[Coral-List] Evidence that ocean warming has caused most Caribbean coral loss

Lescinsky, Halard hlescinsky at otterbein.edu
Tue May 2 11:30:49 EDT 2017

As a fellow geologist I’d like to respond to Ulf’s comments and the
importance of understanding geological time.   Unfortunately, I can’t help
but lapsing into lecture mode, so it’s a bit long.   First off, he is
absolutely correct that climate has fluctuated through a series of iceages
(about every 100k) for at least the last million + years, and that during
this time there has been very little species extinction.  For example, in
the Caribbean *Pocillopora* disappears after the last (125k) ice age, as
might a columnar species of *Montastrea (Orbicella*), but mostly the fossil
evidence is that the same species existed throughout multiple iceages, and
the coral zonation and ecology seem pretty consistent.  Take home
message:  Coral
extinction is unlikely to occur due to Pleistocene-like climate change
under “natural conditions”.

This of course begs two other questions:  1.  what will the short term
effects be to coral abundance and distribution (as opposed to
extinction/survival), and 2.  Is current climate change comparable to
"natural" Pleistocene changes?

As to the immediate impacts on ecology, it is important to note that reefs
we see today were generally actively accreting only during periods of sea
level rise and not during sea level fall and therefore our record of coral
abundance and zonation in the past is mostly limited to the 10-15% of time
that sea levels were high (as they are today).  For 85-90% of the
Pleistocene we have either no record of what reefs were doing, or the reefs
existed as lowstand reefs deep under water (100m) where we have been able
to collect little ecological information.  For example there is a submerged
lowstand barrier reef along the coast of India, and many submerged reefs in
the Gulf of Mexico near Florida, but we know little about their ecology.  We
have observed range shifts in corals during warmer and colder Holocene
intervals, but that is about it.  Take home message:   We don’t have
paleoecological data to state much of anything about how reef ecology, or
coral cover abundance reacted to past climate changes.  Corals didn’t go
extinct, but our resolution of what happened for example at the onset of
warming or as temperatures cooled (sea level dropped) is simply not good
enough to answer detailed questions.  Thus the bad state that reefs are in
today may (or may not) be attributable to “normal” climate change- we don't
have the paleontological data to prove or disprove it.  Pollution would
also impact coral abundance as well, of course, but data does not require
us to rule out “normal” climate change as the cause of the species and coral
cover declines we see today.

As to the point of whether today’s climate change is of bigger magnitude
than that in the past, I’ll leave the specifics to the climate experts, but
we have all seen the Antarctic ice core data that shows that today’s CO2
levels are far above those found during the last 6 iceage cycles.  This
would seem to bespeak to a different magnitude and rate of change.  Not
that today’s change is entirely unique in the history of the earth.  We
have had much higher levels of atmospheric CO2 and we have had as rapid
rates of CO2 release at various times in the past.  High CO2 levels in
geologic time become buffered in ocean water (ex. dissolution of limestone
in the ocean sediments) and may have little impact on reefs.  Rapid rates
of CO2 rise (for example by the rapid release and oxidation of Methane
Hydrates) have occurred in the past as well.  Of key note however:  rapid
releases of CO2 are associated with massive extinctions and the demise of
reef systems.  The best example is the Paleocene-Eocene thermal maximum,
but the End Permian extinction is probably another (and even more
detrimental) case.  Take home message:  Rapid changes (such as we are
seeing now) are not unique to the present, BUT when they happened in the
past, the results were extinctions and the loss of reef ecosystems from the
rock record for hundreds of thousands to millions of years.
In summary- As a geologist I agree it is important to use the rock record
to frame our recent questions about climate change.  However, the lack of
extinction associated with glacial outburst floods, or the various other
short term rapid fluctuations that geologists have now documented since the
last glacial maximum have little direct bearing on what is happening now,
or the fate of corals over the next hundred years or so.   Geologic data
suggest that a pulse of CO2 did trigger extinctions in the past, and we
simply don’t have the coral abundance data to say exactly how well or
poorly coral did in reacting to climate change at particular times in the
past.  This is why ongoing climate change is viewed by the vast majority of
the geoscience community as a principle factor in reef demise.
Hal Lescinsky
Otterbein University

On Tue, May 2, 2017 at 8:18 AM, Ulf Erlingsson <ceo at lindorm.com> wrote:

> Richard,
> What I am saying is,
> 1) In the very recent past there were temperature changes more dramatic
> than what is predicted to happen in the coming century,
> 2) there were global transgressions more dramatic than what is predicted
> to happen in the coming century,
> 3) all now living coral species survived all of this, and they probably
> have experienced many such events.
> 4) Of course, many coral REEFS went from being barrier or fringing reefs
> to becoming submerged reefs, but so what? New species take over.
> Here is an article for you to start digging: https://www.researchgate.net/
> publication/230135618_A_jokulhlaup_from_a_Laurentian_
> captured_ice_shelf_to_the_Gulf_of_Mexico_could_have_
> caused_the_bolling_warming <https://www.researchgate.net/
> publication/230135618_A_jokulhlaup_from_a_Laurentian_
> captured_ice_shelf_to_the_Gulf_of_Mexico_could_have_
> caused_the_bolling_warming>
> The biggest upset was not to the corals, it was to the human civilizations
> that existed close to the sea. Many cities were buried, many civilizations
> went under and are only preserved in myths. What Plato writes about the
> sinking of Atlantis is with high probability based on actual events, the
> sinking of Dogger Bank in the North Sea around the year 8,200 BC as a
> result of a global transgression punctuated by a megatsunami at a critical
> time when only a low island remained. However, the western seaboard of
> Europe is full of accounts of sunken cities. Such myths abound around the
> world. Some have suggested they have to do with psychology but they don't;
> they all reflect real events. How can I be sure? Because on the island of
> Gotland that instead has risen from the sea, the creation myth talks about
> the island risking from the sea. And take the Lakota myth of the water
> monster Unktehi that blocked the river and then let out all the water. That
> is just what the inland ice sheet
>  did according to recent geological findings (around the year 14,600 BC).
> A huge flood on the Mississippi is also recorded by Native American myths
> further down river. And all of this is confirmed by geology; every ice age
> of our present ice age period (i.e. the last million years or so) has
> created a separate canyon and submarine fan in the Gulf of Mexico,
> accumulating miles of sediment (in thickness).
> What do you think the inflow of all that glacial meltwater in less than a
> year did for the corals in the Caribbean? You'd expect them all to be dead
> by now, wouldn't you? Each of those mega floods raised the global sea level
> by meters. Yet all the coral species living there naturally today survived,
> because there has been no migration over the Central American isthmus
> since. The mega floods must also have plaid havoc with the circulation in
> the Caribbean Sea. All societies founded on deltas and lowlands must have
> been wiped out (except those with enough foresight to build a boat, like
> Noah; speaking of which, the Biblical account of the deluge forms part of
> these myths that tell the story of the last mega flood: It tells us that
> the water rose by 15 cubits, i.e. around 7 meters, and that is in the realm
> of where geology says if was).
> Now, returning to the issue of why corals are dying. The coral death
> NOT YET HAPPENED. So even if the predictions are true, and even if they
> would be unprecedented (which they are clearly not), it can still not
> explain the coral decline already observed. THE ONLY REASONABLE EXPLANATION
> We don't have to point out which chemical and how it affects the cells. It
> is enough to take a geographical / geological approach and say, the last 2
> centuries the humans have released an ever larger number of completely new
> chemical species in the environment, many of which are sure to be very
> toxic to at least some species, most of which is probably still unknown.
> What goes up in the atmosphere gets mixed up in a matter of months or
> years; what goes into the surface of the ocean gets mixed up in a matter of
> decades through the gyres; and what goes into the deep ocean gets mixed up
> in a matter of millennia through the thermohaline circulation. Most of the
> North American pollution reaches the Gulf Stream, and some circulates back
> to the Caribbean, another branch goes past Europe and sinks to become new
> global bottom water, emerging in a thousand years or so in the eastern
> Pacific from where it will then bathe the Pacific corals. Remember Silent
> Spring? What happened to fresh
>  water lakes and rivers back then also happens to the ocean, it just takes
> a lot longer time, but eventually all the hens will come home to roost.
> What to do about it? Change paradigm, do as the European Union: Instead af
> allowing everything except what is banned, ban everything new until it has
> PRODUCTS. The U.S. law that allows ingredients to be secret is appalling
> and mind-boggling.
> Ulf Erlingsson
> Lindorm, Inc.
> http://lindorm.com
> > On 2017-05-02, at 06:29 , Richard Plate <richarp33 at gmail.com> wrote:
> >
> > Ulf,
> >
> > I'm unclear about what you mean by "dramatic" in this context.  Are you
> saying that we have geological records showing us climatic changes similar
> to the current changes in magnitude and rate of change that did not result
> in massive reduction of corals and other species?
> >
> > If so, could you direct me to a paper where I could read more about that
> kind of comparison?
> >
> > I'm referring to this statement:
> >
> > "The hypothesis of those who warn of climate change seems to be that the
> anthropogenic temperature changes at the present time are more dramatic
> than anything in the past, and that they will lead to consequences that are
> unique. They seem to think that past changes were never that dramatic. That
> is where I beg to differ. In what we Earth Scientists call "Recent" time,
> as late as a few hundred human generations ago, there were much larger and
> at least as dramatic changes according to the geological archive."
> >
> > Thanks for your help.
> >
> > -Richard
> >
> > On Fri, Apr 28, 2017 at 7:32 AM, Ulf Erlingsson <ceo at lindorm.com
> <mailto:ceo at lindorm.com>> wrote:
> > Doug,
> >
> > The hypothesis of those who warn of climate change seems to be that the
> anthropogenic temperature changes at the present time are more dramatic
> than anything in the past, and that they will lead to consequences that are
> unique. They seem to think that past changes were never that dramatic. That
> is where I beg to differ. In what we Earth Scientists call "Recent" time,
> as late as a few hundred human generations ago, there were much larger and
> at least as dramatic changes according to the geological archive. And if we
> look at absolute temperatures, then it is disingenuous to compare to the
> 19th or 20th century as a baseline, since that was the peak of the Little
> Ice Age.
> >
> > Furthermore, after the existence of an Ice Age covering northern Europe
> (Germany, Poland, Holland) had been convincingly shown by Swedish geologist
> Otto Torell in the 1860's, and it later was understood that there had been
> several, combined with the evidence of falling temperatures, science
> started worrying about a new ice age. It was in that atmosphere (no pun
> intended) that Swedish physicist Svante Arrhenius in 1896 calculated that
> our emissions of greenhouse gases might actually prevent a new Ice Age.
> >
> > However, we still don't know for sure why the Ice Age happens, although
> I have an idea which I have presented as a project on ResearchGate, which
> has to do with ocean circulation, and if that is true, it is very unlikely
> that global warming can do more than delay the onset a little.
> >
> > But back to corals: I am convinced that the biggest issue is NOT global
> warming, but POLLUTION.
> >
> > Ulf
> >
> >
> > > On 2017-04-27, at 20:13 , Douglas Fenner <douglasfennertassi at gmail.com
> <mailto:douglasfennertassi at gmail.com>> wrote:
> > >
> > > Ulf,
> > >     It may be that geologists, because of their understanding of the
> vast expanse of earth history, which has included periods of larger
> temperature variation than the last few decades, and which some groups of
> organisms survived, have been more resistant to the evidence of
> human-caused global warming in recent decades.  However, my understanding
> is that most if not all geological societies now agree that the recent
> rapid warming of the earth is mostly caused by humans, by greenhouse gas
> emissions, deforestation, carbon soot on snow absorbing heat, positive
> feedback from melting of Arctic ice which reflects light more than water,
> etc.  In fact, some of the effects of humans, such as the emissions of
> aerosols (such as SO2 from burning fossil fuels) actually work to reduce
> global temperatures, though the effects of other emissions are greater and
> cause net global warming.
> > >      Am I wrong about the geological societies?
> > >     Cheers,  Doug
> >
> > also responding to this:
> >
> > > Ulf,
> > >     My understanding is that climate science data supports the view
> that the rapid increases in world temperature in recent decades has been
> caused mostly by human emissions, while earlier, more gradual temperature
> increases were caused mostly by natural processes (in spite of claims that
> we are in the beginning of a new ice age).  Both of these were present in
> the graph John presented in his essay.  However, it seems unlikely to me
> that corals either understand the causes of temperature increases, or care
> what those causes are.  Corals are impacted by temperature increases,
> whatever the causes of those temperatures are, surely.  That includes
> turning up the heat in aquaria in experiments.  So it seems to me that
> John's graph of increasing temperatures IS relevant to the question of
> whether corals in the Caribbean have been impacted by temperature increases
> or not, and I don't see the relevance of the question of what caused the
> temperature increases, at least to the ques
>  ti
> >  on of impacts on corals.  The effect of increasing temperatures on
> corals is a mechanistic thing, higher temperatures stress or kill corals.
> Cause of temperature increase is irrelevant for that.
> > >      That said, it is good to remind us of the broader processes over
> geological time.  That could include the fact that present temperature
> increases exceed those that have happened in a very long period of time,
> well beyond the range of time you've referred to.
> > > Cheers,  Doug
> > >
> >
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