approaching a neutral solution). This can be accomplished simply by adding water.

Reply to  James Barrante
March 21, 2016 2:01 pm

I have often made the distinction between Alkaline and acidic, to which they always reply “moving in the direction of acidity”. Dances With Words 🙂

Reply to  James Barrante
March 21, 2016 2:07 pm

As I pointed out above you’re not talking about alkalinity of the oceans which is in fact the sum of the excess proton acceptors and it is constant when CO2 is added to the water. By adding CO2 to the water you’re in fact ‘acidifying’ it, [H+] increases. What you’re talking about is the [H+].

Clyde Spencer
Reply to  Phil.
March 22, 2016 10:01 am

Phil,
Yes, as a number changes from 9 to 8, it is becoming more negative!
The important thing is the ratio of hydronium ions to hydroxyl ions. The properties and behavior of a solution changes when the ratio is other than 1:1. “Acidification” is an information-poor word because it says nothing about where on the pH scale the solution currently resides. It only provides information on the direction of change. In the interest of communication, one should either say that the pH is being lowered, or that the solution is becoming less alkaline. Focusing on the H+ concentration, and citing percentage changes, ignores the context of more than 14 orders of magnitude of potential change. But then, “lowered pH” isn’t as scary as “more acidic.”

March 21, 2016 12:20 pm

Maybe the alarmists should go look at lake Natron in Tanzania where water gets as hot as 140f. It literally calcifies flamingos and other animals.
The lake is fed by hot springs of mineral rich water, and no doubt oceanic vents also release mineral rich water. We have no real clue about this issue of OA. Oceanic crust adds dolomite and other dissolved minerals to the water as it is filtered, this water transfers heat from the crust too, nice hot mineral absorbing water, another part of the story.
It takes a lot of mineral input to keep ocean seas at 8.1 pH, given there is no single larger buffer substance to regulate ocean pH then one would assume the constant mineral addition keeps pH up, the battle is always to stop water returning to neutral which it is inclined to do if minerals are taken out.
The CO2 cycle may just keep ocean waters at a pH range, and lack of said CO2 could mean pH too high for most ocean life as it has currently evolved.
it could be that ocean carbon capture geoengineering could raise pH to dangerous levels, creating an imbalance between gas and mineral input that life has evolved in.
There is far more mineral in the oceans than CO2, my bet is CO2 has a pH limiting function rather than driving a pH drop.

Editor
March 21, 2016 12:43 pm

First, Dr. Barrante, thanks for your essay. Always glad to see new guest authors.
However, you start out very badly when you say:

It is well-known that ocean pH has decreased from approximately 8.2 pH units to 8.1 pH units in the last 150 years.

This is nonsense. We have so few measurements in the last 50 years that the change is not even statistically significant. 150 years ago we had doodley-squat in the way of pH measurements. Heck, the very concept of pH was only developed in 1909.
Sorry, amigo, but when you start out your discussion with what is obviously a very slanted view of your subject, and you are willing to twist the facts to suit your view, I lose interest …
In addition, it is not clear which pH you are discussing. There are three pH scales for seawater—”total” pH, “free” pH, and “seawater scale” pH … which one are you using?
Next, you make an extraordinary claim when you say:

In fact, if the measurement of ocean pH were not so complicated, and we had that data for the last 150 years, I would bet that we could show exactly that the increase in atmospheric CO2 from 280 ppmv to 380 ppmv in the last 150 years is an ocean temperature effect and not at all related to burning fossil fuels.

Me, I’d bet that is not true. The temperature of the planet has not warmed anywhere near enough for the change in atmospheric CO2 to be a result of outgassing from ocean warming.
Finally, I busted out laughing when you claimed that the “preindustrial temperature” was 288.2°C, and the “postindustrial temperature” was 290.2°C … how on earth would you know the pre-industrial temperature to a tenth of a degree, and what time spans are you talking about?
And this was not the only howler. You claim to know all kinds of variables about the ocean in pre-industrial times, pK1 and pK2 among others … really? Unless you have a time machine, you’re just pulling numbers out of the air.
Sorry, Dr. B., but there are far too many holes in your claims for them to be valuable.
w.

Reply to  Willis Eschenbach
March 21, 2016 2:18 pm

And this was not the only howler. You claim to know all kinds of variables about the ocean in pre-industrial times, pK1 and pK2 among others … really? Unless you have a time machine, you’re just pulling numbers out of the air.
pK1 and pK2 are measures of the equilibrium constants of the deprotonation reactions, as such they are thermodynamic constants and are the same now as the always were.

Reply to  Phil.
March 21, 2016 4:10 pm

Phil. March 21, 2016 at 2:18 pm Edit

And this was not the only howler. You claim to know all kinds of variables about the ocean in pre-industrial times, pK1 and pK2 among others … really? Unless you have a time machine, you’re just pulling numbers out of the air.

pK1 and pK2 are measures of the equilibrium constants of the deprotonation reactions, as such they are thermodynamic constants and are the same now as the always were.

Not according to Dr. Barrente,viz:

Pre-industrial
pK1 = 6.4149; pK2 = 10.4202
Post-industrial pH
pK1 = 6.4105; pK2 = 10.4063

w.

Reply to  Phil.
March 21, 2016 7:42 pm

Willis: ln(K)= -ΔGº/RT
So pK = -ΔGº/RT
ΔGº is the free energy change of the reaction and R is the universal gas constant and T is the absolute temperature.
Consequently the differences are due to the small difference in the assumed temperature, the constants are unchanged.

Bartemis
Reply to  Willis Eschenbach
March 21, 2016 4:30 pm

“The temperature of the planet has not warmed anywhere near enough for the change in atmospheric CO2 to be a result of outgassing from ocean warming.”
If the ocean were a static pool of water. It isn’t.
The very name of the Thermohaline-Circulation tells you it is temperature dependent. And, when you have a continuous transport process which is modulated by temperature, you end up having properties for which the rate of change depends on temperature. Like this:
http://i1136.photobucket.com/albums/n488/Bartemis/temp-CO2-long.jpg_zpsszsfkb5h.png

Ferdinand Engelbeen
Reply to  Bartemis
March 23, 2016 10:35 am

Bart,
As discussed already last time, the MOC/THC is 70% driven by wind, 30% by temperature, where the main sink rate is caused by freezing, not by a small change in temperature of the waters themselves.
Your graph shows that most of the variability is caused by temperature. As that is mainly a proven transient response of vegetation, but vegetation is a net sink over periods longer than 3 years, it is not the cause of the trend, which is from a separate process. Oceans are a minor cause, as these can supply not more than 16 ppmv/°C. Human emissions were twice as high as the measured increase. Thus the most probable cause. Here the same graph where all variability is caused by temperature and ~90% of the slope by human emissions, ~10% by temperature:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/had_co2_emiss_nat_deriv.jpg

Bartemis
Reply to  Bartemis
March 23, 2016 5:56 pm

This is just a contrived similarity, which requires a great many assumptions and fine tuning. Occam’s Razor comes firmly down on the side that the rate of change of CO2 is simply proportional to appropriately baselined temperature anomaly.

Ferdinand Engelbeen
Reply to  Bartemis
March 24, 2016 2:53 am

Bart,
The only assumptions I have made is that most short term CO2 rate of change variability is temperature driven, what you assume too. The second assumption is that the sink rate is linearly proportional to the increased pressure in the atmosphere above the steady state level for the average surface temperature. Which is proven by the similar average ΔpCO2 / net sink ratio over the full 55 years. The third is that natural CO2 levels follow Henry’s law for the solubility of CO2 in seawater. No “fine tuning” necessary at all, only three very basic assumptions. The combination of these three gives the same fit as your completely arbitrary match of the two slopes, which either gives a mismatch in amplitudes or a mismatch in slopes…
Your “match” violates:
– Henry’s law for the solubility of CO2 in seawater for the current area weighted ocean surface temperature.
– The observed area weighted ΔpCO2 which is 7 μatm higher in the atmosphere than in the ocean surface.
– The increase of CO2/derivatives in the ocean surface with decreasing pH everywhere longer time series were taken.
– The 13C/12C ratio decline in atmosphere and ocean surface.
– The oxygen and 13C/12C balances which prove that the short term variability is caused by the reaction of the biosphere (mainly the Amazon) on short term temperature variability, but not the cause of the long term increase in CO2: vegetation is a net, growing sink for CO2. The earth is greening.
Violating only one observation destroys the finest theory. Violating every available observation doesn’t even convince you that your theory may be wrong…
The short term transient response of CO2 to temperature is 4-5 ppmv/°C. The long-term process that increases the CO2 levels in the atmosphere according to you gets over 100 ppmv/°C (while Henry’s law says 16 ppmv/°C). If you think that is from the same process, then you have a remarkable view on transient processes…

Samuel C Cogar
Reply to  Willis Eschenbach
March 22, 2016 7:55 am

Willis Eschenbach – March 21, 2016 at 12:43 pm

Me, I’d bet that is not true. The temperature of the planet has not warmed anywhere near enough for the change in atmospheric CO2 to be a result of outgassing from ocean warming.

The “temperature of the planet”, ….. HUH, …… as if someone actually knew what that was?
A better question is, ……. how many degrees has the ocean waters “warmed” after being subjected to 500+ years (from about 1300 to about 1850) of the extremely cold near-surface temperatures of the Little Ice Age?
Anyone who would base their argument on the accuracy of the Historical Temperature Record(s) …… has no basis for a scientific argument to begin with.
Anyone that thinks or truly believes that the UAH near-surface global average temperatures have anything to do with the yearly increase in atmospheric CO2 ppm …… really needs to study this graph and explain the reasoning for their belief, to wit:
http://i1019.photobucket.com/albums/af315/SamC_40/1979-2013UAHsatelliteglobalaveragetemperatures.png

March 21, 2016 2:11 pm

Ocean dead zones, do they generally have more towards acidic conditions due to the absence of oxygen?
Another thing that I often wondered about, oxygen rich surface water is not great at taking on CO2, or am I mistaken?

Ferdinand Engelbeen
Reply to  Mark
March 23, 2016 10:40 am

Mark,
Uptake and release of any gas in solution is a matter of partial pressure of each gas on itself, no matter the rest of what is in the atmosphere.

Jeff Alberts
March 21, 2016 4:07 pm

The pH of seawater (ionic strength of approximately 0.7) can be determined at any temperature a modified form of the Henderson-Hasselbalch equation

Sure, but what about the Anderson-Hasselhof equation?

Don K
March 21, 2016 4:07 pm

Willis Your reaction is understandable, but if you read Barrante’s last paragaphs and the first few comments, you’ll find that Barrante seems to have no more faith in conventional wisdom about ocean pH measurement and pH change than do you (or I). He just doesn’t seem to think it’s important. I’m about 90% sure that what he is doing here is to apply the principles of Physical Chemistry to “Ocean Acidification”. That results in the horrifying equations he presents. In my opinion that’s a useful contribution, and not one that we’re likely to encounter elsewhere because applying physical laws to ocean pH is extremely complex, quite difficult, and tedious as well.
I think, not 100% sure, that his conclusion is that “ocean pH” (no matter what we, he, or anyone else thinks that is) is going to be dictated by ocean temperature, not partial pressure of CO2. And it’s going to be small for any realistic temperature change.
I have some doubts that his conclusions match what passes for data, but OA really is not a subject I wish to bother my pretty little head about. The smart kids can (and I predict will) argue about that one for all eternity
I could be all wrong on this.

Reply to  Don K
March 21, 2016 7:10 pm

Don K March 21, 2016 at 4:07 pm

Willis Your reaction is understandable, but if you read Barrante’s last paragaphs and the first few comments, you’ll find that Barrante seems to have no more faith in conventional wisdom about ocean pH measurement and pH change than do you (or I). He just doesn’t seem to think it’s important. I’m about 90% sure that what he is doing here is to apply the principles of Physical Chemistry to “Ocean Acidification”.

Thanks, Don, but when a man says:

It is well-known that ocean pH has decreased from approximately 8.2 pH units to 8.1 pH units in the last 150 years.

… it sure sounds like he has faith in conventional wisdom.
You also say:

I think, not 100% sure, that his conclusion is that “ocean pH” (no matter what we, he, or anyone else thinks that is) is going to be dictated by ocean temperature, not partial pressure of CO2. And it’s going to be small for any realistic temperature change.

Oddly enough, I thought his conclusion was that causation went the other way, viz his claim that:

In fact, if the measurement of ocean pH were not so complicated, and we had that data for the last 150 years, I would bet that we could show exactly that the increase in atmospheric CO2 from 280 ppmv to 380 ppmv in the last 150 years is an ocean temperature effect and not at all related to burning fossil fuels.

He’s not just saying that pH is a function of temperature. He’s also saying that atmospheric CO2 is a function of temperature.
With all that said, I did like very much his 3-D plot of temperature, pH, and CO2 levels. I’d never thought of that. I’ve been able to reproduce it closely in R, using the “seacarb” package, although I get slightly greater slopes than he gets.
An examination of the data shows that for each 10 ppmv of increased atmospheric CO2, the pH at a constant temperature should drop at about -0.08 pH units. It also shows that at a constant CO2 level, the pH should increase by about .016 pH unit per degree of warming.
SO … let’s assume for the sake of argument that the temperature warmed by 2°C and the atmospheric CO2 went from 180 to 400. The warming of two degrees would increase the pH by about .03 pH units.
On the other hand, the change in atmospheric CO2 of 220 ppmv would cause a theoretical decrease in pH of about 22 times 0.08 = -0.17 pH units. The net of these is a slight neutralization of the ocean waters, of about -0.14 pH units.
HOWEVER … and it is a big however, this assumes that the salinity, the phosphate concentration, the total silicate concentration, and the several equilibrium “constants” do not vary … and in the real world, this is always a suspect assumption. To mangle Shakespeare, there are more buffers in heaven and earth (and the ocean) than are dreamt of in the usual philosophy …
Best to all, thanks to Dr. B,
w.

Phil.
Reply to  Willis Eschenbach
March 22, 2016 6:59 pm

Willis Eschenbach March 21, 2016 at 7:10 pm
HOWEVER … and it is a big however, this assumes that the salinity, the phosphate concentration, the total silicate concentration, and the several equilibrium “constants” do not vary … and in the real world, this is always a suspect assumption. To mangle Shakespeare, there are more buffers in heaven and earth (and the ocean) than are dreamt of in the usual philosophy …

It’s not so much an assumption as a measurement Willis. The constancy of the sea water composition of the major elements was first measured in 1819 and has been confirmed multiple times since. The residence time of major species such as Na+, Mg2+, K+, Sr2+,, Cl-…….. is over 3 million years, Ca2+ is about 800,00 years. The equilibrium constants, as I told you yesterday depend on the free energy of the products and reactants in there standard states, they don’t change.

Reply to  Willis Eschenbach
March 22, 2016 9:28 pm

Phil. March 22, 2016 at 6:59 pm

Willis Eschenbach March 21, 2016 at 7:10 pm
HOWEVER … and it is a big however, this assumes that the salinity, the phosphate concentration, the total silicate concentration, and the several equilibrium “constants” do not vary … and in the real world, this is always a suspect assumption.

It’s not so much an assumption as a measurement Willis. The constancy of the sea water composition of the major elements was first measured in 1819 and has been confirmed multiple times since. The residence time of major species such as Na+, Mg2+, K+, Sr2+,, Cl-…….. is over 3 million years, Ca2+ is about 800,00 years.

Thanks, Phil. Well, to start with the salinity certainly varies and is far from constant in either space or time. Similarly, the silicate concentration of the ocean not only varies from the surface to the deeps, it also varies from one ocean to another. And the phosphate concentrations vary from about zero in the tropics to 2 mmol/m^3 around Antarctica.
So I’m sorry, Phil, but your claims are simply not true. As I said, salinity, phosphate, and silicate all vary over time and space. Not only that, but each of these is temperature dependent in some measure, so there are subtle interactions between the various variables.
In addition, in theory you are correct when you say that “The equilibrium constants, as I told you yesterday depend on the free energy of the products and reactants in there [sic] standard states, they don’t change.” But in the real ocean, reactions affect each other, reactants may or may not be removed by either chemical or physical processes, various substances move both into and out of solution, and buffers of various kinds come into play. All of these can affect the rate at which a reaction proceeds, regardless of the theoretical equilibrium constants.
Finally, life intervenes always and everywhere in the ocean. In the ocean, chemistry doesn’t rule life—instead, life rules chemistry.
My best to you,
w.

Phil.
Reply to  Willis Eschenbach
March 23, 2016 7:12 am

Willis Eschenbach March 22, 2016 at 9:28 pm
Phil. March 22, 2016 at 6:59 pm
So I’m sorry, Phil, but your claims are simply not true. As I said, salinity, phosphate, and silicate all vary over time and space. Not only that, but each of these is temperature dependent in some measure, so there are subtle interactions between the various variables.

Willis I would ask you to grant me the courtesy that you expect for yourself, please quote the exact words you disagree with.
In addition, in theory you are correct when you say that “The equilibrium constants, as I told you yesterday depend on the free energy of the products and reactants in there [sic] standard states, they don’t change.” But in the real ocean, reactions affect each other, reactants may or may not be removed by either chemical or physical processes, various substances move both into and out of solution, and buffers of various kinds come into play. All of these can affect the rate at which a reaction proceeds, regardless of the theoretical equilibrium constants.
They are the actual equilibrium constants, as such they define where the composition will end up, regardless of the rates.

Reply to  Willis Eschenbach
March 23, 2016 9:48 am

Phil. March 22, 2016 at 6:59 pm

So I’m sorry, Phil, but your claims are simply not true. As I said, salinity, phosphate, and silicate all vary over time and space. Not only that, but each of these is temperature dependent in some measure, so there are subtle interactions between the various variables.

Willis I would ask you to grant me the courtesy that you expect for yourself, please quote the exact words you disagree with.

Phil, I already did exactly that in the comment, viz:

Willis Eschenbach March 21, 2016 at 7:10 pm
HOWEVER … and it is a big however, this assumes that the salinity, the phosphate concentration, the total silicate concentration, and the several equilibrium “constants” do not vary … and in the real world, this is always a suspect assumption.

It’s not so much an assumption as a measurement Willis. The constancy of the sea water composition of the major elements was first measured in 1819 and has been confirmed multiple times since. The residence time of major species such as Na+, Mg2+, K+, Sr2+,, Cl-…….. is over 3 million years, Ca2+ is about 800,00 years.

So your claim was that the the levels of phosphate, silicate, and salinity do not vary.
Sorry, but they do vary, and widely, both in time and in space.
w.

Reply to  Willis Eschenbach
March 23, 2016 10:01 am

Phil. March 23, 2016 at 7:12 am

In addition, in theory you are correct when you say that “The equilibrium constants, as I told you yesterday depend on the free energy of the products and reactants in there [sic] standard states, they don’t change.” But in the real ocean, reactions affect each other, reactants may or may not be removed by either chemical or physical processes, various substances move both into and out of solution, and buffers of various kinds come into play. All of these can affect the rate at which a reaction proceeds, regardless of the theoretical equilibrium constants.

They are the actual equilibrium constants, as such they define where the composition will end up, regardless of the rates.

No, they are not actual equilibrium constants. They are theoretical equilibrium constants, and are only valid if the reaction is going on in pure water and no other reactions are going on that might interfere, and no other buffers exist and no life forms interfere with the process … and as I said above, in the ocean none of those are true.
And not only are they theoretical equilibrium constants … but different authors calculate them slightly differently. More to the point, rather than being constant, they vary with both temperature and salinity. Here are the flags for the choices of constants K1, K2, Kf, and Ks in the software I use:

k1k2
“l” for using K1 and K2 from Lueker et al. (2000), “m06” from Millero et al. (2006), “m10” from Millero (2010), “w14” from Waters et al. (2014), and “r” from Roy et al. (1993). “x” is the default flag; the default value is then “l”, except if T is outside the range 2 to 35oC and/or S is outside the range 19 to 43. In these cases, the default value is “m10”.
kf
“pf” for using Kf from Perez and Fraga (1987) and “dg” for using Kf from Dickson and Riley (1979 in Dickson and Goyet, 1994). “x” is the default flag; the default value is then “pf”, except if T is outside the range 9 to 33oC and/or S is outside the range 10 to 40. In these cases, the default is “dg”.
ks
“d” for using Ks from Dickon (1990), “k” for using Ks from Khoo et al. (1977), default is “d”

and here are the comments on those choices:

The Lueker et al. (2000) constants for K1 and K2, the Perez and Fraga (1987) constant for Kf and the Dickson (1990) constant for Ks are recommended by Dickson et al. (2007). It is, however, critical to consider that each formulation is only valid for specific ranges of temperature and salinity:
For K1 and K2:
Roy et al. (1993): S ranging between 5 and 45 and T ranging between 0 and 45oC.
Lueker et al. (2000): S ranging between 19 and 43 and T ranging between 2 and 35oC.
Millero et al. (2006): S ranging between 0.1 and 50 and T ranging between 1 and 50oC.
Millero (2010): S ranging between 1 and 50 and T ranging between 0 and 50oC. Millero (2010) provides a K1 and K2 formulation for the seawater, total and free pH scales. Therefore, when this method is used and if P=0, K1 and K2 are computed with the formulation corresponding to the pH scale given in the flag “pHscale”.
For Kf:
Perez and Fraga (1987): S ranging between 10 and 40 and T ranging between 9 and 33oC.
Dickson and Riley (1979 in Dickson and Goyet, 1994): S ranging between 0 and 45 and T ranging between 0 and 45oC.
For Ks:
Dickson (1990): S ranging between 5 and 45 and T ranging between 0 and 45oC.
Khoo et al. (1977): S ranging between 20 and 45 and T ranging between 5 and 40oC.

My best to you,
w.

March 21, 2016 4:17 pm

Reblogged this on gottadobetterthanthis and commented:

Not in-depth, but its thermodynamics, mathematics, and chemistry (in other words, you can figure it out if you want to). So, the short version, the ocean is entirely too complex to suppose driving your SUV matters to it.

D.I.
March 21, 2016 6:10 pm

So the so called ‘Professor’ guesstimates the PH of the Oceans 150 years ago.
It seems that ‘Guestimates’ is the new science of today.
It’s very sad that so called ‘Science’ in some fields today is becoming ‘on par’ with Astrology.

John Harmsworth
March 21, 2016 7:05 pm

I see a lot of detailed analysis in this thread from people who obviously know their chemistry. Is it really impossible to put a paper together for publication and demand that any respectable outlet that has carried ocean acidification nonsense do the responsible thing and publish it.

J. Paul Lanier
March 21, 2016 9:11 pm

One problem is Barrante’s speculation:
“In fact, if the measurement of ocean pH were not so complicated, and we had that data for the last 150 years, I would bet that we could show exactly that the increase in atmospheric CO2 from 280 ppmv to 380 ppmv in the last 150 years is an ocean temperature effect and not at all related to burning fossil fuels.”
That would never make it past peer review.

March 21, 2016 9:35 pm

Sorry, I had some trouble posting for the first time. I accidentally posted twice. Please remove this and leave the first one in. Thank you, J. Paul

Edward Hurst
March 22, 2016 1:29 am

Well that was a lively discussion. Thank you!

Ferdinand Engelbeen
March 23, 2016 11:04 am

Dr. Barante,
While pH is difficult to measure with sufficient accuracy – forget all glass electrode measurements of the past oceans – the current new colorimetric methods of seawater pH are of a much better accuracy, but these series are much too short. An alternative is that pH can be calculated out of other measurements (total alkality and DIC). See the trends in Hawaii, Fig. 1 in:
http://www.pnas.org/content/106/30/12235.full.pdf
Fig. 3 shows the influence of temperature on the local pH.
Further, if pH was the cause of the increase of CO2 in the atmosphere, the total inorganic carbon content (DIC) of the ocean surface would decrease with pH. If the pH decrease is caused by increased CO2 in the atmosphere, then DIC increases. The latter is what is observed. See the discussion in the above essay.

Ferdinand Engelbeen
March 23, 2016 1:17 pm

Dr Barrante,
A few remarks:
pH measurements with glass electrodes were by far not accurate enough to measure the changes in the oceans. Colorimetric measurements are far better but their use is only quite recently. There is an alternative: older measurements were made for total alkalinity and DIC (dissolved inorganic carbon) the combination of both gives a quite good alternative.
See: Fig. 1 in:
http://www.pnas.org/content/106/30/12235.full.pdf
Further, if a lower pH / higher temperatures were the cause of the CO2 increase in the atmosphere, that would result in a reduction of DIC in the ocean surface. If the lower pH is caused by the increase in the atmosphere, then DIC increases. The latter is what is observed, as mentioned in the discussion section.
BTW, Henry’s law + the resulting dissociations gives not more than 16 ppm/°C in steady state equilibrium between oceanic sources and sinks at one side and the atmosphere at the other side…
The influence of temperature on pH at Hawaii is shown in Fig 3.
In FIg.1 one can also see that the pCO2 of the ocean increases together with that of the atmosphere, but in average the pCO2 of the atmosphere is higher than of the oceans. That is the case, not only in Hawaii, but also ain Bermuda and other places where is measured over longer periods. Even worldwide. See the compilation by Feely e.a. at:
http://www.pmel.noaa.gov/pubs/outstand/feel2331/exchange.shtml
With an area-weighted average 7 μatm higher CO2 pressure in the atmosphere than in the ocean surface…