University of South Florida (USF Innovation)
TAMPA, Fla. (Aug. 30, 2019) – An international team of scientists have discovered evidence in the geological formations in a coastal cave showing that more than three million years ago – a time in which the Earth was two to three degrees warmer than the pre-industrial era – sea level was as much as 16 meters higher than the present day. Their findings have significant implications for understanding and predicting the pace of current-day sea level rise amid a warming climate.
The scientists from the University of South Florida, University of New Mexico, Universitat de les Illes Balears and Columbia University published their findings in today’s edition of the journal Nature. The analysis of deposits from Artà Cave on the island of Mallorca in the western Mediterranean Sea, serves as a target for future studies of ice sheet stability, ice sheet model calibrations and projections of future sea level rise, the scientists said.
“We can use knowledge gained from past warm periods to tune ice sheet models that are then used to predict future ice sheet response to current global warming,” said USF Department of Geosciences Professor Bogdan Onac.
Sea level rises as a result of melting ice sheets, such as those that cover Greenland and Antarctica. However, how much and how fast sea level will rise during warming is a question scientists have worked to answer. Reconstructing ice sheet and sea-level changes during past periods when climate was naturally warmer than today, provides an Earth’s scale laboratory experiment to study this question, said USF PhD student Oana Dumitru, the lead author.
The project focused on cave deposits known as phreatic overgrowths on speleothems. The deposits form in coastal caves at the interface between brackish water and cave air each time the ancient caves were flooded by rising sea levels. In Artà Cave, which is located within 100 meters of the coast, the water table is – and was in the past – coincident with sea level, said Professor Joan J. Fornós of Universitat de les Illes Balears.
The scientists discovered, analyzed, and interpreted six of the geologic formations found at elevations of 22.5 to 32 meters above present sea level. Careful sampling and laboratory analyses of 70 samples resulted in ages ranging from 4.4 to 3.3 million years old, indicating that the cave deposits formed during the Pliocene epoch.
Sea level changes at Artà Cave can be caused by the melting and growing of ice sheets or by uplift or subsidence of the island itself, said Jacky Austermann an Assistant Professor at Lamont-Doherty Earth Observatory, Columbia University and member of the research team. She used numerical and statistical models to carefully analyze how much uplift or subsidence might have happened since the Pliocene and subtracted this from the elevation of the formations they investigated.
One key interval of particular interest during the Pliocene is the mid Piacenzian Warm Period – some 3.264 to 3.025 million years ago – when temperatures were 2 to 3ºC higher than pre-industrial levels. The interval also marks the last time the Earth’s atmospheric CO2 was as high as today, providing important clues about what the future holds in the face of current anthropogenic warming, Onac said.
This study found that during this period, global mean sea level was as high as 16.2 meters (with an uncertainty range of 5.6 to 19.2 meters) above present. This means that even if atmospheric CO2 stabilizes around current levels, the global mean sea level would still likely rise at least that high, if not higher, the scientists concluded. In fact, it is likely to rise higher because of the increase in the volume of the oceans due to rising temperature. The authors acknowledge that this sea level rise would not happen overnight but it would take hundreds to thousands of years to melt such large amounts of ice.
Considering the present-day melt patterns, this extent of sea level rise would most likely be caused by a collapse of both Greenland and the West Antarctic ice sheets, Dumitru said.
The authors also estimated that sea level was 23.5 meters higher than present about four million years ago during the Pliocene Climatic Optimum, when global mean temperatures were up to 4°C higher than pre-industrial levels.
###
The research team also included Senior Research Scientist Victor J. Polyak and Professor Yemane Asmerom of the Department of Earth and Planetary Sciences at the University of New Mexico in Albuquerque, and Associate Lecturers Joaquín Ginés and Angel Ginés of the Universitat de les Illes Balears in Mallorca.
This research is the result of a collaborative National Science Foundation (NSF) project between the University of South Florida and the University of New Mexico and part of the bilateral agreement between USF and UIB, and has been funded by NSF and the Spanish State Research Agency.
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I read this study, was annoyed by its pretense at being science, and thought about commenting. However, with the exception of some of the usual suspects, I see that WATTS commenters have very nicely summed up the gist of the report, which is the variables, both identified and still unknown, greatly exceed the claimed scientific findings being reported, so I have no need to comment and I won’t.
Too late!
For those interested in how much the land might have risen or sunk since the Pliocene it is interesting to calculate the claimed precision in determining the rise or fall of the land since the Pliocene:
(19.2-5.6 meters)/3.04 million years = +- 0.002 millimeters per year
And compare it to actual measured rates and uncertainties over the vastly shorter (117,000 years) since the last interglacial:
https://perso.univ-rennes1.fr/laurent.husson/PAP/pedojaetal14.pdf
In this world-wide compilation there is not one single datapoint with a precision even approaching the one claimed in the paper (over a 25 times longer period). Which would incidentally be equal to determining the sea-level during the previous interglacial with a precision of +- 9 inches, or the Holocene highstand to a precision of about +- 2/3 of an inch.
Absurd.
“Considering the present-day melt patterns, this extent of sea level rise would most likely be caused by a collapse of both Greenland and the West Antarctic ice sheets, Dumitru said.”
Not at all sufficient, together they would only yield about 10 meters of sea-level. It would require that an appreciable part of the EAIS also melted. The difficulty with this is that there is irrefutable geologic evidence that East Antarctica has been permanently glaciated for about 14 million years.
Incidentally the Greenland ice-sheet can melt, but not collapse, but “collapse” sounds more terrifying. And the ice in the East Greenland highlands has not melted completely at least since the Oligocene.
tty
This is totally typical of alarmist research-to-order.
A finding is presented massively different from anything in current geology and it doesn’t even cross their minds to check with other geological evidence.
This is not science, these are not scientists.
I had a AGW alarmist recently ask me why any climatologist would need to know anything about geology. I told him that a true climatologist would need extensive training in a multitude of disciplines to even begin to understand climate (statistics, chemistry, physics, geology, oceanography, etc). He seemed to believe that “climatology” was a scientific field unto itself and that no other disciplines were needed in attempting to elucidate the mysteries of climate. Sad.
Georg Ruf September 2, 2019 at 3:51 am
Venice is on the AEgeic- Anatolic Plate (the edge is in the middle of the Italian Apenine mountain),
_________________________________________
Yes, and:
Thetis ocean is the predecessor of nowadays North / East hub built by the river Rhine: south / north
and River Danube: west / east.
_________________________________________
Parathetis south of the European Alps is the predecessor of the nowadays Mediterranean Sea.
The African tectonic plate INCLUDING Mediterranean sea + Italy presses North folding up the European Alps.
https://images.app.goo.gl/abaQV2CN3WnDM86o6
Hmmmm….. some mystical stuff here makes this all unclear.
CO2 levels “maybe higher than today”…. OK, where did it come from? Your breath, maybe?
And what does that have to do with the Present? Nothing. Attempting to compare some spot in a cave that formed 3++ million pre-Hooman Florida years ago with current planet-wide Hooman existence and industry is ludicrous.
Non sequitur. This is too silly for anyone, with or without pre-prandial caffeine ingestion, to read and NOT start with the Skeptical Response.
I’m quite sure that, based on current events, this was another way to get more grant money to continue this “study” and get even more carbon-biased conclusions, to get more grant money.
Try harder.
Sea level 20m higher than today 3Mya means total earth land surface 3 Mya about half what it is today.
Did the authors discuss the implications of this massive change that geologists had somehow missed – rather like discovering a new hitherto unknown continent the size of Africa, in 2019.
Did they discuss it’s coherence with other evidence – evidence of a major land surface change would not be hard to find.
Of course not.
This smells strongly of a “result-you-like” research finding served to order by alarmists to bolster a flagging sea level alarm story.
Did the authors think to look at all the places currently less than 20m above sea level, and look for evidence of being under sea level 3 million years ago?
Of course not.
This would be the first thing real scientists would do.
These however are not real scientists but thieving power-grabbing scammers.
One gets the feeling that “evidence” is already a denyer – right wing – Judeo-Christian – oppressively paternalistic etc.. word and concept that progressives would never use.
To be fair, there are different sects of “progressivism”. In fact, there was a statistically significant schism between the two leading sects within the past several years, where members of one sect, the “media” sect, would assault prominent members of the other sect, for political and social progress, leverage, and, it seems, giggles.
“We can use knowledge gained from past warm periods to tune ice sheet models that are then used to predict future ice sheet response to current global warming,” said USF Department of Geosciences Professor Bogdan Onac.
– says it all: USF Department of Geosciences Professor Bogdan Onac, the ice sheet models tuner, searching for super computers climate models control knobs.
– climate vs. real world observations: fasten seat belts.
Postmodern science belongs in the same place as postmodern art.
https://remodernreview.wordpress.com/2019/08/27/8-times-trashy-postmodern-art-got-thrown-into-the-garbage/
“This study found that during this period, global mean sea level was as high as 16.2 meters (with an uncertainty range of 5.6 to 19.2 meters) above present.”
Why that far back when the geology of Hallett Cove in South Australia shows-
“The level shore platform has been eroded by wave
action across the rocky coastline during the past
7000 years. The big fold was formed during the
mountain building about 500 million years ago.
During the Recent ice age about 20 000 years ago,
sea level was about 130 metres lower than today
and South Australia’s coastline was about 150
kilometres south of where Victor Harbor now is.
The ice cap started to melt about 15 000 years ago.
Sea level began to rise and reached its present level
about 6000–7000 years ago.”
(Hallett Cove geological Trail, Government of South Australia, Primary Industries & Resources SA, 2010)
That can be an average annual SLR of 16.25mm/year for 8 millenia babe compared with what the CSIRO reckon of late- https://www.cmar.csiro.au/sealevel/sl_hist_few_hundred.html
So that’s it we’re all doomed obviously but not to worry the climate changers will turn back the seas and save us all just like last time there was a dreaded dooming-
https://www.adelaidenow.com.au/news/south-australia/adelaide-remember-when-clairvoyant-john-nash-predicted-earthquake-and-tidal-wave-would-obliterate-adelaide-in-january-1976/news-story/e11935a6d44b5281a47bbfdd65b2dc2d
That’s the beauty of doomings as without them you can’t possibly be saved.
But, but.. will the Obamas new beach house be safe? Won’t somebody think of the Obamas?
I don’t see any reason at all to be dismissive of the study out of hand. The authors identified a confounding variable of the height of the land and they believe they have dealt with it. This isn’t the only place in the world where ancient sea levels can be measured. Their conclusions will either be confirmed, disconfirmed, or adjusted.
The reason to be dismissive out of hand is that they make the assumption that the atmospheric CO2 levels tell you how much ice there will be. But CO2 levels “the last time they were this high” were driven by the equilibrium of CO2 in the oceans/atmosphere as a result of temperature. Now the CO2 is quite likely being driven by man. This has effectively decoupled atmospheric CO2 from (ocean) temperature.
So IF the world were at that previous temperature for a long time and IF the antarctic sheet collapsed then sea levels might be that high. But temperatures are clearly not that high right now and since the rate of warming is far below the levels predicted for a climate dominated by CO2, this is all nonsense.
This is not unlike the way people make the suggestion that some things that have been proposed as powerful feedbacks are reacting faster, therefore the world will warm faster. But indeed, the world is warming slower than predicted, so we’ve not verified warming, we’ve instead disproved the strength of the feedback. In the global warming debate almost everything is presented with those kinds of correlations inverted…the cart drawing the horse.
Long after the “CO2 is bad” propaganda has done its work, Steve O.
This sounds like a classic Scientific-Technological Elite result Ike warned about in his farewell address. Government grant money showered down on compliant “scientists” who yield back to the Government the results said Government desired all along. It is corrupt, shameful, and most of all, dangerous.
I saw this article a few days ago, read it with some interest and then ignored it. There are much simpler ways of knowing that sea levels have raised and fallen quite dramatically by using ones eyes! Two raised beaches on Portland bill,Dorset England sit at 16m above present sea level, dated to 200,000 bp and another at approx 12m above present sea level dated to 125,000bp.couple this with at best limited isostatic rebound in this area and with uplift in the nw of the UK and current dropping of the land level in the south of the UK leads me to deduce that this article doesn’t prove anything of any real interest. Sea level has been as high as that, more recently with accompanying low levels of co2. Conclusion co2 is no driver here now or in the past. I even asked my kids why a beach was sitting on top of a cliff. 12 year old said..sea level was higher. 9 year old said or land was lower, or both combined. That’s science and hope for the future of science
At the higher end of their numbers, is there enough water in the world, even if all were melted, to do this?
Richard Aubrey September 2, 2019 at 11:21 am
At the higher end of their numbers, is there enough water in the world, even if all were melted, to do this.
___________________________________________________
Good question.
The water volume stayed ( almost ) the same.
The difference is:
– Ice caps, ( water volume ) sitting on top of land, land mass subducted.
– Ice caps melted, melt water volume added to ocean volume, land mass elevated.
Gives some handy arithmetic formula.
Oh, the unintended humor contained in the above article. To wit:
“One key interval of particular interest during the Pliocene is the mid Piacenzian Warm Period – some 3.264 to 3.025 million years ago – when temperatures were 2 to 3ºC higher than pre-industrial levels. The interval also marks the last time the Earth’s atmospheric CO2 was as high as today, providing important clues about what the future holds in the face of current anthropogenic warming, Onac said.”
So, the researchers admit the Earth was previously warmer in a “pre-industrial” era when atmospheric CO2 levels were as “high as today”. And this admission works out exactly how, specifically, to provide “clues” about the future “in the face of current ANTHROPOGENIC warming”, which today remains unsubstantiated??? (My capitalization applied for emphasis.)
Was there a land mass at or near either pole three million years ago? that also would
make a difference.
That’s the main reason I ignored the article, it looked for a time co2 was as high as today and then proposes that because of that co2 level we will have the same environment as then. which is exactly how it was reported online, stating that we still have 16m of sea rise and 3c of warming locked in because of our current co2 levels. Not true, not science
Yes. Antarctica has been in a polar position for more than 200 million years. Continents don’t move much in 34 million years.
Landmass distribution / Khan Academy:
https://www.khanacademy.org/science/cosmology-and-astronomy/earth-history-topic/plate-techtonics/v/pangaea
I think they haven’t quite thought this through. This paper in effect argues that Mallorca has been extremely stable tectonically.
However if this is true then there is a problem. The Eemian (last) interglacial sea-level in Mallorca is extremely well documented and is only about 2 m above the current sea level (in contrast to the 7-9 meters of the “party line”):
https://core.ac.uk/download/pdf/154377054.pdf
So if Mallorca is indeed tectonically stable, all talk about the West Antarctic Ice Sheet collapsing during the Eemian is definitely off, even the Greenland Ice Sheet can’t have shrunk by more than about 25%, despite 10,000 years of 5-8 degrees warmer climate than today.
I didn’t see a mention in this excerpt of them correcting for where we were in the Milankovitch cycle.
There are several Milankovich cycles of different length, and they by themselves don’t affect sea level, only indirectly through the amount of glacial ice.
During the Pliocene the 41,000 year obliquity cycle was dominant, and dating is hardly exact enough to distinguish that.
So, CO2 atmospheric levels were roughly the same back then as today, and the sea levels during the Pliocene epoch were much higher than sea levels currently. The takeaway of that study should be that sea levels are independent of CO2 levels.
Or so tenuously related that James Burke couldn’t connect them.
Gibraltar which is about same Tectonic plate and very near has risen 0.10 – 0.15 mm/year last 128 ka = ~ 12 – 20 m. The Eurasian and Afrikan plates push each and create this an upward lift. The 128 ka is very short time indeed compared to the time scale mentioned in this article.
Decades ago I had an opportunity to travel in countryside of Morocco. In many places e.g. in Agadir you could see fossils of Sea biota some twenty meters above Current Sea level.
https://www.researchgate.net/publication/248242416_Coastal_uplift_in_continental_collision_plate_boundaries_Data_from_the_Last_Interglacial_marine_terraces_of_the_Gibraltar_Strait_area_South_Spain
Piacenzian Warm Period Temp 2 to 3 deg C higher than present.
Piacenzian Warm Period Sea Level 16.5 meters higher than present.
Piacenzian Warm Period CO2 about the same as present.
If the conclusion is that current CO2 levels will eventually result in sea levels rising another 16.5 meters and temperatures rising another 2 to 3 degrees C, what is the mechanism that will drive this? According to their logic the sea levels and temps should mirror those of 3 million years ago.
It doesn’t make sense.
Same tired sea-level scaremongering. Sea water licking your toes? Walk back a few feet. Or just live away from the shore.
The maxim is “correlation does not equal causation”. That is, except for global warming. With global warming, correlation ALWAYS equals causation.
There was some research suggesting that the straits near Istanbul were once elevated, so that what is now the Black Sea was a dry depression, and later on an earthquake opened the straits and allowed Mediterranean water to pour into the Black Sea.
If the previous warm period studied by this article’s researchers occurred before the opening of the Black Sea, the water level of the Mediterranean Sea could have been 16.2 meters higher, to account for the volume of the water currently in the Black Sea.
This is admittedly speculation, but so is the assertion that a future warming of the climate would raise the Mediterranean Sea by 16.2 meters.
Some years ago I wrote about the recession of the seas over millionsof years as the earth continues to expand and I received a fair share of redicule for it. Now a group of scientists have found that what I said is true. I also went on to show that all civilizations started the higest regions of earth because of the height of sea levels back then. So all this to say that my three books are a Trilogy of this development. The books are’ IS PLANET EARTH EXPANDING” THE MYSTERIOUS RECEDING SEAS’ and ‘THE ASCENT OF MAN:DOWNHILL ALL THE WAY”. All these books take the subject fro m the beginning to where we are today as the earth continues to exopand and the seas continue to recede/ Richard Guy. Author.