Super El Ninos Are Like London Buses – You Wait 100 Years For One To Turn Up, Then Three Arrive



I am prompted to write this post following a long and somewhat fractious conversation at Ken Rice’s blog, ATTP, in response to a guest post by Geoff Price on coral reef bleaching. As the post referred to me personally and to a blog post I wrote on Cliscep over a year ago, I decided, against my better judgement, to comment. This current essay is written as a kind of formal response to some of the less obnoxious comments on that thread at ATTP – and a few of the more obnoxious ones. It is also written as a kind of follow up to my original post on coral bleaching and my recent post on the 1876-78 super El Nino. Coral bleaching, as you may know, is still a very contentious issue ‘out there’ and has cost James Cook University professor, Peter Ridd, his job for having the audacity to question accepted wisdom that climate change was destroying the Great Barrier Reef. Ridd has raised funds to legally contest his dismissal and the case is set for 26-28 March. I wish him well.

My argument, which the denizens at ATTP steadfastly refused to grasp in its utter simplicity, expressed on that thread and in my original blog post, was that the series of mass and global coral bleaching events since the early ’80s were caused primarily by the occurrence of three super El Ninos (plus lesser ones in between) between 1982 and 2016 and not by the long term secular global warming trend since 1850. The study which I criticised in my coral bleaching article, published in 2018, authored by Hughes et al, manifestly points the finger of blame at global warming for mass coral bleaching events since 1980:

Coral bleaching occurs when stressful conditions result in the expulsion of the algal partner from the coral. Before anthropogenic climate warming, such events were relatively rare, allowing for recovery of the reef between events.

Tropical reef systems are transitioning to a new era in which the interval between recurrent bouts of coral bleaching is too short for a full recovery of mature assemblages.

As global warming has progressed, tropical sea surface temperatures are warmer now during current La Niña conditions than they were during El Niño events three decades ago. Consequently, as we transition to the Anthropocene, coral bleaching is occurring more frequently in all El Niño–Southern Oscillation phases, increasing the likelihood of annual bleaching in the coming decades.

Let’s look at that specific claim: As global warming has progressed, tropical sea surface temperatures are warmer now during current La Niña conditions than they were during El Niño events three decades ago. Here’s a graph of monthly tropical SSTs from 1979 to January 2019 according to data compiled by NOAA (solid line is running 37 month average):


The paper was published in January 2018, so one presumes by ‘current La Nina conditions’ they meant the modest La Nina conditions which prevailed at that time (the DJF Nino3.4 anomaly was -0.9C). You can clearly see the La Nina on the above graph, at the beginning of 2018. The tropics at the time were about -0.1C below the 1981-2010 mean. There were two El Ninos in the 1980s ‘three decades ago’ – 1982/83 and 1987/88. The tropics when they peaked were between 0.5C and 0.6C warmer than the 1981-2010 mean. This means that when El Ninos were in full swing during the 1980s, the tropics were warmer by about 0.6C-0.7C than they were during the early 2018 La Nina.

So it would appear that Hughes at al’s claim that current La Nina tropical SSTs are warmer than El Nino tropical SSTs three decades ago is bullshit. It just isn’t so. This false claim doesn’t exactly bode well for the quality of science on offer in the rest of the paper. But then neither does the comment that we are ‘transitioning into the Anthropocene’, on account of the fact that the Anthropocene is not an officially recognised geological epoch and that we transitioned into the Meghalayan stage of the Holocene geological epoch some 4200 years ago and are still there.

You don’t have to read much further to uncover the next instance of bullshit in this ‘scientific’ paper:

The average surface temperature of Earth has risen by close to 1°C as of the 1880s (1), and global temperatures in 2015 and 2016 were the warmest since instrumental record keeping began in the 19th century (2). Recurrent regional-scale (>1000 km) bleaching and mortality of corals is a modern phenomenon caused by anthropogenic global warming (310).

That statement is unequivocal by the authors: Recurrent regional-scale (>1000 km) bleaching and mortality of corals is a modern phenomenon caused by anthropogenic global warming (310). So naturally, I went to the two citations which presumably would demonstrate the veracity of this statement. Here is what I found:

The causes of small scale, isolated bleaching events can often be explained by particular stressors (e.g., temperature, salinity, light, sedimentation, aerial exposure and pollutants), but attempts to explain large scale bleaching events in terms of possible global change (e.g., greenhouse warming, increased UV radiation flux, deteriorating ecosystem health, or some combination of the above) have not been convincing.


This statement belies the certainty expressed by Hughes et al that modern mass bleaching is caused by global warming. The cited paper was published in 1993. I cited a study probably published in 1996 which actually demonstrated the point I was trying to make, rather than contradicted it (despite the risible efforts of ATTP’s clientele to prove otherwise) and was roundly criticised for doing so by commenters seemingly enamoured of Hughes et al. How odd. The next cited paper (published in 2010) is even better:

Coral bleaching, during which corals lose their symbiotic dinoflagellates, appears to be increasing in frequency and geographic extent, and is typically associated with abnormally high water temperatures and solar irradiance. A key question in coral reef ecology is whether local stressors reduce the coral thermal tolerance threshold, leading to increased bleaching incidence.

Our records indicate that the 1998 mass bleaching event was unprecedented in the past century, despite evidence that water temperatures and solar irradiance in the region were as high or higher mid‐century than in more recent decades. We tested the influence on coral extension rate from the interactive effects of human populations and thermal stress, calculated here with degree‐heating‐months (DHM). We find that when the effects of chronic local stressors, represented by human population, are taken into account, recent reductions in extension rate are better explained than when DHM is used as the sole predictor. Therefore, the occurrence of mass bleaching on the Mesoamerican reef in 1998 appears to stem from reduced thermal tolerance due to the synergistic impacts of chronic local stressors.

[My bold.

Noting that we may have lurkers from the depths of ATTP’s poisoned well (courtesy of yours truly according to the Williard) on this page, I shall re-iterate very clearly the significance of the above quoted passage for the benefit of those readers who may be lacking in the English comprehension department:

Hughes et al cited a study which should affirm their conclusion that global warming is causing mass bleaching events after 1980. It doesn’t. It directly contradicts that assessment in the case of of the Mesoamerican reef, which is the subject of the study, by noting that waters were warmer during the mid 20th century and the principal cause of mass bleaching in 1998 was reduced tolerance to not unprecedented heat stress caused by chronic local stressors related to the human population.

Oh dear. On ATTP, I presented an essay which makes exactly this point: that coral reef bleaching is a complex process and that there are many stressors involved. It’s just too simplistic to state that ‘global warming’ is making coral reefs disappear. Even if this is the case and the modest (I can use that term here without being accused of anthropocentrism – or anthropomorphism according to Steven Mosher) secular trend in tropical ocean warming is causing mass coral bleaching, it still cannot be viewed in isolation from local stressors. My personal opinion is that three successive super El Ninos since the beginning of the 1980’s (unprecedented in recent history) have contributed far more to mass coral bleaching than the secular global warming trend, but I shall discuss this in a follow up post, so as not to bombard readers with too much information on one post.



  1. Thanks Jaime, a timely reminder of how dishonest politically motivated scientists and their fawning ontourage can be. Whenever I read Rice’s blog I’m reminded of Roy Spencers’ comment about Neil deGrasse Tyson in ‘An Inconvenient Deception’:
    “The fact that an astronomer knows so little about the inherent uncertainties in different scientific disciplines suggests to me that our current crop of pop science icons should be largely ignored for information outside their specific areas of expertise.”
    Amen to that.

    Liked by 1 person

  2. Jaime,
    Noone claimed that global warming is the only coral reef stressor. However, global warming is clearly intensifying heatwaves and increasing their frequency. A more recent source says

    Climate change is warming oceans and causing them to remain hotter during the summer months (4). This warming is one of many threats corals are facing and is the cause of recent bleaching events (2).

    Furthermore, if global warming exceeds 2C the impact on coral reefs could be significant. One of your own links says

    If projected rates of sea warming are realized by mid to late AD 2000, i.e. a 2°C increase in high latitude coral seas, the upper thermal tolerance limits of many reef-building corals could be exceeded. Present evidence suggests that many corals would be unable to adapt physiologically or genetically to such marked and rapid temperature increases.

    Liked by 1 person

  3. Oh please Ken, give me a break! You’re quoting an advocacy essay from the Public Science Institute! There is absolutely no evidence whatsoever for the first statement. Please don’t tell me that hot weather caused by ‘climate change’ is keeping the oceans warm in summer. The second statement is entirely irrelevant to the point I am making.

    Tell me this: three massive El Ninos in the space of just 34 years and several lesser in between. What’s causing the oceans to remain hotter during summer months? The putative incremental increase in global tropical SSTs due to the steady build up of GHGs or consecutive huge pulses of extra warm water being pumped around the globe?

    Atkings also writes:

    “Most of the corals woes are coming from an increased amount of carbon dioxide in the air; check out our PSI summary on carbon dioxide for more information about carbon pollution. If you would like to reduce coral bleaching events, reduce your carbon footprint!”

    Dumb. You expect me to take seriously her opinion on what’s caused mass coral bleaching after 1980?


  4. I’ve already had this conversation on your blog Ken. It concerns the word ‘triggered’. Can you please explain to me how an incremental long term increase in global tropical SSTs can ‘trigger’ anything? The three pan tropical events noted by the authors are all coincident with El Ninos, two of those, extremely powerful El Ninos. It is far more likely therefore that those naturally occurring El Nino episodes ‘triggered’ the mass bleaching events. What of those occurring outside the El Nino windows? Did climate change ‘trigger’ those events? No, extreme weather and/or excess UV and possibly even extreme low tides were most likely the trigger needed for mass bleaching to occur. Note I am not assuming attribution here, just causation.


  5. The corals are fine, bleaching occurs when winds combine with tides and warm water to expose the tops of coral reefs.
    They recover.
    Just as with Arctic sea ice or large floating ice shelves in the Antarctic, coral in regards to climate is irrelevant.
    Just as with Polar Bears, the real scandal is how pseudoscientific people like Prof. Rice get when people try to show them reasons to not be so afraid.
    The other scandal is how people like Prof. Rice treat other scientists who speak out about their catastrophist obsessions.


  6. Jaime,
    I really don’t know how to explain this any more clearly than it’s already been explained.

    How do I treat other scientists who speak out against what you call my “catastrophist obsessions”?


  7. average global temperatures in the last 130,000 years were no more than two degrees higher than before the beginning of the industrial revolution.


  8. Ken,

    Of course neither you nor your band of merry ‘Physics’er’s at ATTP can explain it clearly, because it cannot be explained, rationally or clearly. One cannot simultaneously claim that an underlying warming trend is both triggering and causing discrete mass bleaching events which are the direct result of a complex interplay of many stressors, two globally occurring events of which have been triggered, no question about it, by naturally occurring El Ninos (1998 and 2016), two mass bleaching events of which have also been triggered by El Ninos (1982/83 and 2010). You can argue that, at the root of the problem with mass bleaching, lies global warming. However, you have presented no real evidence or any logical explanation which would give credence to that claim, other than the assertion that a modest increasing trend in global mean ocean tropical temperature somehow made corals uniquely more sensitive to thermal and other stressors post 1980, but not before, presumably because some ‘critical threshold’ was reached then. I remain deeply unconvinced.

    Liked by 1 person

  9. ATTP your defense and support of the gang attacks on dissident women are fortunately well documented.
    So now you are going to start pretending that you’re not obsessed or not obsessed with climate doom?


  10. Jaime, It looks like you have rather conclusive evidence for our position. It rather reminds me of the polar bear fiasco with the Harvey et al paper that spawned several blog posts. Harvey et al’s model of polar bear populations is clearly wrong, but the senior scientists in the field keep covering this up. They also have been very nasty in attacking their critics.

    Liked by 2 people

  11. Since my previous post appears to have become somewhat corrupted, I’ll try again.

    The infamous 2°, which is related only to some vague “pre-industrial” and never officially determined temperature was plucked out of the air (on his own admission) by Schellnhuber to give the politicians a nice easy target because politicians like something simple to keep them happy. It is of no scientific significance.

    If you don’t believe me, here is the link: His argument “that average global temperatures in the last 130,000 years were no more than two degrees higher than before the beginning of the industrial revolution” (the only bit of my original post to survive!) is also open to challenge. “Average” is a highly convenient concept in this context and no more reliable as a metric than “global average temperature”.

    If you want to know what is really happening to coral reefs, and polar bears, the way to find out is to talk to the people who actually study them and live with them in the real world, not those who draw conclusions from theoretical “models”.

    Both are doing fine and have been around longer than mankind. Live with it.


  12. “One study found that between 1985 and 2012, the reef lost an average of 50 percent of its coral cover. Starfish predation was responsible for almost half that decline, along with tropical cyclones and bleaching. The cause of the outbreak is unknown. One hypothesis is that currents are bringing nutrient-rich water from the deep sea up into the shelf, which correlates with starfish larvae growth.”

    “Humans are actively destroying the coral reef ecosystems on our earth. Reefs are overfished, bombed and poisoned, smothered by sediment, and choked by algae growing on nutrient rich sewage and fertilizer run-off. They are damaged by irresponsible tourism and are being severely stressed by the warming of the world’s oceans. Some 58 percent of the world’s reefs are reported as threatened by human activities.

    The key threats to today’s coral reefs are poverty and overpopulation. Hungry people don’t care about conservation! Coral reefs support the livelihoods of millions of people, but for how long? Human populations are increasing and today especially reefs in developing countries are seriously threatened.”

    Constructions along coasts is often done with materials removed by dredging and dynamiting from the living coral reef. Construction will often result in heavy sedimentation and siltation. Corals are not only removed for construction material but also sold as souvenirs. The coral harvesting business and urban development (for example for tourism) are some of the major threats to coral reefs.

    Deforestation, mining or farming upstream and logging in tropical forests result in large quantities of sediment and soil going into coastal waters and onto coral reefs. This dirt, silt or sand can make the water cloudy or muddy, smothering the coral which then can’t get enough light to survive.

    Slash-and-burn agriculture and the use of fertilizers are the cause for an increased nutrient flow into reef water. Human sewage also flows into coastal waters and leads to the rapid growth of algae which chokes coral polyps, cutting off their supply of light and oxygen. Trash dumped into the water can also kill coral reef life. Plastic bags are often confused with jellyfish. Turtles and some fish swallow these bags and because they can’t digest them, the bags block their digestive tracts, causing the animals to starve to death.

    With modern fishing equipment, outboard motors and refrigeration, most coral reefs within range of transportation are commercially exploited. As nearby stock becomes depleted, the fishermen have to go farther and farther away to get their catch. This leads to over fishing and larger and larger areas being depleted.

    Coral reefs are often dynamited to harvest small fish. Although it is illegal, it is practiced in many countries worldwide and is a major threat to coral reefs. This destructive fishing methods uses bottles filled with explosives made from potassium nitrate (a common fertilizer). The explosives create an underwater shock wave that ruptures fish swim bladders so they float to the surface where fisherman can easily collect them. Not only fish are killed but also other inedible reef animals. Often a certain reef area is dynamited twice, first to kill the smaller fish, then again to kill the larger predators attracted by the carnage. But the most damage is caused by the destruction of the corals by the blast, reducing the surrounding area to lifeless rubble. These areas don’t recover very fast, because larvae have a hard time to find places to hold on in this kind of rubble.

    Fisherman often use potassium cyanide and other poisons to stun and capture valuable reef fish. Divers squirt a cyanide solution from bottles directly onto fish resting on corals, killing the corals and stunning the fish. The fish often escape into crevices and the fishermen have to break apart the coral to get to their paralyzed prey. With this technique not only the fish are poisoned, but also the coral polyps and other creatures in the area. Places where cyanide was spread will first form black slime, then they will just become dead coral rock.

    When people grab, kick, walk on, or collect coral, they also contribute to coral reef destruction. Careless boating, diving, fishing, and other recreational uses of coral reef areas can cause damage to them. On some islands the resorts use dynamite to create a passage for their boats. If here are no buoys, anchors are dropped which crush or break corals. Good meaning tourists feed reef fishes, but this results in changing their feeding behavior and don’t graze on algaes anymore which can choke the corals.

    Reefs were used to test atomic bombs. Huge areas were flattened and poisoned for a long time by radioactive substances. For example the Bikini-Atoll (1946 ) was the location of 23 atmospheric atomic bomb tests from 1946 through 1958.

    Oil spilled by leakage or from ships cleaning their holds floats on the water and pollutes large areas of the ocean. Petroleum products and other chemicals dumped near coastal waters eventually find their way to the reefs and poison coral polyps and other marine life. The same amount of oil can do more damage in some areas than others. Coral reefs and mangroves are more sensitive to oil than sandy beaches or seagrass beds, intertidal zones are the most sensitive.”

    Liked by 1 person

  13. Thomas, thanks for finding that. Coral reefs are being increasingly stressed by local populations. This does not explain of course the pattern of regional and global scale mass bleaching, but, if reefs are also being subjected to periodic regional and global scale thermal stress via recurrent powerful El Ninos (or extreme weather events), then it seems not unreasonable to conclude that die-offs of already highly stressed reefs will become more widespread. If this is the case, then the attribution by scientists of coral reef mass bleaching almost exclusively to man-made global warming risks real local problems not being addressed or given the prominent attention which they deserve.


  14. I don’t know the scale of other human impacts on coral reefs. I’m tempted to gather this in with other 1% impacts, such as biodiversity, where climate alarmists say x is caused by global warming when in fact global warming does contribute, but at a 1% level.

    Liked by 1 person

  15. ATTP, we’ve gone through this before. When I am moderated, I see the post go up with the notice that it is waiting for approval. When I am banned it disappears. When the same post disappears four times, it’s a pretty good hint that I have been banned.

    Why should we not treat you the way you treat us?


  16. Amazingly it is official IPCC consensus that a mere 2 degree rise in global temperature would be able to wipe out the majority of current corals, whereas in the geological past corals survived easily TWELVE degrees during the PETM.


  17. As Jaime quotes above


    The surface temperature consists of two parts, land and ocean data. HADCRUT4 data since 1850 is as follows.

    Recent land warming is significantly greater than ocean warming. Further, the warming in the tropics is less than the global average, with the greatest warming being north of the tropics. NASA GISS have maps of trends across the globe. The default is to compare the most recent month with the 1951-1980 average.

    The largest coral reef on the planet is the Great Barrier Reef off the North West Coast of Australia. From the map the warming is -0.2 to 0.2 °C. By implication, Hughes et al are claiming that coral bleaching in the Southern Hemisphere is being caused not by local average surface temperature rise but by a global average heavily influenced by land-based northern hemisphere temperature rise.

    Liked by 1 person

  18. Manic, I tried to get this point across over at ATTP, that the tropical oceans have warmed rather less than the global average, but it didn’t seem to have much impression and I was presented with a graph of global temperature rise which indicated that land-based corals were in danger of extinction too! I did find a web page which actually quantified the rise in temperature of the tropical oceans compared to the global mean, some areas of which had increased in temperature less than 25% of the mean, but I can’t seem to find it now. The whole point is, oceans have warmed less than land, tropical oceans have warmed less than temperate oceans and some areas of the tropical oceans where corals are supposedly threatened by 1C/1.5C/2.0C of global warming have warmed relatively little since 1850.

    Hans, I believe the resilience of coral species to heat stress has been underestimated. They’re fragile, but not that fragile. The problem today is, I believe, corals are being stressed by many other things besides sudden rises in water temperature. Yet still, their ability to recover once those stressors are lessened or removed, is proving to be a bit of a surprise.

    Liked by 2 people

  19. Jaime, indeed the smart adaptability by corals lies in the fact that there is a free swimming phase during their metamorphosis. If the environment is not to their liking they move away. They are thriving in the Red Sea, which is the hottest ocean water in the world. I think the major threat to corals is diver urine and waste water from overcrowded coral islands.


  20. I decided to have a look at some of the comments at on Geoff Price’s piece at the blog “…and Then There’s Physics“. In particular this comment from Computational Astrophysics Professor Ken Rice, under his ATTP pseudonym. 

    Jaime,You can’t just keep claiming things. If you have some convincing evidence to back this up, then please show it. Ideally, something more than your own interpretation. Let’s not do science on blogs. Or, if you do want to do blog science, maybe you could make this clear (i.e., at least acknowledge what the scientific literature says, even if you disagree with it).

    This comment admits that “…and Then There’s Physics” is not a science blog, yet the very name gives the impression that it is. In my opinion this shows the discriminatory practices of so-called climate science. A statement made in the literature must be acknowledged as scientific, even though that is contradicted by the empirical evidence. But empirical evidence that is not recognized by the scientific community is considered misinformation and shouted down with vague opinions and abuse.
    An example of ATTP’s discrimination is from the reaction to Mike Risk’s comment at March 6, 2019 at 1:47 am. In particular

    But let’s not blame global warming for this. The Caribbean lost over half its coral cover before 1980. Corals on the GBR stopped growing a decade ago. Florida went from 45% cover to 4% in a decade-and bleaching had nothing to do with it.

    At 7:50am Ken replied

    Mike,It’s certainly my understanding that other human factors have also contributed to stressing coral reefs. I do think, however, that climate change is one of the biggest risks, partly because it’s essentially irreversible on human timescales.

    There is no demand for references to the claims that loss of coral reefs had nothing to do with global warming, nor for an acknowledgement of scientific beliefs to the contrary. Further, despite the loss of coral reefs currently being one of the most visible signals of climate catastrophism, it does not alter Ken’s opinions of the risks. Which seems to verify John Ridgway’s views recently expressed

    Liked by 4 people

  21. Manic,
    What an odd comment. I think that if people are going to make strong claims that overthrow some well-established scientific results, they should either provide pretty convincing evidence, or should admit that they’re just doing what I call “blog science” (i.e., posting some graphs on a blog, waving hand wildly, and claiming to have found empirical evidence in support of their supposed scientific position).

    Also, I don’t think there is much dispute that factors other than global warming are impacting coral reefs. However, global warming appears to be a key factor in why there have been a number of global/mass bleaching events and, if we continue to dump CO2 into the atmosphere, we will continue to warm, and this will continue to negatively impact coral reef systems. The impact could be very substantial if we warm by ~2C.


  22. Kevin,

    At the beginning of that comment thread, Ken Rice says this:

    Our emission of CO2 into the atmosphere is warming the planet. Hence, the primary reason why we’re seeing more heatwaves, and more intense heatwaves, is because of human-mediated climate change. One can argue about terminology, or claim that we can’t completely rule out some alternative, but this it is almost certain that it is pre-dominantly our influence.

    Then later he says this:

    This is all a bit moot, though. ENSO cycles are clearly internal cycles that really can’t play a role in long-term warming. The real reason for the increase in the frequency and intensity of heatwaves is our emissions of GHGs into the atmosphere, not internally-driven cycles.

    Then this:

    I’m not quite sure what you’re really expecting. You’re making all sorts of claims without providing any evidence and without really providing any indication that you actually really know what you’re talking about, or why it’s even all that relevant. The increase in the intensity and frequency of heatwaves really has nothing to do with internally-driven cycles.

    He never once tried to justify these assertions by reference to empirical evidence or logical arguments. It appears it’s one rule for Ken on his blog, another rule for climate alarmism sceptics. Sadly for Ken, the evidence doesn’t support his view, evidence provided by none other than Dan Smale (et al) in a 2018 study on marine heat waves, Dan being the author of the Conversation piece on marine heatwaves which I was criticising and which ATTP blindly endorsed, seemingly oblivious of the actual facts! I shall be going into this in more detail in a follow up blog post.

    Liked by 2 people

  23. Ken,
    As usual you avoid the subject at hand and come back with more waffle.
    It would be nice to know in climatology
    1. Which are the well-established scientific results.
    2. The scientific process by which these results were established.


  24. Manic,
    Why don’t you commit to spending some time actually asking more specific questions of those who work on this topic? Many (myself included) are more than happy to have discussions about this, but your questions are rather vague, so it’s not entirely clear what it is you’re trying to understand, and you don’t really give the impression of being someone who is really interested in understanding this better.

    I’ve no idea in what way you think Dan Smale’s work contradicts what I said. Here is his latest paper, the abstract of which says

    MHWs, which will probably intensify with anthropogenic climate change3, are rapidly emerging as forceful agents of disturbance with the capacity to restructure entire ecosystems and disrupt the provision of ecological goods and services in coming decades.


  25. There is no evidently that reefs hit with bleaching events die out.
    They recover.
    As they always have, unless the water is polluted with bad runoffs.
    The catastrophists skip over this part in order to keep their obsession alive.


  26. Jaime, you say:


    Now here is what Hughes et al say later on in their paper:

    “We tested the hypothesis that the number of bleaching events that have occurred so far at each location is positively related to the level of postindustrial warming of sea surface temperatures that has been experienced there (fig. S4). However, we found no significant relationship for any of the four geographic regions, consistent with each bleaching event being caused by a short-lived episode of extreme heat (12, 19, 20) that is superimposed on much smaller long-term warming trends. Hence, the long-term predictions of future average warming of sea surface temperatures (13) are also unlikely to provide an accurate projection of bleaching risk or the location of spatial refuges over the next century.”

    which seems to be rather similar to what you are saying! And rather different from what Hughes et al say earlier on, or what Ken and his cronies are saying.

    Here is that figure S4:

    Liked by 1 person

  27. Ken, you’re quite welcome to contest my observations about marine heat waves, tropical marine heat waves in particular, based upon my reading of Smale et al, 2018, in my next post.


  28. Exactly Paul, but because Hughes et al contradict their own findings via their coral reef alarmism expressed forcefully throughout the rest of the paper, because other coral alarmist scientists similarly express – with little real evidence – that climate change is responsible for mass and global bleaching events after 1980, it’s taken as a given by ATTP and others that this must be so. Crazy.

    Liked by 1 person

  29. As I understand it, the point being made in the correlation figure is that it is still the extreme heatwaves that are causing the bleaching events. Hence, there isn’t a simple link between the underlying warming trend and these bleaching events. However, the underlying trend is causing the extreme heatwaves to increase in frequency and hence the return time between events is going down. The paper says quite clearly

    Inevitably, the link between El Niño as the predominant trigger of mass bleaching (3–5) is diminishing as global warming continues (Fig. 1) and as summer temperature thresholds for bleaching are increasingly exceeded throughout all ENSO phases.


  30. There’s nothing ‘inevitable’ about it. Hughes et al snookered themselves by demonstrating that there is no statistical correlation between the frequency of bleaching events and the post industrial rise in mean SST at each location. Therefore they have to advance a hand-waving theory worthy of the best of ‘blog science’ (better even than my blog science!) that ‘extreme heating events’ (El Ninos and hot summers) will inevitably become more frequent and more extreme as ‘global warming progresses’. There’s no evidence for the former and the ‘evidence’ for the latter consists solely of extreme weather attribution ‘science’, where scientists pronounce sagely that such and such a heatwave has become X times more likely according to global climate models. I’m afraid the entire field of coral alarmism ‘science’ linked to catastrophic global warming is like a Chihuahua barking up a tree at a big brown bear who’s soon going to realise he’s a big brown bear and there really isn’t anything to be afraid of. Or perhaps more appropriately the dog will be a cross between a Shih Tzu and a Jack Russell, which, I’m reliably informed by a man I met today who has one, is called a Jack Shit.

    Liked by 1 person

  31. In a comment at my blog, Paul Matthews asked if there was any sea surface temperature data available by location. There is in the form of 5 x 5 degree gridcells in the HADSST3 database, or at least the anomalies. I have extracted the gridcells for 145-150E/10-15S and 145-150E/15-20S which cover most of the Great Barrier Reef, plus a large area besides. Looking at the annual average anomalies.

    1. There is no warming trend, unlike for the global mean.
    2. In the last 50 years the warmest year for the GBR was 1973.
    3. Year-on-year changes in anomalies are many times greater than for the global average.
    4. The major coral bleaching years were 1998, 2002, 2006 and 2016. 1998 shows a small peak in the data, but the other years are not particularly warm.

    If sudden leaps in annual sea surface temperatures anomalies lead to coral bleaching events then bleaching should have occurred in 1993, 2003, 2008 and maybe 2013. However, bleaching occurs in the summer months, so the true verification is looking at the anomalies for January, February and March.

    If you believe that conjectures ought to be verified / falsified by the data then please see my updated post.

    Liked by 3 people

  32. You could try this site.

    Sea surface temperatures in north-eastern Australia warmed, on average, by 0.12 degrees per decade since 1950. In the Coral Sea over the past century, 15 of the 20 warmest years occurred in the past 20 years.

    The sea surface temperature on the Great Barrier Reef, when averaged across the last 30 years, has increased by about 0.4 degrees, compared to records averaged across 30 years in the late 1800s.

    In 2016, sea surface temperatures on the Great Barrier Reef were the hottest ever recorded for the months of February, March and April.

    Analysis of coral cores in centuries-old corals suggests current temperatures are warmer now than over the past three centuries.


  33. aTTP, I’m genuinely interested. What follows are straight questions, and I’m not trying to be tricky.

    1. The first para you quote suggests to me an increase in 0.8 degrees (C, I assume) since 1950 in sea surface temperature in north-eastern Australia since 1950.

    2. The second para you quote suggests the sea surface temperature on the Great Barrier Reef has increased by about 0.4 degrees (C, I assume again) since the late 1800s.

    3. How do you square those two statements? The second suggests twice the warming since 1950 than since the late 1800s, unless I’m missing something.

    4. The final para you quote says analysis “in centuries-old corals suggests current temperatures are warmer now than over the past three centuries”. Do we know anything about temperatures before that?

    Thanks in anticipation.

    Liked by 1 person

  34. Mark,
    I’m not entirely sure, but I think the difference is partly because the two regions are not the same (sea surface of north-Eastern Australia versus the GBR specifically) and because by taking averages over 30 years you somewhat suppress the total warming. I don’t know if we know anything about temperatures earlier than 3 centuries ago.


  35. Ken

    I look at the direct data, whilst you look at a secondary source.
    When Paul Homewood started looking at the temperature data four years ago I was not really interested until you interjected with a hit piece. Instead of looking at the data you misdirected readers. I charted your approach and that of other bloggers.

    There is one comment that I got wrong.

    If temperature records have systematic adjustment biases then climate science loses its’ grip on reality. The climate models cease to be about understanding the real world, but conforming to people’s flawed opinions about the world.

    Climatology never had a grip on reality. The ultimate foundation is not the natural world, but mantras like “global warming is real, human-caused, serious and solvable“.
    An example of this was when you were explaining temperature homogenisation.

    What one has to do is look at the data for each site and see if there’s anything that doesn’t look right. We don’t expect the typical/average temperature at a given location at a given time of day to suddenly change. There’s no climatic reason why this should happen.

    Then in the next paragraph

    What if there isn’t a full record, or you can’t find any reason why the data may have been influenced by something non-climatic? Do you just leave it as is? Well, no, that would be silly. We don’t know of any climatic influence that can suddenly cause typical temperatures at a given location to suddenly increase or decrease. It’s much more likely that something non-climatic has influenced the data and, hence, the sensible thing to do is to adjust it to make the data continuous.

    My view is that the temperature data is of poor quality. Homogenisation is not a one-off exercise, but has been performed a number of times over the years on the same data. If people go adjusting with a view of how it the data should look like, then it is inevitable it will gradually come into line with the data. at the top level Cowton and Way 2013 and Karl et al 2015 are two examples where believers in AGW have found reasons to eliminate to anomalous pause in the temperature data post 2000. 
    Your vague and biased opinions are a liability to true science matey. 

    Liked by 1 person

  36. Ken,

    From that same web page you linked to above:

    Severe bleaching is linked to climate phenomena such as El Niño events. These typically warm sea surface temperatures around the Great Barrier Reef, resulting in sustained elevated regional temperatures.

    Extreme El Niño occurrences are projected to increase due to climate change.

    This is rubbish. No evidence that ENSO has been ‘supercharged’ by climate change and no convincing research that it will be.

    Liked by 1 person

  37. And the net effect of El Niños is to remove heat from Earth, not create it. And there is no significant change in them, just as with cyclones, floods or droughts.


  38. aTTP, thank you for the candour and speed of your response.

    I’m grateful for the candour, not least as I think it leaves a lot of questions unanswered. We’re having a proper discussion, I believe.



    Sort of, but you draw the wrong conclusion. ENSO events can lower the sea level in the Western Pacific and there is evidence that it is the lowered water levels that cause the bleaching rather than higher temperatures.

    A much deeper discussion of these events can be found here:-

    Liked by 1 person

  40. “After perusing Hughes 2017, it was clear they had been led to incorrectly embrace the prevailing bias of CO2-induced catastrophic bleaching because they failed to address the fall in sea level before and during the 2016 El Niño, and likewise they failed to address how weather created by El Niños promotes clear skies and increased solar heating. To add insult to injury, because sea level drops bleached reefs in both good water quality and bad, and bleaches reefs in both protected preserves and unprotected, Hughes 2017 presented a statistical argument that disparaged any significant value of ongoing conservation efforts to minimize bleaching by reducing nutrient loading and by protecting reefs from overfishing. By belittling or ignoring most critical factors affecting coral bleaching other than temperature, Hughes suggested our only recourse to protect reefs “ultimately requires urgent and rapid action to reduce global warming.”

    Indeed Bill. Hughes et al 2018, just like Hughes et al 2017, though even more so, is basically just an exercise in global warming propaganda. Both papers distort the truth and ignore vital facts in order to promote the misguided policy of global CO2 emissions reductions.


  41. It is difficult these days to establish exactly what the environmental conditions are for thriving hermatypic coral reefs. We all have seen video or been fortunate to see the real thing. Shallow, clear seas, bright colours, no algae except on the back reef or of the calcareous kind. It comes as somewhat of a shock to find find flourishing reefs in settings where you have been informed they definitely would not prosper. I first learned of reefs living in muddy waters of a river delta in Thailand. Later I learned about a coral reef sited in the mouth of the Amazon. Off Safaga, in the. Egyptian part of the Red Sea, not only are the waters hot, but they are more saline than anywhere else that reefs grow, but usually very turbid so that in 2 metres of water you couldn’t see the bottom.
    I find it extraordinary that reef specialists are able to pontificate about the adverse conditions that cause bleaching and coral mortality whilst still ignoring just how resilient reefs are. I have only seen a bleached reef once, so am not in a position to speculate, but what I noted was that all coral species were affected and secondly bleaching affected corals well below any possible low tide mark.
    The conclusion I reach is that I don’t understand reefs, and I suspect most others don’t. One major fact that few people consider is that that major shelf edge reefs like the GBR and that along the Yucatan coast only grew during some interglacials and were completely absent from others. And we don’t know why. Interesting isn’t it?

    Liked by 2 people

  42. LOL. Slightly off topic, but Greenpeace heads have exploded after Trump retweeted Patrick Moore’s views on climate change ‘Fake Science’. In their desperate effort to discredit climate deniers they have become full blown history deniers and claimed that Patrick Moore was not a co-founder of Greenpeace! It’s so amusing how just one Trump tweet can trigger mass hysteria and cognitive dissonance in climate alarmists.


  43. A great moment Jaime. The first time I’ve explicitly said “I agree with Trump” on Twitter.

    Very sorry you’re not still with us. Though maybe you are. People do creep back …

    Can’t say who that is of course. Physicist and Silicon Valley venture capitalist Eric Weinstein is rightly highlighting the censorship problem more generally eg this today.

    Liked by 1 person

  44. I have taken a further look at the data that for increasing coral bleaching on the GBR being the result of heat stress, whether in the form of actual average surface temperature rise, or more extreme heatwaves.

    One of the unspoken issue is what part of the massively increased observations of coral bleaching is due to increase in observations, and what part is due to an actual increase in coral bleaching. I came across a chart of mass coral mortalities produced in 1993. This has similarities to the EM-DAT database used in the IPPR report. Only with EM-DAT it was possible to make allowance for the observational bias over time by looking at recorded disaster deaths. I am not sure how to control for observational bias in coral bleaching observations.

    Liked by 1 person

  45. I had a further look at another HADSST3 gridcell, this time corresponding to the southern end of the Great Barrier Reef. It showed slight warming in the late 1990s of less than 0.5C, unlike the north and middle why show no warming since the 1980s. Major coral bleaching occurred in the southern end of GBR in 1998, 2002, 2016 and 2017, but in the north was on bleaching was less in 1998 and 2002. Support for the theory of heat stress causing increased bleaching?
    The problem is that heat stress events occur in the summer. For the summer months only, the situation is reversed. Summer temperatures have increased in the northern GBR (where it was a little warmer to start off with) but there has been no sign of an increase in the south. Here are the couple of charts I produced.

    Liked by 1 person

  46. Manic, thanks, another thought-provoking post which raises important questions about coral bleaching along the GBR. It occurred to me also that there might be some bias in observations of bleaching over the entire period (1870-2016). It seems fairly obvious that monitoring of coral reefs would have been very patchy the further one goes back in time, especially on a global scale.

    For instance, it would be instructive to know the scale and frequency of bleaching events around 1876-78, the only recorded super El Nino prior to the 1980s. There doesn’t seem to be much info though and the only comparison between 1876-78 and late 20th century events re. coral bleaching I can find is the number of DHWs – calculated to be much less in the late 1870s compared to the latter period, therefore presumably much less coral bleaching in 1876-78, but no direct observations AFAIC to back this assumption up.

    The Global Coral Reef Monitoring Network was only set up in 1994. As you point out though, quantifying this bias, assuming it is real, is difficult.


  47. Jaime,
    There will be a distinct lack on data from the 1870s on DHWs. Even more so on the extent of coral bleaching as most vessels would have stuck to navigable channels through the reef.

    As an example of lack of data I have looked at the number of observations in the HADSST3 database for the 9 gridcells 140-155E and 10-25S. This is an area of around 2.5m km2, of which I guess 1.5m km2 is ocean. The monthly records per million sq km (an area twice the size of Spain) in the 1870s was about 15 or one reading every other day. Only in the late 1960s that figure rose above 100. Since the Argo floats it the reading now average 3000 per million sq km.

    In terms of the ocean, unless you had someone marooned on a coral island with the right equipments, I do not think you will get DHW data.

    Liked by 1 person

  48. Kevin, interesting. I wonder what the impetus was for the quite dramatic increase in the number of observations after 1880? Obviously, the rapid decline in observations after 1914 is very likely due to WW1.


  49. Jaime I don’t actually know why observations increased around 1860 but I suspect it was increased overall interest in the oceans around that time that led to the later voyage of the Challenger and the earlier setting up of United States Naval Observatory under Maury studying marine meteorology, winds and currents (almost certainly for strategic and commercial purposes. According to Wikipedia other nations sent observations to Maury at the Naval Observatory where they were collated.

    I doubt if there was any single reason for the increase, it was a product of a general increase in interest the science of the globe, one of the delayed benefits of the greater reach of science brought about by the industrial revolution.

    Liked by 1 person

  50. Alan, that pesky Industrial Revolution, eh? If it wasn’t for that, scientists wouldn’t need to be going around measuring sea surface temperatures in the first place!


  51. A major question is whether observed severe coral bleaching is related to global warming? After all, dying corals are replacing polar bears as the poster child of how human emissions of fossil fuels are wrecking the planet.
    Geoff Price quotes from
    Spatial and temporal patterns of mass bleaching of corals in the Anthropocene – Terry Hughes et al 2018. Science DOI: 10.1126/science.aan8048

    It is open access.
    The supplementary data figure 4 tests the relationship.

    For Australia R2 = 0.0001. You get better from two random unrelated data sets.
    The best relationship is for the West Atlantic – mostly the Caribbean. That is R2 = 0.0939. But does the downward slope imply a negative relationship?

    Liked by 1 person

  52. Jaime
    A further reason to take a look are the Supplementary materials of the Hughes paper is the Fig 2A

    Click to access aan8048_Hughes_SM.pdf

    Note that this is cumulative recorded severe bleaching events. The relative size of individual years is from the increase in that year.
    For Australasia, the three standout years are 1998, 2010 and 2016/2017. These are El Nino years, confirming your hypothesis.
    For the West Atlantic the were also an unusual number of severe bleaching events in 1995 and 2005. No El Ninos there, but 2005 saw a record number of hurricanes in the area, and 1995 also saw an unusually high number including Hurricane Andrew, the last category 5 to make landfall in the USA. Although excess heat might be the principal cause of stress in coral reefs, I am sure they might also get stressed by severe storms, with the accompanying storm surges.
    If severe storms can lead to bleaching there is a problem with observation of bleaching. Since the 1990s satellites have made twice-weekly recording of surface temperatures are 0.5 degree grids (about 50km), then comparing with the SST data to detect unusual runs of DHWs. Since 2015, a new product was launched with just 5km grids. It is then left to some intrepid scientists to go out in a boat, dive down and take samples.
    If severe storms do not have unusually high temperatures, then there will be no alerts of bleaching.

    For Australasia 2002 & 2005 there appears to be no sudden leap in bleaching events either in Fig 2A or in Fig 2B. The years that supposedly contradicts your El Nino thesis does not show up on the charts. But Geoff Price only links to a website that gives descriptions of severe years, without measurable data. However for 2002 after some bleaching was observed

    “GBRMPA implemented the world’s most comprehensive survey of coral bleaching in collaboration with AIMS, the Cooperative Research Centre for the Great Barrier Reef (CRC Reef) and the US National Oceanic and Atmospheric Administration (NOAA). ”

    2002 excess bleaching for the GBR appears to be a clear case of observation bias, rather than actual evidence.

    Liked by 1 person

  53. Having looked further at Geoff Price’s piece, I think Professor Rice has done a service by making widely available an example of the dogmatic pseudo-science supporting the conjecture that global warming is causing a rise in coral bleaching.
    For instance if observed increase in coral bleaching is as a result of global warming resulting in extreme water temperatures, there is a question of the most appropriate measure of global warming. As corals are mostly within a few meters from the surface I would think the most appropriate measure of warming would be average sea surface temperature anomalies, which measure temperatures just below the surface. Price references the increase in heat content for 0-700m.

    Even worse are the media sources of global warming causing mass bleaching. Examples

    1. A NYT article at the beginning states “large-scale coral bleaching events……were virtually unheard-of before the 1980s“, whereas later on is stated ”before 1982-3, mass bleaching events across wide areas were nonexistent.” The distinction between perceptions and reality is important when observations have improved many times in both quantity and measuring quality over the last 40 years.

    2. Evidence of global bleaching is from a gallery of pictures from around the world. No dates to show the increase.

    3. Japan has the most severe case of coral bleaching referenced at Sekisei lagoon in Okinawa, with up to 99% of the reef lost. The reference blames this on warmer temperatures. After a bit of a search I found article from the Japanese Ministry of Environment

    (C)orals in the (Sekisei) Lagoon have extensively diminished since park designation because of various reasons: terrestrial runoffs of red clay and wastewater; coral bleaching due to high water temperatures; and outbreaks of the predatory crown-of-thorns starfish (Acanthaster planci).

    4. From Florida Keys, the evidence of bleaching is about how loss of coral reefs will adversely impact the tourist industry.

    5. From the South Pacific is a April 2016 blog post, predicting that the recent high temperatures will cause bleaching.

    There are far more details in my article.


  54. Ken is up to his usual avoidance tactics on Twitter


  55. Manic, thanks for keeping this going. I tried arguing with Geoff Price last year in comments under my original post and on Twitter. I gave up in the end. He’s absolutely convinced that global warming is killing off reefs and that’s that. No amount of contrary evidence will convince him otherwise. I’m still rather puzzled why Ken chose to re-publish his ideological hit-piece over a year later.


  56. Jaime 21 Mar 19 at 5:27 pm
    You may find the Twitter exchange I had with Ken interesting. Have screen dumped in a couple of comments below. His usual evasiveness and high-level trolling is evident. Would be vaguely interesting to know his real justification for posting Price’s claptrap after a year. My guess it is to get back at you. Attacking opponents, getting off topic and pseudo-scientific waffle are the only options when you have no case to make.


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