Bishop Hill Revkin does low climate sensitivity
Feb 4, 2013 Andy Revkin has taken a long hard look at the trend towards low climate sensitivity estimates and seems to conclude that things are just as the sceptics have said.
I can understand why some climate campaigners, writers and scientists don’t want to focus on any science hinting that there might be a bit more time to make this profound energy transition. (There’s also reluctance, I’m sure, because the recent work is trending toward the published low sensitivity findings from a decade ago from climate scientists best known for their relationships with libertarian groups.)
Nonetheless, the science is what the science is.
It's a must-read.
Bishop Hill
Anthony has further insights, gleaned from an email exchange Revkin had with Gavin Schmidt of NASA. Schmidt's view is this:
Andy, I think you may be slightly misrepresenting where the ‘consensus’ on this issue has been. While there have been occasional papers that have shown a large tail, and some arguments that this is stubborn – particular from constraints based on the modern tranisent changes – there has always been substantial evidence to rule these out. Even going back to the 2-11deg C range found in the initial cpdn results in 2005, many people said immediately that the high end was untenable (for instance).
Indeed, the consensus statements in the IPCC reports have remained within the 1.5 – 4.5 range first set by Charney in 1979. James’ work has helped improve the quantifications of the paleo constraints (particular for the LGM), but these have been supported by work from Lorius et al (1991), Kohler et al (2010), etc. and therefore are not particularly radical.
By not reflecting that, you are implying that the wishful thinking of people like Ridley and Lindzen for a climate sensitivity of around 1 deg C is tenable. It is not, and James’ statement was simply alluding to that. For reference, James stated that his favored number was around 2.5 deg C, Jim Hansen in a recent letter to the WSJ quote 2.5-3.5 (based on the recent Palaeosens paper), and for what it’s worth the CMIP5 GISS models have sensitivities of 2.4 to 2.7 deg C. None of this is out of the mainstream.
Lindzen has of course argued for sensitivity around 1deg;C, but Ridley was arguing for 1.6 in his WSJ essay. The idea that figures like this are "untenable" seems to me to be extraordinary given that our only fully empirical estimate and a series of other studies give precisely this figure.
To Schmidt's comment, Revkin adds this:
In policy circles, including popular calculations of emissions trajectories necessary to avoid a high chance of exceeding 2 degrees C. of warming, the hot tail has not been trimmed (unless I’m missing something?).
To me, that says the climate science community — including the Intergovernmental Panel on Climate Change science working group — has not adequately conveyed the reality you state here.
And Richard Betts agrees:
You’re right – see, for example, the Stern Review, Table 1.1 right-hand column, citing Meinshausen (2006) to give a wide range of warming for different stabilisation levels, and compare that with the other 2 columns (TAR range and Hadley Centre model range) – the Meinshausen range was then used later in the review to inform the economic impacts modelling (Box 8.1, page 220)
So Stern used a fat-tail distribution not the TAR distribution.
Bishop Hill
I'm struggling to reconcile Richard Betts' observations with the remarks on climate sensitivity by Chris Hope on the PAGE2002 model (the basis of the Stern Review) as reported in my post on Climate Sensitivity and the Stern Report.
The mean value is unchanged from the default PAGE2002 mean value of 3°C, but the range at the upper end is greater. In PAGE2002, the climate sensitivity was input as a triangular probability distribution, with a minimum value of 1.5°C and a maximum of 5°C.
I'm going to ask Richard and Chris to clarify. Please don't jump to conclusions in the meantime.
Bishop Hill
Gavin tweets:
@Revkin somewhat overstates impacts of changes in CS. It is not too small to be negligible, nor so large to be a nightmare
Reader Comments (147)
Entropic Man,
Enough of the sophistry. During the Cretaceous period, carbon dioxide levels up to 15 times pre-industrial levels have been indicated by serious authors. If you are suggesting that our recent and relatively trivial increases could be injurious to marine life, then maybe you'd like to consider the prehistorical biological response to raised atmospheric carbon levels. We sometimes call it chalk.
Clearly, since carbonate-based shells and exoskeletons weren't a problem back then - they're not likely to be now, either.
"Citizen scientists doubtful that small pH changes matter should remember that pH is the inverse decimal logarithm of the hydrogen ion concentration. A one unit drop in pH increases hydrogen ion concentration tenfold."
Oh boy, you believe citizens are beneath scientists do you? Well maybe, but I believe that scientists who do statistical analysis of data are citizen statisticians.
Science is about humility, no scientist of any worth would dismiss the views of anyone by describing them as citizen scientists, and therefore beneath contempt. Gavin Schmitt will live to regret this hubris. I don't know you will because your'e parrotting what he believed, before it became apparent that he was way off target.
Humility my friend is best for all of us with regard to science, you have apparently assumed that your heroes are cleverer than those who don't have the necessary "qualifications", something that no real scientist would assume.
@entropic man
'Curious you should say that the work has not been done, when I have just given you links to large database of collected observations'
If you did that, I apologise for my oversight.
But I thought I had looked carefully at the links you did provide..and they seemed only to refer to Central and Northern California and contained about 200 observations at most. If I have overlooked some more comprehensive and bigger series - covering a few more oceans, a few hundred more observation sites and about thirty years, please show where I have misled myself.
The analogy is with the estimated 50,000,000 observations that were analysed to show that global warming was occurring.
I wonder if Gavin has taken these gents to task then?
http://media.treehugger.com/assets/images/2011/10/mit-climate-wheel.jpg
/apologies if someone already mentioned/linked this - it's a long thread, and I may have missed it.
Mr. Entropic Man,
I never written, or spoken, the words you attribute to me. What on earth makes you think that I did?
I have, so far, despite our disagreements, taken you for an intelligent person.
@entropic
It seems our last two posts crossed in their creation. I will study the new data you have provided with interest.
I'm glad you brought the logarithmic nature of pH to my attention. Without your prompting I might have forgotten it. It was, after all, a few years since I received my Masters degree in Chemistry. But reassuring to know the the definition hasn't changed.
Entropic Man,
Excuse my poor English grammar.
Make that "I had previously taken you for a moderately intelligent and decent person."
@entropic
Thank you again for the links to the new data. I have studied it and have the following observations
1. The 'informal map' you link to is not a record of any observations of pH changes since pre-industrial times, but an estimate based on a computer model based only on recent observations.
Since the model itself most likely assumes that pH will change with CO2 concentration. how much
credence would you suggest we place on results from such a model? Seems to me that the logic is faulty. First you assume that pH varies with CO2. Then you run the model. Then you show that when CO2 was lower, pH was different. This is a circular argument.
Or, if I have missed the step that allows the circle to be broken, please describe it for me.
2. I didn't doubt that 'oceanography' is being done in lots of places, and your database shows the progress of some research ships around the world. Indeed I have a distant relative who is an ocenaographer in UK and who occasionally works on such vessels.
My question is solely about the process of 'ocean acidification'. Note that it is said to be a process, and to show a process, you need to have a progression (time series) of data from the same site. The voyages of the oceanography ships do not provide such data. If I say that the pH yesterday at Lat xN. Long yW is 8.27, that tells us nothing about any processes. It only has some context if I can also say that last year it was 8.25 and the year before 8.23 (or whatever the case may be) and so on.
Similarly, the standalone observation that the temperature in my back garden right now is 4.8C tells us nothing about any processes of global warming.
Again. if I have missed the point ad there are indeed pH times series for defined sites hidden within the links you provided, please point them out, since they are not obvious to this 'citizen scientist'.
Unlike our other correspondent, I have no objections whatsoever to being so described. It makes a nice distinction between 'citizen scientists' and 'Big Grant-funded scientists'..
Yes, we know. It's that way for a reason. You might as well say that measuring temperature changes in microdegrees C would be a good idea because it will make the numbers big and scary. Similar things have in fact appeared in alarmist literature. "Millions of acres" is quite a common one.
Mr. Entropic Man,
I never written, or spoken, the words you attribute to me. What on earth makes you think that I did?
I have, so far, despite our disagreements, taken you for an intelligent person.
Feb 5, 2013 at 3:48 PM | michael hart
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Please refer back to your earlier post. This was the last sentence before the identifier.
Seek, and ye shall find whatever you want.
Feb 5, 2013 at 4:27 AM | michael hart
@NW
'It's that way for a reason'
I think that the real reason is that acidic concentrations vary so much in nature, that a log scale is the only way that we can sensibly keep track of them without using very large or very small numbers.
As an example, consider your blood. It is pretty well regulated at about pH 7.4 (alkaline overall, but slightly less so than seawater). But it is in pretty close contact with the lining oyour staomach which contains gastric acid at about pH 2.5. We can cope with the difference of 5 units on the pH scale in calculations and conversation.
But it represents a one hundred thousand fold difference (10^5) in the concentration of hydrogen (or hydroxyl) ions.
It is a matter of some surprise to me that since we all manage to wander about quite happily with this huge acidity gradient sloshing around inside us and no apparent problems, that other organisms are predicted to be incapable of handling concentration changes measured in a few tens of percent, rather than hundreds of thousands of times. And erathworms - pretty much immersed in the soil they live in seems to be able to survive in conditions where the pH varies by 2 (100 fold concentration difference) between 'acidic' and 'alkaline' soil.
But we are told that the wee quivering beasties of the oceans - who evolved hundreds of millions of years ago under very different conditions - are such shrinking violets that the slightest disturbance of their delicate pH balance will lead to their immediate extinction. Somehow I am not entirely convinced.
Latimer Adler
The modern data for that "informal map" was drawn using a graphics package, not a model.
The modern data came from the GLODAP database. The historical data is from a variety of sources, since many countries maintained research ships and the HMS Challenger voyage in the 1870s was one of many.
I've been trying to pull pH data from the digital archive of the documents from that expedition, but one of the scientists aboard hd the initials P.H. and search requests keep finding the man, not the data :-(.
http://www.hmsc.19thcenturyscience.org/
Or put more simply, scientific units are chosen to be of practical use in dealing with whatever they represent. Thus we use pH because it scales the chemistry to changes which actually matter in practice.
EM is simply applying a variation of the well worn alarmist trick of selecting units to produce Big Scary Numbers rather than meaningful ones. This is effective when used on the general public who are less educated than most people here. There is a good reason why the media measure area in Football Pitches, height in Nelson's Columns and power in One Bar Electric Fires.
NW, Latimer Adler
Some marine organisms are tough as old boots where pH is concerned. Others are very sensitive even to small changes.
I'll move away from the scientists for a moment to another group intimately concerned with salt water pH.
I f you have ever kept a marine aquarium tank, you spend an enormous amount of time, effort (and money!) trying to keep the conditions liveable in the tank. For a typical mix of fish and invertebrates, a typical optimum pH is 8.1 - 8.4. The occupants will tolerate temporary excursions outside this range, but will not remain healthy if the deviation is sustained.
"Generally, pH levels ranging from 8.1 to 8.4 are acceptable in saltwater tanks."
http://www.aquaticcommunity.com/marineaquarium/ph.php
Corals are regarded by aquarists as more sensitive,
Returning to the science, This paper uses growth patterns in long-lived corals to investigate pH changes on the Great Barrier Reef. The technique detects the 22 year solar cycle, the PDO and an
additional recent progressive pH reduction.
http://www.webpages.uidaho.edu/envs501/downloads/Wei%20et%20al.%202009.pdf
Cretaceous CO2? There's some review of this at
http://www.realclimate.org/index.php/archives/2008/01/the-debate-is-just-beginning-on-the-cretaceous/
The high levels are estimated to have produced temperatures up to 23C higher than today in some regions, along with some temporary cold spells and ice sheets. As to what's going on. Nobody knows yet!
To those discussing ph levels. Some time back, long before I had any interest in climate change, I was for several years the Secretary of a local, largish coarse angling club. Due to the foresight of previous committees, we were in the happy position of actually owning many of our waters and were able to continue buying more. During that time we had an algae bloom problem on one of our lakes and we employed the services of a consultant to find a solution. As part of what he did, he monitored the ph levels in the lake over a period of a year or so. Not really knowing much about ph levels, I was nonetheless surprised to find how much the levels varied. Not only were there large seasonal differences, but also very noticeable variations on a daily basis too, even down to the time of day the readings were taken. There were even differences from one end of the 3 acre lake to the other. At the end of this, the consultant told us that the variations we saw were perfectly normal and nothing to worry about (he made other recommendations regarding the algae blooms which did actually solve the problem). I have no idea how the ph levels in a freshwater lake would relate to the ph levels in the oceans and whether those oceans undergo such daily and seasonal changes, but logic dictates that there must be at least some similarity in variation. Perhaps others here would know.
@entropic
1. Since the term pH wasn't invented until 1909 (see Wikipedia for 'pH'), it is hardly surprising that you can find no hits in data from HMS Challenger collected 40 years beforehand. Searching on a database of computer magazines from the 1970s finds few references to iPads or Google ...and for the same reason. The trerm was not in use at the time the data was written
If you are able however to find some useful 'acidity' data therein, I;d be extremely interested to knwo how you plan to show that it is of the supposed accuracy (three significant figures of pH) that .you need to demonstrate 'ocean acidification'. And you'd need to be pretty sure that today's measurements were taken in exactly the same place as Challenger's.
To my 'citizen scientist's' eye, both of these requirements look to be very challenging (pun intended)
2. With respect the map you cited was indeed created using a model. There is no 'pre-industrial' data to base it one and so they used a mathematical modelling technique to try to recreate it from today's data.
Here's what the GLODAP entry says about it:
'Additionally, analysis has attempted to separate natural from anthropogenic DIC, to produce fields of pre-industrial (18th century) DIC and "present day" anthropogenic CO2. This separation allows estimation of the magnitude of the ocean sink for anthropogenic CO2, and is important for studies of phenomena such as ocean acidification.[3][4] However, as anthropogenic DIC is chemically and physically identical to natural DIC, this separation is difficult. GLODAP used a mathematical technique known as C* (C-star)[5] to deconvolute anthropogenic from natural DIC (there are a number of alternative methods). This uses information about ocean biogeochemistry and CO2 surface disequilibium together with other ocean tracers including carbon-14, CFC-11 and CFC-12 (which indicate water mass age) to try to separate out natural CO2 from that added during the ongoing anthropogenic transient. The technique is not straightforward and has associated errors, although it is gradually being refined to improve it. Its findings are generally supported by independent predictions made by dynamic models.
And to my non-academic eye the faint praise is really saying 'and we know its a load of crap but we haven't got anything else'
Meanwhile, we are still nowhere nearer getting somewhere like the 10,000,000+ pH observations needed to show that 'ocean acidification' is actually occurring. We're not even up to 10,000.
The work has not been done.
I'm always astounded at how alarmists, who are unwilling to consider the early records from expeditions to the poles on our understanding of ice cover changes, are eager to grab date from isolated cruises like the Challenger expedition to support the idea of long term changes in ocean pH. In one situation, "data" only begins with the satellite era. In the other, we must utilize anything from the past that we can...
@entropic
I looked at the paper about the GBR.
The takeaway for me was that (assuming the very convoluted method they used is valid at all, which isn't obvious) the natural pH variation before any possible ACO2 contribution is wide...from 7.7 (1940) to 8.2 (1960,and 1990). Very difficult to get excited over a supposed change of 0.02 per decade when Mother Nature manages 25 times that range naturally. (Figure 8)
But we're still nowhere near the 10,000,000+ measurements needed to show that global warming was occurring.
Entropic Man,
Your RealClimate link has no mention whatsoever of CO2 impacts on oceanic pH. I've no doubt that temperatures have been estimated to have been 23°C higher in some places during the Cretaceous than today. We scientists are adept at all sorts of estimations.
Schmidt: "impacts of changes in CS ... is not ... so large to be a nightmare"
Gavin's statement parses to that a large enough downwards revision in CS *would* be a nightmare. Indeed, Gaia's safety is the climateers' nightmare. No "thank God we were wrong" from these fellows, they wake in a sweat at night at the thought that our grandchildrens' futures are bright.
NZ Willy -
Frankly, that's just silly. Gavin is guilty of being a little careless with his antecedents, but I see no reason to assume that he finds the reduction in ECS to be nightmarish. In his comment, "it" refers to climate sensitivity, not to the changes.
Heh, Gavin's in a real bind, he gives up nightmares or he's a sociopath.
H/t Joshua(I can't believe he had this insight. Maybe he didn't)
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All these climatists talking about sensitivity either don't care or don't know or are just too stupid to know about experimental observations concerning their subject. By definition, sensitivity is the increase of global temperature when the amount of atmospheric carbon dioxide is doubled. I just finished explaining the Miskolzi observation that radiosondes cannot detect any absorption of radiant energy when carbon dioxide is added to the atmosphere. And without absorption there can be no warming, which makes the sensitivity, if you still care, zero. More to the point, without absorption the theory of anthropogenic global warming by the greenhouse effect is simply dead. And with it dies any justification for emission controls or expensive and useless mitigation of an imaginary warming. What remains to be done is to clear up the mess created by unnecessary and harmful legislation to enforce these projects. That's how it is today. I expect that some of the more intelligent will jump out of that leaking boat before it sinks. Unfortunately there are flat-earthers and warmists who have penetrated deeply into the political structure of the world and will not easily give up their ill-begotten gains.
"It is now at 390ppm. 390/265 = 1.47
So 1.47 gives c. 1.5C warming.
therefore a doubling gives 1.5C x 2/1.47 = 2C."
Feb 4, 2013 at 6:33 PM | Registered Commenterlapogus
You should be using a logarithmic relation between temperature and CO2 concentration rather than a linear one. Using a logarithmic relationship with your figures, one would get about 1.74C for a doubling of CO2 based on warming since the little ice age assuming all the warming was man made.
Latimer Adler
Thank you. That's why I could'nt find it. Challenger did not measure pH, They measured carbonic acid levels and the two correalate.
http://ion.chem.usu.edu/~sbialkow/Classes/3650/Carbonate/Carbonic%20Acid.html
There are also biological proxies such as this.
http://epic.awi.de/10529/1/Hni2004a.pdf
Just out of curiosity, why are you sure that ocean pH has not changed if there is no data?
SayNoToFearmongers
The high Cretaceous CO2 lvels were accompanied by massive chalk accumulations, which may have kept dissolved CO2 levels, and hence pH, within survivable bounds. There;s also the matter of timescale. Even a rate of change of 0.1 pH unit
per century is far faster than any Cretaceous organism probably had to adapt to.
http://tos.org/oceanography/issues/issue_archive/issue_pdfs/22_4/22-4_kump.pdf
Note also recent evidence supporting the high CO2/ acidification hypothesis as a possible contributor to the Permean extinction.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2889361/
Don't be hard on Revkin. Imagine the views of almost every single friend, peer, student, and co-worker he has. You know how similar climate True Believers are to a religious cult. How quickly would they cut Andy off if he came out as some sort of "denier?' I believe he will go where the science takes him and as everyone here knows that will eventually lead to "Global warming ain't no big thing!" But in the meantime he keeps peace in his life and is content to provide..what, exactly? A mainstream blog that is ostensibly pro-AGW but provides a comment forum split evenly between skeptic and Believer. And we're a vicious lot, on both sides. Ask kim, she knows. But he doesn't snip as long as we do not insult public figures, like Mann. I'm a cantankerous, Tea Party, no science background, rabble rouser myself but I'm more likely to be snipped at Climate Audit than I am at DotEarth. Andy is the Ned Flanders of the climate world and he is going to surprise you some day. Please visit and comment there often.
"Thank you. That's why I could'nt find it. Challenger did not measure pH, They measured carbonic acid levels and the two correalate."
Entropic Man, are you saying that the Challenger measured carbonic acid levels at a precision and accuracy that would allow conclusions to be made regarding differences of a tenth of a pH unit?
And regarding your boron isotope paper, all I see is assumptions, presumptions, and judgments that allow them to conclude that a measured pH difference of 0.1 +/-0.5 is "consistent" with a derived pH difference of 0.6 (with no error given).
All they claim is a "promising" technique that can help fill in the paleo pH record.
oops,
0.6 shoud be 0.06.
dang...
0.1 +/- 0.05.
Entropic Man
One would assume that the pH would have been rather comfortably 'survivable' given that chalk is entirely a byproduct of coccolithophores. That'll be biodiversity in NGOSpeak - algae, phytoplankton, the staff of all marine life. Not really extinction territory, judging by the White Cliffs of Dover, not least because plants (which, of course, phytoplankton are) *like* CO2.
Not sure we're all on the same page here - I thought that was primary school geography stuff - it was in mine anyhow.
Odd how Revkin took a swipe by referencing 'libertarian groups' but forgot to mention that Connolley is a politically active green/leftist.
@entropic man
'Just out of curiosity, why are you sure that ocean pH has not changed if there is no data?'
I think you have finally understood the essence of my point.
Without the data we do not know what the pH is doing, I do not know, You do not know. The cleverest oceanographer with the most qualifications and the biggest grant cheques does not know. My old Mum does not know. Nobody knows.
And yet a lot of people who claim to be 'scientists; have been content to build an intellectual castle in the air based on the assumption that the case has already been proved. Just about every possible oceanic effect has been blamed on this effect that hasn't even been conclusively shown to exist.
This is flabby, tired, unchallenging 'going through the motions' 3rd class 'science' at best. No curiosity, no vigorous discussion, no consideration of alternatives...poor and weakly stuff
Note also that I have been extremely careful not to express an opinion about what the pH data (if it is ever collected) may or may not show..so you have equally no information about what I may or may not believe. Don't make the mistake of theorising ahead of your data a second time.
Re Carbonic acid...are you sure that this is what was measured and that it correlates? Seems to me that they boiled the seawater and then measured the CO2 given off. Not the same thing at all. Might be a way to measure atmospheric CO2 concentration, but not pH.
Re: proxies. H'mmmm. The antics of Michael Mann might give one huge pause before relying on proxies too much for measuring important and sensitive data. And I note that the paper you cite was yet another piece of work done off Hawaii. We don't need to know about pH off Hawaii..we need to know what it is in all the other places around the world.
@entropic man
' Even a rate of change of 0.1 pH unit per century is far faster than any Cretaceous organism probably had to adapt to'
Maybe so. But we know that today's organisms can survive and thrive in far greater rates of change than that.
The GBR paper you referred to shows that pH has regularly changed by approaching 0.15 units per decade...even going back to pre-industrial times (1800-1810). And one place (Arlington Reef) seems to have survived a reduction (from 8.05 to 7.70) of 0.35 units in just about seven years around 1930. That is not 0.1 units per century-- but 0.05 units per year. Twenty times faster.
Perhaps the real biosphere is a lot more resilient to small pH changes than is generally believed?
The double whammy is that there is no or very little data AND those who draw alarmist conclusions from it frequently seem to be ideologically committed to the political measures supported by those conclusions.
Skeptical Science have a post on the Annan blog post and related issues
EM, if you re-read your post I objected to, may realise that it appears you are attributed the second quotation to me. (I wasn't commenting on the quote, just the attribution)
Latimer,
"Perhaps the real biosphere is a lot more resilient to small pH changes than is generally believed?"
Yes. It's worth remembering that within a given cell there exists many separate organelles which have wide variations in pH, much greater than those discussed here. All these are constantly maintained by ion pumps.
I've also read that the calcite/aragonite precipitation actually occurs BEHIND cell membranes, not on the exterior, so it can be controlled by the cell.
Somewhere on Jonova's blog in the last ~12 months I read someone state that the current, permanent, difference in pH between the Northern and Southern ends of the Great Barrier-Reef is greater than any predicted changes, and that it was growing fine (barring the odd ship running aground.)
michael hart
Apologies, I'll be more specific next time.
The fault was partly mine , Entropic man. If I had read it twice before commenting I might have reacted differently.
I was browsing around and found this. It compares the 1988 stances on climate sensitivity of Hansen and Lindzen with the subsequent temperature data.
http://www.skepticalscience.com/lindzen-illusion-2-lindzen-vs-hansen-1980s.html
michael hart
I think you overestimate the survival tolerance of coral reef organisms. Do not confuse optimum pH with survivable pH.
Your own body functions healthily within a blood pH range of 7.35 - 7.45. Go outside that range and metabolic problems set in. Go above 7.9 or below 6.9 and you die.
http://en.wikibooks.org/wiki/Human_Physiology/The_respiratory_system#Regulation_of_Blood_pH
I discussed above how aquarists find that their reef communities only thrive within the pH range 8.1 to 8.4 and die if the pH remains outside that range for too long.
I'm also pointing you towards four papers on reef decline, the references at the bottom of this newsletter.
http://climatescientistsaustralia.org.au/assets/files/csa_gbr-factsheet_may10.pdf
With reference to JoNova's blog on the Great Barrier Reef, it's a bit vague. Can you point me towards the data on which she based her comments.
Entropic man,
I will struggle to make a short reply to your several points. I will probably fail.
"I think you overestimate the survival tolerance of coral reef organisms. Do not confuse optimum pH with survivable pH."
-I don't think I do overestimate survivable tolerance to pH changes (if that is what you meant). That was the main point of my previous comment. At the cellular level, an external pH change of ~0.1 pH units is trivial, or less. Organisms face much greater pH ranges internally and externally, night and day, 24/7/365.
Do not conflate 'survivable pH' with other changes accompanying the dynamics of a complex ecosystem that is never at equilibrium. The many confounding factors are not easily disentangled in aquariums, never mind the ocean. Tahl Kestin's document (that you linked to) highlights one such: temperature. In addition, salinity, solar irradiation (visible and ultra-violet), and nutrients can quickly be added to this incomplete list. Population genetics is probably the most important and least understood factor. Sediment from Jacques Cousteau's boat, tourists and researchers who find polar bears too scary, come further down the list.
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"Your own body functions healthily within a blood pH range of 7.35 - 7.45. Go outside that range and metabolic problems set in. Go above 7.9 or below 6.9 and you die”.
-Human cells are not really relevant to the oceans. But: I cultured mammalian cell lines as part of my experimental work during my time as a grad student. Other members of the lab who did tissue-culture all the time occasionally had to get up in the middle of the night to attend to their awkward cells in the lab, but ranges in pH greater than 7.35 - 7.45 occurred routinely without problems. Outside the systemic 'lethal' pH ranges you describe, such pH levels are likely the result of what killed you, not the direct cause. When your blood exceeds those sort of pH numbers, then the wheels have already come off.
In medicine, substances such as ammonium chloride (often also in OTC cough-syrups) are administered orally to render the urine acidic without harmful effects on the whole body. It's generally no big deal with acids and bases that have pKa values not far distant from that of water. It has to be thus: Otherwise water itself would not support earth's life forms. Carbonate and phosphate buffers are the defining buffers of living organisms, and organisms also control their local pH by controlling the bicarbonate and phosphate buffer systems. This comes at relatively low energetic cost. And one of the enzymes they use to do it, is carbonic anhydrase (which the BBC have not yet learned how to spell properly).
The cells I mentioned earlier were always, by standard procedure, incubated at 37 Celsius and 4% CO2. That's 40,000 ppm, about 100 times higher than current atmospheric levels and far far beyond what humans could achieve by burning fossil fuels. No catastrophic acidity problems there.
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"I'm also pointing you towards four papers on reef decline, the references at the bottom of this newsletter."
-They appear to go no further than the usual argument about it causing the dissolution of the (dead) inorganic carbonate structures, at the basic level essentially an argument derived from high school chemistry. I commented on this in my earlier post. Living organisms can still calcify at lower pH values (and consider cold water corals in more acidic waters). When there is good long term data then arguments about the long term may start to hold water.
Assigning cause and effect to calcification observations needs some work in my opinion. An earlier poster drew attention to the paucity of data for pH measurements. I'll bet far fewer, and less precise/accurate reef calcification studies exist. The oceanic "genome" is too large a subject to more than mention here.
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"With reference to JoNova's blog on the Great Barrier Reef, it's a bit vague. Can you point me towards the data on which she based her comments."
-The comment I mentioned was from a reader and I cannot find or recall it at present, not least because JoNova and Anthony Watts have posted many times on the matter.
e.g.
http://joannenova.com.au/2012/01/scripps-blockbuster-ocean-acidification-happens-all-the-time-naturally/
http://wattsupwiththat.com/2012/11/06/earth-on-a-bad-acid-trip/
Many commentators who claim to grow corals and aquariums seem to reject outright that their corals suffer at all from having similar or greater pH changes as compared to those predicted, or from having CO2 bubbled through the tank. Some corals may be sensitive and difficult grow, but so are truffles and many orchids. Coral reefs in the tropics seem to take the role that polar bears do in the Arctic: disaster is routinely forecast for them and routinely fails to appear. What does appear is blamed on humans anyway (Crown-of-Thorns Starfish?).
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I grow weary.
I invite you to refresh you memory about pH-buffer systems . A graph showing the carbonate/bicarbonate/carbonic acid buffer system can be seen here:
http://braukaiser.com/wiki/images/d/d1/Carbonic_acid_dissociation.gif
Note how the intersection of the titration-curves cross at the sweet-spot between pH 8.0 and 8.5, which is where the oceans lie. For good reasons, it is one of the most important equilibria in biochemistry: Pushing the pH out of that “pH well” with added (or subtracted) CO2 is disfavored from a thermodynamic standpoint.
Note that nowhere here have I argued that higher CO2 levels (whatever the source) would have no effects on coral reefs, but I don't buy the argument that carbon-based life forms in the oceans are in trouble from increased CO2 that is within the historical ranges during the evolution of life, is an integral part of their biochemistry that evolved over billions(?) of years, and is constrained by the primary buffer system of the oceans.
Will forests be affected by increased CO2 in the atmosphere? Maybe. Will they suffer significant adverse effects due to “acidification” from CO2? I think not, and they don't have a surrounding ocean to buffer them from this alleged problem. But some of them may reap greater benefits than others.
The fact that your tissue culture colleagues had to get up in the middle of the night to attend their cultures suggests that they took the pH transients very seriously.
In my marine tank, the problem with CO2 was not with the addition of CO2 during the day, which was added to assist photosynthesis by algae in the coral and did not affect pH. The low pH transient problem came as respiratory CO2 accumulated at night.
Part of the porblem with reef depletion is to separate out the effects of temperature, pH from dissolved CO2, pH from acidic river runoff, sediment and human interference. As yo say, more work to be done here.
I hope you are not espousing Latimer Adler's concept that you make no inferences until all the data is in. Hypotheses generated from what data you have help guide further experimental work.
This discussion has gone on so long than "not banned yet" has written a science fiction story about it!
Time to agree to disagree?
Entropic man,
It wasn't that the pH went out of the range with the cells (the supernatant changed colour when that happened), it was other multifarious, unquantified, factors.
Yes, it is indeed often a judgement call as to when you think you have enough data to draw working conclusions. But the CO2 issue is a $$multi-trillion decision. We've come a long way with fossil fuels, and I don't want us to throw it away based on unsubstantiated arguments. If we impoverish ourselves then nobody, not even David Attenborough, will get to travel around the world and view it's wonders.
I expect we can disagree about that.
michael hart
Yes, it is indeed often a judgement call as to when you think you have enough data to draw working conclusions. But the CO2 issue is a $$multi-trillion decision.
Exactly, and its a bet based on incomplete data, like most real world decisions.
On my side of the debate are people betting that the future damage done by unmitigated climate change would be greater than the damage due to mitigation.
On the other side are people betting that the future damage due to climate change is overestimated and no mitigation is necessary.
If correct, my view is more expensive in the short term with a lower overall cost in the long term.
If correct, the sceptic view is that the economic cost of mitigation is being wasted.
We'll probably both be dead by the time this particular betting slip is taken back to the bookie.
Humanity being what it is, the reluctance to spend money will probably prevail until we're in obvious trouble.If that day never comes, you were right. If it does come, sceptic short-termism will have made things worse.
What can I say? Sensitivity is zero and not worth talking about. There is more carbon dioxide in the air today than ever before in recorded history but there has been no warming for the last 15 years. Clearly the claim that CO2 absorbs outgoing longwave radiation is false because it passes right through that thick cloud of CO2 and goes right into outer space. That is exactly what the Miskolczi theory of greenhouse gases predicts but no one has had the guts to even mention him, in both pro- and anti- warming camps. He introduced his theory [1] with a forty page highly mathematical treatise in 2007 and was immediately attacked by ignoramuses in the blogosphere. No peer reviewed articles opposing him have appeared, however, and in 2010 he found a way to prove it with existing data [2].. NOAA has a database of weather balloon observations going back to 1948 and he used it to study the absorption of infrared radiation by the atmosphere over time. And discovered that absorption had been constant for 61 years while carbon dioxide at the same time went up by 21.6 percent. This means that the addition of this substantial amount of CO2 to air had no effect whatsoever on the absorption of IR by the atmosphere. And no absorption means no greenhouse effect, case closed. All predictions of doomsday warming based on the greenhouse effect are thereby rendered invalid. And any emission control laws passed with the aid of such predictions were passed under false premises and should be voided. The greenhouse effect as defined for carbon dioxide by the Arrhenius theory is incomplete because it only looks at carbon dioxide and ignores other species of greenhouse gases. Miskolczi theory specifically includes the effect of all simultaneously absorbing greenhouse gases. The total absorption of these simultaneously absorbing gases is not the arithmetic sum of their individual absorptions. It can be shown that there exists an optimum absorption window for simultaneously absorbing gases that is maintained by the gases jointly. For earth atmosphere the gases that count are water vapor and carbon dioxide. The optical thickness in the IR of their joint absorption window is 1.87. It corresponds to 15 percent transmittance or 85 percent absorbance in the infrared. If we now add CO2 to the atmosphere it will start to absorb and the optical thickness will increase. But as soon as this happens water vapor will start to decrease and rain out until the original optical thickness is restored. This is why the absorption recorded in the NOAA database did not increase despite the addition of CO2. The reduction of atmosphereic water vapor by this process is equivalent to negative water vapor feedback, the exact opposite of what the IPCC is trying to sell us. And since addition of CO2 to atmosphere does not cause warming sensitivity becomes zero. The current lack of warming is not the only one or even the longest one on record. Satellite observations tell us that there was another period of no-warming that started in 1979 and lasted for 18 years. But if you start to look for it on non-satellite temperature curves you find that in its place is a warming in the eighties and nineties. It shows a temperature rise of a tenth of a degree per decade. In doing research for my book "What Warming?" I realized that this so-called "late twentieth century warming" was bogus and said so when the book came out. For two years nothing happened but then GISTEMP, HadCRUT, and NCDC deicided, all in unison, to stop showing this warming and adjusted their data into conformity with satellites. This was done secretly and no explanation was offered. Together this no-warming period and the current warming pause amount to 34 greenhouse-free years. It is not likely that any period before 1979 could have been a greenhouse period. It follows that any warming previously identified as greenhouse warming is simply natural warming, misidentified by over-eager scientists looking for proof of global warming.
[1] Ferenc M. Miskolczi, “Greenhouse effect in semi-transparent planetary atmospheres” Quarterly Journal of Hungarian Meteorological Service 111(1):1-40 (January-March 2007)
[2] Ferenc M. Miskolczi, “The stable stationary value of the Earth’s global average atmospheric greenhouse-gas optical thickness” E&E 21(4):243-262 (2010)