Why did physicist Dr. Ridd conclude that corals thrive in warmer water and will flourish as global warming increases?

The above question appeared on Quora and the responses are instructive.  The first commenter, Hirsekorn, started out with an incorrect "ad hominem" assertion about Dr. Ridd's academic background.  I quote from Ridd's page at his university: 

"Peter Ridd is a geophysicist with the following interests: coastal oceanography, the effects of sediments on coral reefs, instrument development, geophysical sensing of the earth, past and future climates, atmospheric modelling. In addition with his group in the Marine Geophysics Laboratory "

So Dr. Ridd's background leaves him amply qualified to speak on reef problems.

The next point made by the same author, Hirsekorn, is that individual corals differ in the optimal temperature of the waters surrounding them.  That is undoubtedly true but it offers no scale for that effect.  The acceptable range of temperature could be large and it could differ for individual corals.  And in fact it does, as we see here

So the comments by Hirsekorn have no merit whatever and, as such, are of the standard we have come to expect from Warmists defending their addled theory.

The second comment, by Reiner, is well informed, extensive and perfectly correct.  In particular, it has now been shown that sea level variations in recent times have been the major cause of coral bleaching.  I was unaware that Peter Ridd had predicted that some years back so he is revealed as a good scientist:  One whose theories are borne out by reality

The two original Quora comments below:


Answer by Alex Hirsekorn, lifetime seashore aficionado:

Assuming that you’re referring to Prof. Peter Ridd of James Cook Univ. I would guess that he reached such a conclusion because he is not a biologist but a geophysicist that apparently doesn’t talk to biologists very much.

There are something like 1,000 species of "reef building" coral worldwide and if you plot them by geographic location versus species you will see that they have definite preferences regarding temperature. Looking a bit more carefully will demonstrate that any given species’ numbers will diminish as you leave its temperature ‘sweet spot’ for waters that are either colder or warmer.

You don’t need to be a professor to understand this concept. I’m willing to give the benefit of the doubt and say he was probably misquoted; the alternative explanation is that he’s either a moron or willfully ignorant.


Comment by Bryson Reiner, studied at PhD in Biochemistry:

Peter Ridd is a marine physicist and has published multiple studies on sediments and their effect on coral reefs. Having spoken with Dr Ridd, my understanding is that he was suggesting corals do well not directly due to increased temps-but rather due to increased sea levels. From what I can recall, and my memory is admittedly foggy on this as it was over 5 years ago, that the Great Barrier Reef along the Queensland coast has suffered from declining sea levels which destroys coral. I am pretty sure he was inferring that rising sea levels as a result of a warming trend would increase coral growth-not as a direct result of temperature increase.

To professor Ridd’s credit, he is a strong advocate for reproducibility in the marine sciences and decries sensationalism in science. In particular he mentioned the inability to reproduce studies indicating changes in ocean pH as huge shifts in pH occurred with upwelling and even recent rains which caused short term changes but the studies results were not reproducible over long term. As an aside, certain corals will die in cooler temps just as some may die in warmer temps.

Empirically, as an avid diver-I can attest to the fact that inshore reefs are very likely affected by run off. I've been diving at an unusually inshore reef with huge coral mounts not 20 m from shore since the early 80s which was almost inaccessible as it was on the side of a small mountain in the carribean with only 3 houses nearby and a sheer dirt road that was often washed out. The reef was healthy and vibrant until 2013 when a high end housing development went up complete with a paved road. The effect was immediate as the reef went from vibrant reds, yellows, greens and blues to dull gray. The coral closest to shore was the most affected with another swath of graying coral that went well out to 100 m from shore which I couldn't quite figure out until I saw it rain which produced a huge outflow that ran along a rock jetty as a current which ran identical to the swath of dead coral. The coral has become progressively grey with each visit being worse than the last although the most affected areas remain the ones described. Yes, pollution in petroleum products and detergents certainly have an effect on coral-but to suggest that all, or even most instances of coral bleaching are due solely to temperature change is likely not the case and has yet to be determined at best.

Additionally, there are thriving corals that survive with dramatic changes in temperature near and in the Atlantic gulfstream which shifts its location by tens of miles regularly with temperature changes greater than 20 F-it's a literal column of water where within 10 meters you'll have a 60 F reading and a 80 temp. These corals are still healthy and vivid in color with life teeming all round and withstand these temperature changes on a regular and frequent basis. To suggest less than 1 C degree of change is wiping out corals is likely an overstatement.

I'm a firm believer that coral should be protected as they serve as oceanic estuaries and are simply beautiful little wonders to observe. But I suspect we'll get much better results by investing resources in controlling run off and spills rather than trying to manage the global climate. Specific efforts targeted directly at saving our reefs and coral seem more feasible in this instance vs macromanaging daunting things like the climate which in this instance is inconclusive in the degree to which it may affect the viability of coral. I'll go a step further and guess that managing directly runoff and spills will have a more immediate and dramatic effect on coral health and sustainability than even a successful attempt to change global climate.

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