Public Release: 19-Dec-2018
The quest to discover what drove the last, long-term global climate shift on Earth, which took place around a million years ago, has taken a new, revealing twist.
A team of researchers led by Dr Sev Kender from the University of Exeter, have found a fascinating new insight into the causes of the Mid-Pleistocene Transition (MPT) – the phenomenon whereby the planet experienced longer, intensified cycles of extreme cold conditions.
While the causes of the MPT are not fully known, one of the most prominent theories suggests it may have been driven by reductions in glacial CO2 emissions.
Now, Dr Kender and his team have discovered that the closure of the Bering Strait during this period due to glaciation could have led the North Pacific to become stratified – or divided into distinct layers – causing CO2 to be removed from the atmosphere. This would, they suggest, have caused global cooling.
The team believe the latest discovery could provide a pivotal new understanding of how the MPT occurred, but also give a fresh insight into the driving factors behind global climate changes.
The research is published in Nature Communications on December 19th 2018.
Dr Kender, a co-author on the study from the Camborne School of Mines, based at the University of Exeter’s Penryn Campus in Cornwall said: “The subarctic North Pacific is composed of some of the oldest water on Earth, which has been separated from the atmosphere for such a long time that a high concentration of dissolved CO2 has built up at depth. When this water upwells to the surface, some of the CO2 is released. This is thought to be an important process in geological time, causing some of the global warming that followed past glaciations.
“We took deep sediment cores from the bottom of the Bering Sea that gave us an archive of the history of the region. By studying the chemistry of sediment and fossil shells from marine protists called foraminifera, we reconstructed plankton productivity, and surface and bottom water masses. We were also able to better date the sediments so that we could compare changes in the Bering Sea to other global changes at that time.
“We discovered that the Bering Sea region became more stratified during the MPT with an expanded intermediate-depth watermass, such that one of the important contributors to global warming – the upwelling of the subarctic North Pacific – was effectively curtailed.”
The Earth’s climate has always been subjected to significant changes, and over the past 600,000 years and more it has commonly oscillated between warm periods, similar today, and colder, ‘glacial’ periods when large swathes of continents are blanketed under several kilometres of ice.
These regular, natural changes in the Earth’s climate are governed by changes in how the Earth orbits around the sun, and variations in the tilt of its axis caused by gravitational interactions with other planets.
These changes, known as orbital cycles, can affect how solar energy is dispersed across the planet. Some orbital cycles can, therefore, lead to colder summers in the Northern Hemisphere which can trigger the start of glaciations, while later cycles can bring warmer summers, causing the ice to melt.,
These cycles can be influenced by a host of factors that can amplify their effect. One of which is CO2 levels in the atmosphere.
As the MPT occurred during a period when there were no apparent changes in the nature of the orbit cycles, scientists have long been attempting to discover what drove the changes to take place.
For this research, Dr Kender and his team drilled for deep-sea sediment in the Bering Sea, in conjunction with the International Ocean Discovery Program, and measured the chemistry of the fossil shells and sediments.
The team were able to create a detailed reconstruction of oceanic water masses through time – and found that the closure of the Baring Strait caused the subarctic North Pacific became stratified during this period of glaciation.
This stratification, that argue, would have removed CO2 from the atmosphere and caused global cooling.
Dr Kender added: “Today much of the cold water produced by sea ice action flows northward into the Arctic Ocean through the Bering Strait. As glaciers grew and sea levels fell around 1 million years ago, the Bering Strait would have closed, retaining colder water within the Bering Sea. This expanded watermass appears to have stifled the upwelling of deep CO2-rich water and allowed the ocean to sequester more CO2 out of the atmosphere. The associated cooling effect would have changed the sensitivity of Earth to orbital cycles, causing colder and longer glaciations that characterise climate ever since.
“Our findings highlight the importance of understanding present and future changes to the high latitude oceans, as these regions are so important for long term sequestration or release of atmospheric CO2.”
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It’s the University of Exeter folks.
They were last published here some months ago with equally absurd claims.
The city has a magic Rugby team though.
What this proves is that any weasel worded idea, coulda, woulda, shoulda, can get published, and probably paid grant money, if it starts with the assumption of a co2 control knob. Very stupid at its core.
Earth’s orbital cycles certainly did occur prior to ~1 Myr ago. And, the presented graphs of 18O/16O clearly are cyclical. It is the specific timing of those early cycles that cannot be accurately calculated, because of subtle drifts in orbital parameters. Changing solar insolation at 65N latitude most likely still played a major role in these temperature cycles, which well may have been enhanced (or repressed) by secondary effects such as north Pacific stratification.
Any graphs ive seen have co2 lagging temperature shift.
co2 is the climate passenger not the driver.
neep neep.
Magic rugby, magic molecule, perhaps there is a connection ?
Just need to write up a proposal for serious funding
Way to go, HotScot I think you are onto something there.
Another lesson on how to get something/anything peer reviewed and published and most likely either paid for directly or through a grant.
There doesn’t need to be any specific cause of the MPT. It could simply have been an already existing threshold was slowly approached and passed.
I would assume Javier would have some thoughts on this topic.
“The subarctic North Pacific is composed of some of the oldest water on Earth, which has been separated from the atmosphere for such a long time that a high concentration of dissolved CO2 has built up at depth.” How does this layer of water build up CO2 in the first place? If it is stratified, then CO2 would have to diffuse downward through several hundred meters of water or more to get to it. That is too slow. If cold water is absorbing CO2 and then sinking, water somewhere else must rise. Looking at some measurements of total CO2 (dissolved CO2 and bicarbonate ion) for the North Pacific, the maximum concentration occurs near 1 km depth, and drops a bit as the depth increases. Pretty clear that CO2 sources from the bottom are not significant. Therefore, the CO2 has to come from the atmosphere, but if the layer has been sequestered, how did it get there? I don’t see that their mechanism for this proposed layer of CO2-rich water is feasible.
The Bering Strait is only 100m deep! All these glacial maximums stop the flow from the Bering Strait, so the conditions they describe occur every cycle. The Atlantic side with no barriers provides most of the circulation of water in and out of the Arctic. They’ve juggled a few kilos of mud and globagerina ooze that they didn’t understand and solved a riddle of the ages! There are a literally thousands of papers a decade that report colossal advances in this nutty science.
As long as they support co2 as a control knob they get past peer review, get financial support and get published. What a travesty!
So, if the globe starts to warm dangerously, wouldn’t a man-made barrier across the Bering Strait be more feasible than trying to control the CO2 “knob” using tax and subsidy schemes across a hundred + economies?
We could hire the Dutch to do it.
+100! Actually the idea of getting rid of CO2 at $100s of trillions instead of a thoughtful cheap method as you note is a measure of the terminal linear thinking of the climate sci arithemeticians. Im sure other clever solutions could be found if needs be.
RE: “….and found that the closure of the Baring (sic) Strait caused the subarctic North Pacific became stratified during this period of glaciation.”
The shallow Bering Strait did not ‘close’. The ocean level dropped sufficiently to expose the strait floor and make volume transfer of ocean waters across it impossible until sufficient glacial melting occurred during the the next interglacial warming period.
Missing from this summary is discussion of a significant body of data in the historic record that CO2 lags, rather than leads temperature over the years. It would seem that the data must have sufficient resolution to determine that, since so much other profound analysis was concluded.
Every day I say a little prayer that hopes CO2 causes a little warming. Because in the long term scheme of things we are on our way to CO2 starvation as is evidenced by the glaciations since the beginning of the Pleistocene. The Earth’s core has also cooled somewhat since earlier glaciations hundreds of millions of years ago, so hoping for long term vulcanism is less of a probability to rescue the good Earth with CO2 for dependent life and from a permanent deep freeze.
We should be worshiping the life giving invisible magic molecule, not demonizing it and blaming it for everything that goes wrong with the weather. But of course, the truth is often ironic. CO2 is being crucified on the humanistic alter by a delinquent academia, so those priests can have their way with our political and economic institutions. It is really no different than the ancient priests (take your pick) of sacrificing the ‘prisoners’ to the gods, so as to ensure a bountiful harvest. Same crap!
So even less than 3% from human emissions?
What I find most telling is that the majority of the comments here simply reject the research because it doesn’t align with a narrative. It doesn’t matter how well the research is done (since most don’t take the time to read the actual research paper), it is simply wrong. It’s used as another excuse to ridicule and condemn scientists or anyone who thinks that CO2 has an effect of climate – much less anthropogenic CO2.
Even worse are those who reject science because scientists habitually use words like “could,” “might,” etc. This is a function of the the fundamental nature of science: it does not claim to “prove,” but always leaves room for debate and improvement. It is a strength, not a weakness. It’s like filling out a difficult crossword puzzle, knowing that some of the answers are provisional until verified by more evidence – the answers fit, and are most likely correct, but it’s always possible that a different answer is needed to complete the whole.
Evidently such dismissive people don’t care what scientific research reveals, so how can they possibly take any rational, science-based stance? If they never fill in a square because they assume the answer is wrong, they will never complete the puzzle. It’s as if any word with C and O in it is deemed blasphemous. It’s nothing but ideology. It reflects poorly on skepticism in general when those skeptics who do try to form intelligent, informed opinions don’t take such knee-jerk reactions to task.
I find it quite telling that you seem unable to confront the possibility that CO2 could/might have little or nothing to do with climate. What does your ‘narrative’ say about ‘the Medieval Warm Period’, or the ‘1940’s blip’ which had to be erased in order for the CO2 warming theory to survive?
Could/might there be a little ‘projection’ going on here?
Silber
I ‘could’ win the lottery is a statement of faith. However, the probability that I will win is more like real science.
Projection much, kristi?
That part appears to have been exemplary research, well thought out, hopefully well executed, but after that they really jumped the rails. So tell me, who’s reading papers and trying to figure this out, and who’s clinging to “…the narrative…”
Looked at the paper and found plenty of speculation, anecdotal evidence and more than a few assumptions which lead to a highly speculative hypothesis which sometime next century will be tested. Did I miss anything Kristi?
I should add Kristi as speculative as this paper may be it pales into significance to what hard science can do … if I may offer this gem
https://phys.org/news/2018-12-universe-extra-dimension.html
Hey its a new model built around a new dimension so that makes 12 as string theory already has 11 … things always come in dozens.
It’s fantastic science built on the time honoured technique that you just have to stake enough wild guesses out there in an effort to try and snag a Nobel prize. Besides publish or perish is always a driver.
Kristi, the Strait is only 100m deep and sea level drops more than that during glaciations. This means the conditions they describe occur every time not just a one off.
Yes we have our share of unthinking contrarians, but picking holes in research and conclusions is the sceptics job. It used to be, believe it or not, that the scientist was supposed to embody the scepticism. The free-for-all of onesided clisci and the terrible plans the policy wonks have for us is why sceptics outside the direct ‘discipline’ if I can call it that under the circumstances, were drawn in to fill a terrible void. What efforts dissenting clisci types could mount were stymied by gatekeeping, pressuring of editors out of a job if they published dissenters, blackballing journals that didnt toe the line, fire scientists who don’t go along…
Essentially this resulted in outsourcing of scepticism and its effectiveness (Im sure you will agree there is a lot of talent interspersed in the noise) gave rise to its becoming a perjorative label – never before this. If the measily number of them (3%? – thinking of dissidents in the Soviet U it seems about right) with mostly no funding at all can be so disrupting, it means there must be something a little bit “…rotten in Denmark”. If the theory is sound, it shouldnt need such pampering.
Tell me kristi, you must be a little bit sceptical of some of it. You must be a little bit disappointed in some of the unseemly stuff of gatekeeping, firings, moving goal posts, blacklisting journals failed predictions which are measure of the uncertainty and the quality of the theory.
Above, you argued, despite the trillions of dollars to be spent to erase CO2 emissions with its destruction of civilization, iron control on citizens of a centrally planned set up, that “they” arent saying CO2 is essentially the climate control knob? This my friend is either a walkback or a shift in goalposts. Are you okay with this?
BTW, I am a geologist and engineer and even studied paleoclimate in my courses back when well over 99% of people had bever never heard of it
kristi silber
“This is a function of the the fundamental nature of science: it does not claim to “prove,” but always leaves room for debate and improvement. It is a strength, not a weakness.”
So why is the “science settled” then?
When the Isthmus of Panama volcanically sealed the two continents together, world ocean circulation had to dramatically change, and the climate with it. When the Bering Strait opens up, northern hemisphere ocean circulation changes and the climate with it. When the Strait of Gibralter opened up and created the Mediterranean Sea, world climate would have changed. When the Bosporus Strait opened up and created the Black Sea, regional climate would have changed.
+10!
But the reality is that, despite the hype, there is no real evidence that CO2 has any effect on climate. There is plenty of scientific rationale to support the idea that the climate sensitivity of CO2 is zero. Cooler temperatures cause more CO2 to be absorbed by the oceans but there is no real evidence that a decrease in CO2 causes cooling. The greenhouse gas theory of climate change depends upon the existence of a radiant greenhouse effect in the Earth’s atmosphere caused by trace gases with LWIR absorption bands. Such a radiant greenhouse effect has not been observed in a real greenhouse, in the Earth’s atmosphere, or anywhere else in the solar system. The radiant greenhouse effect is science fiction so hence the greenhouse gas theory of climate change is science fiction as well. So the so called research that we are talking about i nothing but science fiction.
I guess you just can’t get any research funding unless you attribute climate change to CO2.
Bering Strait is very shallow.
Climate Research is very shallow because the heat hides in the deep … just saying 🙂
When climate research funding depends upon supporting the CO2 hypothesis, expect studies to highlight some link between climate change and CO2.
CO2 is not, and never has been, the Earth’s temperature control knob! Yes CO2 is a greenhouse gas, but it’s effects reached near-saturation at levels below that necessary to keep plants alive! In an atmosphere with living things, fuhgeddaboudit!!! That was enough reading of the press release on this insipid research!!! If that was paid for by tax dollars, I want my money back!
At least they acknowledge that we live in an ongoing Ice Age which got somewhat colder. This fetish for CO2 as an answer to everything is troubling. When will we get past the urge to include “CO2” in order to get published or to get funding? And how long will it take to purge the bias from the literature of the selfishness which drove this topic?
On virtually every time scale, CO2 and temperature only have an occasional, accidental correlation. On the one with a strong correlation (Al Gore’s infamous graph, for example), it’s temperature that’s driving CO2 into and out of the oceans. If anything, CO2 is the beat-up wimp that gets blamed for the fake “bad” and forgotten for all the good.
More to the point who in government decides what t line of research will or will not get a government grant ?
Pres. Trump could instruct the various government departments to not make such grants if the subject matter includes the word CO2. Assuming of course that he does control them ?
MJE
Bering Sea circulation is going to change northern hemisphere storms and rainfall immediately. CO2 playing a role is theoretical compared to changing ocean circulation along the polar vortex route. Perhaps even the formation of low pressure centers in and just to the SE of the strait is affected by that circulation.
One of the best proofs that CO2 does not regulate ice age temperatures, is that fact that all interglacials are linked to rises of Milankovitch insolation in the NORTHERN hemisphere.
If a global feedback like CO2 was assisting temperature rises, then we would have interglacials occurring on both northern and southern Milankovitch maxima. But we don’t – they only occur on northern maxima.
Why? Because the true feedback agent is albedo. And all the continents, and therefore the ice sheets, and therefore the albedo changes, are all in the northern hemisphere.
Ralph
There was no climatic shift at the Mid-Pleistocene Transition, for the simple reason that there was no Mid-Pleistocene Transition. It doesn’t exist. It is an artificial division humans have invented in a very long cooling process because we don’t understand well the determinants of interglacials. It is just a human marker for our limited knowledge. No climate change took place at the time between before and after. Most climatology is just bad science.