More Play Station science from the University of New South Wales-cr
UNIVERSITY OF NEW SOUTH WALES
The deep ocean circulation that forms around Antarctica could be headed for collapse, say scientists.
Such decline of this ocean circulation will stagnate the bottom of the oceans and generate further impacts affecting climate and marine ecosystems for centuries to come.
The results are detailed in a new study coordinated by Scientia Professor Matthew England, Deputy Director of the ARC Centre for Excellence in Antarctic Science (ACEAS) at UNSW Sydney. The work, published today in Nature, includes lead author Dr. Qian Li—formerly from UNSW and now at the Massachusetts Institute of Technology (MIT)—as well as co-authors from the Australian National University (ANU) and CSIRO.
Cold water that sinks near Antarctica drives the deepest flow of the overturning circulation—a network of currents that spans the world’s oceans. The overturning carries heat, carbon, oxygen and nutrients around the globe. This influences climate, sea level and the productivity of marine ecosystems.
“Our modelling shows that if global carbon emissions continue at the current rate, then the Antarctic overturning will slow by more than 40 per cent in the next 30 years – and on a trajectory that looks headed towards collapse,” says Prof England.
Modelling the deep ocean
About 250 trillion tonnes of cold, salty, oxygen-rich water sinks near Antarctica each year. This water then spreads northwards and carries oxygen into the deep Indian, Pacific and Atlantic Oceans.
“If the oceans had lungs, this would be one of them,” Prof England says.
The international team of scientists modelled the amount of Antarctic deep water produced under the IPCC ‘high emissions scenario’, until 2050.
The model captures detail of the ocean processes that previous models haven’t been able to, including how predictions for meltwater from ice might influence the circulation.
This deep ocean current has remained in a relatively stable state for thousands of years, but with increasing greenhouse gas emissions, Antarctic overturning is predicted to slow down significantly over the next few decades.
Impacts of reduced Antarctic overturning
With a collapse of this deep ocean current, the oceans below 4000 metres would stagnate.
“This would trap nutrients in the deep ocean, reducing the nutrients available to support marine life near the ocean surface,” says Prof England.
Co-author Dr Steve Rintoul of CSIRO and the Australian Antarctic Program Partnership says the model simulations show a slowing of the overturning, which then leads to rapid warming of the deep ocean.
“Direct measurements confirm that warming of the deep ocean is indeed already underway,” says Dr Rintoul.
The study found melting ice around Antarctica makes the nearby ocean waters less dense, which slows the Antarctic overturning circulation. The melt of the Antarctic and Greenland ice sheets is expected to continue to accelerate as the planet warms.
“Our study shows that the melting of the ice sheets has a dramatic impact on the overturning circulation that regulates Earth’s climate,” says Dr Adele Morrison, also from ACEAS and the ANU Research School of Earth Sciences.
“We are talking about the possible long-term extinction of an iconic water mass,” says Prof England.
“Such profound changes to the ocean’s overturning of heat, freshwater, oxygen, carbon and nutrients will have a significant adverse impact on the oceans for centuries to come.”
JOURNAL
Nature
DOI
METHOD OF RESEARCH
Computational simulation/modeling
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Abyssal ocean overturning slowdown and warming driven by Antarctic meltwater
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So this “research” gets you into MIT? hopeless
This could be worth several dozen miles of the high speed rail to nowhere in California if Jerry Brown was still around to mine the red flag for federal dollars. Gavin is distracted with other bad public policy expeditions for now.
Antarctic Ocean Circulation only can stop if all other circulations stop as well- or none, or all – so none.
“Our modelling shows that if global carbon emissions continue at the current rate, then the Antarctic overturning will slow by more than 40 per cent in the next 30 years…”
That’s nothing! MY modelling, based on the fact that the Antarctic ice can sublime and rise into the air to become snowflakes, suggests that in 20,000 years there will be a massive snowball hovering above the South Pole of our planet weighing about 3×10^16 tonnes….
I’m sorry but I don’t believe computer modeling should bear the term study, the term study implies observation of the real world. Computer modeling is guess work, now maybe if the computer model accurate reflects the real world over an extended period of time (without constant adjusting of the parameters to fit the real world at any moment of time), say 30 to 40 years, then a degree of trust could be earned,
I’ve been modeling Earth systems on my Vic 20 and can definitely say the planet could stop rotating when CO2 in the atmosphere reaches 616 (not to be confused with 666). Following rotation ending, cessation of the deep ocean circulation might happen between 40 and 44 years, average 42 {medium probability}. By this time both I and Prof England might be dead {high probability}.
Rrrrrrrrriiiiiight. Because that volcanism causing them is just gonna turn off because someone forgot to include it in their “””””””””””””””””””””””study”””””””””””””””””””””””.
This is just like those “models” that would have been linear progressions if they weren’t 58% fabricated data and based on falsified equations using selective unrelated inputs.
August 4th 1944 in the Black Forest: 554ppm; impossible by the IPCC’s “data” but written down by a German scientist.
Another could, might, may study. There’s no shortage of those
Carl Wunsch has said that ocean models do not converge. One might ask the authors about their ocean model. Does it converge? Does their prediction have any physical meaning? Or does it just ‘look reasonable.’?
Wunsch, 2002: “Some simple “back-of-the-envelope” calculations show the scope of the problem. Consider one example. Much of “climate” is governed by the movement through the ocean of fluid properties (temperature, salt, carbon, etc.).
“Suppose one’s model has a 1 mm s⁻¹ systematic error in the computed velocity (Lagrangian) of a fluid particle. Then at the end of 100 years, one has a 3000 km position error for that particle. In terms of where enthalpy, carbon, etc. are located in the ocean, and where and how they may re-enter the atmosphere are concerned, errors of this magnitude can completely reverse the sign of the atmosphere-ocean exchange. Do ocean models have errors of this size? I have no idea, as it seems not to have been worthy of study, because “everyone knows” the ocean is laminar and simple. F. Bryan (personal communication, 2000) has shown that the so-called POP-model (Smith et al., 2000) undergoes a sign reversal in the air-sea heat flux in the crucial area of the Grand Banks when the model resolution is shifted from 0.2° laterally to 0.1°.
“In general, ocean models are not numerically converged, and questions about the meaning of nonnumerically converged models are typically swept aside on the basis that the circulations of the coarse resolution models “look” reasonable.” (my bold)
Yet again, evidence that climate modelers do not seem competent to evaluate the physical reliability of their own models.
Alarmists are getting better at making claims that nobody can verify.
There needs to be a moratorium on publishing any study that deals with RCP /SSP 8.5.
As usual the “end of the world” scare is based on computer modelling. Bigger, faster computers just make these whackos more confident in their wild ideas. It hasn’t changed the validity of their analysis.
If crap like this is what I can expect from my tax dollars I think it is time to consider a moratorium on government funded studies. I am tired of my money being pissed away.
There are massive ‘leaks’ all around you.
Yes I can feel it.
Why do so many apparently intelligent university-educated folk seem to think that today’s events are unique in the long life of Earth, and that other evidence of previous events is to be disregarded since today’s man is so much more advanced than who went before? Perhaps university life is unsuited to the recognition that we are NOT omnipotent – perhaps it is that university life which needs to be reviewed, rather than accepting the views of those who are immersed in it? Perhaps this is one of those rare instances where the belief in a supernatural god could benefit us all?
Ancient people were generally smarter than modern humans. The ones with poor judgement were sorted quickly. Today, they get tenured faculty positions.
Where is the explanation for the slowing down of the overturning circulation outside of Antarctica? IF the oceans warm (for which there is zero evidence), then the edges of the Antarctic ice pack will supposedly melt nearly unmeasurably faster, which is supposed to do what, exactly? Freshwater ice melt would still be at 32 deg F/0 deg C … exactly the same temperature the edges of the ice pack are now.
It’s models all the way down.
“Our modelling shows…”
That’s all I needed to see.
1 degree of warming had no impact on this current.
But a few hundredths to a few tenths of a degree that may or may not happen over the next 40 years is going to cause a collapse.
Are these morons that desperate to be published?
But, the tipping point®… we’re really close, now.
Yes, they probably are.
They are getting really,really desperate. How the hell is a trace CO2 increase in the atmosphere going to possibly halt the circualtion of 1.35×10^18 Metric Tons of water on the surface of a roughly oblate spheroid planet with oddly shapen 30% land surface area rotating at 1,000 mph at its surface on the equator? At least the prediction is measurable over the next 30 years and no way will there be a 40% reduction of Antarctic overturning.
Still waiting on the latest data for the NASA Vital Signs Antarctic Ice Sheet page. Over the past few years, by their figues, things we stable/increasing, but no data now since November 2022. I read somewhere they were updating something in the system in the way the data is managed.
https://climate.nasa.gov/vital-signs/ice-sheets/
“Our modelling shows”.
Their models are backwards in two different ways.
Their model “findings” prove nothing, they come entirely from the errors coded into their models in the first place.
“Our modelling shows…” exactly what we programmed our models to show.
All based of what temperature rise in Antarctica? Must be based upon West Antarctica with it’s abundant Ring of Fire volcanism.
This apparent travesty of research, must be an April 1st joke, pre-published on purpose to disguise it’s real purpose.
RCP-8.5 again. I thought that the UNFCCC declared that they weren’t going to use that implausible scenario any more.
But not to worry, they are consistently talking about carbon, not carbon dioxide. Nothing to see here, please keep on moving.
My models predict that by 2050 the POTUS will be an extraterrestrial. Claims that this has already happened I dismiss as mere tinfoil-hattery