A new study suggests that some coral reefs could be protected from bleaching by a natural ‘ocean thermostat’ that regulates sea surface temperatures in the western pacific warm pool.
The paper was published in GRL on 9th February:
GEOPHYSICAL RESEARCH LETTERS, VOL. 35, L03613, doi:10.1029/2007GL032257, 2008
Joan A. Kleypas, National Center for Atmospheric Research, Boulder, Colorado, USA
Gokhan Danabasoglu, National Center for Atmospheric Research, Boulder, Colorado, USA
Janice M. Lough, Australian Institute of Marine Science, Townsville, Queensland, Australia
Abstract:
Several negative feedback mechanisms have been proposed by others to explain the stability of maximum sea surface temperature (SST) in the western Pacific warm pool (WPWP). If these “ocean thermostat” mechanisms effectively suppress warming in the future, then coral reefs in this region should be less exposed to conditions that favor coral reef bleaching. In this study we look for regional differences in reef exposure and sensitivity to increasing SSTs by comparing reported coral reef bleaching events with observed and modeled SSTs of the last fifty years. Coral reefs within or near the WPWP have had fewer reported bleaching events relative to reefs in other regions. Analysis of SST data indicate that the warmest parts of the WPWP have warmed less than elsewhere in the tropical oceans, which supports the existence of thermostat mechanisms that act to depress warming beyond certain temperature thresholds.
The study is also reported on the BBC website: ‘Ocean thermostat can save coral’
Jen reminded me about the OLO article by Peter Ridd: ‘The Great Great Barrier Reef Swindle’
“The scientific evidence about the effect of rising water temperatures on corals is very encouraging. In the GBR, growth rates of corals have been shown to be increasing over the last 100 years, at a time when water temperatures have risen. This is not surprising as the highest growth rates for corals are found in warmer waters. Further, all the species of corals we have in the GBR are also found in the islands, such as PNG, to our north where the water temperatures are considerably hotter than in the GBR. Despite the bleaching events of 1998 and 2002, most of the corals of the GBR did not bleach and of those that did, most have fully recovered.
Of course, some corals on the Queensland coast are regularly stressed from heat, viz. the remarkable corals of Moreton Bay near Brisbane which are stressed by lack of heat in winter. A couple of degrees of global warming
would make them grow much better.”
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
Not overwhelmingly surprised to see Ridd’s ill-informed comments being quoted again, especially not on this blog. I’d like to extend an open invitation to Dr Jennifer Marohasy (or anyone else here) to provide evidence from the scientific literature that warmer waters will be holistically beneficial to corals from the Great Barrier Reef, and look forward to your response (http://www.climateshifts.org/?p=168).
Here’s my previous post on corals:
http://www.jennifermarohasy.com/blog/archives/002381.html
Perhaps OveHG can provide proof in the form of hard verifable scientific data, on this site, to show that the waters over the Great Barrier Reef have in fact warmed at all; by how much; and over what timespan?
Ove,
We can start with primary school scientific literature. Corals are found mostly in warm seas close to the equator. The hot spots in coral diversity, growth rate, calcification rate are all found close to the equator. As I have mentioned before the only regularly thermally stressed corals in Qld are in Moreton bay because it regularly gets too cold. (Marine Biology 101)
Yes you can kill corals (mostly the short lived weed species acropora etc) with short periods of hot weather, but you know better than anybody that these corals can take in different clades of zooxanthelae which protect can protect against (van Oppen et al and other work by Willis etc).
Growth rates of the large massive corals hav been shown to increase over the last 100 years, consistent with the increasing water temperature (Barnes and Lough). However I concede that there is some soon-to-be-published-work that give the opposite result.
Despite the bleaching events we have seen (most notable in 1998 and 2002), most of the reef did not bleach and most that did has almost fully recovered (see reports by GBRMPA) You know this literature.
Also, your own dire prediction in your 1998 paper (Climate change, coral bleaching and the future of the world.s coral reefs, Mar.Freshwater Res, see figure 11)
has also been shown to be spectacularly wrong. You predicted that by 2010, 50% of the corals would bleach each year (i.e exceed your artificial non varying threshold) and that by 2020 all of the coral would bleach. All we have seen since 2002 is very minor bleaching, some of which occurred due to cold weather this year. (Hoegh-Guldberg).
Of course see level rise is what we really need to reclaim the now dead reef flats that were caused by sealevel fall since 5000 b.p. (Larcombe et al.).
There is a good case for the proposition that moderate warming is a good thing. One or two degree would be ideal, any more than that too quickly is another matter.
The other unknown is the influence of CO2 concentrations on ocean pH.
Are the critical issues the “speed” of climate change, reef water chemistry (the CO2 pH issue) and what pattern of Los Ninos and Las Ninas we may receive.
Back to back events might be interesting combined with a rising temperature trend. But yes extrapolation and some speculation at this stage. General oceanic SST temperatures may also not reflect the inner reef conditions.
It is quite interesting actually looking at the SST patterns in the bleaching years assocaited with El Nino – the western Pacific SST is typically cooler in El Nino years but the specific patterns close to shore and on the reef do not necessarily follow the larger regional pattern. And I guess water conditions in the post Xmas months are critical.
I’m not really sure that warmer waters are exclusively responsible for coral bleaching. I note that the waters of NW Australia are about 31C at the moment. This is higher than that what they have been over the last couple of years plus they got there quite rapidly over the last couple of months from the winter lows.
It will therefore be interesting to see how much coral bleaching occurs there.
Tell us how much bleaching there has been this year Ove. Oh Ooove, are you there?
The high SSTs associated with coral bleaching result from extended periods of calm not unusually hot weather. Hitching bleaching to the AGW bandwagon has provided extensive research funding and recognition for what would otherwise be an unremarkable natural fluctuation of minor interest.
In December I made an extensive cruise over some 600 Km of the far northern GBR. The general condition of the reefs we visted was superb with high levels of coral cover and no observable evidence of bleaching.
The big risk in prophesy is always reality.
“Of course see level rise is what we really need to reclaim the now dead reef flats that were caused by sealevel fall since 5000 b.p.”
Can anyone else relate to this sealevel fall since 5000 b.p and explain it’s cause?
There is NO appreciable long-term warming of the GBR and a small amount of recent warming can be attributed either to preceding El Nino conditions or to variations in cloud cover. (Those graphs end at July 2007 at best so maybe the sea has cooled even further by now.)
See http://mclean.ch/climate/GBR_sea_temperature.htm for details.
Gavin,
The sealevel fall is a very well documented in the geological literature, and evidence can be seen of it all over the NQ area. Ancient raised oyster beds are one example I have worked on with my colleagues here at JCU (Pier Larcombe Bob Carter and others). My understanding is that the rise is due to the rebound of the continental plate boundary after it was inundated with water at the end of the last ice age. Corals which reached the max sealevel 5000 years ago were slowly but surely left high and dry at low spring tides.
“My understanding is that the rise is due to the rebound of the continental plate boundary after it was inundated with water at the end of the last ice age”.
Thanks Peter, now I’m intrigued.
Yes, I am aware of old sea coasts elsewhere slightly above our present day beaches but how do you know which way these changes are going compared to one another and over what time frame?
Gavin, there’s been a lot of work at the Geological Survey of Western Australia on Holocene seal levels. I know Dr Phil Playford and Bob Gozzard have both looked at recent sea levels around Perth (they are very well exposed on Rottnest Island). Last I heard there were around 3 levels in the past 8000 years. 2.4m, 1.1m and 0.5m above the present level, with the lowest level the oldest (but after the last glaciation), and the highest the youngest at between 4800 and 5900 years old. Sea level fluctuation is complicated as local changes (subsidence etc.) will overwhelm any isostatic changes. More recent studies by Bob, I believe, showed the sea level more up and down even more in that time period, so it’s very difficult to say that recent changes are soley due to rebound.
Thanks for the Graphs, John, they represent reality.
Ove has not responded to invitation to provide hard data on this site to support his case.
Why? Simply because he can’t.. Warming sea water and bleaching corals along with rising sea-levels, drowning polar bears, etc etc are all part of the great hoax of the AGW propaganda machine.
They don’t even need their own propagand media dept., when they have a compliant and willing ‘pink/green’ media to do their work for them.
In reply to Sid and John:
The most reliable information on how the conditions surrounding the Great Barrier Reef have changed comes from the work of Dr Janice Lough at the Australian Institute of Marine Science. You can find a very nice summary of this work in chapter 2 of the Vulnerability Assessment produced by Great Barrier Reef experts last year (http://www.gbrmpa.gov.au/__data/assets/pdf_file/0018/22590/chapter02-climate-scenarios.pdf). There are a number of other references that you might want to read by digging deeper. Though these changes to water temperature look small, they are large relative to the rate of change over the past 420,000 years. An analysis of this can be found in Table 1 of a recent science article which we compiled with 16 other experts (http://www.sciencemag.org/cgi/content/abstract/318/5857/1737).
Ove – you wouldn’t convince the guys here there was any risk until half the reef had karked and there a surf beach at Townsville.
The perennial arguments are that the corals have endured through many changes in geological history and have been enduring, bleaching evenst occur from time to time naturally, corals currently persist in a range of water chemistries and temperatures, water quality/chemistry varies in the inner reef already, and that the Reef looks pretty good at the moment.
I can accept we’re not there in the future yet and of course that the future might change circumstances quickly. But what does one say to the hard-liners?
In response to Peter Ridd:
Firstly, we certainly can move on from the primary school literature after noting that Moreton Bay is a marginal environment with non-reef building scleractinian communities. Enough said.
But let me give you a slightly more lengthy answer to help you understand the subtle biological issues here.
There is no question that corals vary in their sensitivity to temperature across the planet. As you mentioned, corals have different thermal thresholds depending on where you find them. In oceans that have sea temperatures that warmer on average, the corals will be better able to cope with higher temperatures (yes, that is called evolution). Therefore, corals at the southern end of the Great Barrier Reef are 2°C more sensitive to temperature than those at the northern end (the distance between them being over 2000 kilometres). Now the problem, is that these corals are genetically (and geographically) separated (most of the information that we have today suggests that corals are locally adapted at the 10-100 kilometres scale and that they don’t travel hundred even thousands of miles between generations – I can direct you to some excellent science here if you are interested) and hence are not readily available to invade the southern Great Barrier Reef if temperatures go up by 2°. Any rapid change in sea temperature therefore catches corals off-guard (if you like, they can’t move fast enough from a population point-of-view).
Secondly, in regard to your comment that Acroporids are “short lived weedy species”: this is simply not correct. If one looks at the Great Barrier Reef, Acroporids are major habitat builders. Go to the Caribbean and you find that the two main species of Acropora (Elkhorn and Staghorn) are key framework builders and have persisted since the Pleistocene. Their loss from the Caribbean over recent decades has made a fundamental change to the nature of those coral reefs.
As for corals “taking in different clades” of zooxanthellae, there is considerable scientific debate about this in the literature, and you are clearly being selective here. For a review, see Goulet (2006) “Most corals may not change their symbionts” MEPS 321:1-7 (http://www.int-res.com/abstracts/meps/v321/p1-7/). The big point these authors make is the lack of data … you need to pay more attention to the full account of scientific debates like this. The general consensus (against the optimistic “adaptive bleaching hypothesis” formulated in the literature is that corals will not take in different clades of zooxanthellae – van Oppen and Willis’s work is far from conclusive. See my response to this here http://www.climateshifts.org/?p=40 (and Van Oppen’s comments at the bottom of that link – the team that did the actually did the work don’t support your conclusions).
In regard to your comments about Porites: Good that you note that the most up-to-date literature shows the exact opposite (http://www.ingentaconnect.com/content/bsc/gcb/2008/00000014/00000003/art00007;jsessionid=eappbb51q5ke.victoria). Fair enough – sometimes we are wrong – however, you are clearly skirting around the issue of thermal thresholds of corals, and have been since we started this debate.
In regard to your comments on bleaching and damage. Before you start dragging GBRMPA into this debate, I suggest you read their overview on climate change (http://www.gbrmpa.gov.au/corp_site/key_issues/climate_change/climate_change_and_the_great_barrier_reef). From this I draw your attention to the statement ‘However, approximately five per cent of reefs in the Great Barrier Reef were severely damaged in each of the 1998 and 2002 mass coral bleaching events. Projections of future water temperatures suggest coral bleaching could become an annual event in the course of this century.” You know this literature too, including the projected increases in the severity and frequency of coral bleaching events and the ecological responses of GBR coral communities to this.
With regard to a paper I wrote almost 10 years ago. I think the best way to handle this is to say that I have not been ‘spectacularly wrong’. I don’t think the occurrence of the Caribbean bleaching event in 2005 (unprecedented and devastating) is out of line with the projections but I made in 1999. But, you are right; science necessarily evolves under the influence of more accurate modelling and an understanding of the inherent variability of the system. These have improved significantly over the past 10 years. I suggest that you also go to a number of other studies have been done since then. To understand the complex issues of adaptation, temperature change and the future risks of climate change to coral reefs, recommend that you go and read the article by Donner et al 2005 (http://www.blackwell-synergy.com/doi/abs/10.1111/j.1365-2486.2005.01073.x?cookieSet=1&journalCode=gcb).
As a final point on this issues: I don’t think I need to outline the difference year to year variability in weather and climate, as opposed to overall warming trends. It’s just plain silly to to discuss whether or not this year was cold and whether or not we had bleaching as if these single points were evidence for or against the phenomenon of climate change. It’s the overall trends that are important. Surely as a physicist, you understand the difference between signal and noise?
And now to your last points:
“Of course see level rise is what we really need to reclaim the now dead reef flats that were caused by sealevel fall since 5000 b.p. (Larcombe et al.).”
My response: You do a good job of dealing with each point individually, whilst ignoring the synergistic effects of the projected change. It’s overwhelmingly simplistic to suggest that “sea level rise is really what we need”, neglecting projected increases in ocean acidification and coral bleaching that significantly decrease survivorship of corals in the “dead reef flats”.
“There is a good case for the proposition that moderate warming is a good thing. One or two degree would be ideal, any more than that too quickly is another matter.”
My response: This is merely speculation and negates a phenomenal quantity of literature on the thermal thresholds and tolerances of corals on the GBR. It’s far too simplistic to say that “one or two degree would be ideal”, moreover, what are you defining as “quickly”? OK – given we are being evidential here – show me the refereed paper that outlines how 1-2oC will be ‘ideal’ for us.
“The other unknown is the influence of CO2 concentrations on ocean pH.”
Peter, I’m surprised that in your position you call this an “unknown”. I think that you should go and read the Royal Society of London Report on Ocean Acidification (http://royalsociety.org/displaypagedoc.asp?id=13539). I refer you also to the recent article “Coral Reefs Under Rapid Climate Change and Ocean Acidification” which should address your shortcomings in both this and the previous question (http://www.sciencemag.org/cgi/content/short/318/5857/1737).
If you know different – why don’t you write a refereed article in Science to refute this one? That is called the scientific process.
In response to Peter Ridd:
Firstly, we certainly can move on from the primary school literature after noting that Moreton Bay is a marginal environment with non-reef building scleractinian communities. Enough said.
But let me give you a slightly more lengthy answer to help you understand the subtle biological issues here.
There is no question that corals vary in their sensitivity to temperature across the planet. As you mentioned, corals have different thermal thresholds depending on where you find them. In oceans that have sea temperatures that warmer on average, the corals will be better able to cope with higher temperatures (yes, that is called evolution). Therefore, corals at the southern end of the Great Barrier Reef are 2°C more sensitive to temperature than those at the northern end (the distance between them being over 2000 kilometres). Now the problem, is that these corals are genetically (and geographically) separated (most of the information that we have today suggests that corals are locally adapted at the 10-100 kilometres scale and that they don’t travel hundred even thousands of miles between generations – I can direct you to some excellent science here if you are interested) and hence are not readily available to invade the southern Great Barrier Reef if temperatures go up by 2°. Any rapid change in sea temperature therefore catches corals off-guard (if you like, they can’t move fast enough from a population point-of-view).
Secondly, in regard to your comment that Acroporids are “short lived weedy species”: this is simply not correct. If one looks at the Great Barrier Reef, Acroporids are major habitat builders. Go to the Caribbean and you find that the two main species of Acropora (Elkhorn and Staghorn) are key framework builders and have persisted since the Pleistocene. Their loss from the Caribbean over recent decades has made a fundamental change to the nature of those coral reefs.
As for corals “taking in different clades” of zooxanthellae, there is considerable scientific debate about this in the literature, and you are clearly being selective here. For a review, see Goulet (2006) “Most corals may not change their symbionts” MEPS 321:1-7 (http://www.int-res.com/abstracts/meps/v321/p1-7/). The big point these authors make is the lack of data … you need to pay more attention to the full account of scientific debates like this. The general consensus (against the optimistic “adaptive bleaching hypothesis” formulated in the literature is that corals will not take in different clades of zooxanthellae – van Oppen and Willis’s work is far from conclusive. See my response to this here http://www.climateshifts.org/?p=40 (and Van Oppen’s comments at the bottom of that link – the team that did the actually did the work don’t support your conclusions).
In regard to your comments about Porites: Good that you note that the most up-to-date literature shows the exact opposite (http://www.ingentaconnect.com/content/bsc/gcb/2008/00000014/00000003/art00007;jsessionid=eappbb51q5ke.victoria). Fair enough – sometimes we are wrong – however, you are clearly skirting around the issue of thermal thresholds of corals, and have been since we started this debate.
In regard to your comments on bleaching and damage. Before you start dragging GBRMPA into this debate, I suggest you read their overview on climate change (http://www.gbrmpa.gov.au/corp_site/key_issues/climate_change/climate_change_and_the_great_barrier_reef). From this I draw your attention to the statement ‘However, approximately five per cent of reefs in the Great Barrier Reef were severely damaged in each of the 1998 and 2002 mass coral bleaching events. Projections of future water temperatures suggest coral bleaching could become an annual event in the course of this century.” You know this literature too, including the projected increases in the severity and frequency of coral bleaching events and the ecological responses of GBR coral communities to this.
With regard to a paper I wrote almost 10 years ago. I think the best way to handle this is to say that I have not been ‘spectacularly wrong’. I don’t think the occurrence of the Caribbean bleaching event in 2005 (unprecedented and devastating) is out of line with the projections but I made in 1999. But, you are right; science necessarily evolves under the influence of more accurate modelling and an understanding of the inherent variability of the system. These have improved significantly over the past 10 years. I suggest that you also go to a number of other studies have been done since then. To understand the complex issues of adaptation, temperature change and the future risks of climate change to coral reefs, recommend that you go and read the article by Donner et al 2005 (http://www.blackwell-synergy.com/doi/abs/10.1111/j.1365-2486.2005.01073.x?cookieSet=1&journalCode=gcb).
As a final point on this issues: I don’t think I need to outline the difference year to year variability in weather and climate, as opposed to overall warming trends. It’s just plain silly to to discuss whether or not this year was cold and whether or not we had bleaching as if these single points were evidence for or against the phenomenon of climate change. It’s the overall trends that are important. Surely as a physicist, you understand the difference between signal and noise?
And now to your last points:
“Of course see level rise is what we really need to reclaim the now dead reef flats that were caused by sealevel fall since 5000 b.p. (Larcombe et al.).”
My response: You do a good job of dealing with each point individually, whilst ignoring the synergistic effects of the projected change. It’s overwhelmingly simplistic to suggest that “sea level rise is really what we need”, neglecting projected increases in ocean acidification and coral bleaching that significantly decrease survivorship of corals in the “dead reef flats”.
“There is a good case for the proposition that moderate warming is a good thing. One or two degree would be ideal, any more than that too quickly is another matter.”
My response: This is merely speculation and negates a phenomenal quantity of literature on the thermal thresholds and tolerances of corals on the GBR. It’s far too simplistic to say that “one or two degree would be ideal”, moreover, what are you defining as “quickly”? OK – given we are being evidential here – show me the refereed paper that outlines how 1-2oC will be ‘ideal’ for us.
“The other unknown is the influence of CO2 concentrations on ocean pH.”
Peter, I’m surprised that in your position you call this an “unknown”. I think that you should go and read the Royal Society of London Report on Ocean Acidification (http://royalsociety.org/displaypagedoc.asp?id=13539). I refer you also to the recent article “Coral Reefs Under Rapid Climate Change and Ocean Acidification” which should address your shortcomings in both this and the previous question (http://www.sciencemag.org/cgi/content/short/318/5857/1737).
If you know different – why don’t you write a refereed article in Science to refute this one? That is called the scientific process.
In response to Arnost:
Corals thrive in the upper thermal limits of their environment. Coral bleaching occurs when the thermal threshold is exceeded. See this graph for Scott Reef (NW Australia) http://coralreefwatch.noaa.gov/satellite/images/current/SST_Scottreef.png showing satellite sea surface temperatures and thermal thresholds generated from NOAA data.
As I have outlined to Peter, water temperatures vary across our planet and corals are locally adapted to the temperature at which they are growing. Therefore, corals at the northern end of the Great Barrier Reef can survive at water temperatures which 2°C warmer than those seen at the southern end of the Great Barrier Reef. This is due to the fact that corals are locally adapted (probably at the 10-100 kilometres scale). So even though corals in north-west Australia by living at water temperatures of 31°C – they don’t bleach because their thermal thresholds have not been exceeded. If I were to take coral from the southern Great Barrier Reef, however, and place it up all to north-west Australia of these temperatures, they would bleach and die.
Now, you might ask why don’t corals simply evolve like this in response to global warming? The problem is one of rate. That is, the corals that have evolved to live at the higher temperatures have done so over hundreds if not thousands of years. Current rates of sea temperature change, however, are occuring at orders of magnitude higher rates than that seen over the past 420,000 years. Basically, the rate at which corals can involve the temperature change cannot keep up with the rate of sea temperature change that is being driven by global warming.
Response to Walter:
I also find your comment about scientists getting recognition and more funding as a result of this quite amusing. It sounds similar to the idea that there is a conspiracy of climate change scientists that all intent on fame, glory and funding. Science actually works the opposite way. Being the guy who has the irrefutable evidence that goes against the grain of what everyone else is thinking is the winner strategy in science. Hence, if I were able to show that global warming and its effect on natural ecosystems was wrong, I would gain more recognition, glory and funding. In fact, if you look at the profile of so-called skeptics, you will see that they are getting far more attention relative to their actual scientific credentials in the area of climate change and biology. They are clear evidence that appearing different from the crowd is the way to go. However, the problem is that don’t have the refereed and solid scientific to back up their claims.
That aside – let’s keep the discussion scientifically focused. – What exactly do you define as “not unusually hot weather”? Can you cite any literature to back up such a statement?
Further responses to Walter:
Your wrote: “In December I made an extensive cruise over some 600 Km of the far northern GBR. The general condition of the reefs we visted was superb with high levels of coral cover and no observable evidence of bleaching.”
I think in any of these spot visits to the Great Barrier Reef you’ve got to realise that there is variability in space and time with respect to the condition of coral communities across the Great Barrier Reef. I think that the best thing I can do for you is to get you to read Bruno & Selig’s excellent study ““Regional decline of coral cover in the Indo-Pacific: timing, extent, and subregional comparisons” (http://www.climateshifts.org/sciencereview/?p=3) which summarises the results of 6000 measurements of coral cover over the past 40 to 50 years. The results indicate that coral cover is sliding downwards at 1% per year, and may have doubled over the past decade.
You then said “The big risk in prophesy is always reality.”
Until you cite literature to back up your statements, I remain convinced that your “reality” is based upon your perception and that alone.
In response to Gavin:
I think that the complete scientific picture differs from your conclusion here. I think that you should read the chapter by Dr Janice Lough from the Australian Institute of Marine Science that outlines the subtleties of the changes we’ve seen over the past 100 years (http://www.gbrmpa.gov.au/__data/assets/pdf_file/0018/22590/chapter02-climate-scenarios.pdf).
Good point Luke … they’d wait until it was all over and they would still be pontificating without evidence!
In response to Ian:
Have a look at the answers above. If you are still not convinced – tell me why but please back up your points (as I have) with the appropriate scientific literature. I am not interested in your opinion or gut feeling.
The point of this blog post is that things aren’t as gloomy as alarmists try to make out.
Anyway, by what mechanism can humans manipulate sea surface temperatures predicatably or otherwise?
Regards,
King Canute
Dear Paul – Thanks for putting a rosy spin on things: I wasn’t aware that this was the point of Jennifer’s blog, but hey, next time I read about the Spectacular Scarlet Bean or the Robber Flies I shall make sure I realise that reality isn’t as gloomy as I thought it was before reading the blog!
Regards,
Ostrich
p.s. Congratulations for entirely avoiding the science in this post!
Ove,
You said “The most reliable information on how the conditions surrounding the Great Barrier Reef have changed comes from the work of Dr Janice Lough at the Australian Institute of Marine Science.”
I looked at the chapter that you referred me too and here’s what I found (in order of that chapter)
(a) the unproven hypothesis that carbon dioxide has been a significant cause of warming
(b) uses the highly dubious HadCRUT3v temperature dataset for the southern hemisphere. Why dubious? Because there’s plenty of instances of temperatures in a data cell being remarkably different to the surrounding cells and where data in the cells shifts radically over time compared to adjacent cells. (The only saving grace is that the dataset does show the Great Pacific Climate Shift – see http://mclean.ch/climate/Aust_temps_alt_view.pdf for more information)
3. The temperature data (mean? min? max?) for Queensland, like the HadCRUT3v data, seems cherry-picked for October to September. Why not use January-December or didn’t it show what the author wanted?
4. The chapter repeats the usual claim “The Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report also presents new and stronger evidence compared with the Third Assessment Report23 that ‘warming of the climate system is unequivocal’, that there is ‘very high confidence’ that this warming is the net effect of human activities since the Industrial Revolution, and that most of the observed global warming since the mid-20th century is ‘very likely’ due to the observed increases in greenhouse gas concentrations.” and obviously the author is unable to rationally assess the evidence produced by the IPCC. (see http://mclean.ch/climate/IPCC_evidence.pdf)
5. Fig 2.6, showing composite temperature profiles for 21 El Nino events and 21 La Nina events relies on the HadSST 1875-2001. What on earth makes you think that this data can be trusted back to that time? Do you know how sea temperatures were historically taken? Once per day (no min and max) via a bucket thrown over the side of the ship and maybe the water came from 1 metre below sea level or maybe 5 metres. Later the temperature came from engine intakes but ships vary in size so again maybe 1 metre below sea level and maybe 5 metres. The graphs are a joke because the data has no credibility.
6. I can’t see a source for the climate projections shown in Table 2-2. Were the the unproven models used by the IPCC or the rather poor models used by the CSIRO (see http://mclean.ch/climate/EE%2017-1_03%20McLean%20ok.pdf)
7. Figure 2.8 shows that temperatures have risen since the Great Pacific Climate Shift of 1976, which Guilderson and Schrag (details in ref given above in 2) determined was due to a reduction in upwelling cold water. The result is that the Pacific Ocean is now warmer and is biased towards El Nino events whereas it had been biased towards La Nina. This accounts very well for the observed change in temperatures. If models that are tweaked to make the CO2 emissions relate to observed temperature also ignore the shift in ENSO conditions then the output of those models is useless.
8. On page 32 I see copies of the maps from the CSIRO’s climate report from Queensland. What a shocker this report was. Look carefully and you’ll find that the CSIRO had to use different Y-axis values on what should have been a matching pair of graphs (observed & simulated historical) in order to make the results look vaguely similar. (reference given above in point 6)
9. The claims about sea level (page 41) must be treated as dubious. Church and White (2006) needs to be treated with the utmost scepticism. I have not been able to find any details about the accuracy of such estimates and I have found several instances where apparent sea level variations are caused by movement in tidal gauges (see http://mclean.ch/climate/VCS_submission.htm) Just one tidal gauge in North Queensland is cited (near Townsville) so we have no idea about any vertical seismic shifts. Even if this tidal gauge was accurate, sSea level is also driven by ENSO conditions and by wind so these would need to be precisely determined and then removed from the data.
10. Globally the pH of the oceans varies by a lot more than the 0.1 that is mentioned and it has doubtless varied over time. I suggest that you calculate the number of hydrogen ions involved in the projected shift in pH and determine the real likelihood of such a change. Given that the carbon exchanges within the oceans are poorly understood and poorly quantified (e.g. transfer into bottom water and amount stored there) I think it rather presumptuous to claim that certain marine organisms will be badly impacted and to say “By 2040 the whole GBR will [sic!] be marginal for coral reefs.”
11. Section 2.4.7 (on ENSO) is a howler. It has the audacity to claim “The instrumental ENSO record dating back to the late 19th century shows repeated occurrence of ENSO extremes. However there is no obvious trend toward more frequent El Niño or La Niña conditions…” What??? No either the author was amazingly unaware of The Great Pacific Climate Shift of 1976 or is amazingly unaware that the ENSO system is not three distinct states but a continuum. Anyone can quickly see that since 1976, conditions towards or even reaching the El Nino threshold have dominated whereas prior to that year it was La Nina that was dominating.
SUMMARY – The chapter to which you referred me contains grains of reasonable data but on the whole is loaded with false assumptions about causes, unwarranted faith in certain data sources and in climate models, and a lack of knowledge about the ENSO system and the 1976 climate shift. I probably wouldn’t give it a “pass” in the second year of a university course.
John – since those comments were not addressed to me, I won’t answer them directly. But: are you able to cite anything other than John McClean, a “Computer consultant and occasional travel photographer” as evidence? (preferably not cited in Energy and Environment, the very same journal that was cited by one of it’s authors, the very same Peter Ridd who commented above, as “third rate”)?
Thomas Moore – why don’t you stop avoiding the question and tell us the answer to:
“by what mechanism can humans manipulate sea surface temperatures predicatably or otherwise?”
The sceince here is evidence for a natural ocean thermostat that regulates SST in the WPWP.
Afterthought for Ove…
Have you not heard of the Clausius-Clapeyron equation?
According to my sources the maximum sea surface temperature is about 31 degrees and then the heat will both spread out and the uplift of warm moist air will cause surface cooling. There’s your natural thermostat.
The GBR temperature rise with negative SOI (i.e. towards El Nino) and just occasionally that means a tad over 29 C.
Any projections that put sea surface temperatures above 31 C or averages over about 28C (allowing annual range of about 5C) are very doubtful. (eg. Fig 2.12)
By the way, while looking for an example for the above I found “Land and sea surface temperatures are projected to continue to warm and sea level is projected to continue to rise during the 21st century. These projections have a high degree of certainty.” (pg 45 of the reference you gave)
Aboslute nonsense! Either several models produce similar figures (which basically means little because all could easily be wrong) or the author of this paper or the authors of whatever report the comment is based on are simply expressing their own confidence in their calculations.
Science like this does not operate on degrees of certainty!
“The Great Pacific Climate Shift of 1976”
Can anybody please explain? Was it a climate pulse?
Ove: Given I’m seeking a reliable alternative to SST data, Dr Janice Lough’s bit on SL (2.4.5) seems weak in detail.
John: Your recent Victorian Sub illustrates too well the problems with all old data. In tracking errors we need a comparison system using different references. A tide gauge standing in mud is less reliable than rows of shells buried in old coastlines.
Dear Paul,
Surely your question is rhetorical, right? You are one of Jennifer’s hatchetmen writing for a blog entitled “Politics and the Environment”, and you are asking the general audience “what mechanism can humans manipulate sea surface temperatures”? Either you are trying to set up a very, very obvious answer to which you will say AHAH! But AGW DOESNT EXIST!!! (in which case, very clever, I must applaud you on your originality), or you really are more ignorant than I first thought.
John’s on a roll. Good to see he’s back on the horse again.
The Great Pacific Shift is a load of speculative bogosity and we’ve been through that before. Maybe some of these decadal oscillations don’t even exist at all except in statistical fairy land. I mean all this nonsense is derivative of shonkadelia like Iceap trot out – which Tamino has recently sliced and diced.
http://tamino.wordpress.com/2008/02/03/exclamation-points/#more-572
Predictability of PDO – diddly squat. And more relevant for us the IPO – even less.
The fact that there is a thermal signature of warming through the North and South Pacific, North and South Atlantic and North and South Indian Ocean seems to have been overlooked in John’s critique. So we’ll call this number 12 !
Vol. 309. no. 5732, pp. 284 – 287
DOI: 10.1126/science.1112418
Penetration of Human-Induced Warming into the World’s Oceans
Tim P. Barnett,1* David W. Pierce,1 Krishna M. AchutaRao,2 Peter J. Gleckler,2 Benjamin D. Santer,2 Jonathan M. Gregory,3 Warren M. Washington4
A warming signal has penetrated into the world’s oceans over the past 40 years. The signal is complex, with a vertical structure that varies widely by ocean; it cannot be explained by natural internal climate variability or solar and volcanic forcing, but is well simulated by two anthropogenically forced climate models. We conclude that it is of human origin, a conclusion robust to observational sampling and model differences. Changes in advection combine with surface forcing to give the overall warming pattern. The implications of this study suggest that society needs to seriously consider model predictions of future climate change.
Now having said all that – I reckon the actual conditions of bleaching events seem to be a might specific – not just what the broad trends in SSTs are doing. Currents and winds all have a role. Devil’s in the details.
I reckon with these plates popping up and down and ice coming or going over millennia or two, sea temperatures and Ph changes over a decade are somewhat irrelevant in the grand scheme of things, both natural and unnatural.
Thomas – by what mechanism can humans manipulate sea surface temperatures predicatably or otherwise?
BTW – did anyone actually read the paper in detail or if your GRL subs aren’t up to date – did anyone read the BBC report on the paper down to the end? Sort of seems not in full thematic agreement with the said lead post here. But that’s just me.
Gavin – for PDO explanation have a squiz at http://en.wikipedia.org/wiki/Pacific_decadal_oscillation
Biggsy – by putting a flotilla of sampans over the reef with shiny alfoil roofs – I read it on the Internet. House prices are so dear that that’s all Gen Y will be able to afford anyway – and under Labor house interest rates will rise at least to 30%.
BBC:
The study, carried out by scientists from the US National Center for Atmospheric Research (Ncar) and the Australian Institute of Marine Science (Aims), appears to support a theory that natural processes prevent ocean sea surface temperatures exceeding 31C (88F).
“Global warming is damaging many corals,” lead author Joan Kleypas explains, “but it appears to be bypassing certain reefs that support some of the greatest diversity of life on the planet.
“In essence, reefs that are already in hot water may be more protected from warming than reefs that are not; this is rare hopeful news for these important ecosystems.”
“This year is the International Year of the Reef, and we need to go beyond the dire predictions for coral reefs and find ways to conserve them,” says Dr Kleypas.
But her Ncar colleague, Gokham Danabasoglu, warns that projections do not paint an optimistic picture.
“Computer models of Earth’s climate show that sea surface temperatures will rise substantially this century,” he says.
“Unfortunately, these future simulations show the Western Pacific Warm Pool warming at a similar rate as the surrounding areas, instead of being constrained by a thermostat.
“We don’t know if the models are simply not capturing the processes that cause the thermostat, or if global warming is happening so rapidly that it will overwhelm the thermostat.”
Luke: Must we go back to tree rings for evidence?
“A PDO signal has been reconstructed to 1661 through tree-ring chronologies” wiki
From Ove,(http://www.gbrmpa.gov.au/corp_site/key_issues/climate_change/climate_change_and_the_great_barrier_reef). From this I draw your attention to the statement ‘However, approximately five per cent of reefs in the Great Barrier Reef were severely damaged in each of the 1998 and 2002 mass coral bleaching events. Projections of future water temperatures suggest coral bleaching could become an annual event in the course of this century.”
And these projections would be the ones that extrapolate from the late 1990’s El Nino induced temperature spike. The only problem is that the temperature has not continued to spike as the projections claimed. Global temperatures, and Southern Hemisphere temps in particular, have declined for the past decade. And this current La Nina year will be no exception.
Put simply, any projections based on pre-2003 data have been rendered redundant by subsequent temp records which, by the way, include an extended El Nino event but with no associated temperature increase.
So Ove, and the GBR mafia, are in the curious position of promoting a projection based on a single part decadal spike while trying to argue that a subsequent decade of contradictory data is a bit of background clutter.
And frankly, Ove, anyone who would quote that pathetic paper by the UK Royal Society on oceanic acidity has seriously soiled their credibility.
I’m going to be too busy today to pay much attention to this blog so here’s some brief responses to “Thomas Moore” and “Luke”.
Thomas Moore – why do you lack the intellectual capability to evaluate my statements? Why do you rely only on the opinions of others, which in this case means to an opinion of the quality of a journal (rather than the papers it contains) or to the absence of an impressive title or cluster of characters after my name? Do you also not accept the word of a patent clerk or amateurs who messed around with electricity? Surely whether a scientific statement is true does not depend on the standing of the individual who makes it.
Luke – I see that like Moore you can’t do the work yourself but merely hand-over to Tamino who in fact doesn’t mention the Great Pacific Climate Shift. Why don’t you go and read Guilderson and Schrag and come back and tell us what you think? Maybe you don’t have the qualifications in any relevant subject…
You also quote Barnett et al saying “A warming signal has penetrated into the world’s oceans over the past 40 years. The signal is complex, with a vertical structure that varies widely by ocean; it cannot be explained by natural internal climate variability or solar and volcanic forcing, but is well simulated by two anthropogenically forced climate models.”
The IPCC claims that the ESNO system is internal climate variability but at the same time says it was responsible for the high temperature of 1998.
If anyone cites a climate model as proof of anything – and even more so when they claim that an anthropogenic component needed to be added – you can either stop reading or start laughing.
If a paper claims that an anthropogenic component needs to be added then there’s a huge and unproven assumption that the model was correct when it included only natural forces. Climate models are still pretty hopeless and there’s a plethora of papers and articles that say so. Take a look at the CSIRO’s efforts in the paper that I mentioned if you have doubts because it mentions several instances of big errors and it refers you to the original reports so you can check for yourself.
Why anyone would think that scientists fully understand the pattern of heat distribution is beyond me. They are still arguing over the existence of Ferrel Cell Circulation, which is notionally a mid-latitude bridge between the northern edge of Hadley Cell Circulation and Polar circulation.
CO2Science.org, 13th February:
Lough and Barnes (1997) determined annual density, linear extension and calcification rates of numerous massive Porites colonies based on data obtained from several coral cores extracted from 35 sites along Australia’s Great Barrier Reef, stretching from 9° to 23°S, which provided information about variability in coral growth there since the late 15th century. All three of the studied parameters showed a general decrease in values when progressing from the north (warmer) to the south (cooler). The data also indicated that the growth characteristics of Porites species are “highly variable,” with extension and calcification rates varying “as much as ±20-30% about the mean, both from year to year and over 10-30-year periods,” while the temporal variability of coral density was much less at ±10% about the mean, both inter-annually and over one- to three-decade periods.
Noting that their data showed frequent and extended periods of coral growth that were both above and below the long-term mean, the two researchers cautioned that “it would be unwise to rely on short-term values (say averages over less than 30 years) to assess mean conditions,” adding that it would actually be “rash to compare one year’s value with another and it would be reckless to compare individual years in different decades without analyzing the long-term trends.” In addition, their analysis of calcification rates revealed a statistically significant correlation with sea surface temperature that suggested long-term variations in Porites calcification rates on the Great Barrier Reef are driven by variations in this parameter; and using their derived relationship, they calculated that an increase in sea surface temperature from 20° to 21°C would tend to increase calcification rates by about 3.5%.
In viewing the researchers’ long-term record, it is also evident there has been a recent decline in calcification rates in this region. However, their data show that “a decline in calcification equivalent to the recent decline occurred earlier this century and much greater declines occurred in the 18th and 19th centuries.” Furthermore, analyses of annual density banding from the coral samples indicated that “the 20th century has witnessed the second highest period of above average calcification in the past 237 years.” As a result, they concluded that “the observed decline in coral growth in recent decades may be, simply, a return to more ‘normal’ conditions.”
Also studying the response of Porites corals on Australia’s Great Barrier Reef to episodes of intense warming were Hendy et al. (2003), who report it has been suggested that since certain massive corals there, some as old as 700 years, “died as a result of the 1998 bleaching event, it must have been the most severe such event to hit the Great Barrier Reef over the last seven centuries (Hoegh-Guldberg, 1999).” Examining this contention in more detail, they considered “the likelihood of observing, in cores taken from Porites colonies, past mass coral mortality events equivalent in intensity and scale to the 1998 bleaching event,” noting that “an historic record of past coral mortality events is needed to gain some perspective on current events and the impact of recent environmental change.” This exercise included the careful examination of eight long Porites cores extracted from inshore and midshelf reefs in the central Great Barrier Reef; and it indicated the presence of two hiatuses in coral skeletal growth that were accurately dated to 1782-85 and 1817. Telltale “die-off scars” were observed in only one core for each event; and contemporary historical and proxy-climate records indicated that El Niño conditions occurred at the times of both growth discontinuities, with those of 1782-83 being termed “exceptional” by Whetton and Rutherfurd (1994). Other data indicated that low salinity from river runoff was a contributor to bleaching during the 1817 event; and the three researchers note that similar environmental conditions were associated with the 1998 bleaching of the Great Barrier Reef. Together, these findings demonstrated that Porites colonies can readily recover and continue growing for centuries after a partial mortality event such as that experienced on the Great Barrier Reef in 1998.
Based on the work of Marshall and Baird (2000), who studied the bleaching responses of different coral taxa to the environmental conditions that produced the 1998 event in the Great Barrier Reef, Hendy et al. additionally calculated the probability of sampling an event of equivalent severity that may have occurred in the more distant past. The results of this effort suggested that the chance of seeing an event across all eight of the cores they examined is exceedingly unlikely, “even for one as dramatic as the 1998 bleaching event.” In fact, they calculated that “a growth discontinuity is most likely to be observed in only one of the cores in any sample population size smaller than 17 cores,” which finding suggests that such coral bleaching events may well have occurred periodically in past centuries, but that they may be difficult to detect without massive multiple-coring studies. Until such work is conducted, therefore, we will not be able to accurately assess the uniqueness of the 1998 bleaching event, although there is now solid evidence that indicates it may not have been as unusual as climate alarmists have claimed it was.
Also working in Australian waters, Webster and Davies (2003) analyzed variations in lithology and coral assemblages of long drill cores made in the northern Great Barrier Reef by the International Consortium for Great Barrier Reef Drilling (Alexander et al., 2001). One of the cores came from an inner-shelf reef (Boulder Reef) and one from an outer-shelf reef (Ribbon Reef 5) located 5 and 49 km east of Cooktown on the northeast coast of Australia, respectively, which they used to characterize the nature of the Great Barrier Reef throughout the Pleistocene. This work revealed “the repeated occurrence of similar coral assemblages in both drill cores,” which demonstrates, in the words of the two researchers, that “the Great Barrier Reef has been able to re-establish itself and produce reefs of similar composition again and again over hundreds of thousands of years, despite major environmental fluctuations (i.e. sea-level and temperature changes).”
Last of all, Linsley et al. (2000) retrieved a 3.5-meter core of continuous coral from a massive colony of Porites lutea far to the east of Australia on the southwest side of Rarotonga in the Cook Islands, from which they obtained Sr/Ca ratios on 1-mm-interval sections spanning the entire core (representing 271 years of growth), as well as δ18O values at the same resolution from 1726 to 1770 and from 1950 to 1997, the latter of which they used for calibration purposes together with sea surface temperature (SST) data, ultimately constructing a long-term temperature history of the area. Interestingly, their analyses revealed the existence of a quarter-century period centered on about the year 1745 when SSTs in the vicinity of Rarotonga were at least 1.5°C warmer than they were at the end of the 20th century. This finding clearly demonstrates that corals in this region have survived sustained temperatures of a magnitude supposedly great enough to destroy them — according to typical climate-alarmist thinking — which obviously did not happen and demonstrates the incorrectness of their thinking.
In conclusion, substantial evidence indicates recent major bleaching events experienced by coral reefs of the South Pacific Ocean are not as unusual as recent observations might seem to imply, as much longer records reveal instances of similar bleachings in prior centuries. In addition, there is substantial evidence for much earlier greater-than-present sea surface temperatures that did not elicit dramatic bleaching; and when such bleaching has occurred, it typically has not spelled the end of the reefs involved, for many of them have regularly reconstructed themselves in their own prior image.
References
Alexander, I., Andres, M.S., Braithwaite, C.J.R., Braga, J.C., Davies, P.J., Elderfield, H., Gilmour, M.A., Kay, R.L., Kroon, D., McKenzie, J.A., Montaggioni, L.F., Skinner, A., Thompson, R., Vasconcelos, C., Webster, J.M. and Wilson, P.A. 2001. New constraints on the origin of the Australian Great Barrier Reef: results from an international project of deep coring. Geology 29: 483-486.
Hendy, E.J., Lough, J.M. and Gagan, M.K. 2003. Historical mortality in massive Porites from the central Great Barrier Reef, Australia: evidence for past environmental stress? Coral Reefs 22: 207-215.
Hoegh-Guldberg, O. 1999. Climate change, coral bleaching and the future of the world’s coral reefs. Marine and Freshwater Research 50: 839-866.
Linsley, B.K., Wellington, G.M. and Schrag, D.P. 2000. Decadal sea surface temperature variability in the subtropical South Pacific from 1726 to 1997 A.D. Science 290: 1145-1148.
Lough, J.M. and Barnes, D.J. 1997. Several centuries of variation in skeletal extension, density and calcification in massive Porites colonies from the Great Barrier Reef: A proxy for seawater temperature and a background of variability against which to identify unnatural change. Journal of Experimental and Marine Biology and Ecology 211: 29-67.
Marshall, P.A. and Baird, A.H. 2000. Bleaching of corals in the Great Barrier Reef: differential susceptibilities among taxa. Coral Reefs 19: 155-163.
Webster, J.M. and Davies, P.J. 2003. Coral variation in two deep drill cores: significance for the Pleistocene development of the Great Barrier Reef. Sedimentary Geology 159: 61-80.
Whetton, P. and Rutherfurd, I. 1994. Historical ENSO teleconnections in the eastern hemisphere. Climatic Change 28: 221-253.
Come off it John – go and read Barnett – stop the obfuscatory nonsense – you can’t explain the profile in ALL oceans by natural forcings alone. Do youself a favour and read it which you clearly have not done.
And don’t start the qualifications stuff again or we’ll have to remind you appear to have ZERO qualifications in this field despite happily letting various press articles suggest you as having such. Correct me if I’m misinformed. And if you are a great Australian Climate Data Analyst you don’t need David Jones to do your analysis for you. You should be telling us and publishing (and somewhere other than E&E pls).
As for “The IPCC claims that the ESNO system is internal climate variability but at the same time says it was responsible for the high temperature of 1998.” – yes – so?
And how is the photography and COBOL going?
Ove,
No AGW conspiracy is suggested, just herd instinct and influence of funding and recognition.
The warmest coastal air temperatures in the GBR region(>40°C)come from winds off the inland. These are short lived and do not cause SSTs and bleaching events. Extended calms are necessary for bleaching. Regional wind and temperature records are readily available and you can easily find them if you want verification.
My recent observations on the northern GBR are indeed only spot checks. Do you have conflicting evidence?
The reef surveys you refer to are overwhelmingly coastal. Many were conducted to assess local impacts or bleaching from the 1998 El Niño. More recent surveys showing extensive recovery from the bleaching were not included. They are not representative of oceanic reefs and not indicative of damage from climate change.
My comments are based largely on direct observations not citing from literature.
This is a truly fascinating debate (although some of the lines of discussion are a tad hard to following and I still have no idea what “the Clausius-Clapeyron equation” is, which perhaps disqualifies me from saying anything more).
Walter Starck said: “The reef surveys you refer to are overwhelmingly coastal. Many were conducted to assess local impacts or bleaching from the 1998 El Niño. More recent surveys showing extensive recovery from the bleaching were not included. They are not representative of oceanic reefs and not indicative of damage from climate change.”
Walter, assuming you are referring above to the Bruno and Selig study Ove mentioned, that is not at all the case. The analysis included 1902 independent surveys of a little over 200 reefs on the GBR. This included surveys going back to the late 1960s and up to 2003. You can actually download a google plug in of all the survey sites (so you can see exactly where they are) at:
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0000711 (click on Map S1)
-Very few of the reefs were “coastal” even by GBR standards. Most were of offshore and very isolated reefs.
-None that I can think of were performed to quantify the effects of the 98 El Nino. Although Walter brings up a fair point. The studies would be biased and non-representative if they were simply single-site documentaries of local gloom and doom. Luckily, for the GBR, the AIMS folks perform a truly astounding amount of annual monitoring of reefs that were selected decades ago, so the survey reef choice is not biased by current conditions.
-The AIMS GBR data indeed contains evidence of recovery, in terms of total coral cover, of some reefs, particularly on the southern GBR, but from what I understand, this is mostly recovery from COTS outbreaks and cyclones. Local declines in coral cover (on other reefs) due to bleaching in 98 and 02 balances this out.
-Overall, the best available data indicates that the coral cover of the GBR began to decline a few decades ago. It has been more or less static for the last decade. But we think it is far below the historical baseline.
The take home point from work by Ove and many others is that even under the most conservative (optimistic) climate scenarios, the frequency and spatial extent of bleaching will expand. Nobody is predicting that corals will go extinct or that reefs will totally disappear, but we could loose a big chunk of them. Given the immense economic value of reefs, why take the risk? Reefs far surpass any other single entity (human or natural) in the Aussie economy in terms of net monetary output. So then why are conservative and financial/business types not even more hysterical about the threats to this giant ATM in the ocean than nature lovers like Ove and myself?
JB
JB,
The Bruno and Selig study is based on 2667 reef surveys of which the GBR surveys make up less than 10%. The overwhelming majority of the surveys were of coastal and inshore reefs in SE Asia which are often heavily impacted by local human activity. They are not representative of oceanic reefs or even the extensive less impacted reefs in the same region.
We may perhaps be using a different definition of “coastal”. By this term I do nor mean fringing reefs but rather reefs immediately adjacent to large land masses (i.e.within a few km.)
Like those elsewhere, GBR reefs have largely recovered from the 1998/2002 bleaching. There is no real historical baseline for coral cover on the GBR or anywhere else for that matter. Surveys earlier than 1980 are too few and scattered to be meaningful.
The economic value of the GBR has been vastly exaggerated by equating it with the total value of tourism in the region. Only about half of visitors even make a reef trip. For most of these it is a one time one day activity. The value of such reef cruises is similar to the value of commericial reef fishing.
Incidentally, the commercial fish harvest on the GBR is tiny. It is restricted to 3061 mt/annum. This is less than 1% of the conservative estimate of sustainability for reef fisheries.
None of this is meant to suggest the reef is not a wonderful natural asset or should should not be treasured. However, after some 40 years of phony claims and poor science regarding purported threats to the reef it seems past time to reserve a modicum of skepticism regarding the current ones. Already, they seem headed for the same discredit.
You ask, “why take the risk?” I ask, do we have any real choice? Do we pull the plug and collapse our own ecology committing mass suicide to perhaps avoid an unknown risk of climate change or do we do what we must do anyway and seek alternatives over coming decades as fossil fuels become scarcer? Suicide is certain. Life’s a risk. I’ll take the risk.
Walter,
“The Bruno and Selig study is based on 2667 reef surveys of which the GBR surveys make up less than 10%.”
JB’s correction: about 30% of the reefs and surveys were on the GBR.
“The overwhelming majority of the surveys were of coastal and inshore reefs in SE Asia”
The majority (~ 65%) were, but this is because a majority of the reefs in the world are coastal and inshore reefs in SE Asia.
“which are often heavily impacted by local human activity.”
This would be an argument for another day and the science on this is still developing, but it actually doesn’t look like reefs close to human activities and population centers are any worse off that isolated reefs. This is because the major regional stressors including bleaching, disease, COTS outbreaks and storms, are not influenced by local human activities.
“They are not representative of oceanic reefs”
The database did indeed include surveys of highly oceanic reefs such as those in the NW Hawaiian Islands Preserve and on the outer GBR. But it doesn’t matter-these reefs are in the same shape and suffering the same fate. Ill point you to two recent papers document coral loss on isolated reefs:
Vroom P.S., Page K.N., Kenyon J.C. & Brainard R.E. (2006) Algae-dominated reefs. American Scientist, 94, 430-437
Alling et al. 2007 Catastrophic Coral Mortality in the Remote Central Pacific Ocean: Kirabati Phoenix Islands. Atoll Research Bulletin no. 551
You can get this at: http://www.botany.hawaii.edu/faculty/duffy/arb/545-555/default.htm
“They are not representative of …. or even the extensive less impacted reefs in the same region.”
JB’s correction: Also not true, in fact a weakness of the analysis was that for several regions (not the GBR) a majority of the surveys were performed by Reef Check which instructs its survey teams to survey the most pristine reefs they can find. Thus the analysis probably underestimates coral loss and overestimates reef health in these regions.
“Like those elsewhere, GBR reefs have largely recovered from the 1998/2002 bleaching.”
Sure some reefs have recovered or are recovering (e.g., Palau) but lots of others have not (e.g., the Maldives, Belieze, the FL Keys, etc.) But that isn’t really the point. Nobody is surprised that these reefs are beginning to recover from the particular disturbances of 98 and 02, but the issue at hand is whether with anthropogenic climate change we will see more frequent and widespread disturbances that will effectively keep the system at a lower level.
“There is no real historical baseline for coral cover on the GBR or anywhere else for that matter. Surveys earlier than 1980 are too few and scattered to be meaningful.”
Understanding the historical baseline is really tricky. And the surveys do get spotty before 1982 and especially before 1970. But we also have paleo data, e.g., from coring studies that tell us something about coral cover back in the day. But yes, there is a lot of uncertainty. Big surprise.
“You ask, “why take the risk?” I ask, do we have any real choice? Do we pull the plug and collapse our own ecology committing mass suicide to perhaps avoid an unknown risk of climate change or do we do what we must do anyway and seek alternatives over coming decades as fossil fuels become scarcer? Suicide is certain. Life’s a risk. I’ll take the risk.”
I don’t follow that entire argument/rant, but it is more of a personal philosophy and tough to argue with. You can take the risk if you want, but these natural resources are “owned” by all of us. For the rest of us that aren’t nileists, we’d rather not take the risk. We wear seat belts and suntan lotion, if we are business owners we lock the doors to the store at night so nobody makes off with the goods and we change the oil in our cars. These are just simple precautions to take care of our stuff! We should be applying the same precautionary principle to the GBR and coral reefs in general.
Cheers,
John
Dear Ian,
Unfortunately, you have failed yet again to understand these projections. The 1998 spike gave us insight into what corals could and couldn’t handle. Corals dont care whether it was a spike or not! We then worked with the best climate modelers of the time (Max Planck Institute) to use their projections of the future to see if these tolerances (discovered in 1998 and in previous bleaching events) were exceeded. And guess what – they were.
By the way, if you think the Royal Society of London is a bunch of mugs, why aren’t you a member?
Best wishes,
Ove
Those who think the work by Janice Lough is subtle and hard to understand – dig into the references and email Janice. I am sure she can help you understand the issues and the work. Detecting change over decades is difficult stuff – but it is scientfically based as you will see from the supporting evidence.
Regards,
Ove
“Detecting change over decades is difficult stuff”
Well said Ove
Thanks.
John,
Many reefs are commonly subject to periodic natural devastation and recovery. Add to this local human impacts and an unquantified sample bias from surveys conducted specifically to assess reef damage. Then leave out recent recovery from the 98 bleaching. Although the Bruno and Selig study may well indicate a modest decline in coral cover there is certainly no indication this is due to climate change.
How do you propose avoiding the risk of AGW other than massive and immediate reduction in fossil fuel consumption? How do you envision doing this on a global basis without collapsing the global economy? How do you expect to force other nations to do it? Why do you ask me and other readers of this blog when we have virtually no chance of having any meaningful influence no matter what we may personally feel or do? Do you really think a purported reduction in coral cover is going to cause billions of people to voluntarily impose great hardship on themselves and those they most care about?
So all that Ove can come up with to refute hard data showing that waters over the reef are not warming….is the ramblings of a Dr Janice Lough, which resemble fables or urban myths.
“Dr Janice Lough is a Principal Research Scientist leading the Responding to Climate Change Team at the Australian Institute of Marine Science and a Partner Investigator with the ARC Centre of Excellence for Reef Studies. Trained as a climatologist at the Climate Research Unit (UK), her research interests focus on understanding the nature, causes and impacts of climate variability and climate change in tropical marine environments. She also specializes in obtaining historical perspectives on coral reefs and the significance of currently observed changes using the rich archive of proxy environmental information contained in long-lived massive coral skeletons”
http://www.coralcoe.org.au/events/webseminar/webseminar.html
“Coral reefs are the global canaries, as they are already showing rapid responses to climate change at the global scale. Scientists, managers and policy makers can use reefs to examine the effectiveness of international attempts to understand and respond to the impact of global warming”
http://www.ids.org.au/~cnevill/marineTownsvilleDeclaration2002.htm
Says Sid Scientist from Muckadilla … not “a Dr Janice Lough” but “the Dr Janice Lough” mate. Dr Lough to you though. So how is your zooanthellae research going Dr Sid?
Walter – not sure how I can help further if you think peer-reviewed science is bunk but don’t have anything to refute it with. You need to back up what you say with something more than your gut feelings and sporadic accounts of great diving trips!
Ove,
This discussion is not about the pros and cons of peer review but about misrepresentation of the Bruno and Selig study as supporting the assertion of climate change being responsible for a purported decline in reef condition.
As for diving, it is now a multi-billion dollar global industry that embodies a much more extensive and intensive contact with reef conditions than does the surveys you cite. It is highly sensitive to reef conditions. The dive tour companies and opinion leaders in the industry have the world to choose from and extensive global experience to draw upon. They are not reporting the global decline you assert.
On the one hand we have a small group of office based academics whose funding and reputation rests upon research into purported reef threats. They claim to be experts but as a group have a lengthy track record of failed predictions. They claim the situation is dire and more money is needed for research, please!
On the other hand is a much larger group with widespread long term daily contact with reefs. Their economic well being is strongly influenced by discriminating customers with a global range of choice. As a group they say their reefs are great. Their veracity is directly tested by millions of customers who come and see for themselves. Their experiences flood the Internet with accounts and photos.
I draw upon both sources as well as some 50 years of my own extensive and intensive observations. I recognise limitations in all three sources but on the whole am less impressed by the self proclaimed experts than you appear to be.
Perhaps I’m too biased by repeated past experience with experts and observations that refute ever changing current theory. Only one thing seems certain. A drastric cut to fossil fuel use seems highly unlikely anytime soon and AGW theory will almost certainly be fully tested.
The future is rarely as good as we hope or as bad as we fear. Mostly it is what we didn’t expect at all.
How many more years of global cooling and no widespread bleaching will be required before a new reef threat has to be found?
hello Dear
I am student of environment pollution in Ms.C in Iran i want to selec py teisis to analys heavy metal on the coral reef in south of Iran in Persian gulf . but i havnot method for this and iran didnt work and experience a bout them can you help me and introduce a good method and guid me or send me agood article similary that worked in other place
best regard
sharifan