“RESEARCHERS in Australia say the growth of coral on the country’s iconic Great Barrier Reef has fallen since 1990 to its lowest rate in 400 years”, variations of this message have been repeated around the world with global warming, and the associated acidification of oceans, claimed to be the cause. 
That was at the beginning of this year, in January, and the media frenzy was based on a paper by Glenn De’ath, Janice Lough and Katrina Fabricius published in the peer-reviewed journal ‘Science’. 
Canadian statistician Steve McIntyre has recently had an opportunity to download all the data used to construct the key illustrations that suggested catastrophe.
Mr McIntyre concludes that looking at just yearly averages (above graph) there has been a general trend of increasing coral calcification rates at the Great Barrier Reef since the late 1500s.
In recent years there have been fewer measurements of coral at the Great Barrier Reef and the apparent downward spike in 2004-05 may be an artifact of the data – lack of data. 
Mr McIntyre writes:
“To see the impact of unsmoothed data, I did a simple plot of the average calcification by year over the data set. I understand that the coral data spans a considerable length and that various sorts of adjustments might be justified, but it’s never a bad idea to plot an average. Here are two plots, showing a simple average, first from 1572-2005 and then in the 20th century. Based only on the first plot, one could NOT say that even the 2004-2005 results were “unprecedented in at least 400 years” – values in 1852 were lower. So I can confirm that the values before adjustment are unprecedented since at least 1852.
Visually, this graph looks to me like calcification has been increasing over time, with a downspike in 2004-5…”
Mr McIntyre goes on to comment that there is a very high correlation (0.48) between calcification and the number of measurements available in a year. The unsmoothed data gives a very different impression … Unsmoothed, years up to 2003 were not particularly low; it’s only two years – 2004 and 2005 – that have anomalously low values.
Glenn De’ath et. al. commented on ocean acidification in the same paper in ‘Science’ but provide no data. Wei et al have recently published on the pH history of Arlington Reef, which is part of the Great Barrier Reef, and they conclude that there was a ten-year pH minimum centered at about 1935 and a shorter more variable minimum very recently. Apart from these two non-CO2-related exceptions, the majority of the data fall within a band that exhibits no long-term trend in acidification – according to Sherwood, Keith and Craig Idso writing for C02 Science. [4,5]
Notes and Links
1. Global Warming Unlikely Reason for Slow Coral Growth, by Jennifer Marohasy, January 4th, 2009
2. G. De’ath, J.M. Lough and K. Fabricius (2009) Declining Coral Calcification on the Great Barrier Reef. Science. Volumne 323, pages 116-119
3. “Unprecedented” in the past 153 Years, by Steve McIntyre on June 3rd, 2009
4. The Ocean Acidification Fiction, Volume 12, Number 22: 3 June 2009
5. Wei, G., McCulloch, M.T., Mortimer, G., Deng, W. and Xie, L. 2009. Evidence for ocean acidification in the Great Barrier Reef of Australia. Geochimica et Cosmochimica Acta 73: 2332-2346.
Click on the above graph for a better/larger view of calcification rates for the Great Barrier Reef shown simply as yearly averages.
Since there is no evidence at all that the ocean is acidifying, the AGW promoters are only clouding the issue of coral health.
If there is a coral health issue, chasing AGW gremlins will only delay or prevent finding a real answer.
Something I do not understand about the whole argument is this. Oceans are alkaline at a bit above 8 ph. Oh dear oh dear if we continue this way they will get a bit below 8. The doom and gloom people say it is becoming acid! No it’s not this means the water is getting closer to neutral. Acid means we have passed 7 ph and that is well nigh impossible.
Ian Mott says
Spot on DHMO. The work by the UK Royal Society is, and remains, complete crap.
And looking at this graph, one can only wonder which part of the term, “within the historical range of variation”, these climate morons cannot understand?
What it does show is a continuous improvement in calcification from the 1600’s along with temperatures. Could it be that coral have had no problems in adjusting to the gradual warming that has taken place as we have exited the Maunder Minimum? Could the most recent drop indicate that coral are less able to adjust to sudden 0.5C drops in temperature of the kind we have seen since 1998?
Once again, a competent statistician, “Sir Steven McIntyre” has found another skunk in the climate mafia’s back yard. Another bunch of climate spivs are exposed for extrapolating from limited data.
spangled drongo says
And what about the hundreds of desal plants bursting forth upon the scene?
Ph will be 9 before it is 7.
“Something I do not understand about the whole argument is this. Oceans are alkaline at a bit above 8 ph. Oh dear oh dear if we continue this way they will get a bit below 8. The doom and gloom people say it is becoming acid! No it’s not this means the water is getting closer to neutral. Acid means we have passed 7 ph and that is well nigh impossible.”
It’s becoming more acidic than it is. Much of the sea life is adapted to the less acidic levels. You are just arguing with yourself and don’t understand what is being claimed.
SJT….. I advise you to read Ian Plimer’s book ‘Heaven and Earth. Global Warming: The Missing Science.”
In that very interesting and well researched book you will find a chapter pertaining to Coral and “acidification” of seawater…. Your, ” Much of the sea life is adapted to the less acidic levels.”, is basically meaningless.
This is a good example of the relentless data manipulation practised by the alarmists. Looking at the graph posted here it is perfectly clear that 1. calcification is highly variable over relatively short periods of time and 2. the overall trend over the industrial age is a small increase. The only possibility of generating panic here is by ignoring everything except the few points after 2000. In the discussion on CA (link 3 above) it is claimed that data from just one or two sites is responsible for these few points, and that the longer term average for these sites is less than for all the data combined; so the dip comes about by dropping (because data is not available, not deliberate manipulation) data with higher values. But quite apart from this it is obvious from the graph presented above, without any statistical analysis, that there is no cause for concern. Levels are higher than in the pre-industrial age and the rate of change is similar to many earlier periods. But in the form the data were presented in the Science article (see Figure 2 in CA, link 3 above) the completely unnecessary smoothing removes information about the short-term variability in the data; that is, removes exactly the information you need to conclude that the recent variability they seem to show is quite normal. The second effect of the smoothing is to exaggerate the decline in the data around 2000+ to make it appear more significant and unusual (it seems they used cubic splines, which are particularly prone to this kind of artifact).
So the message is: never believe an AGW graphic until you have seen the unprocessed data.
If the acidification of sea water by CO2 absorption gives you uncertainty, you would be better advised to look at the real science (or perhaps the engineering understanding of this). Apologies to the science fraternity’s sensibilities.
CO2’s inclusion into water is the primary action of pure water (condensate) to infuse a gas within its liquid substance. This makes pure water a major sink for CO2. However, on absorbing CO2, water becomes only a weak acid (carbonic acid is only a weak acid that can only be detected by means of a sensitive electronic test and can’t be detected by a “litmus” test because the “litmus paper” contaminates the test)! Yes! It’s that sensitive!
So how is CO2 the proponent of “acidification”???
Sulphur is more believable!!!
Best regards, suricat.
Ian Mott says
There are never, ever, mere coincidences in climate alarmism. The false reporting of a limited data set is no mere error. It is a deliberate act of omission. The failure to provide the historical range of variation is also a deliberate act of omission. And the fact that it comes from the GBR branch of the scumnoscenti is proof enough for all.
These people have minds that run all information, be it fact or opinion, through an ideological filter to distinguish between “cool”, good, green/left information to be emphasised, and “uncool”, bad, straight/rightwing information to be suppressed.
We need to start demanding that these people do their job properly and deal with all information fairly. And if they cannot discharge this core obligation properly then they must be sacked. We need to burn a few effigies on these people’s front lawns so their neighbours know what sort of scum reside in their street.
Well that’s about you’d expect from a waddler like Mottsa – so we’ll add this to the estate torching, decking Goolwa residents, smacking out dept officers, crawling around the undergrowth seeing who’s lights are on. And we’re herding whales but not roos.
BUT NOW – we’re burning effigies ! Gramps medication isn’t holding is it?
Wow – you’d have to see it in print to believe it. How un-Australian can you get.
Turn off the Foxtel – and toddle (slowly) off back to the prickle patch ! Stop indulging in suburbia bitching about the neighbours.
And isn’t it amusing – if you labelled temperature instead of coral acidification on the same graph the denialist scum would say there’s a massive cooling trend – but here – there’s no trend. No doubt you all love to have your cake and eat it too. You hypocrites – you couldn’t lay straight in bed.
In any case the data sets are all archived. The analysis stands. Look forward to Maccas published rebuttal and the reply – hahahahahahahahahahaha !!
Oh that’s right – he doesn’t publish …
Walter Starck says
There are several curious unmentioned anomalies in the De’ath et al. study.
Almost all of the purported decline in calcification took place in the last year of growth in samples taken in 2004 and 2005 with the 2005 samples showing little decline in calcification in 2004.
The SSTs involved are lower on the GBR than in the Coral Triangle area where these same corals flourish. The pH in the Coral Triangle area is also lower than on the GBR.
Strangest of all, the paper was published in 2009 but the most recent samples were 2005. With all of the import accorded this study it seems inexplicable that ongoing samples were not included. Especially since De’ath et al. Are based at a marine institute right in the middle of the GBR and have easy year around access to it.
It is worth noting as well that the GBR suffered a widespread bleaching event in 2002. This was more severe in many places on the GBR than the 1998 El Niño bleaching event but the reef has subsequently recovered with surprising rapidity.
Whatever may be involved in the calcification decline reported by De’ath et al. AGW seems at best only a remote runner up.
Don’t try and spin it mate.
“Because of the imbalance of sampling intensity
over years and the desire to focus on time scales
varying from a few years to centuries, the records
were broken into two data sets for further analyses.
The 1900–2005 data set contained all 328 colonies,
whereas the 1572–2001 data set focused only on
long-term change and contained 10 long cores from
colonies that covered all or most of that period.”
And what were the EXACT conclusions.
“The data suggest that such a severe and
sudden decline in calcification is unprecedented in at least the past 400 years. Calcification
increases linearly with increasing large-scale sea surface temperature but responds nonlinearly to
annual temperature anomalies. The causes of the decline remain unknown; however, this study
suggests that increasing temperature stress and a declining saturation state of seawater aragonite
may be diminishing the ability of GBR corals to deposit calcium carbonate.”
And in the actual paper which most of the denialist goons here will not have read – this is elaborated on in detail. The results are not presented as unequivocal.
You must be kidding Luke, you couldn’t be serious.
Only someone who had never seen any coral, or had only ever seen it in the one zone, on one reef, could ever believe this cr4p.
Are these people smug twits, or just con men. The ones from AIMS I tried to give a bit of info to, back in the 80s, were too smug to know just how little they understood.
And what would a self confessed Hasbeen know about this. You frigging drongo ! Have you made any measurements yourself – or having hooned around a few reefs in your day think you know something. Piss off. Goons like you should say it to their face !
And I’ll bet dollars to doughnuts you haven’t even read the said paper – if you haven’t you’re talking through your arse
The Idiotsos have totally misrepresented the Wei at all paper as well. But what would you expect from denialist scum.
louis Hissink says
I’ve downloaded the data and confirm Steve McIntyre’s analysis.
Looking at the graph Jennifer posted above, there is a clear change in visual trend at an inflection point ~ 1875. Before that the variable increased with time, afterwards it seems to have slowed, or not changed.
To then surmise from that data catastrophic outcomes suggests a serious absence of experience in the physical sciences.
Tipping points might well be recognised in uncontrolled computer simulations, but such events are not generally observed empirically.
I suppose it all depends on one’s priorities – Money or scientific truth.
meanwhile back at the Coral Triangle:
“We have discovered reefs in great condition, supporting exquisite coral gardens and corals ranging in age from youngsters less than a couple of years old to others exceeding 1,000 years in age. We have seen damage – extensive damage – but also vigorous recovery. Yes, they have been hit hard, but they are bouncing back too.
At the outset of the expedition, I was keen to test our hypothesis that Halmahera was a gateway to the Coral Triangle from the Pacific and a key piece of the climate change puzzle.
As we suspected, the corals and fishes around Halmahera are extremely diverse. But, more than that, they are showing good reproduction, connectivity and recruitment around much of the island and strong recovery. These are key elements of resilience. But the corals also show a large range in sizes from young to old. This tells us that there is regular good recruitment and excellent prospects for recovery from damage. Some of the oldest corals we saw might even have settled in the time of Jesus, but certainly during the life of the Prophet Muhammad.
Its really sobering to think how societies have evolved and the world has changed since the time of those two great influences on the world and that there are corals around Halmahera that have lived through that time of change. It boggles the imagination.”
my appolgies – source http://www.nature.org/wherewework/asiapacific/coraltriangle/features/reflections.html
The question is how are changes in coral growth related to CO2 and AGW?
Clearly not by pH, since that has not changed.
It seems, if Luke’s indecipherable replies are an example, that AGW faith is related to magical properties believers attribute to CO2.
A sort of pseudo-scientific transubstantiation of CO2 into a vector of Gaia’s wrath.
It is always easy to know when AGW believers have no basis for their disagreement. They simply call skeptics ‘denialists’ or ‘denialist scum’.
The Dea’th paper is abit of a joke; right up there with anything Charlie Veron says or Hoegh-Guidberg predicts; the facts are;
1 No discernible acidification of the oceans;
2 No ACO2 correlated decline in coral growth
3 No correlated upward trend in ocean heat with ACO2 emissions
4 Consistent misunderstanding by alarmists of coral resilience;
After all coral has survived much warmer and colder periods. Coral is a iconic bell-wether for the alarmists but it, like all the other icons, polar bears, ice levels, sea levels etc, simply won’t play ball with the cries of doom.
“After all coral has survived much warmer and colder periods. Coral is a iconic bell-wether for the alarmists but it, like all the other icons, polar bears, ice levels, sea levels etc, simply won’t play ball with the cries of doom.”
It’s only just starting, or haven’t you read the report yet?
SJT says: “It’s only just starting, or haven’t you read the report yet?”
Which leaves me with these questions about what he is going on about:
1) Acidification impacting coral?
2) ACO2 increases impacting coral?
3) ACO2 increases increasing seat temps?
Just what is it that is just starting that will be SOOOOOOO BAD???? Oh, and so bad for what/whom?
SJT: “It’s only just starting, or haven’t you read the report yet?”
You mean the NIPCC report? The one that point by point refutes the major IPCC claims? RealClimate says “Some of us thought that the “NIPCC” report was so self-evidently nonsense that we shouldn’t even give it the benefit of any publicity. …” which does indeed suggest it’s only just starting. Even RealClimate isn’t confident that it can pretend it doesn’t exist.
Predictable that the denialist scum that infest this blog would attempt to marginalise the debate into catastrophism. So if you’re not confronted with immediate disaster on an apocalyptic scale you morons will always bung on the “so what” ruse.
So here we have a perfectly reasonable bit of work that the goons here have not read. You’re projecting your own conclusions into the paper from your own prejudices. The paper made it clear that the reason for the sharp downward spike was unclear, it did discuss the complexities of calcification rates, but did some hypothesising about causes. If you’re commenting on what you think the paper says and haven’t read the paper then you’re a twit ! But hey – most denialist scum are.
Of course ocean heat content hasn’t dropped as Coho el legalo well knows from recent paper. And the changes in ocean chemistry documented infer a small decrease in pH since 1850s.
It’s not about change – it’s about the pace of change. Cumulative impacts of various factors.
Well, yes, luke, change, quite; noone’s denying it except by inference the AGW crew; they say without mans’ influence climate would not be changing as the hockeystick purports to show; it’s only after man comes on the scene that change for the worse occurs; I think that’s an indisputable aspect of AGW theory. As for ocean heat; I don’t think so; even Levitus shows a mixed bag; fig S9;
And Loehle’s study is pretty clear-cut;
Louis Hissink says
Changing the goal posts again are we Luke? Now it’s the rate of change that is the defining issue?
spangled drongo says
“And what would a self confessed Hasbeen know about this.”
Better bein’ a “hasbeen” like Hasbeen than a “never was” like you.
“It’s not about change – it’s about the pace of change.”
Ya mean like climate sensitivity? you catch on real quick.
Loehle – another E&E publisher.
Levitus – “but the linear trend in ocean heat content remain
similar to our earlier estimate.”
The principle that we are proceeding from alkaline to acidic going through neutral on the way is really worrying. Here we have about 10 ten road deaths a year. The efforts being made to lower it pushes the figure lower every year. What if it goes to zero and then even lower and people start coming back to life? I don’t know of anyone stating we will get to 7 ph and there is much scientific opinion that such is not possible. So I think probably raising the dead is more likely.
M Ryutin says
Luke, you seem to be into fully reading reports. How about you read the whole CA piece (and comments – under Reference 3 in this post) and demolish the demolishers. Until you help me out it looks like you are defending the indefensible.
A simple question for a simple mind:
Are the oceans acidifying?
Chris Schoneveld says
Comment from: SJT June 6th, 2009 at 12:08 am
“It’s becoming more acidic than it is. Much of the sea life is adapted to the less acidic levels. You are just arguing with yourself and don’t understand what is being claimed.”
This blatant lack of understanding or knowledge of chemistry demonstrated by SJT’s remark provoked no comments from anybody.
Maybe because it is a bit pointless to educate someone who is so ignorant on the subject, so I’ll just repeat the obvious: The sea is not acidic (as you claim) but is becoming slightly less alkaline.
I pointed that out in my first post.
AGW true believers literally cannot understand that the ocean’s pH is a fairly strong base, and that there is no direct evidence at all that it is becoming less so.
There are models that infer it may be.
There is no evidence that the ocean pH of today does not support coral health just fine.
AGW is, once again, soaking up all of the air on the topic, and instead if finding out if in fact there is a coral calcification issue, and if so, what is causing it, AGW promoters are just claiming that CO2 is the cause. It is rather religious of the AGW believers. But the impact is to reduce knowledge, not to increase it.
Luke: “Predictable that the denialist scum that infest this blog would attempt to marginalise the debate into catastrophism.”
Was it 3 years ago that James Hansen of NASA said that we had only 3 years to live if we didn’t do what he said? I recall that he said that “creation” itself was under threat (that is, even cockroaches and E.coli are in danger from our evil). Could you post a link to something peer-reviewed that doesn’t say he said this, to prove your point?
“I’ll just repeat the obvious: The sea is not acidic (as you claim) but is becoming slightly less alkaline.”
I never claimed it was acidic. It is just a matter of people wilfully misinterpreting a relativistic measurement of a scale that divides it’s positive and negative regions with different names. The point is obvious and simple. If you have a liquid that is a base, and make it less basic, then it’s moving towards the acidic part of the scale. I can’t believe such a simple concept becomes the basis for a pointless and diversionary argument.
SJT, why do you bother? Comments such as yours just serve to undermine the AGW cause, IMHO. And FYI, I am firmly in the denialist camp.
Actually, if the oceans were lowering their pH (which they are not), they would be approaching neutral, not acidic. The pH would have to drop even further to reach acidic. But you actually have to have ‘evidence’ to support the claim. And you do not.
The ‘simple concept’ is that the AGW community has worn out the ‘global warming’ scam, and is hoping to sort of ease over to ocean acidification as the delusional reason to declare apocalypse.
It is a transparent, cynical move. This time, however, the AGW community is not riding on the good will they once had. People see the profiteering, the religious fervor, the falsified predictions, and they are pointing out the lie more quickly on this iteration of fear mongering.
Davidc – well you’re making the point denier – where’s YOUR citation reference !
Only the brain dead denialists would be having trouble understanding that any reasonable text on ocean acidification well discusses the current alkaline pH and and that any small drop would still leave it alkaline. (oh I forgot deniers on read blog bilge – I’m sorry).
And it’s quite apparent that the ocean pH has dropped about 0.1 since 1850.
I have found just thing fo those wishing to feel smug an pious as they save the planet!
I have read it, and I do, unlike the AGW true believers, understand that the oceans are not becoming acidic.
There. Is. No. Observational. Evidence.
Only inferrences and projections.
As I pointed out sometime ago, AGW is lowering the intelligence of scientists. If every question’s answer is ‘AGW’, then why bother to look further?
Mark P says
The idea that anthropogenic carbon dioxide emissions can noticibly acidify the oceans is the suggestion which ultimately proves how scientifically illiterate the alarmists are. Human CO2 emissions barely even register in the atmosphere so how could they possibly acidify oceans containing around 1.5 billion cubic kilometers of water? The idea is so ridiculous that it’s disturbing to think that some people actually believe it. Clearly, it’s agenda before logic as far as the alarmist mentality goes.
Utter rot Hunter – that’s why you guys are simply denialist scum
The link is interesting. It shows…..nothing much is happening. No wonder you are so ticked off.
And to read the linked studies, I love how even when they inject massive amounts of CO2, amounts that are not even realistically projected, the corals do OK.
If my religious tenets were getting knocked over like your have been, I would be tempted to be as rude and irrational as you have chosen to be.
Fear mongering is fun, but it is time to let it go, Luke. Come back to the good side. Even you can be rational and civil.
spangled drongo says
“Fear mongering is fun, but it is time to let it go, Luke. Come back to the good side. Even you can be rational and civil.”
Hunter, Yeah, but he hates it.
We should settle this with a game of cricket.
Denialist Scum v Alarmist Creeps.
Played on a crushed coral pitch using a stunned mullet for a bat and a crown of thorns for a ball.
Jen as ump and her word is final. No correspondence entered into etc.
You’d have to be a numb nuts to read that into it hunter. I’m not fearmongering – I’m calling your b/s one by one. As for rude and irrational – nah I’m civilised compared to denialist scum.
And as usual assertions with no cites. “the corals do OK” Predictable denialist style.
spangled drongo says
Done a bit of sea water testing have we Lukie?
Like around coastal acid sulphates where you can get as low as 2, or around thick seawater algae where you can get as high as 10?
I’ve been doing it for the last few years on Telstra T2 grants for coastal waterways and thats a little of my experience.
Try it sometime, you bundle of information.
I was reading from the cites of your own paper. It is the one where they ran CO2 way up and the coral slowed down, but did OK.
None of the papers show anything like a significant reduction in pH. None.
Disagreeing with someone is not the same as being disagreeable to someone.
I disagree with you, but I am not rude to you.
However, you are apparently incapable of not being rude.
That AGW true beleivers cannot avoid the pseudo-righteous sturm and drang when dealing with those who point out the problems and failures of AGW dogma is simply evidence that AGW is a social movement.
AGW is to climate science what eugenics was to evolutionary science:
A popular consensus, embraced by policy makers and scientists, and wrong.
steve from brisbane says
This is what the abstract to the Wei paper actually says, contrary to the claim by CO2 Science that it finds nothing unusual in terms of ocean acidification:
“Correlations of δ11B with δ13C during this interval indicate that the increasing trend towards ocean acidification over the past 60 years in this region is the result of enhanced dissolution of CO2 in surface waters from the rapidly increasing levels of atmospheric CO2, mainly from fossil fuel burning. This suggests that the increased levels of anthropogenic CO2 in atmosphere has already caused a significant trend towards acidification in the oceans during the past decades. Observations of surprisingly large decreases in pH across important carbonate producing regions, such as the Great Barrier Reef of Australia, raise serious concerns about the impact of Greenhouse gas emissions on coral calcification.”