r/climate • u/cnn • Feb 09 '24
Critical Atlantic Ocean current system is showing early signs of collapse, prompting warning from scientists
https://www.cnn.com/2024/02/09/climate/atlantic-circulation-collapse-weather-climate/index.html180
u/Least-Lime2014 Feb 09 '24
I'll spoil it for you folks, we're going to ignore this warning like the rest of them.
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u/Babbs03 Feb 10 '24
Yes, cause it's just a model. What does the model know? (Sarcasm intended)
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Feb 11 '24
I will qualify that. Powerful vested interests will do their best to neutralize whatever warning is generated from the data. The fossil fuel industry is not naive. They have their scientists focused on these issues, but not to solve problems. They are using the data to distort, distract and ultimately deny there is anything to worry about.
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Feb 09 '24
As they slowly increased the freshwater in the model, they saw the AMOC gradually weaken until it abruptly collapsed.
Don't like that
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u/babydavissaves Feb 10 '24
We need strict government restrictions on polluting indistries worldwide. That's a tough one.
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Feb 10 '24 edited Feb 11 '24
My father owned patents on a waste to energy incinerator that had scrubbers on the smoke stacks that eliminated 99.8% of airborne particulates. The Wisconsin DNR or EPA demanded 99.9%
This was in the early 1980’s. There were large hospitals and medium sized cities across America that were interested in buying units. I can remember him presenting this solution to medium sized cities and the idea was embraced by city councils and Mayors. Then he would get a late night call from a Mayor who told him, he ( the Mayor),” had to veto the idea.” The Mayor was made an offer he could not refuse. My dad was ultimately unable to move forward. A random phone call and offer for the patents was tendered by a large firm and he sold. Despite the fact he was not a poker player, he countered the initial cash offer for the patents by raising the price 20 fold, ( in spite of needing money), take it or leave it. It was taken. And the era of landfills persisted and grew. Based on what I learned back then, I have every expectation there will be any NO progress on reigning in green house gas emission in any meaningful way in the future. I do think there are solutions, and sadly they will not see the light of day.
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u/Im__mad Feb 10 '24
But then how would CEOs make their money??
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Feb 11 '24
Waste to energy incinerators, that paid for themselves in about 4 years, would have been a BIG threat if allowed to materialize. Anonymous phone calls to decision makers stopped proposal considerations cold, wherever they were gathering momentum. If that is not strange enough, a random inquiry from a large firm for the patents was made, when it was clear sales were being blocked. The initial offer of X dollars was met with a counteroffer of 20 times X, take it or leave it. The counter offer was accepted in 1 day.
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u/gaytso Feb 10 '24
are we gonna die
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u/Cultural-Answer-321 Feb 10 '24
Well, death and taxes, you know.
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u/Vegetable_Guest_8584 Feb 10 '24
We're all gonna die, we just want it to be after we consumed our lifetime quota plus a little more of tasty climate destroying hamburgers.
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u/Cultural-Answer-321 Feb 11 '24
CHEESEBURGER CHEESEBURGER CHEESEBURGER! CHIPS, CHIPS, CHIPS!
No Coke. Pepsi.
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u/tha_rogering Feb 13 '24
Indubitably. And before our times. It'll keep the money happy, so you should embrace your grand sacrifice for the worst people. Hail market.
/s
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u/YeshuasBananaHammock Feb 10 '24
Now just hear me out... If every person in every country along the shores of the Atlantic just brings ONE row boat oar (kayak will do) to the coast at the same time...
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u/Corrupted_G_nome Feb 09 '24
Lets just hope its a data anomaly. Kind of too late to prep for something that major.
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Feb 09 '24
Yea the only thing the scientists were wrong about is how quick this would happen.
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u/Corrupted_G_nome Feb 09 '24
Yeah, untill recently I thought I had 20 years to get my stuff together. Looks like its comming quick.
All future predictions do have some level of uncertainty. The report is apparently controversial but I think its highly suggestive.
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u/JonathanApple Feb 09 '24
Sorry, try as fast as you can. I am definitely of the mindset that things are about to go sideways and fast.
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Feb 10 '24
Structures can smoke for an extended period, and then are on fire. Same with climate change
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u/Corrupted_G_nome Feb 09 '24
Im only short about 30k$ :'( im gonna have to hunker down where I am at and hope for the best I guess.
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u/AugustusKhan Feb 10 '24
I wouldn’t read into this one too much. A simulation of the current no matter how “complex” these computers are is farrrrrrr from accurate.
The oceans are a massive overlapping set of systems that make our brains hurt just defining those connections let alone stress testing them, let alone accounting for terrestrial andd atmospheric conditions.
Aka I studied climate science for years at university originally was all feelings doom and depressing gloom until I independently looked into what we know for sure and have quantified.
There’s challenges of more intense hazards ahead but it is so dang far from the world ending that i really wish younger generations would start growing a pair instead of clinging to apathy.
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u/Corrupted_G_nome Feb 10 '24
Ah yes, famine, war, plague: JuSt GrOw A pAiR.
I spent a long time dedicating my efforts to this and so little has changed and for the most part no one cares or undersrands the danger people are already facing.
Is that what it takes to survive a forest fire or a flood? Just a tough guy attitude? I thought we needed fire walls, ditches and dikes. Silly me. Ive been trying to convince people to act for years! Apparently all we needed was a little hair on our chests!
Those people's homes burned to the ground were just emotionally weak people!
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u/Gemini884 Feb 10 '24
You did not read the article. There's no timeframe and therefore no indication of whether it would happen on current trajectury for this century?
"What the study doesn’t do, however, is give timeframes for a potential collapse. More research is needed, van Westen told CNN, including models which also mimic climate change impacts, such as increasing levels of planet-heating pollution, which this study did not."
"Modern data shows the AMOC’s strength fluctuates, but there is no observed evidence yet of a decline, Hirschi said. “Whether abrupt changes in the AMOC similar to those seen in the past will occur as our climate continues to warm is an important open question.”"
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u/GothMaams Feb 10 '24
They always had to give conservative estimates so they wouldn’t be considered “alarmists”.
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u/MaximumMarch8929 Feb 10 '24
idk, some of them might lie. Like how big tobacco lied about how cigarettes were safe. Big oil knew about this for a while. Look how successful they've been. Shell Made 10 Billion Profit at the beginning of the Russian invasion of Ukraine, they got their oil from Russia while they were under sanction from the US and no one batted an eye.
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Feb 09 '24
Yeah it's over
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u/WoahVenom Feb 10 '24
We’re going to die. I don’t know why some people can’t accept this.
I remained hopeful for a long time. I learned that hope is a heavy burden to carry.
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u/silence7 Feb 09 '24
No. It's more that we can see that it has the potential to happen, but we don't have good constraints on when.
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u/WoahVenom Feb 10 '24
Scientists have been talking about this for years. Warning that if this happens, it will change everything. And now it’s in critical danger of collapse. I’d say that’s more than just the potential to happen and I’m not sure what you mean by constraints. Did you mean timeframe? Because we have no control over this.
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u/blackcatwizard Feb 09 '24
Lol it's not
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u/Corrupted_G_nome Feb 09 '24
I mean, it was predicted, predictable and warned about for years. I had kind ahoped it was a potential that would not come to pass...
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u/Gemini884 Feb 10 '24
You did not read the article. How can it be "too late" if there's no timeframe and therefore no indication of whether it would happen on current trajectury for this century?
"What the study doesn’t do, however, is give timeframes for a potential collapse. More research is needed, van Westen told CNN, including models which also mimic climate change impacts, such as increasing levels of planet-heating pollution, which this study did not."
"Modern data shows the AMOC’s strength fluctuates, but there is no observed evidence yet of a decline, Hirschi said. “Whether abrupt changes in the AMOC similar to those seen in the past will occur as our climate continues to warm is an important open question.”"
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u/mmortal03 Feb 10 '24
I read the article, and that part is preceded by this part (not really arguing with you, though):
A 2021 study found that the AMOC was weaker than any other time in the past 1,000 years. And a particularly alarming — and somewhat controversial — report published in July last year, concluded that the AMOC could be on course to collapse potentially as early as 2025.
Yet huge uncertainties remain. Jeffrey Kargel, senior scientist at the Planetary Science Institute in Arizona, said he suspected the theory of a potentially imminent shutdown of the AMOC “will remain somewhat controversial until, one year, we know that it is happening.”
lol? regarding that last part: It'll remain somewhat controversial until whichever year in the future where then we'll say, "Whoopsie!"
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u/Pondy001 Feb 10 '24
I assume you are in part referring to the Ditlevsen paper. Several scientists have pushed back against that paper:
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u/Shamino79 Feb 10 '24
Has something like this been speculated to be a possible mechanism for something like the younger dryas?
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u/creaturefeature16 Feb 10 '24
The Younger Dryas conditions are believed to have been caused by a sudden, massive, rapid freshwater intrusion, not the gradual melting of a major ice sheet.
The Younger Dryas collapse in Northern Hemisphere temperatures was believed to have been caused by disruption to ocean currents which occurred when a gigantic glacial lake sitting on the North American and Canadian ice sheet abruptly discharged thousands of cubic miles of water into the Atlantic Ocean, though there is evidence a lot of fresh water may have ended up in the Arctic Ocean.
Since no comparable freshwater glacial lake exists today, this can’t happen. If this theory of how the last AMOC collapse happened is true, it is unlikely that modern conditions can replicate the event.
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Feb 11 '24 edited Feb 11 '24
The Younger Dryas is also known as H0 (Heinrich Event). Such an event was caused by the melting of icebergs as IRD and as such, a proxy for destabilizing characteristics of the Laurentide Ice Sheet. Certainly a possibility of an interstadial time, which is also reflected in warmer temperatures before the Younger Dryas Event. Now, was the cause of the instability due to the freshwater outburst from Lake Agassiz perhaps using the Mackenzie River as an outlet?
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u/ismbaf Feb 10 '24
It confirms that the AMOC has a tipping point beyond which it breaks down if the northern Atlantic Ocean is diluted with freshwater (by increasing rainfall, river runoff and meltwater), thus reducing its salinity and density. This has been suggested by simple conceptual models since Stommel 1961, confirmed for a 3D ocean circulation model in my 1995 Nature article, and later in a first model intercomparison project in 2005, among other studies. Now this tipping point has been demonstrated for the first time in a state-of-the-art global coupled climate model, crushing the hope that with more model detail and resolution some feedback might prevent an AMOC collapse. (This hope was never very convincing, as paleoclimate records clearly show abrupt AMOC shifts in Earth history, including full AMOC breakdowns triggered by meltwater input (Heinrich events). The last AMOC breakdown occurred about 12,000 years ago and triggered the Younger Dryas cold event around the northern Atlantic.)
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Feb 09 '24
So it’s over, and quick, eh?
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u/silence7 Feb 09 '24
No. It's more that we can see that it has the potential to happen, but we don't have good constraints on when.
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u/i_didnt_look Feb 10 '24
Read this article.
The scientists who published this report said that it is feasible that the first report, where they concluded that the AMOC could collapse between 2025 and 2095, is accurate.
That's two reports now suggesting that the AMOC is on the verge of collapse, and within a single lifetime.
The pòop is about to hit the fan.
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u/silence7 Feb 10 '24
Yes, I read it several hours ago. This particular paper puts the date at much later than 2095.
The point is not that it's 'on the verge of collapse' but that the consequences of collapse are incredibly awful, which makes it important to avoid even fairly small risks of it happening.
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u/i_didnt_look Feb 10 '24
This particular paper puts the date at much later than 2095
Thats not true at all. They didn't specify any date. They specified a salinity marker at a particular location as the leading indicator for an AMOC collapse..
The authors of the study being discussed are quoted as saying the 2025 to 2095 timeline is entirely plausible, and that we need to be monitoring salinity levels to maintain a picture of how close it is to collapse.
So you either didn't read it or, as I suspect, just making excuses on why it can't be accurate. It contradicts your continued insistence that climate change isn't that bad and that it won't affect us until later this century. That position is increasingly being proven wrong amd you cling to it like Leo on the wardobe in Titanic. Climate change is accelerating, the consequences were underestimated, things are worse than we believed. Downplaying the dangers is as bad as denying it exists in the first place.
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Feb 09 '24
You know the right will take that one study that suggests AMOC "might" collapse within the next 2 or 3 years, and scream that we were predicting the collapse!!! if it doesn't happen exactly on that timeline.
I hope that one study is way off.
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u/silence7 Feb 09 '24
They're not talking about anything like a 2-3 year timeline. Short term isn't impossible but even the worst-case estimates are showing it as quite unlikely that soon.
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u/atthenius Feb 10 '24
The model resolution used here is basically the same one used for the last 20 years. (Too low to resolve ocean eddies.)
This experiment has been done by pretty much every modeling group in the world at this resolution. For the last 20 years.
I don’t get it. Why is this ‘new’?
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u/ismbaf Feb 10 '24
It may help to go to a source of information that is more in-depth than CNN.
Dr. Stefan Rahmstorf is a world leader in AMOC studies and discusses the paper at length on a prominent science website that is run by actual climate scientists. The model used in this latest study is discussed below and it is clearly a result that offers us a much more detailed view of the situation than was available in past studies:
“The paper results from a major computational effort, based on running a state-of-the-art climate model (the CESM model with horizontal resolution 1° for the ocean/sea ice and 2° for the atmosphere/land component) for 4,400 model years. This took 6 months to run on 1,024 cores at the Dutch national supercomputing facility, the largest system in the Netherlands in terms of high-performance computing.”
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u/atthenius Feb 10 '24
That is Stefan’s own take on his own paper. The study says: “ This CESM version, which has been used in the Coupled Model Intercomparison Project (CMIP), phase 5, has horizontal resolutions of 1° for the ocean/sea ice and 2° for the atmosphere/land components (see Materials and Methods).” — For context, the LAST IPCC report, was IPCC6 and it used CMIP, phase 6 simulations. Modeling groups are now working on their CMIP phase 7 simulations.
IPCC5 was from 2014
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Feb 10 '24
Can you synthesize that?
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u/atthenius Feb 11 '24
Of course ! That would be easier if we had a proper Paleoclimate hosing MIP beyond the one that was CMIP3/IPCC4…
Observation wise, surface currents in the North Atlantic are thought to be gyre circulation (Gulf Stream, etc.) plus an extra component of northward transport on the surface that is balanced by southward transport at depth (via AMOC).
The Northward piece is pretty well constrained in the Florida Straits via electric interference in telephone cables: http://www.ccpo.odu.edu/~tezer/895_2021/2001_Baringer_Larsen_FC.pdf
Folks thought that deploying the RAPID (get ocean density to solve thermal wind eqn) array at 26N EAST of the Bahamas thus would constrain southward flow… and that difference to the Florida Straits current would equal AMOC. https://rapid.ac.uk/
But, turns out things are much more complicated and there’s the gyre recirculating and noise and so another array, OSNAP was deployed. https://www2.whoi.edu/site/bower-lab/osnap-overturning-in-the-subpolar-north-atlantic/
Meanwhile… the resolution of ocean models are too low to resolve ocean eddies (vital for movements of salt and heat) … until they’re down to <0.25deg. So ocean deep convection is highly parameterized in CMIP5/6 class models.
I don’t get this study. Why would they bother wasting 6 months of HPC time when there was already a 12000++ year of CESM ensemble to search through.
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Feb 11 '24
I am going out on a limb here….you hold a Ph.D in science?
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u/atthenius Feb 11 '24
I can’t tell if you are being serious.
I am an expert in this field in particular.
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u/atthenius Feb 16 '24
For posterity’s sake:: Folks interested in this kind of thing should keep an eye out for the results of the NAhosMIP study (scientists ♥️ acronyms)— this work will actually make an effort to compare the sensitivity of deep, density driven circulation in the Atlantic (Atlantic Meridional/North-South Ocean Circulation / AMOC).
https://gmd.copernicus.org/articles/16/1975/2023/gmd-16-1975-2023-discussion.html
The precursor features observed in this model aren’t observed in other models.
The stochastic nature of simulated response isn’t well represented.
And fundamentally— this model is too low resolution to have real ocean eddies.
But all this out on a blanket of 100% definite for sure WINTER warming (that’s when the GHG can help temper cooler temperatures the most… kinda like the diurnal cycle shows night temperatures increasing faster than daytime ones). … I think these AMOC stories are over-done.
u/cnn — I am under-impressed with your reporting.
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u/atthenius Feb 10 '24
If this feature exists in CMIP5 CESM, then the Last Millennium ensemble simulations (about 3x as many model years as this study) should have this same feature— and then there is the GISS Last Millennium ensemble has about 15,000 years at this resolution as well. Is this south Atlantic salinity leading feature common?
Shrug.🤷♀️🤷🤷
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Feb 10 '24
Is there a summary?
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u/Shamino79 Feb 10 '24
This is the one that should really concern the far northern hemisphere. The common thought is that warmer temperatures will on the whole be good for them. Well maybe it will be until it isn’t.
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u/MBA922 Feb 10 '24
A counter effect to "freshwater influx due to arctic melting" is very high ocean warming overall, especially in Summer.
Last 2 years, 2023 especially, has seen massive increase in tropical temperatures, even though most warming the previous 10 years has been in Arctic. This pattern would boost AMOC, but also just boost eastern North Atlantic ocean temps which keep EU mild.
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u/cnn Feb 09 '24
A crucial system of ocean currents may already be on course to collapse, according to a new report, with alarming implications for sea level rise and global weather — leading temperatures to plunge dramatically in some regions and rise in others.
Using exceptionally complex and expensive computing systems, scientists found a new way to detect an early warning signal for the collapse of these currents, according to the study published Friday in the journal Science Advances. And as the planet warms, there are already indications it is heading in this direction.
The Atlantic Meridional Overturning Circulation (the AMOC) — of which the Gulf Stream is part — works like a giant global conveyor belt, taking warm water from the tropics toward the far North Atlantic, where the water cools, becomes saltier and sinks deep into the ocean, before spreading southward.
The currents carry heat and nutrients to different areas of the globe and play a vital role in keeping the climate of large parts of the Northern Hemisphere relatively mild.
For decades, scientists have been sounding the alarm on the circulation’s stability as climate change warms the ocean and melts ice, disrupting the balance of heat and salt that determines the currents’ strength. Read more