A new paper was published in Science Advances today. Its title says what it is about: “Physics-based early warning signal shows that AMOC is on tipping course.” The study follows one by Danish colleagues which made headlines last July, likewise looking for early warning signals for approaching an AMOC tipping point (we discussed it here), but using rather different data and methods.
The new study by van Westen et al. is a major advance in AMOC stability science, coming from what I consider the world’s leading research hub for AMOC stability studies, in Utrecht/Holland. (Some of their contributions spanning the past 20 years are in the paper’s reference list, with authors Henk Dijkstra, René van Westen, Nanne Weber, Sybren Drijfhout and more.)
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.
It is the first systematic attempt to find the AMOC tipping point in a coupled global ocean-atmosphere climate model of good spatial resolution, using the quasi-equilibrium approach which I pioneered in 1995 with an ocean-only model of relatively low resolution, given the limited computer power available 30 years ago.
If you’re not familiar with the issues surrounding the risk of abrupt ocean circulation changes, I briefly summarized ten key facts on this topic last year in this blog post.
But now, let’s get straight to the main findings of the new paper:
1. 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.)
2. It confirms by using observational data that the Atlantic is “on tipping course”, i.e. moving towards this tipping point. The billion-dollar question is: how far away is this tipping point?
3. Three recent studies (for more on these see this blog post), using different data and methods, have argued that we are approaching the tipping point and that it might be too close for comfort, even posing a risk of crossing it in the next decades. However, the reliability of the methods used has been questioned (as discussed here at RealClimate). Based on their epic computer simulation, the Dutch group proposed a new, physics-based and observable type of early warning signal. It uses a diagnostic – the freshwater transport by the AMOC at the entrance of the South Atlantic, across the latitude of the southern tip of Africa – which I proposed in a 1996 study. They do not present a particular time period estimate for reaching the tipping point, as more observations of the ocean circulation at this latitude will be needed for that, but they note about last year’s Ditlevsen study that “their estimate of the tipping point (2025 to 2095, 95% confidence level) could be accurate.”
4. The new study confirms past concerns that climate models systematically overestimate the stability of the AMOC. About the crucial AMOC freshwater transport in models, they point out that most models don’t get it right: “This is not in agreement with observations, which is a well-known bias in CMIP phase 3 (38), phase 5 (21), and phase 6 (37) models.” Most models even have the wrong sign of this important diagnostic, which determines whether the feedback on Atlantic salinity is stabilising or destabilising, and this model bias is a key reason why in my view the IPCC has so far underestimated the risk of an AMOC collapse by relying on these biased climate models.
5. The study also provides more detailed and higher resolution simulations of the impacts of an AMOC collapse on climate, albeit considered in isolation and not combined with the effects of CO2-induced global warming (Fig. 2). They show how particularly northern Europe from Britain to Scandinavia would suffer devastating impacts, such as a cooling of winter temperatures by between 10 °C and 30 °C occurring within a century, leading to a completely different climate within a decade or two, in line with paleoclimatic evidence about abrupt ocean circulation changes. In addition they show major shifts in tropical rainfall belts. These (and many more) impacts of an AMOC collapse have been known for a long time but thus far have not been shown in a climate model of such high quality.
Given the impacts, the risk of an AMOC collapse is something to be avoided at all cost. As I’ve said before: the issue is not whether we’re sure this is going to happen. The issue is that we need to rule this out at 99.9 % probability. Once we have a definite warning signal it will be too late to do anything about it, given the inertia in the system.
Overall the new study adds significantly to the rising concern about an AMOC collapse in the not too distant future. It thus adds even more weight to recent reports sounding strong warning sirens, such as the OECD Climate Tipping Points report of December 2022 and the Global Tipping Points report published December 2023. We will continue to ignore this risk at our peril.
Update 10. February: In the reactions to the paper, I see some misunderstand this as an unrealistic model scenario for the future. It is not. This type of experiment is not a future projection at all, but rather done to trace the equilibrium stability curve (that’s the quasi-equlibrium approach mentioned above). In order to trace the equlibrium response, the freshwater input must be ramped up extremely slowly, which is why this experiment uses so much computer time. After the model’s tipping point was found in this way, it was used to identify precursors that could warn us before reaching the tipping point, so-called “early warning signals”. Then, the scientists turned to reanalysis data (observations-based products, shown in Fig. 6 of the paper) to check for an early warning signal. The headline conclusion that the AMOC is „on tipping course“ is based on these data.
In other words: it’s observational data from the South Atlantic which suggest the AMOC is on tipping course. Not the model simulation, which is just there to get a better understanding of which early warning signals work, and why.
The New, Scientist is the only media outlet so far who gives a quotation by van Westen himself that says that the drastic cooling of Europe is not realistic. See here:
“Unlike in previous simulations, the team added fresh water gradually, rather than in one go. This produced a positive feedback that amplified the effect: as less water sank because of the reduced salinity, less salty water flowed north, reducing salinity still further. This eventually shut down the overturning circulation, causing temperatures to rise in the southern hemisphere, but plummet in Europe. For instance, in the model, London cools by 10°C (18°F) on average and Bergen in Norway by 15°C (27°F). Other consequences include local sea level rises in places such the US East Coast. What’s more, some of the changes seen in the model ahead of the collapse correspond with changes being seen in the real Atlantic in recent decades.”
Then, this:
“However, to produce this collapse, the researchers had to run the model for 2500 years. And they had to add a huge amount of freshwater – less than in previous simulations, but still around 80 times more than is currently entering the ocean as Greenland’s ice sheet melts. “So that is absurd and not very realistic,” says van Westen.”
I wonder why no other media have covered this.
[Response: That refers to my point 4 above: in this model, like in most models, you need to add an unrealistic amount of freshwater, because they are in the wrong part of the stability diagram compared to what observational data imply. And the sentence by the journalist that they “had to” run the model for 2500 years is a misunderstanding: running the experiment very slowly is a choice, it is to trace the stability diagram near equilibrium, so the model experiment avoids rapid forcing changes (like the current anthropogenic warming) in order to stay always near equlibrium. That is the quasi-equlibrium method I pioneered in my 1995 paper as mentioned above. -Stefan]
Hello, I do not have the necessary knowledge to discuss this with experts like you, I am a simple optometrist. But I wonder, would it be possible, viable, to use the Panama Canal as a “tap” for the entry of water from the Pacific Ocean to the Atlantic to anthropogenically regulate the AMOC currents and therefore the climate? Thank you
The Panama Canal is not a straight flow through canal, it has levels. It just so happens the lake is drier now probably due to climate change, so canal traffic has slowed right down.
The Panama canal can not transport water between the oceans as it is not at sea level. It relies on freshwater from the surrounding areas to lift the ships so they can pass through. As Panama is currently in a long drought they have even had to reduce the number of ships allowed to use the canal as they are running out of water. Even if the canal was at sea level the amount of water that could pass through it would be too small to have an effect on climate.
As others have pointed out, the Panama Canal is not a simple trench between oceans. However, there is also the fact that if you transport water, you also transport species–this is a REALLY BAD IDEA. We already have significant problems with invasives moving to places where they face no checks and can destroy ecosystems.
Similar problems with the Great lakes and shipping: https://www.greatlakeslaw.org/blog/2017/03/the-death-and-life-of-the-great-lakes.html – Dan Egan’s The Death and Life of the Great Lakes
The idea of funneling water from one ocean basin to the other is both naive and sadly typical of lay ‘ideas’. I wish everyone would do some work on scale from micro to macro, geological time vs. human time, distances, atmosphere, elevation, space. Reality is fascinating, and curiosity is a great healer if more people enjoyed trying to learn more at the expense of certainty. I wish geography was taught more in early school. I’m never bored with finding out more. It’s all a lot more interesting once one starts looking.
It’s a bit late in the game— the hazards of homogenizing the biosphere by canal and ballast water transport of aquatic species, and the intercontinental exchange of plants and animals were not muct appreciated until the 19th century.
By then botanical gardens and zoos had largely completed intercontinental transplantation , and Suez completed what began in the first millennium BC, when the pharaohs linked the Nile delta and the Red Sea with the Berenice canal .
Air freight and reptile fanciers finished the job.
I’m sure the Spotted Lantern Fly agrees. Native trees…not so much
Rain falls on land in Panama, part of the water runs off into the big lake near middle of canal. That fresh water flows by Gravity into 2 separate sets of locks on either side of lake. That fresh water raises & lowers the ships. Operating the canal requires releasing millions of gallons of old rain water into both Atlantic & Pacific Oceans. Luckily few salt water species could survive several days in the freshwater locks & lake. Also few freshwater species could survive salty ocean water. Sadly, salty sea level Suez Canal let’s sea creatures travel both directions!!!
Re: J Toledo Feb. 10 proposal of opening a seaway across Panama.
In addition to all the monumental technical and ecological problems mentioned already by others, your proposal would likely have the OPPOSITE climate effect to what you think it would have, because the AMOC, in its current form, has been created not by opening but by CLOSING of the Caribbean-Pacific water exchange.
It was the formation of the Panama isthmus couple mln yrs ago that helped to redirect some of the Gulf of Mexico currents to the North, and more importantly – allowed an increase in salinity in the North Atlantic. That, in turn, allowed AMOC in its current form: water evaporates in hot Caribbean, zonal winds dump this moisture in the Pacific, on the other side of the Panama Isthmus. Before the completion of the isthmus – the surface fresh water was free to return to the Atlantic, reversing most of the freshwater export. With the closure of the connection, it was no longer possible – so the salinity of the North Atlantic increased substantially.
Now, when this saltier water was brought by the (possibly strengthened by the closure of the Pacific ‘diversion”) Gulfstream to Greenland – the winter cooling of saltier water created super-dense seawater that sunk and pushed in front of them the existing deep waters – thus driving the AMOC and global Thermohaline Circulation(THC) from the North Atlantic. That’s why most of the today’s deep ocean volume is made either of NADW (N.Atl. Deep Water)- or its continuation (after some admixture from Antarctic) after it flows into the Indian and Pacific Ocean, forming their deep waters., called “Common Water” – named this way since this is the water that the Indian and Pacific Oceans have “in common” with the Atlantic.
The volume of this deep water formation is such, that after it started – it caused a few deg. C drop in deep ocean worldwide. More importantly for climate – the colder water when at surface, can dissolve more atm. gases, including CO2 – so newly formed AMOC would transfer some of atm. CO2 into the deep ocean – lowering remaining global atm. Co2 enough to move us into the current cyclical glaciation period – Pleistocene (with current Holocene being a mere part of latest interglacial)- when the world teeters on the edge – small drop in atm. Co2 and we have a glacial stage, a small increase in atm. Co2 and we have an interglacial.
So opening the seaway across Panama, if large enough to have an impact, would have the opposite effect to what you have envisioned – weaken the AMOC, weaken the Gulf Stream, and reduce the ability of the deep ocean to sequester human surplus of CO2.
In addition to climatic consequences, since cold waters dissolve also more O2, AMOC is the main source of O2 (other than limited vertical mixing and downwelling in places other than N. Atlantic) for all life in the deep ocean in the world – so weakening or shutting down of AMOC would reduce O2 concentration worldwide – would push deep ocean, particularly in the Pacific where the deep water is the oldest, toward hypoxia and anoxia.
These are the problems with geoengineering quick-fix proposals – you are messing up with processes on the global scale, likely to cause massive collateral ecological damage, while the results for the climate may not be what you hoped for.
“but still around 80 times more than is currently entering the ocean”
I am also a simple … something. I understand why you want to add freshwater slowly in the model, but if in order to get to the tipping point you have to use 80 times the current level of freshwater, why isn’t that evidence that we are NOT near the tipping point? Doesn’t it imply you could double the current input and stay stable forever?
Not rejecting the conclusion, just confused.
I have a question Im hoping those of you who understand all of this can explain for me.
My poor understanding of the possible tipping point is that it could lead to a cooling in parts of the Northern hemisphere.
I also just saw a report yesterday that spoke of the possibility of an ice free Arctic within the next decade.
These two things seem like they may work against each other. Hopefully one of you can clear up my confusion. Love this website btw.
Michael, a couple of things that might help.
-“Ice-free Arctic” is an overblown description of what people are actually talking about, which is a month where the sea ice drops below a certain level.
https://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/
Play with the graph… the easiest thing is to turn off everything but the 4 decadal averages. Even a very low September value doesn’t mean everything collapses; since the solar energy input drops dramatically then, the ice comes back. The max value is definitely going down, but not that fast.
-Exactly what happens if the AMOC collapses/slows down… if(when)… is not clear. That’s what the folks like Stefan are trying to figure out.
The potential interaction between the two things is complicated and at this point speculative… we don’t seem to be close to some extreme change for either one.
Thanks, appreciate the answer and link.
Michael Stephen says
5 Mar 2024 at 5:15 PM
Michael, first be cautious and skeptical. I recommend this approach vs Zebras.
Hide all years, turn off 1981 – 2010 median, and the two ranges ….
SELECT
1979-1990 average
2024-2023
2020-2019
2015-2016
2011-2012
2007-2008
See the linear pattern? Roughly speaking, more or less, all the impacts from climate change going back a century or the last 30 years follow a slowly unfolding linear trend line – with occasionally (at times chaotic unpredictable) natural variability. Look at the graph with the selected years. Play around with it, switch on and off others years one at a time. Observe what happens.
Without much warning things move into rapidly increasing / exponential rates of change from global warming. Like mini-tipping points sort of.
Consider the 2023-2024 massive record breaking non-linear exponential spike in SSTs, GMSTs, ENSO activity, low albedo/aerosols, and ice minimums, melts … PLUS CO2 and other GHG atmospheric levels record spikes and the faster RATE of increase, along with the global increase RATE of temperature change. Think logically, know that multiple factors align to produce a Peak High Tide as well.
and know that at some point suddenly and unpredictably climate change and warming impacts erupt non-linearly creating extreme unprecedented outcomes. Coral bleaching events being another good example. Everything aligns to suddenly set new records / unprecedented events
Excluding the rhythmic pattern showing on the charctic graph now with the selected years I suggested, with the TWO YEAR gaps in between, the ASI melt minimums run fairly linearly so far. At some point though, it will break out like all other climate change impacts and will respond chaotically and non-linearly off the scale. When all the driving factors ALIGN into an unprecedented event.
That moment may well be about to arrive this or next year. Or it may take few more years or may be delayed until the 2030s. But when it happens it will be a BIG DEAL and no one in climate science will be predicting that because they cannot think chaotically nor non-linearly or spontaneously nor intuitively.
One year that minimum will literally collapse from being circa 3 to 4 million sq kms to suddenly fall under the 1 million sq klms mark – iow the first Blue Ocean Event in the Arctic.
Originally the IPCC said this would not be happening until the 2090’s ……. that’s climate science for you. Now they say in the 2040s ‘maybe’. They do not know. Why? Climate scientists are like locomotives on a railroad track. They cannot tell you anything about what is outside those tracks. And never will.
They didn’t know the record 2023 – 2024 temperature heat spike was coming either. Though a few did suspect it was very possible given several changes in key data points. Like aerosols and enso and very high ocean heat content and several years of rapidly rising earth energy imbalance.
All of which will also one day make a major impact on the Arctic Sea Ice as well …. guaranteed sooner than later.
Thanks for this, lots of helpful information. Appreciated.
Michael I Stephen says
8 Mar 2024 at 4:01 PM
“Thanks for this, lots of helpful information. Appreciated.”
No problems. I’m glad it helped. So, thank you Michael.
Really nice to interact with an intelligent genuine and respectful person for a change. Best to you.
NK,
@ https://www.realclimate.org/index.php/archives/2024/02/new-study-suggests-the-atlantic-overturning-circulation-amoc-is-on-tipping-course/#comment-819940
[insert spit take here]
EK: Climate scientists are like locomotives on a railroad track. They cannot tell you anything about what is outside those tracks. And never will.
BPL: And people who denigrate climate scientists are like a monkey trying to understand calculate.
Because modeling the Arctic system is complex and difficult. The improvements are demonstrable, and are anything but evidence that the task cannot be done, or won’t be done.
One of the more spectacularly failed similes I’ve ever seen, starting with the fact that locomotives “know nothing, and tell nothing”–outside OR inside the tracks.
Kevin,
Suggesting that just as locomotives are constrained to the tracks and cannot go beyond them, climate scientists are limited in what they can tell about the climate system.
RE : “Because modeling the Arctic system is complex and difficult. ”
Awww shucks. Competence is an overrated value then. You are saying the IPCC and climate scientists can never been wrong because it’s difficult? Interesting ‘world’ in which you live Kevin. Clearly you are not alone.
Are you suggesting that appealing to ignorance will make you shriek a little more every day, Ned?
NK “Suggesting that just as locomotives are constrained to the tracks and cannot go beyond them, climate scientists are limited in what they can tell about the climate system. ”
Scientists are trained in science, maths, observation, logical analysis, and the scientific method. So what are you suggesting they do instead? Read the bible? Consult the entrails of a dead goat? Astrology? Anecdotal information? Gut instincts? What? Could you please elaborate.
Hi Stefan, as much as I know that ESM’s are wrong and the model error will now become most likely exponential (so many subsystem errors now piling up) I do love these small models with high resolution which are well able to understand system changes/regional changes (ESM’s are also usable to understand specific system changes but they can not predict the behavior of whole system).
What I wonder here is the question on what happens if the AMOC breaks down – could just the overturning cell become shallower? I mean from a thermodynamic perspective the system has to pump heat to the poles or not?
Exist here some studies? One I read years ago – also Hansen addressed it.
All the best
Jan[Response: There is also the possibility of a partial shutdown, e.g. just for deep water formation in the subpolar gyre region. That’s a serious risk for humanity as well; I will discuss it in a forthcoming article. There is no fundamental reason why a North Atlantic based overturning must exist, but models tend to predict that if it breaks down in response to global warming it will likely recover – but that could take a thousand years. There is a fundamental thermodynamic reason why deep water formation and overturning has to exist somewhere in the ocean in equilibrium, i.e. it can only be turned off everywhere for a millennium or so (diffusion time scale). But there is no fundamental reason why it has to be active in the North Atlantic, or even the northern hemisphere. -Stefan]
Thx a lot for your kind answer, looking forward for your study, as this subject is highly interesting!
Very interesting indeed. It would also be of interest to read Stefans comments on these two new studies: 1) “Abyssal ocean overturning slowdown and warming driven by Antarctic meltwater”, Qian Li et al. (2023)
https://www.researchgate.net/publication/369618506_Abyssal_ocean_overturning_slowdown_and_warming_driven_by_Antarctic_meltwater and 2) “Multi-proxy constraints on Atlantic circulation dynamics since the last ice age”, Pöppelmeier et al. (2023)
https://www.researchgate.net/publication/369759530_Multi-proxy_constraints_on_Atlantic_circulation_dynamics_since_the_last_ice_age .
Paper one was referred to by a science journalist in The Guardian “The new paper, published in Science Advances, has broken new ground by looking for warning signs in the salinity levels at the southern extent of the Atlantic Ocean between Cape Town and Buenos Aires. Simulating changes over a period of 2,000 years on computer models of the global climate, it found a slow decline can lead to a sudden collapse over less than 100 years, with calamitous consequences.”
https://www.theguardian.com/environment/2024/feb/09/atlantic-ocean-circulation-nearing-devastating-tipping-point-study-finds
Fred Pearce says the same about paper one, among others citing Stefan, here: “A new analysis by Australian and American researchers, using new and more detailed modeling of the oceans, predicts that the long-feared turn-off of the circulation will likely occur in the Southern Ocean, as billions of tons of ice melt on the land mass of Antarctica. And rather than being more than a century away, as models predict for the North Atlantic, it could happen within the next three decades.
Leading ocean and climate researchers not involved in the study who were contacted for comment praised the findings. “This is a really important paper,” says Stefan Rahmstorf, an oceanographer and head of earth system analysis at the Potsdam Institute for Climate Impact Research in Germany. “I think the method and model are convincing.””
https://e360.yale.edu/features/climate-change-ocean-circulation-collapse-antarctica
While on the other hand Fred Pearce on paper two says this: “Meanwhile the long-standing concern about a shutdown of the ocean circulation in the North Atlantic sometime in the 21st century appears to be subsiding. A Swiss study published this month found that, contrary to past belief, the circulation did not fail at the end of the last ice age, suggesting, the researchers say, that it was more stable than previously supposed, and less likely to collapse.”
This reading by Pearce seems to me to be a complete misunderstanding. The scientific paper says: “ln general, our ensemble of different overturning circulations indi-cates that small meltwater fluxes are sufficient to substantially perturbthe AMOC during the early deglaciation with an average reduction ofoverturning strength by 10% per 0.012 Sv of freshwater hosing (that is,a full collapse can be achieved with 30%) close to the level of the B/A, yet these can be realized even with short but pronounced weakening ofthe AMOC. This ‘decoupling’ of Atlantic water mass provenance from overturning circulation is the result of the short duration of the YD.”
( Multi-proxy constraints on Atlantic circulation dynamics since the last ice age. Available from: https://www.researchgate.net/publication/369759530_Multi-proxy_constraints_on_Atlantic_circulation_dynamics_since_the_last_ice_age [accessed Feb 10 2024].)
To call a sixty percent reduction in AMOC overturning in the northern Atlantic relative to the situation during Bølling/Allerød (which had a climate around as warm as the holocene average) “no failure” is to me a clear misunderstanding.
For modern human civilization, especially concerning food production, an abrupt cooling as in the YD (or even just the “Preboreal” = 8.2 ky event) for something like “the short duration of the YD” (1200 years! https://en.m.wikipedia.org/wiki/Younger_Dryas ) or just as in the 8.2 ky event (200-400 years https://en.m.wikipedia.org/wiki/8.2-kiloyear_event ) – would of course be devastating. It is enough to know the huge end moraines in Scandinavia stemming from glacial readvances dated to YD and “Preboreal”/8.2 ky event – or even just what happened during the much slighter cooling of less than one degree C during the little ice age (where fx. some outlet glacier tongues in Norway advanced several kilometers in just a few tens of years) to understand this.
The geological conception of time is very different from the (rather silly) in the media and politics, where one year or even just one week is often viewed as a very long time…
Correction: Unfortunately the most important part of my citation from scientific paper 2) in my comment above about Fred Pearce’s misunderstanding, disappeared in the copy-and-paste process. The correct one is this: “”ln general, our ensemble of different overturning circulations indicates that small meltwater fluxes are sufficient to substantially perturb the AMOC during the early deglaciation with an average reduction of overturning strength by 10% per 0.012 Sv of freshwater hosing (that is,a full collapse can be achieved with 30%) close to the level of the B/A, yet these can be realized even with short but pronounced weakening ofthe AMOC. This ‘decoupling’ of Atlantic water mass provenance from overturning circulation is the result of the short duration of the YD.”
( Multi-proxy constraints on Atlantic circulation dynamics since the last ice age. Available from: https://www.researchgate.net/publication/369759530_Multi-proxy_constraints_on_Atlantic_circulation_dynamics_since_the_last_ice_age [accessed Feb 10 2024].)
Thus my conclusion: “To call a sixty percent reduction in AMOC overturning in the northern Atlantic relative to the situation during Bølling/Allerød (which had a climate around as warm as the holocene average) “no failure” is to me a clear misunderstanding.” It is based on this: “(…) yet relative to the preceding Bølling–Allerød (B/A), this relates to a reduction of ~60% while the decline for HS1 relative to the LGM amounts to only ~30%.” I hope this was clarifying.
It seems to me that much of the concrete climatic expressions seen in the proxy data *on land and along the coastlines* in Scandinavia/the Alps/on Greenland and Iceland as well as in North America and western Siberia, in well-known geomorphological features and other proxy data dated to the glacial readvances and neoglacial advances in YD, “Preboreal” (8.2 ky event) and “the little ice age” (c. 1400-1800 AD), are not taken into account by the oceanographers who are doing most (if not all?) of the climate modelling research on the AMOC and it’s climatic causes and implications. Please correct me if I’m wrong.
This has of course much to do with the specialization in science which often leads to far too little communication between different scientific disciplines and research traditions. The scientific journalism very often (almost always) lacks the nescessary interdisciplinary overview of the subjects to be able to see this. The relentless hunt among the media for clickbaits adds hugely to the growing public and therefore political confusion concerning important climate matters. This confusion is mainly helping the denialists, their fossil fuel sponsors and the political spin and propaganda which is now growing fast from the extreme right wing (Trump, Putin etc.) I think scientists writing fx. here on realclimate need to me much more aware of this problem. My experience from a long life as a high-school teacher in geoscience and as an environmental activist/politician tells me that.
Thank yo so much for sharing this important field of research!!!
Kind regards
Thomas Pieper
Just as an interesting information for you Stefan: “For instance, Zhu et al. (2023) see an increased SSS contrast between the subtropical Atlantic and Indo-Pacific basins of the Southern Hemisphere as an indication
of a weakening of the Atlantic Meridional Overturning circulation (AMOC) in climate model
simulations.”
Zhu, C., Z. Liu, S. Zhang, and L. Wu, 2023: Likely accelerated weakening of Atlantic
overturning circulation emerges in optimal salinity fingerprint. Nat Commun, 14, 1–9,
https://doi.org/10.1038/s41467-023-36288-4.
[Response: Sure, I know the paper. Stefan]
Hi Steffan, could not be sure – but anyhow a highly interesting field of changing saltiness pattern of the global oceans:
With most of the Atlantic becoming saltier while most of the other basins get fresher/saltier at the surface with large annual/seasonal derivations. One image of one study – but fresher gets fresher, saltier gets saltier seems to hold over wide areas – for anybody interested: https://www.nature.com/articles/s43247-021-00161-3/figures/1
Jan Umsonst – the regional changes in salinity would reflect both the changes in currents and changes regional climate (altered Precipitation – Evaporation).
But if we ignore for now the climatic changes in P-E, then the maps are, at least qualitatively, what we would expect from a weakened AMOC:
– fresher water south of Greenland – corresponding to a cold blob -Greenland ice melt + less removal of the salt by formation of deep water
– saltier by the US coast – weaker Gulf Stream lingers longer in the hot-dry climate of subtropics
Thanks for this overview made somewhat more accessible to an average layman.
I always remember Mark Lynda Six Degrees looking at AMOC collapse and realizing how very close it could be.
As a point of interest, at Madrid’s COP25 I spoke to cryosphere scientists who said the cryosphere was already bad enough at 1.1 that we don’t want to reach 1.5. I suggested that ice melt might reduce ocean acidity and they replied it makes it worse as freshwater erodes the ions acting as a buffer between the seawater and CO2.
Felix Von Geyer – I suggested that ice melt might reduce ocean acidity and they replied it makes it worse as freshwater erodes the ions acting as a buffer between the seawater and CO2.
I don’t think it is correct – let’s see the effect of reducing S by 0.3, eg. from S=35, T=3C, TALK=2350 and DIC=2210 to S=34.7, T=3C, TALK=2329.85 and DIC=2191.05.
The corresponding pCO2 drops from 403 uatm (=ppm-v) to 333.9 uatm, thus making more room for the uptake of CO2. It would be further increased, if the meltwater can drop the temperature of the surface seawater (cold blob).
However, globally it would be a minor flux – given the limited horizontal and vertical limitation of the penetration of the ice-melt water.
I have a question regards all tipping points. a new paper McCulloch, M.T., Winter, A., Sherman, C.E. et al. 300 years of sclerosponge thermometry shows global warming has exceeded 1.5 °C. Nat. Clim. Chang. (2024). https://doi.org/10.1038/s41558-023-01919-7 concludes that we have already warmed the planet 1.7 degrees relative to preindustrial and will reach 2 degrees before 2030. How do we interpret this in terms of estimated tipping point temperatures? are we about 0.5 degrees closer or is this just a renormalization?
thank you
[Response: That paper changes nothing in practice, it only suggests to use a different baseline period which would result in different numbers. And it’s overselling local data from the Caribbean to claim it is a global temperature reconstruction. There are good reconstructions of global temperature going back 2,000 years using many proxy data from around the world; this is not one. -Stefan]
Stefan thank you for the explanation
Tony
Stefan:
Permit me here to quote you yourself from remarks you delivered in October 2004, when asked to comment on the climate sciences behind and those depicted in the 2004 SF thriller The Day After Tomorrow (this quote appears in the Wikipedia account of the film):
“Clearly this is a disaster movie and not a scientific documentary, [and] the film makers have taken a lot of artistic license. But the film presents an opportunity to explain that some of the basic background is right: humans are indeed increasingly changing the climate and this is quite a dangerous experiment, including some risk of abrupt and unforeseen changes … Luckily it is extremely unlikely that we will see major ocean circulation changes in the next couple of decades (I’d be just as surprised as Jack Hall if they did occur); at least most scientists think this will only become a more serious risk towards the end of the century. And the consequences would certainly not be as dramatic as the ‘superstorm’ depicted in the movie. Nevertheless, a major change in ocean circulation is a risk with serious and partly unpredictable consequences, which we should avoid. And even without events like ocean circulation changes, climate change is serious enough to demand decisive action.”
That the data and the analyses and the methodologies have been refined over the past two decades is no mystery. What I do find compelling is how quickly the data and the analyses (seem to ) have overtaken your assessment from 2004: “Luckily it is extremely unlikely that we will see major ocean circulation changes in the next couple of decades . . .; at least most scientists think this will only become a more serious risk towards the end of the century.” This is both startling and striking and emphasizes for anyone reading today just how much has already changed in only two decades.
Keep up all good work.
Sincerely,
Edward Burke
[Response: Thanks for reminding me. Indeed I have in recent years changed my mind about the likelihood, mainly based on the observations-based early warning signal papers (I count 4 by now on the AMOC) and on the increasing evidence that models have an AMOC which is systematically too stable, when compared to observations-based stability indicators. -Stefan]
So Stefan — what do you suggest we do?
Double the efforts to get out of fossil fuels.
#1 is stopping all fossil subsidies, explicit and implicit.
The latter implies a price tag on emitting greenhouse gases which reflects the damage they cause.
The money raised should be given back to the people in some form of climate dividend, as some countries already have, to avoid social hardship due to increasing fossil fuel prices.
Stefan, am I correct to understand this as your support for James Hansen’s proposal for a carbon fee and dividend? If so I find that very encouraging – I belong to a group here in Norway of members of the green party and two left-wing parties (which are all represented in the norwegian parliament) working for this proposal since 2012. By now all these parties support the idea in their programmes, but unfortunately their leaders are very reluctant towards this, as also seems to be the case with the green party in Germany. Too many (allmost all) politicians are passively reacting to opinion polls and following the always chaotic media frenzy, instead of putting forward and fighting for bold political ideas like carbon fee and dividend.
Since the socalled “climate negotiations” now seem to have degenerated into something more resembling a Trojan horse for the fossil fuel lobby than any kind of forum promoting effective climate action, I think leading climate scientists need to speak out louder about these very important political issues. Of course I understand that many are reluctant to do so, because of fear of the media and trumpist politicians trying to undermine their scientific credibility and thereby the funding for their research, but this battle was lost long ago anyway. Politicians like Trump etc. will never change their minds, they are anti-science to the core. The political confrontation is inevitable. What is important now, is to convince the common people and especially the youth, that there is a realistic political possibility to cope with the rising climate gas emissions in an effective and socially fair way.
The current populist farmer-protests around Europe being used by fossil fuel lobbyists and the hopeless and apolitical symbolic and monotonous protests by activists from extinction rebellion etc. are leading in the wrong direction, towards right-wing extremism taking over. This is a very dangerous development, and so far the green parties have no clear political response to this other than vague criticisms of the usual greenwashing of business as extremely usual from the political establishment. The fact that despite all investments in “green” (?) energy, the fossil fuel percentage of global energy use rose from around 75 pct. in 1975 to around 82 pct. in 2022 and that this figure is still relentlessly rising, should tell us all, that “green new deal”s, CCS phantasies (“net zero” etc.) are not working, they don’t change anything, they just add a little more “green” (?) energy on top of the relentlessly rising use of fossil fuels. To change this there simply is no way around raising the price of fossil fuels sharply but gradually, and doing it socially fair: a gradually (year-by-year raised) carbon fee and dividend.
Introducing fee and dividend is in the coalition agreement of the German government, thanks to the Green Party, but the free democrats (whose finance ministry should implement it) has been delaying it.
Karsten V. Johansen says
“The fact that despite all investments in “green” (?) energy, the fossil fuel percentage of global energy use rose from around 75 pct. in 1975 to around 82 pct. in 2022 and that this figure is still relentlessly rising, should tell us all, that “green new deal”s, CCS phantasies (“net zero” etc.) are not working, they don’t change anything, they just add a little more “green” (?) energy on top of the relentlessly rising use of fossil fuels. ”
Close enough to correct. The % don’t tell the full story though. How much has total energy consumption / demand increased since, say, 1999 to 2023? Then consider how much has the global economy in nominal GDP terms grown in the same period of time?
Another step is to factor in the EROEI of say, wind/solar, green hydrogen, and BECCS versus say Oil, Coal and Gas and then modern safe modular GenIV Nuclear energy. What does that tell you?
Lastly, just as an exercise, do a global calculation on a range of Carbon Taxes rates, $50, $100, $200 per ton of CO2e ( it has to be global with Border adjustments or forget it – but exclude the impoverished global south nations of course) by applying various CO2e emission factors of each primary form of fossil fuel energy supply system – and Cement production too? – And Agriculture Methane production too?
Of course the biggest Tax will be on Coal, Oil and Gas accounting for around 80-85% of primary energy use. So then you need to add on those three carbon tax rates on that 3 different forms of energy use at pro-rata rate depending on their CO2e emission levels – and those Tax Rates at the Mine Gate/Drilling site will immediately flow into prices and financial services globally before any Dividend is returned to any citizen.
So how much will prices rise and any other related imposts globally as a result?
Do the math on all the above, and see what comes up. It might partly explain why “green energy” isn’t making a dint in total energy use or supply, and why there is no carbon tax and dividend already.
L. Dog: Tax Rates at the Mine Gate/Drilling site will immediately flow into prices and financial services globally before any Dividend is returned to any citizen.
I am not sure why. The government, based on the last year’s emissions of its industries – knows how much taxes it will collect in the year ahead – so it can pay the dividend to the households ahead of these taxes. And even if the initial estimates of taxes collected are off, since the taxes are ramped up gradually, it won’t be a massive shock.
There has been quite a bit of work done on carbon taxes and dividends – for the social acceptability they have to be revenue neutral (all the money collected in tax paid back in dividends) – and a part of coordinated international countries.
William Nordhaus who got “The Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel 2018”
(as close to Nobel Prize as you can get as an Economist …)
“for integrating climate change into long-run macroeconomic analysis” argued that, in addition to the revenue-neutral carbon tax, a group of countries that have put price on carbon form a club – invite other countries to join, but if they are unwilling to put their price on their carbon – subject their exports to the carbon tariffs to even the playing field between the domestic producers paying the tax and imported goods produced without the tax.
This framing meme of “the money raised” seems inverted to me. If nation-states were to enact Step #1, then the recent estimates of $7 trillion dollar socialized “subsidies” by those nation-states (see IMF, IEA, etc.), including somewhat difficult-to=quantify “externalized” social costs, would seem to be cost savings instead. That is, “the money is saved,” not raised. This is why I favor removing government subsidy financing, instead of increasing the pricing.
On a minor (miner) note, if fossils should not be dug up and burned, perhaps we should not refer to them as “fuels,” since that commonly refers to “that which is good to burn.”
Regards.
On a related ‘miner’ note, I’ve pointed out that petroleum products are extremely useful as lubricants–the need for which is not going away anytime soon. I’ve further suggested that if we removed the “future discount” on their pricing as lubricants (not fuels), it’s possible that they are in reality too valuable to be burning so recklessly and shortsightedly.
Victor: – “…what do you suggest we do?”
There are some statements I’ve quoted in an earlier comment, from Professor Johan Rockström, spoken at the 44th TB Macaulay Lecture in Edinburgh, UK on 18 Oct 2023.
https://www.realclimate.org/index.php/archives/2023/11/science-denial-is-still-an-issue-ahead-of-cop28/#comment-816647
I suspect most of the responders here miss Victor’s real point which is “there is nothing we can do so let’s do nothing”.
There is a whole lot less we can do now, largely because denialists like Weaktor have robbed us of 40 years during which we could have been addressing the problem rather than catering to the “Drill, Baby, Drill” lackies and their fascist fossil fuel oligarchs.
LOL. Sorry Ray. I never robbed anyone of anything.
No raindrop thinks that it is the cause of the flood.
What an insult to the millions of people who have installed solar panels on their rooftops, bought EVs, supported dramatic green policies and changed their lifestyles. No wonder you guys are having difficulties. You insult the people you need on your side time and time again.
Never in the history of political movements has one side so consistently wasted their built-in advantages, the primary being the good will bestowed on the environmental movement.
Fools.
My real point was “why go to all this trouble to spread alarm over this particular tipping point when there is realistically nothing we can do to prevent it?” If Stefan really believes cutting back on fossil fuels could do the trick I’m wondering what the scientific basis is for such a claim. Has he found a “study” we don’t know about?
Victor: – “Has he found a “study” we don’t know about?”
Victor, the climate science denier, regurgitator of climate myths, and denier of reality.
https://www.realclimate.org/index.php/archives/2023/10/unforced-variations-oct-2023/#comment-814921
https://www.realclimate.org/index.php/archives/2023/10/unforced-variations-oct-2023/#comment-814936
What’s required to avoid worst-case catastrophic conditions for humanity in the coming decades?
Reduce;
Remove;
Repair.
https://www.realclimate.org/index.php/archives/2023/08/the-amoc-tipping-this-century-or-not/#comment-813939
Yes, absolutely, Victor is clearly wrong and we should do everything possible to stop what a model suggest might happen in 1700 years based on a huge number of assumptions.
Meanwhile we can’t agree on what the PDO is going to be in 4 months time
Victor, you need to worry about your great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-grandchildren’s world
Please read the update under the post again.
Keith (at 11 FEB 2024 AT 10:07 PM), I’d suggest humanity will likely soon have direct experiences to confirm the validity of your earlier assertion that: “A planet 2 degrees warmer is far superior for mankind…”
https://www.realclimate.org/index.php/archives/2023/07/back-to-basics/#comment-813255
When will +2.25 °C on the Y-axis in the graph (in Prof Eliot Jacobson’s Feb 9 tweet) be insufficient? Later this decade perhaps?
https://twitter.com/EliotJacobson/status/1755623313274290315
For the first time in recorded history, the 180-day running mean for the global surface temperature just crossed +1.70 °C above the pre-industrial 1850-1900 baseline.
https://twitter.com/EliotJacobson/status/1756750662371770583
Global Sea Surface Temperatures are literally going off the chart…
https://twitter.com/LeonSimons8/status/1756348352386457714
Do you remember this comment of yours in Nov 2022, aye Keith? Just a reminder…
https://www.realclimate.org/index.php/archives/2022/10/scafetta-comes-back-for-more/#comment-807309
Data indicates that global mean surface temperatures “off the chart as the warmest year on record” have occurred a year earlier.
https://berkeleyearth.org/wp-content/uploads/2024/01/AnnualPlot-2023-1.png
With the EEI more than doubled since 2000, the Earth System warming is beginning to accelerate, and will inevitably get hotter.
https://berkeleyearth.org/wp-content/uploads/2024/01/EEI-2023.png
Do you have any children/grandchildren, Keith?
It seems to me you are betting their lives/wellbeing, and perhaps even your own (if you live long enough to witness it), on Hansen & colleagues being substantially wrong.
https://academic.oup.com/view-large/figure/423296595/kgad008f24.tif
KW: we should do everything possible to stop what a model suggest might happen in 1700 years based on a huge number of assumptions.
BPL: Keith, why do you hate Ray Bolger?
Yes Stephan, I had read that. It just makes so little sense that it wasn’t worth mentioning.
So instead of having a model run for a couple of thousand years, they feed it unrealistic values to make it do what they want, then look at 18 years of observations to see where abouts we are on that path.
Brilliant
Sorry Stefan, made a typo on your name
It’s amazing to me that you have been here so long and have not learned one damn thing.
Stefan, is there a model anywhere which has drilled down to the impacts of a North Atlantic slowdown of, say, 25% , for Gb and Scandinavia, between 2030-40, in terms of mean winter temperatures?
Something I wonder about: Are the cosequences if an AMOC collapse really THAT devastating?
1. The models suggest that almost the entire Northern Hemisphere cools down. This mitigates the heat problem a lot. Isn’t it?
2. Some parts like Scandinavia and UK are getting really cold in winter. Maybe comparable to their roughest winters in the 20th century or even harder. Right? Ok, that’s not nice, but aren’t these rich countries capable of dealing with that? At least it’s the better option than having devestating summer heat in almost the entire northern Hemisphere.
3. I see the problem of the shifting rainfall patterns. But also you have to consider much less evaporation due to much lower temperatures in many regions compared to a global warming without AMOC collapse.
4. I totally see the problem of the even more rising sea Level in some regions.
5. I see the problem of an even stronger warming southern hemisphere, although most people live on the northern Hemisphere.
6. In total I could imagine that the positive effects could outweigh the negative impacts. But since you know much more about the cosequences you can explain why an AMOC collapse is still something like a worst case scenario for the planet.
Max, among other problems, you seem to be ignoring the problems of food production that come with a very rapid change of climate – coordinated worldwide by a collapse of the AMOC.
With a collapse, nearly everyone will find themselves growing crops that are likely to do poorly in the new climate of their region – if they grow at all. In order to adjust, they would need to find out what crops are now better suited for their area and obtain the seeds for those crops. That would require correct modeling of the new situation, and widespread belief in the results of those models. And that also assumes that the new climate would be stable enough to allow useful prediction. At the same time, the seed supply would be under stress, for the same reason. Better seeds may simply be unobtainable for a while. Finally, even if better seeds are available, farmers would need the correct techniques and technology to plant, grow, and harvest their new crops.
While adjustments to the new climate might take place after a few years, a few years is a long time to wait for a proper food supply. What kind of devastation might happen in the interim?
John, you are right, there would be huge challenges for the food production. But remember: the model results shown in this article don’t suggest a drastic change in every region. It wouldn’t mean a worldwide disruption in food production. I totally agree that the big Challenge of asn AMOC turndown would be the fast change… As the new study says, the climate in some regions would drastically change within 10 to 30 years. That means we need to be well prepared for this scenario, otherwise it would be catastrophic. But thanks to probably better models in the coming years we can do this.
The drastic sea level rise in some regions is another big problem though. This is hard to prepare for.
But still I don’t sea the AMOC turndown as the most threatening tipping point. For example the methane release through permafrost could be way more threatening bc it heats up the entire planet with a further casquade of consequences.
Max, I think that there is more to food disruption than first meets the eye.
1. These are 50 model-year averages. Even in places where the average temperature remains fairly stable, if the variance increases, this will decrease agricultural production.
2. Precipitation is changing, as well as temperature. This includes seasonal changes in many areas where total precipitation is fairly stable.
3. Figure S2 supplement to the original publication makes it clear that there would be rather large changes to meridional heat transport, and how it is partitioned between the ocean and atmosphere. There is no way to do this without also making large changes to sensible weather.
4. Precipitation patterns are severely disrupted in the subtropics by the movement of the ITCZ. (See figure S4). These are areas where seeds are produced for use in the temperate growing areas.
5. By analogy with food crises brought on by the Ukraine war and also a 1973 grain shortage, it doesn’t take much disruption in the supply by producing countries to send grain prices soaring. I agree with Geoff Miell that a shutdown of the AMOC would make (at least) northern and central Europe essentially unable to produce crops. This would result in huge food imports. This would soak up the supply from any area lucky enough to still be producing a surplus. Europe has plenty of money, more of which would be devoted to food purchases. Worldwide food prices would be far higher than even in recent crises.
Max, I may get in trouble with John P for bringing up zhaos (my unofficial version of chaos), but the question is… how sure are we about what “cascade of consequences” to expect in any scenario?
I’ve raised the question of what we even mean by “tipping point” before, and I think it is one of the concepts that adds to the confusion.
So, is there some point in time where the melting of permafrost creates a positive feedback which continues to increase the greenhouse effect (GHE) even if we get to zero anthropogenic forcing? If not, it is just another bad effect we have created, not really a “tipping point”.
(OTOH, the release of a deadly virus in Siberia that results in collapse of Russia and loss of nuclear weapons control….)
But to get back to the zhaos point, if the AMOC collapses, or, for example, you get a precipitous decline in winter (not summer) Arctic sea ice, that seems to me a clear indicator that the system has truly moved away from the original equilibrium state. And however we label it, I don’t think we should be overconfident about predicting what the path to the new one will actually be like, except that it probably won’t be much fun.
So, not everything is an existential disaster, as Geoff seems to think, but some things could be symptoms of a very serious disruption.
Max Hartmann: – “Something I wonder about: Are the cosequences if an AMOC collapse really THAT devastating?”
Yep, the consequences could be catastrophic, for example:
1. The East Coast of the United States would be one of the regions most affected by rising sea levels if the AMOC shuts down. Add up to another metre of SLR on top of that already caused by global warming. Warming coastal oceans can also contribute to extreme heat waves over land and fuel more intense storms and rainfall.
2. A collapse of the heat-transporting circulation is a going-out-of-business scenario for European agriculture.
3. Shifting Asian monsoon rainfall patterns and even reversing the rainy and dry seasons in the Amazon.
https://insideclimatenews.org/news/09022024/climate-impacts-from-collapse-of-atlantic-meridional-overturning-current-could-be-worse-than-expected/
The heat from the “heat problem” doesn’t disappear. It’s still there.
Yes. Per the paper, the Southern hemisphere warms “slightly.” Not confident that “slightly” means “inconsequentially,” though.
https://www.science.org/doi/10.1126/sciadv.adk1189
Can you explain why?
Some people will dismiss this kind of study as speculation, and focus on words like ‘might’ and ‘could’, as if the uncertainty means we shouldn’t take it seriously… but it seems to me that we’re changing all kinds of global systems very rapidly in geological terms, and the uncertainty about what’s going to happen and when, is not at all reassuring. No matter how much we study past climates, as I understand it there’s no analogue in Earth’s history for what we’re doing in terms of changing the composition of the atmosphere, cutting down forests, destroying habitats and so on, all simultaneously and in years and decades rather than millennia. I remember Gavin making the point that the way we’re changing the atmosphere is a bit like the PETM in magnitude, but in the space of 200 years instead of 50,000 years. I think this kind of comparison of current events to Earth’s history should be more widely known.
Also see “What the geological record tells us about our present and future climate”, Journal of the Geological Society, Lear et al, vol.178, 2020, by the Geological Society of London:
https://jgs.lyellcollection.org/content/jgs/178/1/jgs2020-239.full.pdf
“the current speed of human-induced CO2 change and warming is nearly without precedent in the entire geological record, with the only known exception being the instantaneous, meteorite-induced event that caused the extinction of non-bird-like dinosaurs 66 million years ago. In short, whilst atmospheric CO2 concentrations have varied dramatically during the geological past due to natural processes, and have often been higher than today, the current rate of CO2 (and therefore temperature) change is unprecedented in almost the entire geological past.”
Thank you so much for this research. Could you explain for the mere mortal what are the next steps ?
On Climate science side:
– How do you plan to calibrate / recalibrate the model in the future ?
– Do we need to better probe the AMOC to get more realistic data ?
For Political / Climate adaptation side:
– Is there any chance to get a more accurate probability of this scenario happening decade by decade ?
– Would it be feasible to have a 5-10 years warning before it happens, or will we know it only once it happens ?
– Could we predict more precisely impact for each region (temperature change by month, humidity and rainfall variation, etc… ) ?
Thanks
Thank you Stefan for your overview.
As an Icelander, deeply attached to my country, if everything here is reflecting reality and if the proxy data are indeed correct (weakest AMOC for 150 years), we in Iceland would not be experiencing extreme melting of our glacier, intense greening (especially in the Western part, facing the cold blob) and record temperature accumulating in the last 15 years. Furthermore, for the last 120 years it has warmed around ~1 C even more in the Western part of the island. Or is it what one would expect? I know this is complex and nuanced. Might it be that the AMOC is not that important for Iceland? (Which is not what I have learned)
Moreover, Faroese and Norwegian direct measurements of some of limbs of the AMOC (the Faroese spanning 30 years) have not seen any weakening, on the contrary a small increasing if anything. Furthermore, OSNAP mooring project, are showing that most of the overturning is not taking place in those regions previously thought to be the locale of the deep water formations (rather it is taking place in the Irminger sea and much less in the Labrador sea as previously thought). Some researchers (Pöppelmeier) have shown (again with imperfect, but best available) that the AMOC might not have shut down as previously thought before last ice age.
How can all these different findings be reconciliated with the all of the models which lead to the conclusion of weakning or even collapsing AMOC?
What also worries me is that science “deniers” will be using this as “experts are not agreeing”. Maybe its time for people like Bogi Hansen, Rossby, Pöppelmeier, Lozier and others on one hand, and modelling community (you, Lenton, van Westen, Ditlevsens, Boers) on the other hand, to have a conference with deep scientific talks to synthesize a common message on how to reconciliate different stratergies on how to collect data and maybe weighing which method are likelier to reflect the Truth (which obviously is not easily obtainable in such a vast and extremely complicatd system).
This is serious business as it can make whole nation states inhabitable if it is indeed reflecting the Truth but not merely approximate Truth or plausible Truth.
Regards,
A very confused amateur
I’ve tried in a number of articles here to help and clarify some of the confusion coming out here.
For the regional extent of the AMOC slowdown effect I’ve posted data images of the ‘cold blob’, and Iceland is not in it after the estimated 15% AMOC weakening. It will be after AMOC shutdown. Temperature maps for both cases are again in the post you are commenting on.
The increased Nordic overflow is also in models; what is not resolved yet (I have students working on it) is whether this is an anticorrelated to the AMOC (for which I have a mechanism), or just unrelated. There’s no reason why they should be in sync.
A frequent source of confusion is also when people talk about short timescales (say OSNAP, 10 years) while we are discussing the long-term large-scale changes. Hope that helps a little, Stefan
Closest point I can shoehorn in a different if related query:
Is warm water into Barents Sea an AMOC weakening signal? It seems that it could serve as a partial shield of Europe from Polar conditions?
Thanks for the reply Stefan.
This clarifies a bit. I look forward to see the latest research.
I however, miss more public conversations between the oceangrahic community and the more computational-inclined community, it could we valuable constructive discourse, even for the amateurs and laypersons
Jóhann
Dear Prof. Rahmstorf,
the paper submitted by the authors in August 2023 included a map showing a sea-level increase around Europe by up to 1 m due to geostrophic balance after a AMOC collapse. I can understand the increase near the US East Coast. Why ist there an increase near Europe.
Best regards, Georg Kury
Just saw it – that the AMOC could collapse soon was just a feeling of the authors while their study result implied otherwise – here is their conclusion:
“In the CESM simulation here, AMOC tipping occurs at relatively large values of the freshwater forcing. This is due to biases in precipitation elsewhere in the models and mainly over the Indian Ocean (37). Hence, we needed to integrate the CESM to rather large values of the freshwater forcing [∼0.6 Sv, about a factor 80 times larger than the present-day melt rate of the Greenland Ice Sheet (55)] to find the AMOC tipping event. The effect of the biases can be seen from the value of the AMOC-induced freshwater transport at 34°S, FovS, which is positive at the start of the simulation. When biases are corrected in the CESM, it is expected that the AMOC tipping is expected to occur at smaller values of the freshwater forcing. As also the present-day background climate state and the climate change forcing are different than in our simulations, the real present-day AMOC may be much closer to its tipping point than in the simulations shown here. Note that the analysis of the early warning signal is not affected by these biases, as this analysis is independent of the background state and precise forcing details.”
https://www.science.org/doi/10.1126/sciadv.adk1189
Fun Fact: in 2012 to 2016 the largest freshwater outbreak took place into the North Atlantic and what happened? The AMOC increased in strength till today from 2012 onward – not that it could not collapse, but the real-world data shows it to be quite stable towards freshwater outbreaks from the central Arctic Ocean – and the cold blob before Greenland is also disappearing in winter the last years – the surface imprint of a weaker AMOC.
What is also important: The Gulf Stream is warming extremely, so the waters get more warm, so a weakening does not translate in a cooling as a smaller volume is partly subsidized by warmer water temperatures. – but could be wrong here, as the AMOC water cools down on its way further north…
Here the Studies:
“Ocean circulation causes the largest freshening event for 120 years in eastern subpolar North Atlantic”; https://www.nature.com/articles/s41467-020-14474-y
“Pending recovery in the strength of the meridional overturning circulation at 26° N”; https://os.copernicus.org/articles/16/863/2020/
“a cooling of winter temperatures by between 10 °C and 30 °C occurring within a century”
If I understand correctly, the timeline of the model was drawn out considerably compared to a real-life AMOC shutdown timeline, for technical reasons. Does this mean that the above-mentioned cooling could happen much faster than within a century?
I am following the computational part of climate modelling with high interest and i am not surprised that we see new effects with smaller grid dim at simulation. I am mot convinced that a grid of 1 x1 degree which is a about 100 by 100 km is fine enough when i compare it to pictures of hotter and colder surface water along eastern north America cost line. Is there a kind of grid size adapting numerical integration method like Shampine Gordon for time dependent systems ? Could not an automatic grid size adaption wipe put the concern of “do we really see all effects”?
Sure this requires effort in distributing computational load to a limited number of available CPUs.
[Response: The problem with adaptive meshes in ocean models is that you need to add resolution over a large fraction of the grid and the overhead of the adaptive mesh then means you were better off just increasing the resolution everywhere. However, every doubling of resolution is about a factor of 10 increase in computation, so to go from 1º (which was standard in CMIP6) to eddy-resolving (say 1/8 or 1/12º) is 1000x more expensive. We aren’t yet there for multi-thousand year simulations. But you are correct in thinking that people are curious to see what impacts this will have. – gavin]
Stefan, may too ask an elementary question , this time concerning the ‘cold blob south of Greenland?
Working with high pressure physicists like Ike Silvera has made me aware that water is remarkably incompressible- it takes a lot of energy to squeeze it to a density of 1..01.
But at the same time, it reaches its maximum uncompressed density at around 6˙ C.
This obviously complicates the role of buoyancy in dynamic heat transfer at the windy air-sea interface of the North Atlantic cold patch, since the temperature induced density fluctuations compete with the energetics of hydrogen bonding in water parcels that bob up and down in it.
Are the energetics large enough for cyclic near surface compression to contribute to the anomalously low temperature of the cold patch ?
Stefan: The difference in density between -1˙C, and +4 ˙C is roughly a part per thousand : ~ .001 which is equivalent to that produced by compression to about 30 atmospheres
To the degree that temperature and pressure are energetically equivalent, the question therefore is whether the wind can extract the heat of compression faster than the density changes with temperature.
Any physicist should know that the gravity effect on fluids is one of a differential effect — gravity will act on the differences in the densities of the distinct stratified layers of fluids. This becomes most evident on stratified layers such as exist at the thermocline — which is a density differential due to temperature. But there are also stratified layers due to density differentials due to salinity, and these are referred to as thermohaline staircases. The biggest disappointment in the research is the overlooking of forcing due to long-period tides modulated by seasonal changes as applied to thermocline-related layers. Tsunami-scaled tidal effects are going on subsurface, yet it’s all being ignored.
Do the math emulation and you will see that the Atlantic Multidecadal Oscillation is likely actually the Atlantic Tidal Oscillation — a few too many letters in
Multidecadal. This can be well calibrated to known tidal forces and cross-validated across time intervals. As we all are observing , Google/NVIDIA/Huawei are spending $millions on AI weather and climate predictions, yet a fraction of this money is needed to do tidal-based prediction — because it’s primarily deterministic and we don’t need to burn all those computer cycles averaging out random and chaotic regimes. It’s really worth exploring, no matter how much the consensus is set in their ways — it’s little risk for great potential reward.https://geoenergymath.com/2023/12/28/atlantic-tidal-oscillation/
As NASA JPL is being fiscally gutted, let’s start working smart.
Time to start connecting the dots and consider that the way that extreme events can occur. No one mentions that something akin to the additive change due to multiple natural factors can be happening. My comment is respect to tides — they are comprised of multiple cyclic forces with the strength caused by reinforcing combinations of these forces. So can have the moon, and it can have 3 reinforcing factors related to its perigee, declination, and strength of declination (a longer period). These can be combined with reinforcing factors due to the sun, and the sun can be highly nonlinear as it plays with the thermocline and freeze/melt. Moreover, these are all incommensurate in their timing so the maximum tides can get quite complicated and the more factors that interact, the longer the time between the extremes (this is similar to the assortment of Milankovic orbital cycles but on a much shorter time scale). No one in climate science is really acknowledging that as a possibility. When and if this current heat spike goes back to normal and/or the AMO starts decreasing again, that’s when the head-scratching for mechanisms will begin anew. Yet, that said, if the numbers stay elevated, then the man-made AGW will retain the focus.
The maximum density of salt water is below the freezing point.
Stefan, many thanks for the temperature shift, but the question remains- can cyclic water compression transfer heat vertically in energetic sea states?
Hi Stefan
How would you feel explaining this (in general terms) to a jury that will be deciding the fate of the first group of six M25 gantries supporters of Just Stop Oil, myself included, going to trial on 4th March 2024. This is the first of several trials of the 50 or so protestors taking action on the M25 on 7-10th November 2022 and so will set a kind of precedent for the rest.
I/ we are looking for a climate scientist willing to act as an Expert Witness for us to ensure that the jury realise the seriousness of the effects of Global Warming on all of us. And that can only come from actual scientists and experts in this field.
I expect that expert witnesses will be called in the second week of the trial, so in the week starting on 11th March, maybe even on my birthday on the 12th!
Would you, Stefan, or a PhD member of your group, or another scientist willing to attend, be able to come to the Court for half a day and tell the jury the facts as you know them?
Thanks
[Response: I’ve done this in Berlin, but I have very limited time and England is full of excellent climate scientists who can be expert witnesses. Best of luck, Stefan ]
Paul Sousek,
I’d suggest you try approaching Professor Kevin Anderson.
https://en.wikipedia.org/wiki/Kevin_Anderson_(scientist)
See my reference to the video with Kevin Anderson:
https://www.realclimate.org/index.php/archives/2023/07/what-is-happening-in-the-atlantic-ocean-to-the-amoc/#comment-813633
Don’t know if they can help (US based), but the Climate Science Legal Defense Fund (CSLDF) has specialized in this kind of work. I believe it was founded by scientists closely allied with RealClimate.
LEGAL SERVICES
We provide a range of free legal services to help scientists understand their rights and responsibilities, including threatened and actual legal proceedings.
https://www.csldf.org/legal-services/
ps. Anyone able and wishing to help, imho this organization is as good as it gets.
Just to clarify, the trial is near London, UK
Please respond by email
Will it recover? Can it?
Would AMOC collapse lead to a longer term climate oscillation, ie a period of (mostly NH) cooling with slowing of the freshwater flows that suppressed it, to restart and (with a enhanced greenhouse) warm rapidly and see those freshwater flows begin over again?
It does seem to be one of those counter-intuitive outcomes, where warming triggers cooling.
Stefan writes “This type of experiment is not a future projection at all, but rather done to trace the equilibrium stability curve ”
You mean trace it under the unrealistic scenario forced into the model?
This paper is little more than an exercise in understanding how the model reacts to a particular forcing.
Save Antartica
Stefan: – “2. It confirms by using observational data that the Atlantic is “on tipping course”, i.e. moving towards this tipping point. The billion-dollar question is: how far away is this tipping point?”
Leon Simons tweeted on Feb 14 (my local time) with “some basic energy and water calculations on the scary AMOC study”. It’s a relatively long tweet with a few graphs and figures, and concludes with:
https://twitter.com/LeonSimons8/status/1757510473275084880
Of course, not all the increasing planetary embodied heat is available to melt all of the Greenland ice sheet immediately, but Leon Simons’ tweet suggests to me that the Greenland ice sheet is now already beyond its tipping point (unless the planet now begins to cool, which requires humanity to rapidly Reduce, Remove, Repair). Its accelerating ice loss will likely induce a further slowdown and ultimate shutdown of the AMOC in the not too distant future.
I’d suggest significantly more than a foot (0.305 m) by 2050 and multi-metre SLR within this century is looking increasingly likely.
https://oceanservice.noaa.gov/hazards/sealevelrise/sealevelrise-tech-report.html
Professor Jason Box suggests more than 20 m of SLR is already committed at current atmospheric CO₂ levels.
https://www.realclimate.org/index.php/archives/2023/08/the-amoc-tipping-this-century-or-not/#comment-813939
These changes are happening faster than forecast.
When you say not too distant fututre do you mean the AMOC could shutdown by 2050? Also what would you expect to happen first, an ice free year in the arctic or the AMOC shutdown?
Greyhound: – “When you say not too distant fututre do you mean the AMOC could shutdown by 2050?”
I’d suggest you should direct your question to the authors of the papers referred in Stefan’s post above.
You may also wish to look at the following:
On 13 Feb 2024, CleanTechnica published a piece by Steve Hanley headlined AMOC Runs Amok, Life In The US & Europe Will Change Dramatically, included (bold text my emphasis):
https://cleantechnica.com/2024/02/13/if-amoc-runs-amok-life-in-the-us-europe-will-change-dramatically/
Greyhound: – “Also what would you expect to happen first, an ice free year in the arctic or the AMOC shutdown?”
On 7 Jun 2023, The Conversation published a piece by Jonathan Bamber headlined Arctic Ocean could be ice-free in summer by 2030s, say scientists – this would have global, damaging and dangerous consequences, beginning with (bold text my emphasis):
https://theconversation.com/arctic-ocean-could-be-ice-free-in-summer-by-2030s-say-scientists-this-would-have-global-damaging-and-dangerous-consequences-206974
Zack Labe maintains a website which contains near real-time climate visualizations, including for Arctic sea ice concentration/extent.
https://zacklabe.com/arctic-sea-ice-extentconcentration/
Perhaps that’s sufficient information to draw your own conclusions?
Thank you for discussing this important matter. To my layman’s understanding, a collapse of AMOC is one of the most dangerous potential effects of global warming.
I have one question, however, regarding model predictions on the next order of feedback: A collapse or significant reduction of AMOC will likely lead to cooler surface temperatures around the North Atlantic and could, thus, lead to increased snow and ice coverage and reverse the polar amplification of global warming. This, in turn may decrease melting rates of glaciers and reduce the fresh water input. As I have no idea regarding the magnitudes of these effects, I am wondering what outcome models are predicting:
a) A further increase of global warming despite this effect,
b) the generation of a new equilibrium and re-start of AMOC (albeit weaker than before),
c) Polar cooling becoming dominant
And are there indications on which timescales such feedback effects might happen?
Best regards
Hannes
According to the Ditlevsen paper, tracking of the AMOC is done by subtracting the subpolar gyre (appears similar to AMO in its multidecadal variability) from the global mean SST.
https://www.nature.com/articles/s41467-023-39810-w
That seems an awful stretch without understanding what the SG/AMO means and whether the AMO is actually even an oscillation according to the latest discussions.
Did you read the cited ref concerning this procedure? That’s what most professionals actually do when something “seems” odd? It’s reference #23.
23. Caesar, L., Rahmstorf, S., Robinson, A. et al. Observed fingerprint of a weakening Atlantic Ocean overturning circulation. Nature 556, 191–196 (2018). https://doi.org/10.1038/s41586-018-0006-5
Bet Stefan’s ever aware the issues, don’t ya’ think?
jgnfld: Did you read my research on understanding oceanic indices such as AMO? It was also published in 2018. Thanks in advance.
Update of my observations of recent anomolous MSL rise around the UK, previouly posted here on an earlier AMOC concerns thread, but still no academic explainer as to what is causing this.
eg Getting ever more apparent from the deep water UK port of Newlyn
The blue and red lines ,should on average, be coincident on
https://ntslf.org/storm-surges/latest-surge-forecast?port=Newlyn&chrt=3
but Newlyn and all other UK ports have been showing similar vertical displacement of these residual curves, and in their archives of the last few years. NTSLF of course allows a figure for global SLR and local GIA, but this anomaly is getting to be unmistakable, despite local issues like dredging affecting individual ports unupdated tidecurves and partially masking this anomaly .
It would be convenient to say there is a problem with the Exeter Met Office/NTSLF big-data surge predictor of the blue. But 2 different analyses independent of NTSLF and independent of each other confirm an anomalous MSL change ,well beyond global SLR and local GIA. Also quiet weather periods, ie just inverse barometer, confirm no problem with the blue curve predictions Newlyn or my local NTSLF port of Portsmouth .
Another paper author I tried emailing recently
“North SEAL: a new dataset of sea level changes in the
North Sea from satellite altimetry”
Denise Dettmering et al,
to see what they make the North Sea rise since their paper cutoff date of 2019 but again no reply.
Since June last year ,each 3 days I’ve algebraically extracted csv files for the blue and red data in those Newlyn graphical plots , and determined the RMS error.
Then curve-fitting along with the monthly NTSLF Newlyn RMS errors in their archive pdfs, back to my arbitrary start of 2020.0
For the 3days to 12 Feb, the rms error was +0.22m .
As the peak would seem to be in May 2024, I expect it to go higher and the below analysis going even higher.
I’m going with a component of Sa annual harmonic constant intruding into the NTSLF tidecurve and so “1.3” residuals plot, amplitude 4cm. Trying a wildcard further harmonic fit was only mm in amplitude and period nothing like a standard astronomic harmonic or any of the compound shallow-water harmonics.
So ignoring that annual cycling component of ampitude and any other periodic component leaves a rising yearly MSL, that comes to ,for the moment (relative amounts are bound to change in the coming months as relatively short time of my high frequency processing of less than one year ,so far)
Increase <1mm in calendar year 2022
Increase of 2.5cm in calendar year 2023
Projected increase of 3.3cm in year 2024
Total Newlyn MSL anomaly currently projected to peak at 0.21m in May 2024 from my arbitrary 2020.0 time start height of 0.15m .
All well above global yearly SLR and subsiding south-UK GIA.
As Newlyn RMS error figure already 0.22m this week , I expect further rise in the next few months.
I suspect with slowing of AMOC and Greenland meltwater and Baltic freshwater and so salinity change , less dense and consequential increasing the sea height. The deep cold return path is not up to the job and water is building up in the NE Atlantic.
A slowing of AMOC from the principle that reductions in the amount of Atlantic bottom water reaching the ocean floor increases sea levels because the warmer water that replaces it takes up more space.
Perhaps a more local change in the sub-polar gyre is affecting the NE Atlantic sea level.
Another possible alternative explanation could be hydro-isostasy from the extra weight of sea water in the last few decades , depressing the NE Atlantic basin. But how that would affect the margin, ie like the UK, up or down is unknown to me , additional to post-glacial GIA, but difficult to see it amounting to about 0.15m in a few years.
Or of course simple warming of N. Atlantic water to depth, increasing sea level .
Unknown to me whether the same anomaly is showing up in Scandinavia or Iceland, or France say. AFAIK NTSLF is the only public-access big-data daily oceanographic Navier-Stokes number cruncher, anywhere in the world, required for such order of cm resolution residual analysis.
Until the mechanism of this additional mean sea level rise is known, its impossible to say whether the anomalous rise is limited, multi-year cyclic or ongoing rise.
Nick Cook
A reply on this UK MSL anomaly topic from a researcher at the
National Oceanography Centre
Joseph Proudman Building
6 Brownlow St, Liverpool, UK
(edited out caveat about why academics use PMSL and BODC data that has been examined to GLOSS standards rather than realtime data sources)
…
All that said, I think you might be right. I haven’t yet looked at the February data, but I’ve just been looking at 2023, and there have been some long anomalies of tens of cm, in particular October-November. They occur simultaneously across several gauges in the southern UK, so appear to be genuine. A lot is explainable by the surge model – a combination of pressure and wind – but not all, so seem to be related to wider conditions in the Atlantic. We’re working on understanding them at the moment.
Latest report back from academe relating to salinity changes around the UK, if not AMOC
Quote
The operational surge model takes little account of salinity, as it is only a barotropic model. One of the ongoing areas of research is into how much effect it has to use a baroclinic model instead, and what proxies can be used to make up the difference if not. We are also investigating this year’s sea-level changes in Newlyn and elsewhere – rest assured this anomaly has not gone unnoticed! We’re also looking at satellite altimetry. Again, NTSLF is not the best source of data for long term trends, as it contains uncalibrated instrumental records for the sake of storm time-scale completeness.
You’ll appreciate that I’ve got several projects ongoing, and have to prioritise, so I’m afraid I can’t promise to keep you updated with the work. There will be a report coming out as part of the Met Office’s “State of the UK Climate” in the summer do so look out for that.
End Quote
Regarding the ‘cold blob’.
The surface northward flux of warm and salty water has two branches. The first one is the subpolar gyre, that brings water to the ‘cold blob’ region. The second one continues northward to the Norwegian and Barents seas.
Maybe less warm and salty water is reaching the ‘cold blob’ region because more of this warm water is taking the second branch?
This sounds consistent with the warming of the Norwegian and Barents seas and with the ongoing ‘Atlantification’ on the Siberian Arctic, doesn’t it?
Hi Steffan,
when I read about the implications this study makes I went a little bit into the details as I stumbled in so many fields on studies what models can do or not do or when they can do it. I thought they had used a model with higher resolution – read too fast your article – but far from it – guess this study result is more like rolling dice as scientific literature is quite clear on what the model they used is able to do – AMOC, with sea ice and meridional heat transport – no chance in terms of best available proof!
They used a Community Earth System Model (CESM; version 1.0.5). which was used as part of the Coupled Model Intercomparison Project (CMIP), Phase 5. It has a horizontal resolution of 1° for the ocean/sea ice components and 2° for the atmosphere/land components (8). So not even the latest version of the models that are currently in phase 6 – CMIP-6.
So here’s a statement from the sea ice people – it’s called the “SIMIP Community” as they should know:
“However, most CMIP6 models do not manage to simultaneously simulate a plausible development of sea ice area and global mean surface temperature. The sensitivity of Arctic sea ice to changes in forcing factors is better captured by CMIP6 models than by CMIP5 and CMIP3 models.” (9).
This means that the authors of the study: “Physics-based early warning signal shows that AMOC is on tipping course” used a model that is in no way suitable for the research subject they are investigating – they should have known that!
So here are the model components they took: “The CESM (in the f19 g16 configuration) is a fully coupled climate model. The Parallel Ocean Program version 2 [POP2; (56)] is used for the ocean component, the Community Atmosphere Model version 4 [CAM4; (57)] is used for the atmosphere component, and the Community Ice Code version 4 [CICE4; (58)] is used for the sea-ice component.” (8) – the modules come from 2010, 2013, and 2008 – so they are completely out of date given the level of knowledge we have today!
Let’s just take the outdated ocean module – because 2010 is old – the POP model is a heavily parameterized module (10): First of all, it has a resolution of 1°, which is very large for simulating currents and eddies, which play here an important role. These ocean eddies were simply parameterized (8) – that is, a metavariable was simply inserted or eddies.
For example, we know that if you simulate the elongated form of Eddies (they didn’t even simulate it), this refinement alone causes the northward heat transport to double (11).
Therefore, here is what the Max Plack Institute says about models that want to simulate the AMOC over Eddies that have only been parameterized:
“Applying the same wind scenarios in a non-eddy-resolving configuration of MPI-OM supports the ocean-eddy hypothesis: The decline in the deep branch cannot be reproduced because the non-eddy-resolving model captures eddies only indirectly via a parameterization. It is therefore likely that also other current-generation climate models, most of which are non-eddy-resolving, miss the complete range of AMOC responses.” (12). Fits perfectly well with the studies finding out how important eddy-resolving models are for currents, mixing etc.
The model cannot correctly understand sea ice, nor the heat transport to the Arctic, nor the AMOC. Atmospheric modules are better because we have had much longer experience with them through weather forecasting. But here too, a much higher resolution leads to much better results as a plethora of studies shows.
In my opinion, if you do such a study with such a message you have to use the best available model + modules for the task at hand…
I do not think that the AMOC can not collapse but currently, it is strengthening somewhat again -but who knows maybe critical slowing down – but a little ice age soon? Really? During past interglacials, Greenland lost lots of its mass before the AMOC collapsed and a little ice age was happening – at least all the examples I found…
In short, I have my doubts!
All the best
Jan
The AMOC is currently strengthening acording to this study: “Pending recovery in the strength of the meridional overturning circulation at 26° N”; https://os.copernicus.org/articles/16/863/2020/
They write: “However, these measurements were primarily observed during a warm state of the Atlantic multidecadal variability (AMV) which has been steadily declining since a peak in 2008–2010. In 2013–2015, a period of strong buoyancy forcing by the atmosphere drove intense water-mass transformation in the subpolar North Atlantic and provides a unique opportunity to investigate the response of the large-scale ocean circulation to buoyancy forcing. Modelling studies suggest that the AMOC in the subtropics responds to such events with an increase in overturning transport, after a lag of 3–9 years. At 45∘ N, observations suggest that the AMOC may already be increasing. Examining 26∘ N, we find that the AMOC is no longer weakening, though the recent transport is not above the long-term mean. Extending the record backwards in time at 26∘ N with ocean reanalysis from GloSea5, the transport fluctuations at 26∘ N are consistent with a 0- to 2-year lag from those at 45∘ N, albeit with lower magnitude. Given the short span of time and anticipated delays in the signal from the subpolar to subtropical gyres, it is not yet possible to determine whether the subtropical AMOC strength is recovering nor how the AMOC at 26∘ N responds to intense buoyancy forcing.” – the graph is interesting as at 45°N it is strengthening again already – but could certainly decline again, no doubt here.
But the interesting part shows another study:
While in 2012 to 2016 we had the largest freshwater outbreak from the central Arctic Ocean but no AMOC Signal happened as it was the opposite:
“We show that the eastern subpolar North Atlantic underwent extreme freshening during 2012 to 2016, with a magnitude never seen before in 120 years of measurements. The cause was unusual winter wind patterns driving major changes in ocean circulation, including slowing of the North Atlantic Current and diversion of Arctic freshwater from the western boundary into the eastern basins. ”
“Ocean circulation causes the largest freshening event for 120 years in eastern subpolar North Atlantic”; https://www.nature.com/articles/s41467-020-14474-y
How about a student contest for movies of AMOC flows ?
The emphasis would be to visualize flows in many different ways, not on models per se
(a subgoal would be to have fun).
Is there a smallish 4d database that might make interesting movies ?
Here are the assessments from other experts on the study – they converge with Ramsdorfs assessment here – but the study could not prove an imminent collapse which it implied at the end and their model was not able to do the job correctly but the experiment gave important insights on AMOC behavior and that the consequences could be drastic… https://www.sciencemediacentre.org/expert-reaction-to-modelling-study-suggesting-atlantic-ocean-circulation-amoc-could-be-on-course-to-collapse/
Given how close or far off the AMOC is near its tipping point (nobody knows for sure), it is however crucial that CO2 emissons decreases. Not only for the climate but also for the ocean acidification which in some subpolar regions is having an effect on livelihoods.
It is crucial that carbon dense fuel (wood, oil and coal) will be replaced by much much more carbon light fuel such as liquid gas in the developing world. Burning gas instead of coal is what has led the almost 30% decreases in CO2 in USA from 1990 to 2020. The funds from the rich world (decided on COP27?) needs to be used to invest in gas burning plants and in green energy technology; solar and wind as well.
Richer countries such build hydropower (where this is possible) plants and nuclear power plants to replace the earth fuel ones.
Furthermore, a carbon tax should be implemented on the most emitting industries so they will eventually invest in (future) carbon seqestering technology.
I’ve come to the conclusion that only investment funds from richer to poorer countries, reinforcing incentives (e.g. carbon tax) and technological progress will help us out of this mess.
This will also lead people from across the political spectrum nearer to a concrete solution in my opinon. The moderate left and moderate right parties in my country could converge e.g. on those proposal listed above.
I think the climate research community should assist policymakers in forming scenarios for decreaseing co2 emissons.
Johann: – “Given how close or far off the AMOC is near its tipping point (nobody knows for sure), it is however crucial that CO2 emissons decreases. Not only for the climate but also for the ocean acidification which in some subpolar regions is having an effect on livelihoods.”
IMO, you begin with some reasonable statements. Then it deteriorates with what seems to me to be a regurgitation of some talking points from the fossil fuel industry to effectively delay, delay, DELAY…
Johann: – “It is crucial that carbon dense fuel (wood, oil and coal) will be replaced by much much more carbon light fuel such as liquid gas in the developing world. Burning gas instead of coal is what has led the almost 30% decreases in CO2 in USA from 1990 to 2020. The funds from the rich world (decided on COP27?) needs to be used to invest in gas burning plants…”
Um… We/humanity need to stop burning all carbon-based substances. I’d suggest you are also ignoring the grossly underestimated ‘fugitive emissions’ from the oil and gas industry, which are now being revealed by recently-deployed methane emission-seeking satellites correlated with ground-based field measurements.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6987228/
https://globalenergymonitor.org/projects/global-methane-emitters-tracker/
Here’s a Jun 2020 Explainer from the Australian Climate Council titled Why Is Gas Bad For Climate Change And Energy Prices?
https://www.climatecouncil.org.au/resources/why-is-gas-bad-for-climate-change-and-energy-prices/
Johann: – “Richer countries such build hydropower (where this is possible) plants and nuclear power plants to replace the earth fuel ones.”
Nuclear technologies cannot save us – too slow to deploy, too expensive, uses finite fuels inadequate to sustain long-term a so-called “nuclear renaissance”, and leaves behind a toxic waste legacy that will long outlast any energy benefits gained. Nuclear is too slow to deploy to make any significant difference for humanity’s need to rapidly reduce greenhouse gas emissions.
https://www.realclimate.org/index.php/archives/2023/12/unforced-variations-dec-2023/comment-page-2/#comment-817546
Johann: – “Furthermore, a carbon tax should be implemented on the most emitting industries so they will eventually invest in (future) carbon seqestering technology.”
Carbon capture has a long history – of failure.
https://thebulletin.org/2022/09/plagued-by-failures-carbon-capture-is-no-climate-solution/
Johann: – “I think the climate research community should assist policymakers in forming scenarios for decreaseing co2 emissons.”
I’d suggest policymakers haven’t been heeding the “climate research community” for decades. New and extensions of existing fossil fuel projects are still being encouraged and approved by regulating authorities around the world. IMO, this is civilisation suicide!
The idea that emissions could continue till 2050 and still achieve the 1.5–2 °C goal was always a con; now it is fully exposed.
https://johnmenadue.com/humanitys-new-era-of-global-boiling-climates-2023-annus-horribilis/
https://johnmenadue.com/part-2-towards-an-unliveable-planet-climates-2023-annus-horribilis/
https://johnmenadue.com/as-warming-accelerates-and-1-5c-is-breached-faster-than-forecast-australia-needs-to-re-think-climate-risks-and-policy/
What’s required to avoid the current trajectory towards civilisation collapse before the end of this century?
Reduce;
Remove;
Repair.
https://www.climatecodered.org/2023/06/three-climate-interventions-reduce.html
Nothing less will do. The Laws of Physics are not negotiable.
Thanks very much Geoff. Red flags on the play went flying as soon as “much much more carbon light fuel such as liquid gas” were uttered.. And, as you found also, it was downhill from there.
By the way, Cornell professor Robert Howarth is publishing a paper that indicates LNG (cryogenic methane) has double the “total GHG emissions” from that of coal, when including transport shipping!
Solar Jim
Looking at that temperature trend map, if the AMOC were to collapse, it might get cold enough in Scotland for glaciers to form in the Cairngorms and Lochaber mountains.
Geoff Miell: The laws of physics are not negotiable.
V: True. But theories based on interpretations of the laws of physics are testable.
Victor: “theories based on interpretations of the laws of physics are testable”
by those who know the law of physics, as well as statistics. Your posts on RC exclude you on both accounts.
Victor: “theories based on interpretations of the laws of physics are testable”
Piotr: by those who know the law of physics, as well as statistics. Your posts on RC exclude you on both accounts.
V: The tests were not performed by me, but by perfectly competent climate scientists. The theory that rising CO2 levels would produce rising global temperatures was tested by such specialists during the years 1940 through 1979. If the theory were correct then they would have observed a rise in temperatures during this period, since CO2 levels had been rising significantly. Instead, a drop in global temperatures was observed. While trained scientists were required to perform this test, it does not require much training in either physics or climate science to interpret the result.
If the theory were correct then they would have observed a rise in temperatures during this period, since CO2 levels had been rising significantly.
Victor, CO2 doesn’t exist in a vacuum and neither does the Climate from 1940 thru 1979.
Global temperatures from year to year and decade to decade are driven by many more forces than a rising CO2 (ghg) levels alone.
You obvious would know this, yes? eg was there any change in the global aerosols levels from 1940 to 1979? Actually was anyone on earth even measuring such things back then.
BTW how much did atmospheric CO2 levels rise from 1940 to 1979 anyway?
During these 4 decades what was the Sun doing +/-? ENSO? Land Use? Economic growth? Consumption? Volcanoes? Methane levels? The Milankovitch cycle?
Victor has had every opportunity to learn this, as there have been many circuits
around the monocausal merry-go-round. But hey, “If you push anything hard enough, it will fall over.”. Maybe your push will be the magic one that finally topples the ramshackle tower of sophistry that is Victor’s ignorance.
V: The tests were not performed by me, but by perfectly competent climate scientists
But you, Victor, a person who has no idea about science and statistics, do not have the intellectual tools to determine whether they are “perfectly competent scientists“. Those who do – determine that they are not: e.g. see the parallel thread “Spencer’s Shenanigans”, where Gavin systematically deconstructs that “perfect competence” of Roy Spencer – reducing the poor fellow to finding the solace in the fact that Gavin … didn’t refute ALL his claims ;-) (not because they were strong butrefuting a lie takes more space than needed to make that lie – so by necessity one has to concentrate on the most outrageous ones: to prove that the house is structurally unsound it is enough to show the problem with foundation and weight-bearing supports – you don’t have to criticize the shingles on the roof.
In the absence of the necessary knowledge (here: science and statistics) you are reduced to picking winners based on your psychological/ideological needs – you a priori assume that climate change deniers are beacons of integrity and scientific competences, so you gladly swallow their claims, hook, line, and sinker.
But your presence here does not be a complete loss – given your lack of tools – you won’t learn here much about the world around you, but you can at least learn something about yourself:
-you could examine yourself and see: confirmation bias, your ignorance feeding your arrogance, and deeply psychological need filled by being a conspiracy theorist: “if everybody else got fooled, but not me, then _I_ must be smarter than them, and my life is no longer so pathetic, right?”.
Life unexamined is not worth living, my dear fellow.
Victor: – “But theories based on interpretations of the laws of physics are testable.”
Would you even know what that means as an apparent persistent climate science denier, a regurgitator of climate myths and ignorer of reality, aye Victor?
https://www.realclimate.org/index.php/archives/2023/11/unforced-variations-nov-2023/#comment-815557
It seems in Jun 2018, Tamino even gave special attention to your persistent denial of reality, aye Victor?
https://tamino.wordpress.com/2018/06/30/weak-sauce-from-climate-deniers/
Hmm. Let’s see. Based on the laws of physics, Svante Arrhenius predicted back in 1896 that human emissions of CO2 would result in a long-term warming trend for the planet. How did he do?
Global temperatures have risen more than 1 deg. C since then. Yes, there have been fluctuations, but atmospheric temperature is a noisy metric.
How about ocean temperatures? They’ve risen pretty much monotonically since 1960, when we started to have pretty reliable temperature readings at depth over much of the ocean . Before that? Well, we can look at the rise in sea level. About 30-40% of the rise in sea level since 1900 has been due to thermal expansion.
We could look at other metrics, but this by itself is sufficient to establish Weaktor and his like as the morons they are.
Ray Ladbury: Hmm. Let’s see. Based on the laws of physics, Svante Arrhenius predicted back in 1896 that human emissions of CO2 would result in a long-term warming trend for the planet. How did he do?
Global temperatures have risen more than 1 deg. C since then. Yes, there have been fluctuations, but atmospheric temperature is a noisy metric.
V: As is well known, the temperature rise during the first 40 years of the 20th century was due almost exclusively to natural variation, NOT CO2 emissions, which were minimal over this period. “[Research] has shown that the temperature rise up to 1940 was . . . mainly caused by some kind of natural cyclical effect, not by the still relatively low CO2 emissions.” Spencer Weart, “The Discovery of Global Warming.”
During the following 40 years, while CO2 levels were rising significantly, global temperatures failed to warm, thus falsifying Arrhenius’s hypothesis. It’s as simple as that. To shrug off evidence collected over a 40 year period as a mere “fluctuation” is to reveal your own confirmation bias. Once a theory is falsified it cannot then be revived on the basis of evidence emerging subsequent to falsification. We have no reason to believe the recent rise in temperatures was caused by anything other than what caused the aforementioned rise from 1910 through 1940. To dismiss such thinking as “moronic” only reveals your own insecurity. Don’t feel too bad though. Confirmation bias is common among scientists in every field.
We’ve been through this before numerous times, Victor. I’m repeating my objections for those who may be relatively new to the site, and don’t feel like wading through voluminous comments.
You haven’t falsified anything, so there is nothing being revived except for your misconceptions.
Here are three reasons why you haven’t falsified the hypothesis that human CO2 emissions are a cause of global warming by pointing to the 1940-79 period as a counter-example:
1. You are making the implicit assumption that global temperatures will reflect CO2 levels almost instantly. This despite known heat storage in the oceans and through glacial ice melt. Both are slow processes. Only if you can show that these processes are unimportant on the time scale of 40 years can you say that the hypothesis is falsified.
2. You are stating that the temperature rise (of roughly 0.2C) from 1900-1939 was due “almost exclusively to natural variation” from unidentified causes. But if that is the case, then the failure of the temperature to rise by the roughly 0.2C expected from the CO2 hypothesis could also be due to unidentified natural causes.
3. You haven’t tested your null hypothesis, which would be “given natural temperature fluctuations of 0.2C persisting over several decades, what are the chances that I can pick a 40 year period, ex post facto, which will show a near zero rise in temperature when the CO2 content of the atmosphere has increased by at least 30 ppm?” Only if you can demonstrate that the probability is very low can you say that you might have falsified the hypothesis. You can’t say for sure unless you have also, at a minimum, satisfied condition 1.
In fact, since other causes of climate variation have been identified, you would also have to eliminate those as possibilities before you can say that the CO2 hypothesis, as you call it, has been falsified.
V: As is well known, the temperature rise during the first 40 years of the 20th century was due almost exclusively to natural variation, NOT CO2 emissions, which were minimal over this period.
BPL: Stop repeating that, because it’s not true. The percentage increase of CO2 was NOT minimal. Do the freaking math.
V: “[Research] has shown that the temperature rise up to 1940 was . . . mainly caused by some kind of natural cyclical effect, not by the still relatively low CO2 emissions.” Spencer Weart, “The Discovery of Global Warming.”
BPL: Do you understand what “mainly” means?
V: During the following 40 years, while CO2 levels were rising significantly, global temperatures failed to warm, thus falsifying Arrhenius’s hypothesis.
BPL: No. Wrong. Arrhenius’s hypothesis was never “only CO2 affects a planet’s temperature.” The “Arrhenius hypothesis” you knocked down was a straw man, and one you persist in addressing instead of learning. OTHER THINGS AFFECT TEMPERATURE BESIDES CO2.
Take a statistics course and learn about multiple regression. Until then, stop offering ignorant and obviously wrong arguments.
During the following 40 years, while CO2 levels were rising significantly, global temperatures failed to warm, thus falsifying Arrhenius’s hypothesis. It’s as simple as that. To shrug off evidence collected over a 40 year period as a mere “fluctuation” is to reveal your own confirmation bias.
Oh, Weaktor, Weaktor, this is just sad. Dude, the thing about “cyclic effects”: They go up and then they go down and then they go up… So, pray, how does your “…some kind of natural cyclic effect…” explain a monotonically rising trend?
Do you ever get tired of battling straw men? Are you really so timid that you can’t bear to even learn what the science actually says?
Ray, he’d do better with a slinky. The (cycle)/spiral goes up, then it goes down. He can’t or won’t look at the trends. One could hope he’d see one of the many long-term animations of warming or other graphics based on the longer term.
“Mainly” does not equal “almost exclusively.”
As for the “minimal” emissions, well:
1750, 280 ppm
1900, 328 ppm (Plus 17%)
1945, 360 ppm (Plus 9%, plus 28% WRT 1750)
So, the usual approximation of CO2-induced warming is the product of the log of the ratio of increased concentration to previous concentration, times the climate sensitivity. Let’s assume a midrange S of 3 C. So what are the respective log values?
1750-1900: 0.2265
1900-1945: 0.12433
1750-1945: 0.35614
So, the expected warming, again respectively:
0.6795 C
0.37266 C
1.06856 C
In BEST, the smooth curve for 1900-1945 looks like 0.30 C or so. Seems like the early 20th C warming could mostly be accounted for by CO2. Theoretically, of course. But we all–well, almost all–know that other factors influence temps. And S is still, as they say’ “not well constrained.”
Nevertheless, it’s pretty weird that our dear Victor wants essentially to arbitrarily set the CO2 contribution to 0.
Sorry, included a Victor paragraph twice. My bad.
Droughts and floods and fires, oh my
AMOC on tipping course, oh my
Antarctica melting into the sea, oh my
Heat waves and sea rise and blizzards, oh my
Loss of Arctic sea ice, oh my
Polar bears facing extinction, oh my
Thousands of species lost, oh my
Global heating on the rise, oh my
Those nasty billionaires pouring out lies, oh my
Oh my oh my oh my oh my oh my
We’re off to consult the experts,
The wonderful experts of Oz.
We know they know what they think they know
Because because because because because
Because of THE PHYSICS, wouldn’t ya know.
From the rhetorical tool-box of Victor:
“ Loss of Arctic sea ice, oh my
Polar bears facing extinction, oh my
Thousands of species lost, oh my ”
Why stop there?
– Evolution, oh my
– Earth is not flat, oh my
– Vaccines don’t cause autism, oh my
– The Moon landing wasn’t fake, oh my ?
Piotr, oh my
V: During the following 40 years, while CO2 levels were rising significantly, global temperatures failed to warm, thus falsifying Arrhenius’s hypothesis.
BPL: No. Wrong. Arrhenius’s hypothesis was never “only CO2 affects a planet’s temperature.” The “Arrhenius hypothesis” you knocked down was a straw man, and one you persist in addressing instead of learning. OTHER THINGS AFFECT TEMPERATURE BESIDES CO2.
V: So what you’re claiming is that Arrhenius’s hypothesis can’t be falsified. Given evidence to the contrary, there will always be “other things” that must be taken into account that could explain the difficulties away. Precisely the sort of thinking Occam’s Razor was designed to discourage. Sorry but a theory that can’t be falsified is not a scientific theory.
Oh, and by the way: what “other things” do you have in mind?
I see three categories of things that might be considered an “unfalsifiable hypothesis.”
First are those scientific ideas for which there are no current tests or obtainable observations. These would include such items as the “many worlds” interpretation of quantum uncertainty. Some of these later become testable, and are thus potentially falsifiable – but not at present. The search for ways to test the hypothesis may be fruitful, even if a hypothesis with no observable consequences is not.
Second are systems of ideas that are tenaciously held by scientific proponents, and overturned only with great difficulty and a large accumulation of evidence for a better system. These are in line with Kuhn’s paradigms. An example – well outside my field – is the controversy about when humans populated the Americas. Evidence that humans were present well before 14k years BP has been appearing for decades, but always in a way that could be questioned. Recently, human footprints were found in dried mud sediments in the Southwest U.S. in a layer between two others dating >20k BP. Now, the only remaining argument is whether the dating is completely accurate. The “more recently populated” hypothesis is falsifiable with sufficiently strong data, which is difficult to obtain. The proponents of the old idea aren’t saying that the “human” footprints are really juvenile Sasquatch prints, or deposited by space aliens to fool us.
Third are a large group of what are really just assertions, since the proponents will never admit that sufficient evidence exists to falsify them. They may be motivated by other primary concerns, such as those arising from religion, politics, or pecuniary interests. Contrary evidence will be met by a variety of evasive tactics, rather than showing in what way it can truly be mistaken. This is where there is a firm departure from science. Science requires evidence must be honestly considered and refuted on a basis of logic. I consider these evasions to be “dead parrot” tactics, captured nicely in an old Monty Python skit.
Victor, your refusal to directly acknowledge or seriously engage the objections to your ideas, over time have placed you in my third category.
Victor
Several things are known to impact Earths temperatures. Just some examples are cyclical changes in solar irradiance, el nino, asteroid impacts, Milankovitch cycles, volcanoes and human factors like deforestation and with Arrhenius CO2 was added to the list. Usually several of these are operating simultaneously. This is based on all the observed and analysed evidence. Occams razor doesnt say “ignore the evidence”. It only says the simplest explanation is usually best.
The difficulty is figuring out what factor or factors are impacting temperatures over some given time period. Scientists have determined that the main warming influence in current decades is CO2. This has not been convincingly falsified.
And nobody back in the early 1990s predicted anthropogenic warming would be a nice smooth straight line or a nice smooth curvilinear line like a parabolic curve. Scientists said there would be ups and downs, and occasional flat periods in the record of around ten years, but that the long term trend would be warming. And this is what’s happened.
V: So what you’re claiming is that Arrhenius’s hypothesis can’t be falsified.
BPL: NO! How in God’s name does that follow from anything I said?
It’s easily falsified. Arrhenius predicted that the trend would be positive and would be correlated with CO2. If either of those things hadn’t happened, his hypothesis would have been falsified.
V: Given evidence to the contrary, there will always be “other things” that must be taken into account that could explain the difficulties away. Precisely the sort of thinking Occam’s Razor was designed to discourage. Sorry but a theory that can’t be falsified is not a scientific theory.
BPL: There will NOT always be “other things” that must be taken into account to save the theory. Those other things ALSO have to pass empirical tests. EVERYTHING IS TESTED. Aerosols DO affect ground temperature. That has been tested in the lab and in the field. It’s a real thing. Stop saying it isn’t. Aerosols matter. The Solar constant matters. Albedo matters. Other greenhouse gases matter. Ocean-air cycles matter. Milankovic cycles matter.
Cosmic rays DO NOT matter. The colors of automobiles DO NOT matter. The efficiency of a goat’s digestive system DOES NOT matter. The color of the sky DOES NOT matter.
Do you get it yet?
Occam’s Razor does not mean, and never has meant, “prefer the simplest hypothesis.” You are dead wrong about that. It means, “prefer the simplest hypothesis THAT COVERS ALL THE FACTS.”
Stop wrongly using Occam’s Razor. And stop attributing to me things I never said.
BPL: There will NOT always be “other things” that must be taken into account to save the theory. Those other things ALSO have to pass empirical tests. EVERYTHING IS TESTED. Aerosols DO affect ground temperature. That has been tested in the lab and in the field. It’s a real thing. Stop saying it isn’t. Aerosols matter. The Solar constant matters. Albedo matters. Other greenhouse gases matter. Ocean-air cycles matter. Milankovic cycles matter.
Please educate MA Rodger about these matters. He seems to think only the 2016 El Nino matters when it comes to the massive rise in temperatures recently. So he concludes it’s not massive afterall and doesn’t matter much if anything. No bananas anymore – a mere blip, a best up. Nothing to see here, it’s juts another El Nino move along please …… lol
This all starts in the Artic ocean and the Beauford Gyre has built up amass of freshwater about the amount of all of the 5 great lakes and will release when it (the gyre) reverses it’s flow to counter clockwise condition.
Most of my family live on the coast and I have warned them about this, but recieved no questions or comments, I wonder just how quickly will this flow start, It will bring on the Super Grand Solar minimum spoken of by Professor Valentina Zharkova
Ree: “I have warned them about [the Beaufort gyre reversal], but received no questions or comments”
Perhaps … it’s not them, but you? You know, like your suggesting that a change in the regional currents on a far-away planet would cause … massive changes in the processes in the Sun (Ree: “ will bring on the Super Grand Solar minimum“) ? ;-)
R: This all starts in the Artic ocean and the Beauford Gyre has built up amass of freshwater about the amount of all of the 5 great lakes and will release when it (the gyre) reverses it’s flow to counter clockwise condition. . . . It will bring on the Super Grand Solar minimum spoken of by Professor Valentina Zharkova
BPL: Please explain the physical mechanism by which ocean currents on Earth affect the sun. Show your work.
[Credit goes to Piotr for getting to this first.]
BPL and Piotr
I think Ree made a typo and really meant to say:: “I wonder just how quickly will this flow start, It will bring on THE SAME LEVEL OF COOLING as ” the Super Grand Solar minimum spoken of by Professor Valentina Zharkova. He would not really believe ocean currents affect the sun. Ree was being sarcastic.
Nigel … There is a distinct lack of ability to discern meaning, and it is constant from these two. The problem is not the Typo or missing words.
Ned Kelly:” Nigel … There is a distinct lack of ability to discern meaning, and it is constant from these two. </
Rather, there is a distinct need of Ned Kelly to compensate his ego, bruised from having his ass handed to him, time and again, by these two.
Ned Kelly: "The problem is not the Typo or missing words.”
Except it is not an innocent, inconsequential, typo – but sloppy writing compounding the underlying ignorance of the science – the timing and length of the Beauford Gyre reversals is all wrong to be driven by that Super Duper Solar Minimum of Zharkova:
the gyre is stuck from early 2000, while Zharkova minimum is supposed to kick in 2020–2053.
Furthermore, Grand Solar Minima have no more than a 0.3°C cooling effect, barely enough to put a dent in …
Sarcasm based on one’s ignorance AND botched in the delivery – discredits not the intended targets, but its author.
Something, judging from your history on this forum, you must be intimately familiar with … ;-)
Ned Kelly:” Nigel … There is a distinct lack of ability to discern meaning, and it is constant from these two. </
Rather, there is a distinct need of Ned Kelly to compensate his ego, bruised from having his ass handed to him, time and again, by these two.
Ned Kelly: "The problem is not the Typo or missing words.”
Except it is not an innocent, inconsequential, typo – but sloppy writing compounding the underlying ignorance of the science – the timing and length of the Beauford Gyre reversals is all wrong to be driven by that Super Duper Solar Minimum of Zharkova:
the gyre is stuck from early 2000, while Zharkova minimum is supposed to kick in 2020–2053. The effect shouldn’t preceed the cause, my dear Watson.
Sarcasm based on one’s ignorance AND on top of that, botched in deliver. Something, judging from your history here, you must be intimately familiar with … ;-)
Ned Kelly:” Nigel … There is a distinct lack of ability to discern meaning, and it is constant from these two. </
Rather, there is a distinct need of Ned Kelly to compensate his ego, bruised from having his ass handed to him, time and again, by these two.
Ned Kelly: "The problem is not the Typo or missing words.”
Except it is not an innocent, inconsequential, typo – but sloppy writing compounding the underlying ignorance of the science – the timing and length of the Beauford Gyre reversals is all wrong to be driven by that Super Duper Solar Minimum of Zharkova:
the gyre is stuck from early 2000, while Zharkova minimum is supposed to kick in 2020–2053. The effect shouldn’t preceed the cause, my dear Watson.
Sarcasm based on one’s ignorance AND on top of that, botched in deliver.
Something, judging from your history here, you must be intimately familiar with … ;-)
V: So what you’re claiming is that Arrhenius’s hypothesis can’t be falsified.
BPL: NO! How in God’s name does that follow from anything I said?
It’s easily falsified. Arrhenius predicted that the trend would be positive and would be correlated with CO2. If either of those things hadn’t happened, his hypothesis would have been falsified.
V: But they didn’t happen. Over a 40 year period CO2 levels rose considerably while global temperatures fell. Forty years should be enough to falsify the claim. Refusal to accept this evidence is equivalent to claiming the theory can’t be falsified.
BPL: There will NOT always be “other things” that must be taken into account to save the theory. Those other things ALSO have to pass empirical tests.
V: What tests do you have in mind?
BPL: EVERYTHING IS TESTED. Aerosols DO affect ground temperature. That has been tested in the lab and in the field. It’s a real thing.
V: It’s a well known fact that industrial aerosols are short lived and localized. I went to the trouble of checking out temperature records from several remote regions where the effects of such aerosols would be minimal or nonexistent and found NO evidence of any underlying warming in any. See https://amoleintheground.blogspot.com/2021/03/thoughts-on-climate-change-part-10.html
The aerosol excuse is a perfect example of how a theories’ supporters can be counted on to deny falsification by invoking ad hoc hypotheses to explain away any difficulties. “Scientists are often skeptical of theories that rely on frequent, unsupported adjustments to sustain them. This is because, if a theorist so chooses, there is no limit to the number of ad hoc hypotheses that they could add. Thus the theory becomes more and more complex, but is never falsified.” (https://en.wikipedia.org/wiki/Ad_hoc_hypothesis)
BPL: The Solar constant matters. Albedo matters. Other greenhouse gases matter. Ocean-air cycles matter. Milankovic cycles matter.
V: Yes they all matter, but have no bearing on the hypothesis in question. There is little to no evidence of any underlying temperature rise over a 40 year period.
BPL: Do you get it yet?
V: Do you?
BPL: Occam’s Razor does not mean, and never has meant, “prefer the simplest hypothesis.” You are dead wrong about that. It means, “prefer the simplest hypothesis THAT COVERS ALL THE FACTS.”
V: Agreed. However, you can cite all the facts you like to account for climate over that 40 year period, but a rise in global temperatures would not be among them.
Victor, you haven’t responded to critiques of the internal logic behind your alleged falsification, haven’t tested it against any null hypothesis, haven’t justified your cherry-picked “forty years should be enough” time period, accounted for other sources of temperature variation, etc.
Dead parrot.
You do realize, don’t you Victor, that that is perilously close to admitting that in fact Arrhenius’s hypothesis was not falsified?
Now maybe you’ll consider why the localized testing of aerosol forcings really isn’t sufficient?
(Or perhaps you won’t.)
V: It’s a well known fact that industrial aerosols are short lived and localized.
BPL: It’s a well known fact that you made up.
nigelj 12 MAR: “I think Ree made a typo”
That’s … very generous of you – “typo” means a wrongly typed letter,
not a botched logic of the central argument.
nigel: Ree was being sarcastic”
Sarcasm is a sharp instrument and when used ineptly cuts not the intended target (here: climatologists), but that who tried to wield it against others.
nigelj:
The difficulty is figuring out what factor or factors are impacting temperatures over some given time period. Scientists have determined that the main warming influence in current decades is CO2. This has not been convincingly falsified.
V: No, that has not been determined, only assumed. And yes it HAS been falsified, only proponents of this theory will always refuse to accept that, as it undermines their agenda. From their point of view. therefor, it will never be falsifiable.
nigel: And nobody back in the early 1990s predicted anthropogenic warming would be a nice smooth straight line or a nice smooth curvilinear line like a parabolic curve. Scientists said there would be ups and downs, and occasional flat periods in the record of around ten years, but that the long term trend would be warming. And this is what’s happened.
V: No there has been no long-term anthropogenic warming trend. The warming during the first 40 years of the previous century was not primarily due to fossil fuel emissions. There was NO warming trend at all during the following 40 years. During the 18 year period from 1998-2016 there was a hiatus during which CO2 levels soared while temperatures remained relatively stable.
(“It has been claimed that the early-2000s global warming slowdown or hiatus, characterized by a reduced rate of global surface warming, has been overstated, lacks sound scientific basis, or is unsupported by observations. The evidence presented here contradicts these claims.” — see https://www.meteo.psu.edu/holocene/public_html/Mann/articles/articles/FyfeEtAlNatureClimate16.pdf — authored by John C. Fyfe, Gerald A. Meehl, Matthew H. England, Michael E. Mann, Benjamin D. Santer,
Gregory M. Flato, Ed Hawkins, Nathan P. Gillett, Shang-Ping Xie, Yu Kosaka and Neil C. Swart )
From 2016 to the present we have seen some warming (measured in fractions of a degree), but this represents a period of only 7 years. Hardly a long-term trend.
Victor.
“No there has been no long-term anthropogenic warming trend…..”
I disagree. Firstly the global climate warmed strongly from the late 1970s until 1998 ( refer any global warming dataset such as hadcrut). Then quoting the paper by Fyfe. Meehl et alia that YOU posted, warming slowed down until 2015, ( It has been claimed that the early-2000s global warming slowdown or hiatus, characterized by a reduced rate of global surface warming). Note that they didnt say it stopped. Then there was stronger warming from 2015 until 2023. This is approximately 45 years of warming in total, from the late 1970s to presently..
Scientists say you need 30 years of data to say we have a meaningful long term climate warming So I would argue that with 45 years of warming we have a meaningful climate trend and thus a “long term warming trend” – and its anthropogenic. The paper you quoted did not argue that the slowed down warming was not anthropogenic or that climate change had stopped or the greenhouse effect had stopped, or is falsified or energy wasnt accumulating in the earths system. Only that surface warming had slowed down due to compounding influence of natural variation.. So we do have long term anthropogenic warming. And one glance at the temperature record shows strong warming ever since the late 1970s albeit with some wiggles along the way..
A flat-out lie. Why?
Because:
1) The primary GH mechanism–that is, increased IR opacity–has been demonstrated in the laboratory multiple times, over better than a century and a half. That’s already more than “assumption.”
2) The ice core record demonstrates a strong correlation between temperature and GHG concentrations over many millennia. This is not proof, but it’s a hell of a lot more than “assumption.”
3) The modern temperature record is entirely consistent with the hypothesis, with the anthropogenic forcing–or rather, its result in the temperature record–emerging from the noise of natural variability in the second half of the 20th century. Still not “determination” but again, much more than “assumption.” The plain fact is, climate science said that if we kept adding CO2 and other GHGs, the climate would warm. And lo, we did, and it has warmed.
4) The modeled ensemble temperature trends match the observed temperature trends well, given that it’s known a priori that the ensemble will be less variable than individual realizations (including the real world.) Much more than “assumption.”
5) Modeled temperature trends cannot reproduce the observed warming without GHG forcing, even though all known natural forcings are included. The best match to the observed record uses both the natural and anthropogenic forcings. Now, that IS a demonstration of the hypothesis. It’s not “proof,” but it is extremely strong evidence that, in fact, “the main warming influence in current decades is CO2.”
6) Not content with this, however, climate scientists have made both in situ and remote measurements demonstrating empirically that radiative forcings have increased consistent with increasing GHG concentrations. Once again, that is “demonstration.” And it is, to use figurative language here, infinitely more than “assumption.”
Of course, Victor could be innocently ignorant of all this–in theory. But since we have seen all this and more explained to him time and again, it can only be concluded that his ignorance is willful. Therefore, he is lying.
Again.
There really are times when I wonder whether Weaktor isn’t just some elaborate performance art, because the alternative is that he really is that stupid. And unfortunately he is not alone.
There are a lot of folks out there who seem to expect physics and history to bend to their political whim.
Fact: We’ve known about the greenhouse effect since the 1820s when Joseph Fourier suggested that the atmosphere serves as an energy reservoir in the climate system.
Fact: The greenhouse mechanism was starting to be well understood by the late 1850s.
Fact: By 1896, the mechanism was well enough understood that Svante Arrhenius proposed that anthropogenic CO2 emissions would result in the globe warming.
Fact: Every major discovery since then has enhanced the importance of greenhouse warming.
Fact: If you do the math right (yeah, I’m talking to you Weaktor), you get a strong correlation between ln[CO2] and warming–precisely what the theory predicts
Weaktor, you cannot just pretend that 2 centuries of scientific advancement didn’t happen. And of course, all Weaktor would have to do to prove himself correct would be propose a mechanism that was physically reasonable and explained the warming better than does the greenhouse mechanism. And:
[Crickets]
I knew a sports board where one of the owners trolled his own board to increase clicks. Surely Gavin et. al wouldn’t do that!
V: there has been no long-term anthropogenic warming trend.
BPL: Regress temperature anomalies on time, See if the trend is statistically significant. (You can do a t test, and if you don’t have the software to estimate the p value exactly, there are plenty of t statistic tables on line). If it isn’t, you’ve proved your case. If it is, you’re wrong. See? Simple.
Victor: “No there has been no long-term anthropogenic warming trend…..”
nigelj: I disagree. Firstly the global climate warmed strongly from the late 1970s until 1998 ( refer any global warming dataset such as hadcrut). Then quoting the paper by Fyfe. Meehl et alia that YOU posted, warming slowed down until 2015, ( It has been claimed that the early-2000s global warming slowdown or hiatus, characterized by a reduced rate of global surface warming). Note that they didnt say it stopped. Then there was stronger warming from 2015 until 2023. This is approximately 45 years of warming in total, from the late 1970s to presently..
V: A LOT depends on one’s interpretation of what happened between 1998 and 2016. Many climate change advocates would like to claim there was no hiatus during that period, that this was just a myth. And if that were the case then you would be right. However, as you know from the paper I cited by Fyffe et al., the hiatus appears to have been real nonetheless. (Hard to argue with a study authored by some of the world’s leading climate scientists.)
As seems clear from the satellite data, there was in fact no overall warming trend during this period. See https://www.drroyspencer.com/wp-content/uploads/UAH_LT_1979_thru_September_2022_v6.jpg
So what you are left with is: 40 years of no warming — 20 years of warming — 18 years of no warming (the hiatus) — 8 years of warming. Sorry but that does NOT add up to a 45 year “long-term” warming trend.”
Victor
“However, as you know from the paper I cited by Fyffe et al., the hiatus appears to have been real nonetheless.”
Yes the paper did claim the hiatus was real, and maybe they are right. But they also said that the hiatus was a “reduced rate of global warming” so there was still warming. ( It has been claimed that the early-2000s global warming slowdown or hiatus, characterized by a reduced rate of global surface warming). Thus we have about 45 years of a warming trend from 1978 – 2023.
“As seems clear from the satellite data, there was in fact no overall warming trend during this period. See https://www.drroyspencer.com/wp-content/uploads/UAH_LT_1979_thru_September_2022_v6.jpg
The Roy Spencer satellite data is not at the surface of the planet. Its the upper atmosphere. And it heavily contested by other climate scientists over its accuracy. It is also inconsistent with the other satellite record RSS.
All the surface records by different organisations show significant warming 1998 – 2015 eg: Nasa giss, Hadcrut, NOAA and there are others:
https://crudata.uea.ac.uk/~timo/diag/tempts_decadesmooth_global.png
https://data.giss.nasa.gov/gistemp/graphs_v4/
https://www.ncei.noaa.gov/access/monitoring/monthly-report/global/202313#:~:text=Updated%20NOAAGlobalTemp%20dataset-,Global%20Temperatures,previous%20record%20set%20in%202016.
So Victor you have got nothing but one temperature record that you have cherry picked that doesnt even apply to the earths surface.. You apparently choose to ignore all other records for no apparent reason. I think its far more likely the multiple surface records are right than Roy Spencers record which is an outlier, has been contested, and is not fully applicable to the surface anyway.
V: “No there has been no long-term anthropogenic warming trend…..”
“A LOT depends on one’s interpretation of what happened between 1998 and 2016…”
hiatus, Spencer, etc.
J: Although you were exclusively concerned with your interpretation of what was happening in the lower atmosphere between 1998 and 2016, the ocean was accumulating heat all the while, a LOT of heat.
In fact, the top 2km of the global oceans accumulated about 160,000,000,000,000,000,000,000 joules of it during that time! https://www.ncei.noaa.gov/access/global-ocean-heat-content/
If you prefer, that’s about 44,000,000,000,000,000 kilowatt-hours of extra energy. All of that energy entered the ocean because it is out of thermal equilibrium due to the extra amount greenhouse gases. The ocean continues storing large amounts of excess heat, even during the most recent El Nino. It also does it during periods when nothing much seems to be happening to mean surface air temperatures, due to the uneven exchange of heat between the oceans and atmosphere over shorter periods of time.
Ignoring the extra heat going into the ocean is giving you a false picture of the effects (or lack thereof, as you think) of greenhouse gases. It is like thinking you know your financial condition by looking at how the balance of your checking account is behaving, while ignoring your savings account. If your checking account balance isn’t changing much, but more keeps going into your savings account, your finances aren’t really having a hiatus. It’s just getting switched between accounts.
Weaktor: “A LOT depends on one’s interpretation of what happened between 1998 and 2016.”
OK, let’s take you at your word. What happened between 1998 and 2016?
https://www.woodfortrees.org/plot/gistemp-dts/from:1998/to:2016/trend/plot/hadcrut4gl/from:1998/to:2016/trend/plot/gistemp/from:1998/to:2016/trend/plot/rss/from:1998/to:2016/trend/plot/uah6/from:1998/to:2016/trend/plot/best/from:1998/to:2016/trend/plot/none
The ONLY data product that doesn’t show significant warming is UAH–which is safely dismissed as an outlier, even if we don’t take into account the known problems with the dataset.
But of course, there are other good reasons to say that there was no “pause” Ocean heat content–which accounts for the overwhelming majority of heat in the climate system–continued to rise apace, even accelerating in some regions over this period.
So, Weaktor, by your own criterion, you should admit that warming continued through the critical period and that climate change is real…unless you choose to ignore 75% of the planet’s surface (and the overwhelming majority of the climate’s energy) and to stubbornly stick to the ONLY dataset that doesn’t show warming for your cherrypicked dates.
I will await your gracious admission.
V: So what you are left with is: 40 years of no warming — 20 years of warming — 18 years of no warming (the hiatus) — 8 years of warming. Sorry but that does NOT add up to a 45 year “long-term” warming trend.”
BPL: If you want the trend over the whole period, regress temperature anomaly on time during that period and see if the coefficient of the independent variable is significant. If you can’t do that, leave the question to people who can, because you’re not competent to have an opinion on the subject.
Victor: – “As seems clear from the satellite data, there was in fact no overall warming trend during this period.”
I seem to recall we’ve been through this before, again & again & again… What “hiatus”, Victor?
https://www.realclimate.org/index.php/archives/2023/12/unforced-variations-dec-2023/#comment-817194
But what can one expect from a climate science denier, a regurgitator of climate myths and ignorer of reality, aye Victor?
A monthly global surface temperature anomalies graph, from 1940 to 2024 above the 1850-1900 baseline, per mathematician Prof Eliot Jacobson, tells a different narrative.
https://twitter.com/EliotJacobson/status/1768599817515843997
And here are some real predictions by climate scientists that have already been observed:
https://twitter.com/EliotJacobson/status/1769045098539741345
nigelj: The Roy Spencer satellite data is not at the surface of the planet. Its the upper atmosphere. And it heavily contested by other climate scientists over its accuracy. It is also inconsistent with the other satellite record RSS.
V: Spencer’s data represents “the lower troposphere,” not “the upper atmosphere.” As Spencer has noted, his results correspond quite closely to radiosonde measurements. As for RSS, it too reveals no warming trend until 2016: https://images.remss.com/figures/climate/RSS_Model_TS_compare_globev4.png
“. . . the thick black line represents . . . the results from the most recent version of the RSS satellite dataset. The yellow band shows the 5% to 95% envelope for the results of 33 CMIP-5 model simulations (19 different models, many with multiple realizations) that are intended to simulate Earth’s Climate over the 20th Century. For the time period before 2005, the models were forced with historical values of greenhouse gases, volcanic aerosols, and solar output. After 2005, estimated projections of these forcings were used. If the models, as a whole, were doing an acceptable job of simulating the past, then the observations would mostly lie within the yellow band.” https://www.remss.com/research/climate/
Victor.
My categorising UAH as measuring upper atmosphere wasn’t technically right.. However it doesnt change the rest of what I said. Spencers data is : “These satellites measure temperature anomalies of the atmospheric layer from the surface to roughly 10km, centered in the Lower Troposphere.” You are however talking about about a zone 10 kms high so hes measuring all that.
https://www.ncei.noaa.gov/products/climate-data-records/mean-layer-temperature-uah#:~:text=These%20satellites%20measure%20temperature%20anomalies,centered%20in%20the%20Lower%20Troposphere.
Spencers data is not the surface, being within a few metres of ground level. The data from NOAA, NASA GISS and Hadcrut measures the surface, with the thermometers typically about 1.5 M above ground level. They show plenty of warming from 1998 – 2023 and the technology is far more accurate and reliable than satellite sensors that dont even measure temperatures directly, then you get all sorts of problems with satellite drift.
So the best evidence we have says there was still warming through the hiatus at least at the surface. Given the doubts about the accuracy of satellite data the lower troposphere may possibly also have warmed during the hiatus. However we live at ground level so thats the area that matters most in terms of temperatures. And as others point out energy continued to accumulate in the earths system during the so called hiatus so the greenhouse effect didnt somehow stop.
Correction. Thermometers at ground level show plenty of warming through the so called hiatus of 1998 – 2015.
Yes, Hadcrut does show exactly what you say…….. now.
but if you rewind 8 months to have a direct Hadcrut3 Vs Hadcrut4 comparison they did manage to turn a fairly benign warming of less than 1 degree/millennia into more than half a degree per century. That’s an 800% increase in the linear trend slope.
Gee that was unexpected! I wonder why it was dubbed the “pause busting” update??
!
Keith,
Yep, It’s a conspiracy of the entire scientific community just to burst your denialist bubble.
Ever notice that real scientists look at ALL the data, while denialists only look at their favorite? Wonder why that is….by the way, how are the cherries?
It is certainly Ironic Ray that you tell me to look at all the data when my whole point was that other datasets showed different results. And I was commenting because nigelj was advocating ignoring the dataset with the best spatial and temporal resolution
Just throwing the word “conspiracy” in there is great also. Anyone who points out a difference between two datasets must wear a aluminium hat
By all means look at all the data–that’s how you can tell when one dataset is a clear outlier…the one that hides that we are warming the planet.
…. because that’s how science works, throw away anything that looks different
Ray Ladbury: OK, let’s take you at your word. What happened between 1998 and 2016?
https://www.woodfortrees.org/plot/gistemp-dts/from:1998/to:2016/trend/plot/hadcrut4gl/from:1998/to:2016/trend/plot/gistemp/from:1998/to:2016/trend/plot/rss/from:1998/to:2016/trend/plot/uah6/from:1998/to:2016/trend/plot/best/from:1998/to:2016/trend/plot/none
V: OMG! This is laughable. Your “trend lines” simply connect starting points in 1998 with ending points in 2016. So it was less warm during the former than the latter. Whoda thunk it. This says a lot about your “mastery” of statistics, Ray. Basket weaving might be more suited to your abilities..
Ray: Ocean heat content–which accounts for the overwhelming majority of heat in the climate system–continued to rise apace, even accelerating in some regions over this period.
V: Ocean heat content typically lags atmospheric temperatures by 20 to 30 years, Ray. So the rise you’ve found “over this period” most likely reflects the runup of atmospheric temperatures from the late 70’s to 1998.
Not the brightest bulb on the tree, are you Ray?
NASA begs to disagree. It takes heat a while–centuries even–to get down to the deep ocean. But NOT the upper ocean, https://www.climate.gov/news-features/understanding-climate/climate-change-ocean-heat-content
More than 90 percent of the warming that has happened on Earth over the past 50 years has occurred in the ocean. Recent studies estimate that warming of the upper oceans accounts for about 63 percent of the total increase in the amount of stored heat in the climate system from 1971 to 2010, and warming from 700 meters down to the ocean floor adds about another 30 percent
But what do they know compared to your own genius?
> 1998
Funny you pick that year, Victor.
Is it a random guess?
Wow, insult as argument, black as white, in the looking glass universe. Lies are not truth. Have a look:
https://skepticalscience.com/graphics.php?g=465
No, Weaktor. They are OLS linear fits to the data, but then, that’s statistics, so I don’t expect you to understand. It says so clearly on the plot, though. Maybe have an adult read it to you. In any case–they all show warming except UAH–the clear outlier. If you had any integrity, you’d at least admit that.
And if ocean heat content lags 20-30 years, where did the warming in the 80s and 90s come from–the trend has been consistent for decades. In actuality, the relationship between atmospheric and ocean temperatures cannot be characterized as a lag. The surface and near surface warm contemporaneously–and they did indeed warm. But we’ve already established our lack of character.
in Re to Victor, 17 Mar 2024 at 1:06 AM,
https://www.realclimate.org/index.php/archives/2024/02/new-study-suggests-the-atlantic-overturning-circulation-amoc-is-on-tipping-course/#comment-820218
Dear Victor,
I guess that when you wrote “Ocean heat content typically lags atmospheric temperatures by 20 to 30 years”, you actually meant something like “ocean temperature rise”, am I right?
Otherwise, I cannot imagine where the excess heat coming from the Earth energy imbalance (EEI) would have stayed before it enters ocean.
In other words, I suppose that ocean absorbs the excess heat coming from the EEI practically instantly and that, accordingly, also the respective ocean heat content changes follow the changes in the EEI practically instantly – simply because I cannot imagine any reasonable mechanism enabling a temporal lag therebetween.
Greetings
Tomáš
Victor would also be well advised to remember the EEI (earths energy imbalance) has been increasing during the modern global warming period and including through the so called ‘hiatus’. So the earth has been gaining heat energy from the greenhouse effect through the hiatus.
https://en.wikipedia.org/wiki/Earth%27s_energy_budget#/media/File:Earth's_heating_rate_since_2005.jpg
Kevin McKinney says
Victor: No, that has not been determined, only assumed.
KM: A flat-out lie. Why?
V: That reminds me of an exchange from my days as a high school teacher.
Student: You farted.
Me: No I didn’t. That must have been you.
Student: No, I can tell if I farted or not and I did not fart. You’re lying.
Me: Would I lie to a kid?
Student: YES.
So yes I lied. Would I lie to a fellow climate blogger? Interesting question. Luckily no one here can tell if I farted, so that’s a good thing. But no, the climate issue is too important to lie about. And since I’m not being paid to lie, I see no reason why I would.
Kevin: Because:
1) The primary GH mechanism–that is, increased IR opacity–has been demonstrated in the laboratory multiple times, over better than a century and a half. That’s already more than “assumption.”
V: Lab tests are conducted under strictly controlled conditions. The climate is a complex, chaotic system that can’t be controlled. What might work in the lab won’t necessarily work when assessing the climate.
Kevin: 2) The ice core record demonstrates a strong correlation between temperature and GHG concentrations over many millennia. This is not proof, but it’s a hell of a lot more than “assumption.”
V: That’s quite a boner, Kevin. As is well known, the Vostok ice core data tells us that atmospheric warming preceded a rise in CO2 levels. So while this data does in fact indicate a strong correlation between temperature and CO2 levels, it cannot be used as evidence that CO2 causes warming. Clearly it was the other way round.
K: 3) The modern temperature record is entirely consistent with the hypothesis, with the anthropogenic forcing–or rather, its result in the temperature record–emerging from the noise of natural variability in the second half of the 20th century. Still not “determination” but again, much more than “assumption.” The plain fact is, climate science said that if we kept adding CO2 and other GHGs, the climate would warm. And lo, we did, and it has warmed.
V: You need to pay attention, Kevin. 40 years of no warming cannot be dismissed as “noise” simply because it doesn’t support your pet theory. In fact, from 1940 through 1979 we did in fact add a considerable amount of CO2 to the atmosphere, yet the globe cooled.
K: 4) The modeled ensemble temperature trends match the observed temperature trends well, given that it’s known a priori that the ensemble will be less variable than individual realizations (including the real world.) Much more than “assumption.”
V: The models are all based on the prior assumption that CO2 is a major driver of global temperatures, the hypothesis which was to be demonstrated. Circular reasoning.
K: 5) Modeled temperature trends cannot reproduce the observed warming without GHG forcing, even though all known natural forcings are included. The best match to the observed record uses both the natural and anthropogenic forcings. Now, that IS a demonstration of the hypothesis. It’s not “proof,” but it is extremely strong evidence that, in fact, “the main warming influence in current decades is CO2.”
V: It’s a demonstration based on circular reasoning. The notion that CO2 contributes in any significant way to warming is an assumption, but it’s treated as a fact from the get-go.
K: 6) Not content with this, however, climate scientists have made both in situ and remote measurements demonstrating empirically that radiative forcings have increased consistent with increasing GHG concentrations. Once again, that is “demonstration.” And it is, to use figurative language here, infinitely more than “assumption.”
V: But clearly that is not the case. There has been no consistent relation between GHG concentrations and temperature, as I’ve demonstrated several times.
K: Of course, Victor could be innocently ignorant of all this–in theory. But since we have seen all this and more explained to him time and again, it can only be concluded that his ignorance is willful. Therefore, he is lying.
V: Would I lie to a fellow musician?
K: The primary GH mechanism–that is, increased IR opacity–has been demonstrated in the laboratory multiple times, over better than a century and a half. That’s already more than “assumption.”
V: Lab tests are conducted under strictly controlled conditions. The climate is a complex, chaotic system that can’t be controlled. What might work in the lab won’t necessarily work when assessing the climate.
BPL: Except it already has. Here are some empirical tests on radiative transfer in the actual atmosphere:
Evans, W.F.J., and E. Puckrin 2006. Measurements of the Radiative Surface Forcing of Climate. 18th Conference on Climate Variability and Change, P1.7
The earth’s climate system is warmed by 35 C due to the emission of downward infrared radiation by greenhouse gases in the atmosphere (surface radiative forcing) or by the absorption of upward infrared radiation (radiative trapping). Increases in this emission/absorption are the driving force behind global warming. Climate models predict that the release of greenhouse gases into the atmosphere has altered the radiative energy balance at the earth’s surface by several percent by increasing the greenhouse radiation from the atmosphere. With measurements at high spectral resolution, this increase can be quantitatively attributed to each of several anthropogenic gases. Radiance spectra of the greenhouse radiation from the atmosphere have been measured at ground level from several Canadian sites using FTIR spectroscopy at high resolution. The forcing radiative fluxes from CFC11, CFC12, CCl4, HNO3, O3, N2O, CH4, CO and CO2 have been quantitatively determined over a range of seasons. The contributions from stratospheric ozone and tropospheric ozone are separated by our measurement techniques. A comparison between our measurements of surface forcing emission and measurements of radiative trapping absorption from the IMG satellite instrument shows reasonable agreement. The experimental fluxes are simulated well by the FASCOD3 radiation code. This code has been used to calculate the model predicted increase in surface radiative forcing since 1850 to be 2.55 W/m2. In comparison, an ensemble summary of our measurements indicates that an energy flux imbalance of 3.5 W/m2 has been created by anthropogenic emissions of greenhouse gases since 1850. This experimental data should effectively end the argument by skeptics that no experimental evidence exists for the connection between greenhouse gas increases in the atmosphere and global warming.
Philipona, R., B. Dürr, C. Marty, A. Ohmura, and M. Wild 2004. Radiative Forcing–Measured at Earth’s Surface–Corroborate the Increasing Greenhouse Effect. Geophys. Res. Lett. 31, L03202
Here we show that atmospheric longwave downward radiation significantly increased (+5.2(2.2) Wm 2) partly due to increased cloud amount (+1.0(2.8) Wm 2) over eight years of measurements at eight radiation stations distributed over the central Alps. Model calculations show the cloud-free longwave flux increase (+4.2(1.9) Wm 2) to be in due proportion with temperature (+0.82(0.41) C) and absolute humidity (+0.21(0.10) g m 3) increases, but three times larger than expected from anthropogenic greenhouse gases. However, after subtracting for two thirds of temperature and humidity rises, the increase of cloud-free longwave downward radiation (+1.8(0.8) Wm 2) remains statistically significant and demonstrates radiative forcing due to an enhanced greenhouse effect.
Feldman, D.R.; Collins, W.D.; Gero, P.J.; Torn, M.S.; Mlawer, E.J.; Shippert, T.R. 2015. Observational determination of surface radiative forcing by CO2 from 2000 to 2010. Nature 519, 339-343.
The climatic impact of CO2 and other greenhouse gases is usually quantified in terms of radiative forcing1, calculated as the difference between estimates of the Earth’s radiation field from preindustrial and present day concentrations of these gases. Radiative transfer models calculate that the increase in CO2 since 1750 corresponds to a global annualmean radiative forcing at the tropopause of 1.82 ± 0.19 W m-2 (ref. 2). However, despite widespread scientific discussion and modelling of the climate impacts of wellmixed greenhouse gases, there is little direct observational evidence of the radiative impact of increasing atmospheric CO2. Here we present observationally based evidence of clearsky CO2 surface radiative forcing that is directly attributable to the increase, between 2000 and 2010, of 22 parts per million atmospheric CO2. The time series of this forcing at the two locations, the Southern Great Plains and the North Slope of Alaska, are derived from Atmospheric Emitted Radiance Interferometer spectra3together with ancillary measurements and thoroughly corroborated radiative transfer calculations4. The time series both show statistically significant trends of 0.2 W m-2 per decade (with respective uncertainties of ±0.06 W m-2 per decade and ±0.07 W m-2 per decade) and have seasonal ranges of 0.1-0.2 W m-2. This is approximately ten per cent of the trend in downwelling longwave radiation5,6,7. These results confirm theoretical predictions of the atmospheric greenhouse effect due to anthropogenic emissions, and provide empirical evidence of how rising CO2 levels, mediated by temporal variations due to photosynthesis and respiration, are affecting the surface energy balance.
Thanks for that response, Barton. Good citations. Will V read any of them, or even bother to recall their existence?
Doubtful, on the evidence to date.
I should add that Victor’s criticism–to which BPL’s citations are good answer–largely misses the point because he conflates the means and the end result. That is, the end result (that increased anthropogenic GHGs, especially CO2, cause the earth system to warm) is not the same thing as the mechanism which brings it about (in this case, the decrease in certain IR mean path lengths due to increased GHGs.)
It’s true that results showing a warming effect due to GHGs, such as Evans & Puckrin (2006), are relatively recent and for instance post-date the early IPCC reports. However, already in 1896 Arrhenius most ingeniously used some of Samuel Langley’s lunar observations to capture CO2’s effect on light passing through the atmosphere. In 1938, Guy Callendar used his background in steam technology to update the application of relevant IR spectrography to the CO2 issue. In 1960, Walter Elsasser (better known for his geophysical work), and working with Margaret Culbertson, developed practical radiative transfer tables for use in temperature forecasting. The same period saw important work in the same general area, soon including computer code applications, by folks such as Kaplan and Plass.
In short, there is a very rich, deep, and detailed history of research into the physics of IR attenuation by GHGs–that is, “the mechanism” by which CO2 warms the earth system. It is precisely that physics, arising from decades of patient work, which is encoded in the climate models. The result is not an “assumption,” as Victor serially alleges, but a conclusion which emerges from the physics so encoded. Victor is apparently blind to the distinction, and therefore feels justified in ignoring knowledge specific to the mechanism, as opposed to the result. It’s basically a version of the pars pro toto fallacy, with a good dash of willful ignorance.
Kevin McKinney says
19 Mar 2024 at 12:35 PM
” It is precisely that physics, arising from decades of patient work, which is encoded in the climate models. ”
Whoopee … it doesn’t fix all the errors they are making all the time, and the cheap averaging and unscientific guessing and oh well, close enough is good enough …. and let’s just take the Mean and assume that is the right one to use today ….. but first let’s throw away all those hot models first they don’t look right, and who cares if we’re totally wrong and the Mean is no where near REALITY and the TRUTH
Nah, that’s why I reject them and no longer accept them as reliable or credible or honest.
Garbage In Garbage Out.
The Models and the IPCC system …. way past their use-by dates now. Unnecessary and intrinsically a core part of the problem of climate change inaction globally. The Incompetents and Egotistical Fools took over the System entirely.
By all means, keep the real science, the real physics, the knowledge and “the real mechanisms” but dump the corrupt and dishonest systems and incompetent Institutions that are in place. and the PEOPLE who lead and CONTROL them ….
Ned is joining contrarians:
https://climateball.net/but-modulz/
https://climateball.net/but-science/
That constrains his repertoire.
Spinning Wheels
https://www.youtube.com/watch?v=SFEewD4EVwU
Willard, thank you again for the work you’ve put into climateball.net. You’ve totally got butScience and butConsensus covered, IMHO.
How long has it been since we saw anything new from contrarians? Virtually all possible pseudo-skeptical objections to the consensus for AGW have already been repeatedly rebutted by trained, disciplined specialists, who stand on the shoulders of their predecessors through the centuries. All the butWhatever arguments are rhetorical zombies, harder to kill than Rasputin. No matter how many times they get raised, they’re still wrong!
One really wants to ask where the unimaginative denialists are getting their information, that they think it’s worthwhile resurrecting the undead on RC of all places. I, for one, am convinced that the incidence of false beliefs about climate change among US voters is due not to a “knowledge deficit”, but to the long, deep-pocketed campaign by the Koch club to fill the deficit to overflowing with skillful disinformation. Correct knowledge is readily available to anyone with a smartphone, but is simply outspent in the competition for eyeballs! Let’s not start another thread about that here, though.
> since I’m not being paid to lie, I see no reason why I would.
C’mon, Victor. You were not paid to lie when you lied to the kids under your tutelage. You simply were a proud asshat.
Come to think of it, this could be a valid reason for a contrarian to keep commenting at Gavin’s after being shown wrong over and over again.
For how long now?
You are wasting your own and everybody else’s time. Your arguments are phony and in any case this is the wrong forum to post this nonsense. Since climate change due to global warming is already affecting you and people you care about, and will get worse, please make an effort to apply yourself to learning about what is going on, rather than continuously promoting fake skeptic arguments.
I could wish that your endless arguments were relegated to the borehole or crankshaft, but apparently our hosts won’t do that, phony phart metaphors notwithstanding.
Take a look around and notice what is happening. Consider that people who actually know stuff about this are in near 100% agreement about the basics. Then look at the weather. Climate is weather over space and time, and the results should by now be obvious even to someone as resistant as you are to the reality all around you.
Susan has a very good point there, Victor. The weather is broke. Most of humanity has noticed it.
V: “But no, the climate issue is too important to lie about.”
Yet Mark Knopfler sang of “Two men claiming to be Jesus/One of them must be wrong.” Similarly, it’s quite evident that for some, the climate issue is too important NOT to lie about.
V: “That’s quite a boner, Kevin. As is well known, the Vostok ice core data tells us that atmospheric warming preceded a rise in CO2 levels. So while this data does in fact indicate a strong correlation between temperature and CO2 levels, it cannot be used as evidence that CO2 causes warming. Clearly it was the other way round.”
The “boner” isn’t mine (and I’m trying not to think about the “brewer’s droop” line from “Industrial Disease” here.) This 2012 RC guest post is old hat now (and I’d like to hear what the current state of play on this issue is), but that just emphasizes how dated and generally toothless this line of attack is:
V: “40 years of no warming cannot be dismissed as “noise” simply because it doesn’t support your pet theory.”
Not “my” theory, so not my “pet” theory, and not my “dismissal” (I’d call it rather a “characterization”):
V: “The models are all based on the prior assumption that CO2 is a major driver of global temperatures, the hypothesis which was to be demonstrated. Circular reasoning.”
Wrong again. The models are based on the radiative physics of GHGs, as determined not only by the lab work mentioned previously, but by decades of in situ observation. (See, for example, Callendar (1938).)
V: “It’s a demonstration based on circular reasoning. The notion that CO2 contributes in any significant way to warming is an assumption, but it’s treated as a fact from the get-go.”
Nope. If I’m exceptionally charitable, that’s a “false assertion.” But since it’s a false assertion in the face of multiple, often extensive, patiently repeated explanations of its falsehood, the most recent of which I finished typing maybe a minute ago, well… I have to think it is a wilful falsehood. By another name.
V: “But clearly that is not the case. There has been no consistent relation between GHG concentrations and temperature, as I’ve demonstrated several times.”
Another cycle about the “merry-go-round.” The attempted “demonstration” was unsuccessful, for reasons explained more than sufficiently. Heck, more than amply. (Claiming “more than redundantly” would be a mere figure of speech, but it’s tempting me all the same.)
V: “Would I lie to a fellow musician?”
Is that really supposed to be hypothetical?
Victor: “That’s quite a boner, Kevin. As is well known, the Vostok ice core data tells us that atmospheric warming preceded a rise in CO2 levels. So while this data does in fact indicate a strong correlation between temperature and CO2 levels, it cannot be used as evidence that CO2 causes warming. Clearly it was the other way round.
Great. In my environmental course I talk about this deniers myth, but it is always better to have a name connected to it, so the students don’t think that made you up. “Victor, the musicologist” – any other information? I ask because Students may wonder what kind of person would fall for such obvious manipulation, so the more information you can provide about yourself – the better.
And do you remember who sold you on that argument?
The same data – the conclusions opposite conclusions than yours:
Milankovic cycles do not change much the total amount of energy reaching the Earth – it matters where this energy gets and when?
The trigger for deglaciation is an increase in insolation in Arctic in summer: Warmer temps there -> more ice/snow melt -> lower albedo -> land and ocean absorb more heat -> air gets warmer, which then melts even more snow and ice and so on. In addition, there are three other positive feedbacks – T with stronger water cycle (more evaporation -> higher abs humidity and/or less clouds), T with more Co2 and T with more CH4 (bacterial decomp and other biological processes run faster in warmer temps.). As a result of all 4 feedbacks T increases even more and that higher T melts more ice, amplifies H2O cycle and increases CO2 and CH4 even more, and so on and so on.
To conclude: the trigger is the initial tiny globally (although significant in Arctic in summer) warming is followed by the massive GLOBAL increase in temperature – ΔGMST (change in Global Mean Surface Temperature) up to 8 C
This means:
1. ΔGMST thanks to the 4 feedbacks is orders of magnitude larger than the global orbital signal alone. In other words they AMPLIFY any change in temp, natural or human-made.
2. Co2 and Ch4 ARE affecting GMST . – if they didn’t, there would be no CO2 with T nor CH4 with T feedbacks and it’s hard to get to massive ΔGMST = 8 C on the strength of ONLY two other feedbacks (water cycle with T and ice albedo with T). If Co2 and CH4 were GHGs during the interglacial, they will be GHGs in ANY conditions, including AGW.
3. the ice albedo and water cycles feedbacks amplified tiny natural (Milankovic) warming,
and they would ALSO amplify ANY warming, including AGW – see the CERES data and Schmidt et al. 2010 – showing that water cycle effect amplified the effects of CO2 and CH4.
This means that climate is MORE, not LESS, vulnerable to human actions, since the two feedbacks would AMPLIFY the effects of our action – would make the warming worse, or make the cooling stronger.
So whoever convinced you otherwise – is not your friend.
“It’s a demonstration based on circular reasoning. The notion that CO2 contributes in any significant way to warming is an assumption, but it’s treated as a fact from the get-go.”
Nope. No more “circular” than “assuming” that lines in stellar spectra show that those twinkly things in the sky at night night are actually giant balls of fusing hydrogen at great distances. Inductive reasoning ALWAYS involves making assumptions, collecting evidence, and modeling.. I mean it’s not like there is any purely experimental proof in a large portion of astronomy and astrophysics. Same with any number of other fields like much of ecology, seismology, and the like.. What would your control groups be, pray tell?
Further, even in true experiments in areas where they where they are possible, the ASSUMPTION is that the ONLY uncontrolled difference between treatment and control conditions is the manipulation made by the experimenter. Made any stars lately? Journeyed/drilled to the Earth’s core? Or constructed totally controlled biomes in the enviroment except for single changes made by you?
I should add that the ASSUMPTION that the experimenter is the sole source of differences between groups in true experiments hardly ever completely holds. That is because said assumption often rests on the further assumption that random assignment will sufficiently control for all other between groups variation or that all individual experimental objects are manufactured to absolute specifications. And the fact of the matter is that that assumption hardly ever fully holds–especially in any single experiment.
Something statistical neophytes often miss is that the statistics used in experiments are simply (usually) regression models of various sorts as well. And we all know you believe that correlation is not causation. So even experimental proof would not be good enough for you, I “assume”.
This Real Climate post covers an important subject. I am wondering whether there is sufficient concern about another current (The Photon Current), and how it might alter AMOC concerns about the AMOC (https://blogdredd.blogspot.com/2024/02/the-photon-current-3.html).
Anyway, thanks for the post.
D,
I don’t believe modern physics recognizes the existence of a “photon current.”
You appear to be referring to IR radiative heat transfer within the ocean. This is not a significant factor, because the ocean is nearly opaque to IR radiation in that wavelength range. Over the short distances that IR radiation can carry within water before being re-absorbed, there is very little temperature difference. Thus, very little energy can be transferred through radiation.
Photons do move at the speed of light, but that can be deceptive. If a photon is absorbed shortly after it is emitted, and it takes a while to emit another, the energy transfer process can be slow. In fact, astrophysicists calculate that on the average it takes heat energy generated in the core of the sun by fusion can take around 50,000 years to reach the surface. Most of the time is spent in the radiative zone in the middle of the sun, where electromagnetic energy is repeatedly emitted and re-absorbed.
One way of looking at the magnitude of the absorption is to realize that water vapor is an important greenhouse gas in the atmosphere. There, the density of water molecules is far lower than in the ocean, and thus the distance between molecules far greater, but it is still a substantial impediment to heat transfer between atmospheric levels.
Re: John Pollack explaining to “Dredd” why comparing the speed of photons in vacuum with the speed of ocean currents is comparing oranges and orangutans.
I might add that our participant Dredd also discovered the wheel:
“ One interesting thing to note is that the deepest layer in those zones, the Hadopelagic is warmer than the shallower depth above it, the Bathypelagic ”
Please look up the difference between the potential and the in-situ temperature.
Willard: C’mon, Victor. You were not paid to lie when you lied to the kids under your tutelage. You simply were a proud asshat.
V: I loved playing games with my students, most of whom appreciated it.
W: Come to think of it, this could be a valid reason for a contrarian to keep commenting at Gavin’s after being shown wrong over and over again.
V: There’s a huge difference between being wrong and lying. Make up your mind.
Oh, and a brief aside to BPL: Thanks for the quotations from what look like very authoritative studies. Very interesting. I wonder, however, whether any of these scientists were able to explain the 40 year drop in temperature from 1940 – 1979. Without reverting to the discredited aerosol excuse, natch.
Ultimately, the proof of the pudding is in the eating.
> Make up your mind.
Assattitude and pride can explain many things, dear Victor. Which kinda undermines your silly ” I see no reason why I would.” Of course you do, unless you learned very little about that life on Earth you enjoyed so far.
There’s no need to know at which point you saying stuff starts to become lying. Only you know when you’re trying to be as entertaining as when you farted in your classroom.
“Without reverting to the discredited aerosol excuse, natch.”
Only “discredited” in the sense that V. doesn’t “credit” it.
Weaktor, what you’re serving up ain’t chocolate pudding.
V: Without reverting to the discredited aerosol excuse, natch.
BPL: It hasn’t been discredited. We know how aerosols work, Victor. You’re denying a very well known physical process.
“40-year drop in temperature”
Not really, despite the repeated assertions.
While you get a negative trend if you calculate OLS over the span of 1940-1979, that doesn’t mean that GMST was actually declining the whole time. If you pick any year between about 1944 and 1979 and calculate the trend up to 1979, it looks like the chance of getting a rising trend versus a falling one is at least 50/50, if not better. (See the light blue line on the Woodfortrees graph linked below as illustation; it gives a rising trend for 1944-’79.) And every year after 1940 is warmer than all but a tiny few of the years before it.
So what we are really looking at isn’t a “40 year drop”, it’s a much briefer spike–only about 4 years–initiating what amounts to an upward step change.
To illustrate, I tested every 40-year span for starting years from 1933 to 1944. Turns out that you only get falling trends for the span 1934-1942. (I’ve shown the next “boundary spans” on the graph–1933-’72 is in the darker blue and 1941-’80 is in mauve; both trends are positive.)
https://woodfortrees.org/plot/gistemp/from:1880/to:2000/mean:13/plot/gistemp/from:1940/to:1979/trend/plot/gistemp/from:1933/to:1972/trend/plot/gistemp/from:1941/to:1980/trend/plot/gistemp/from:1944/to:1979/trend
Looking at it that way–not really scientific either, but preferable to cherry-picking a single 40-year span–the anomalous period is really only about 8 years. And the question about the anomaly is–as really, it already was, just looking at the record in the first place–“Why where the years from 1940 to 1944 so anomalously warm?”
(By the way, it would be fun for someone with the skills and maybe a stats pack to run up a timeline graph of 40-year trends across the period of record. I could do it in Excel, but for me it would be a bit of a slog time-wise, as it’s not in my wheelhouse. I suspect there’s them here as could ‘git ‘er done’ inside of 10 minutes, though.)
Victor the tireless troll will not be silenced. The only way to silence him is to ignore him. He feeds on your attention.
In addition to Susan Anderson, 20 Mar 2024 at 9:15 AM,
https://www.realclimate.org/index.php/archives/2024/02/new-study-suggests-the-atlantic-overturning-circulation-amoc-is-on-tipping-course/#comment-820380
I would like to remind all participants who prefer arguments ad hominem of a sentence ascribed to a Russian author Michail Žvaněckij
http://tapolitika.cz/ze-sveta/ruska-mozaika/michail-zvaneckij-citaty/
It reads
“If you argue with an idiot, there’s a good chance he’s doing the same.”
I perceive it the way that if we argue with an opponent, we implicitly assume that he is NOT an idiot.
In this case, however, we should desist from assigning him as such.
I think that we all frequently express rather our personal beliefs than opinions that we are willing to discuss. I think it is in human nature and there is nothing wrong in it. I suppose that problems arise mainly when people start assuming that others should or must SHARE their personal beliefs.
Viktor does not see the evidence offered in this discussion by others as convincing. I see it oppositely but I still can accept his view as his personal belief. I do not see any reason for dismissing him as a person. He can do the same with respect to me, after all.
Greetings
Tom
Thanks for your very reasonable and responsible post, Tomáš. I’m not sure why there’s so much hostility floating around here. I try to ignore it, but it does get tiresome.
In Re to Victor, 22 Mar 2024 at 3:21 PM,
https://www.realclimate.org/index.php/archives/2024/02/new-study-suggests-the-atlantic-overturning-circulation-amoc-is-on-tipping-course/?replytocom=820454#respond
Dear Victor,
Many thanks for your kind words. I think that hostility may at least partly arise from primary impulsive reaction which is human and natural and consists in perceiving “alien” things, not fitting with one’s familiar environment, as a potential disruption and threat.
Of course, there is a danger of a hostility escalation any time when this natural reaction is triggered. That’s why people invented various communication tools, like respect and politeness, which can prevent and/or mitigate conflicts.
In your case, I think that the majority on this website can be irritated because they think you try to disprove their view on climate change and its mechanisms.
It is, however, my feeling that you rather just say: “Hey, guys, I read your arguments, understand them, but still see the things different. Isn’t it perhaps the same with lot of other people? We may not be silly, although we do not accept your arguments. However, if you think we are, how are you going to convince us?” Please correct me if I interpret you false.
I am not a psychologist or sociologist, it is just my feeling that people often arrive at a belief that there are ideal recipes how the society should work, ideal solutions that must be sought and achieved at any costs and have to be accepted by everyone. Personally, I strongly doubt that the society is so simple and unequivocal. In Czech, there is an idiom “tlačit na pilu” (“push on the saw”) which applies to very intensive and very committed efforts which, however, turn out rather counter-productive. Just as when the saw bites down and gets stuck.
I personally believe rather in assuming that also my opponents may be positively motivated or at least have their reasonable concerns. I strive to accept that others may see things very differently. The discussions on this website show that seeking points of mutual agreement is not easy, however, I do not see any better solution than doing so. I believe that finding compromises which might be acceptable for the broad public irrespective of persisting disagreements between various parts thereof can be better than permanent cold civil war.
With respect to climate change mitigation, I can imagine compromises even between seemingly irreconcilable “alarmists” and “denialists”. I believe that such compromises should be sought and can be achieved. I think that similarly uncertain, concerned people among opponents having very different views may find ways how to act as allies toward a common goal, instead of fighting each other as arch enemies.
Greetings
Tomáš
V: I’m not sure why there’s so much hostility floating around here.
BPL: Yes, that’s one more thing you just don’t seem to get. It never occurs to you to think “Have I done something to make these people so mad?” It’s always the others who are at fault.
> “If you argue with an idiot, there’s a good chance he’s doing the same.”
Passive aggressive personal attacks are still personal attacks, and as such are ad hominem.
Physical plays are fine as long as it allows to get to the ball.
What is the proverb about the “better” of letting intentional idiocies stand as factual?
Tomáš: “people often arrive at a belief that there are ideal recipes how the society should work, ideal solutions that must be sought and achieved at any costs and have to be accepted by everyone. ”
V: Thanks so much for this, Tomáš. You’ve hit the nail on the head. I’ve presented my ideas and observations in the hope of initiating a meaningful debate, but all I’ve managed to achieve here is to stir up a hornet’s nest among those who will accept no alternative other than a so-called “consensus” demanding total obedience to a very narrowly defined view of something they like to call “the science,” as though such a thing could ever actually exist. So engrained is this dogma in their thinking that they will tolerate NO view that diverges from what is in fact a very narrowly defined (and dangerous) “gospel.”
Even if they are right (which I doubt), what they are demanding is (and has been for a very long time now) so extreme as to be utterly unworkable in any case. This has all the characteristics of a cult.
Alright, Victor. I’ll do this just once, just for you.
> I’ve presented my ideas and observations in the hope of initiating a meaningful debate,
https://climateball.net/but-debate-me/
> a so-called “consensus”
https://climateball.net/but-consensus/
> So engrained is this dogma […] “gospel.”
https://climateball.net/but-religion/
> so extreme as to be utterly unworkable in any case.
https://contrarianmatrix.wordpress.com/do-no-harm/
> This has all the characteristics of a cult.
https://climateball.net/but-religion
And we’re already at the end of your rant, calmly composed of ad hominems for the most part. The only interesting bit is your naked assertion about what you believe is unworkable, without identifying what that should be, because factiveness isn’t the point here. The main point is to play the victim.
Cheers.
Nice try, Willard. I’ve heard it all before. Very general. If you truly want to debate me you’ll need to address certain particulars:
1. The FACT that there was no global warming from 1940-1979, despite all the predictions that significantly rising CO2 levels would result in significant warming..
2. The FACT that the cooling affect of industrial aerosols is limited in both time and space. If a warming trend had been masked by industrial aerosols, as has been widely claimed, then we’d expect to see warming in remote regions where aerosol cooling would have been minimal. But that is NOT the case.
3. The sea level rise so many are concerned about began at a time when global temperatures, on both land and sea, were falling.
4. According to a group of highly regarded climate scientists, the so-called “hiatus” was real. During a period when CO2 levels were soaring, global temperatures were either remaining steady or rising only slightly.
Is this, as you and the others would like to think, a pack of lies? Really?
Victor,
Referencing your point #1 FACT, what say you regarding Kevin McKinney 22/03/24 1:32pm addressing the 1940-1979 period? Also, would you help me out by providing a reference for CO2 increase/global temperature increase predictions made in 1940, 1939, or that period that you also refer to in your point #1 FACT? I couldn’t find anything.
Many thanks!
Perhaps Victor missed it?
In Re to Willard, 24 Mar 2024 at 5:48 PM,
https://www.realclimate.org/index.php/archives/2024/02/new-study-suggests-the-atlantic-overturning-circulation-amoc-is-on-tipping-course/#comment-820525
Dear Mr. Willard,
I sought on your website for chapters debunking thoughts / opinions that human interferences with water cycle might have contributed and/or contribute to the observed global warming as another sort of the “climate science denialism” (or “global warming denialism”), and found nothing.
Could you comment?
Greetings
Tomáš
Dear Tomáš,
Try simple sentences. Subject-verb-object.
Also, if you have a point, make it.
And please try to be relevant. Your question has little to do with the comment on which you’re trying to piggyback.
Thank you for your concerns,
W
Tomáš,
You seem befuddled. Victor is stuck in an infinite DO loop of misinformation. Unfortunately, despite years of effort, his archaic, glitchy programming remains inaccessible to anyone outside the bunker of his mind.
We can, however, observe and apply meta-analyses to the awesome volume of baloney that he continues to generate to this very day, and so in that respect, perhaps learn the warning signs that will help others avoid getting tangled up in his time-wasting version of reality.
V: So engrained is this dogma in their thinking that they will tolerate NO view that diverges from what is in fact a very narrowly defined (and dangerous) “gospel.”
BPL: No, Victor. Stop bearing false witness. We will entertain any view THAT HAS EVIDENCE TO BACK IT UP. We will not entertain things already examined that have proved to be false. Once falsified, no longer interested. Do you get it yet? So stuff your self-righteous tirade.