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.
Victor, Ned Kelly, and Tomasz (and, without doubt, others I’ve missed or omitted):
I’m not angry, I’m bored. I suspect I’m not alone. Do better. Do something useful. [Victor, some self-education first, and observation of reality.] Find allies rather than setting yourself at enmity. Don’t waste your own and others’ time.
Sorry, not sorry, to be so bossy and argumentative. After all, I’m just a poster on somebody else’s platform so you may do as you please, within the constraints set by our hosts.
t;hat belonged in UVariations, sorry
A balanced view: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3002211/
Nope. Bjorn Lomborg (this article was from 2010) has been proven wrong not only by careful review but by real events everywhere (which are becoming more obvious, even if the recent ‘bananas’ increase is a blip in the regular progress of predicted global warming increases (which I believe is more likely than not). He makes a lot of money with his shtick, which is popular with the money people who prefer their current wealth and power. His degree is in political science. Here’s a review of his more recent work:
https://www.lse.ac.uk/granthaminstitute/news/a-closer-examination-of-the-fantastical-numbers-in-bjorn-lomborgs-new-book/
An outdated view–14 years old is a long time in this context.
The document Weaktor posts is remarkable for several reasons. First, it is a classic example of the Lukewarmer (or Luckwarmer) perspective. Second, it’s a wonderful example of “both-sidesing” an issue where there is really only one, legitimate scientific position. It emphasizes mistakes by legitimate scientists (e.g. typos that inadvertently exaggerate the severity of the situation, the Climategate nontroversy, etc.), while utterly ignoring the outright scientific misconduct by denialists and fossil fuel interests.
Most of the arguments against action in the piece have been invalidated by the passage of time and the advances in renewable energy.
Finally, it’s nearly a decade and a half old–roughly the minimum you’d have to travel back in time so the luckwarmer position could even argue that his had a fig leaf of legitimacy.
AND STILL: it contains not a scintilla of evidence favoring the position Weaktor argues here. Heckuva job, Brownie!
Ray Ladbury: a wonderful example of “both-sidesing” an issue where there is really only one, legitimate scientific position.
V: Classic cult-speak. There is never only one legitimate scientific position. By adopting such an attitude, you are in effect refusing to accept that the theory you’re defending could be falsifiable,
V: Classic cult-speak.
J: If it’s a cult, who is the leader? Who is telling climate scientists what they have to think? If they’ve come to agreement based on the strength of accumulated evidence, is that a cult?
V: There is never only one legitimate scientific position;
J: What qualifies you to lecture scientists on how science is conducted? “Never” is a very strong term. e.g. Name another legitimate scientific position to the Sun creating its energy through nuclear fusion.
V: unfalsifiable, hiatus, 1940-79, etc., etc.
J: Dead parrot arguments. You’ll never admit that the “GW due to unknown causes but not CO2” bird you’re trying to sell is dead.
Dear John,
I understand that Victor does not like assigning rising atmospheric CO2 level (or, more precisely, rising atmospheric concentration of non-condensing greenhouse gases) as the sole cause of the observed global warming. It is certainly a potentially confusing oversimplification, because there undoubtedly are further anthropogenic “forcings” that do significantly contribute to the observed warming effect.
One of the other oficially recognized “forcings” are athropogenic aerosols which are usually used as an explanation for the imperfect correlation between concentration of greenhouse gases and the observed warming. Personally, I would say that Victor’s objection (that the effect of aerosols should be only local) is in my opinion questionable.
Nevertheless, I have another problem with aerosols, namely the objection raised by professor Kleidon with respect to proposals that aerosols might help mitigate the greenhouse effect
https://idw-online.de/de/news564976
and
https://onlinelibrary.wiley.com/doi/10.1002/piuz.201401381
If his thermodynamic arguments why “geoengineering is no solution” are right, how could aerosols mitigate the greenhouse effect in the past?
Isn’t it contradictory also with the allegedly underestimated role of aerosols as recently emphasized by Dr. James Hansen and others?
I already asked this question elsewhere on this forum, however, no one paid an attention.
Should professor Kleidon be right, then it is my understanding that Dr. Hansen should be wrong. In this case, however, Victor might be perhaps still right, too..
I indeed do not understand why is climate science presented in media as a perfectly oiled machine that gives reliable projections of the future climate, although in fact different top scientific publications dealing with other basic climate drivers than non-condensing greenhouse gases (like clouds, aerosols, ocean currents, land hydrology..) often sound completely contradictory to each other.
Greetings
Tom
To Tomas,
consider that the so-called humidity paradox remains mostly unexplained. Some seem to blame it on best available data, but recent events seem to suggest otherwise.
https://climate.metoffice.cloud/humidity.html#datasets
there we have robust trends in the areas of missing outgoing SW.
https://www.metoffice.gov.uk/hadobs/hadisdh/images/latest_version/TrendMapOLS_HadISDH.marineRH.1.4.1.2022f_BClocalSHIP5by5both_19732022.png
when considering that the increasing disparity between humidity and temperature strictly limits cloud, it is worth exploring this issue with reference to connections to the rapidly degrading continental ecosystem services (and the ocean basins situated amidst them).
Given its essential role to climates, continental moisture depletion even in the absence of any P-E change is cause for interest outside the framework of feedbacks to trace gas (which currently overwhelms perspective). I notice even doubtful scientists such as Roy Spencer refer to any non atmospheric force as a “non-climatic” aspect, which I personally find to be ridiculous and not aligned with classic definitions of climate influences.
The RH decrease over land was once explained as a result of the amplified land warming compared to ocean. This however appears to be a circular explanation as the amplified warming itself arises from the drying land. Previously it was thought that because oceans, which always work at temperature dependent maximum evaporation (i.e. mass and energy flux at saturation), warm too slowly to keep up with transport demands. It think it is much simpler to simply admit to the massive and profound catchment deterioration independent from atmospheric force.
cheers
In Re to JCM, 31 Mar 2024 at 8:38 AM,
https://www.realclimate.org/index.php/archives/2024/02/new-study-suggests-the-atlantic-overturning-circulation-amoc-is-on-tipping-course/comment-page-2/#comment-820747
Hallo JCM,
Indeed, I wonder that although Piotr classifies “vaporism” as one of classical forms of climate (science) denialism, I have not found a single word about land hydrology and water cycle in the entire text of the classical book “Unsettled science” written by Steven Koonin. Who is, at least to my best understanding to Piotr’s criteria, a patented denialist.
As regards my question formulated as “Hansen or Kleidon”, I can, actually, imagine that both of them may be true. More specifically, I think that Hansen may be correct in that the athropogenic aerosol emissions might have roughly compensate the warming caused by anthropogenic emissions of non-condensing greenhouse gases, until the necessary measures against acid rains caused a shift in favour of greenhouse gases.
Independently therefrom, Kleidon may be correct that this is in fact not a true compensation, because, for thermodynamic reasons, keeping the mean surface temperature stable by figting greenhouse gases must come on the expense of changes in hydrological cycle intensity. In other words, Kleidon may be correct in his warning that fighting greenhouse gases with aerosols may be like many other cases of fighting one evil by another evil – not completely free of negative side effects.
Should, however, both of them be correct, then it, in my opinion, implies that humanity disrupted global hydrology not only by “land use” changes such as deforestation, melioration and soil degradation, but (since the start of the industrial era the latest) also by the combined Hansen-Kleidon effect suppressing the water cycle intensity due to combined air pollution by anthropogenic greenhouse gases and aerosol emissions.
It is my understanding that global warming mitigation policies should be defined differently, depending from who is correct:
a) Hansen,
b) Kleidon,
c) both of them.
As I have not noted any reference to a reasonable scientific discussion about this topics during the entire year reading the Real Climate, I am afraid that my doubts about justification and reasoning of present climate policies may not be completely irrational.
Greetings
Tomáš
To Tomas,
I’ve pondered this effect which supposes about a 1/3 difference in the stabilizing latent flux response per K GMST. That is a range of about 2.4 W/m2 per K compared to a 1.6 W/m2 per K change in LE depending on whether the change is forced by insolation effects or LW radiative force.
In Kleidon’s analytical style, this is strictly related to the optimal minimization of the GMST compared to the outgoing radiation temperature through vertical heat transport. In the absence of this transport, and the depletion of the Ts – Tr according to the Carnot limit principle, the greenhouse effect necessarily appears more intense.
My impression is that various models find a wide range for such a latent flux effect per K, with a mean about 2 W/m2 per K. This seems to about split the difference between a LW radiative forcing and an insolation force / feedback (i.e. aerosol forcing or cloud radiative effects).
It’s worth keeping in mind that the actual observed energy accumulation is exclusively in the SW, as reported in Raghuraman 2023 using CERES https://journals.ametsoc.org/view/journals/clim/36/12/JCLI-D-22-0555.1.xml. It’s the same observation which I think is the impetus for the CERESMIP as reported by Schmidt 2023.
A difference of 2.4 W/m2 per K vs 1.6 W/m2 per K, or 3% vs 2% of 80 W/m2 LE, is about 0.8 W/m2 K.
Naturally, assuming a 33K realized greenhouse effect with 80 W/m2 latent flux in associated steady state depletion, that is 80 / 33 = 2.4 W/m2 per K. So it appears to be assumed, using Trenberth style cartoons, that the latent flux arises exclusively from surface available energy from insolation.
It is difficult for me to comprehend why this 2.4 W/m2 per K should only now become lower from the addition of human caused trace gas increase, in line with model expectation. I guess it could be attributed to non linear effects, but it should be kept in mind, owing to the curving vapor pressure saturation curve with temperature, the equilibrium partitioning increasingly favors the latent flux with warming (not the other way around).
My perception is that it could only become lower by suppressing continental moisture availability. That is the only way for it to align with model expectations < 2.4 W/m2.
best
Tomas,
As I explained in another posting, I am a meteorologist but not a climate scientist. There are others on this board who have a deeper understanding of the effects of aerosols and moisture/temperature interactions on climate.
That said, I do not think it is a simple case of Drs. Kleidon vs. Hansen. It is important to remember that aerosols have a variety of sources, compositions, and locations within the atmosphere. Overall, sulfate aerosols – often arising from combustion – will cool the lower atmosphere by reflecting more sunlight at visible wavelengths and increasing cloud reflectivity. They are more easily penetrated at IR wavelengths, and so will result in net surface cooling. From a thermodynamic perspective, less energy received at the surface will result in less evaporation and less average precipitation. I would expect any geoengineering based on putting sulfate aerosols into the atmosphere to result in overall surface cooling, but also reduced precipitation, and also less energy for photosynthesis and primary production of carbon that enters ecosystems.
The chemistry and climatic effects of the various aerosols is quite complex. For example, the sulfate aerosol production over the ocean by ships has fallen recently. Simultaneously, the production over land has increased due to the greater amount of wildfires during the boreal warm season. There is also the production of black carbon (soot) which has different properties.
I use peer-reviewed scientific publications as my main source of climate science information. In general, the popular media can be relied upon to simplify whatever topic they cover. They will package the information with at least some regard to their overall political and financial interests.
Such writing is supposed to be well oiled to appeal to its intended audience.
V: Accusation as confession
Open your mind and look around.
Great, Weaktor. I’d be happy to learn of any significant article calling into question the validity of any significant component of the consensus model of Earth’s climate. Please cite one that has appeared in, say, Nature, Science, JGR,…
Go ahead. We’ll wait. And I’d be happy to examine any evidence that falsifies that theory–the problem is that nobody has produced any. And all you have produced is laughter at your own expense. Just give thanks that you do not possess sufficient self awareness to be embarrasse.
https://www.businessinsider.com/the-ten-most-important-climate-change-skeptics-2009-7
I could add Judith Curry, Willie Soon, Richard Lindzen, Roy Spencer, Roger Pielke, Fred Singer, for starters.
> for starters.
Do go on, Victor – we both know that the contrarian bench is not that big.
And Junior would dispute your association!
Please cite the specific findings in full context any or all of them have produced which falsifies the accepted fact of greenhouse gas warming. That would be actual evidence published in peer-reviewed or other relevant sources that allow others to examine their evidence NOT in blog or so-called think tank “policy” papers.
And NONE of the folks on the BI list are climate scientists…and other than Soon (who has been suitably eviscerated in these pages) when was the last time any of these guys published anything in anything but a vanity journal. You ain’t helping your case.
Still waiting.
Do any of their papers “call[ing] into question the validity of any significant component of the consensus model of Earth’s climate”?
Curry’s thing is uncertainty; Soon’s, solar forcings; Lindzen’s, uncertainty around feedbacks, especially cloud; Spencer’s, the magnitude of practical problems; ditto, Pielke; and Fred Singer–well, is this a “significant component of the consensus model of Earth’s climate?”
Singer: It is worth remembering this sadly staggering summary of the harm he did spreading his noxious fake skeptic denial in his stroll through the halls of power:
http://rabett.blogspot.com/2014/09/a-note-about-roger-revelle-julian.html
“Singer is a celebrity in this field, perhaps the leading contrarian, skeptic, denier at the head of the pack for almost two decades. There are no objective canons of ethics in science (unlike for lawyers), so my charge of unethical can only mean “in my opinion” and “based on my standards.” Not only do I believe my statements to be true, I have substantial evidence backing them up. And, we now have anti-SLAPP legislation in Massachusetts.”
I repeat myself because I firmly believe this gem is well worth archiving. Here is a further related item.
The Big Myth About “Free” Markets That Justified History’s Greatest Heist
A recent book details how the top 10 percent stole $47 trillion via intellectual warfare
https://theintercept.com/2023/08/04/big-myth-book-free-market-oreskes-conway/
—–
note, In the Rabett post, the ‘cosmos’ link under item #15 is gibberish. Anybody who thinks the internet is permanent, take heed. Books last longer.
Also, look at the date on Weaktor’s article. Nothing ever changes for Weaktor. He’s living at least a decade and a half in the past and his epistemic closure will forever keep him there.
Absolutely.
Note: Roger Pielke Jr. belongs on V’s list but his father, Roger Pielke Sr., is not a full on profiteer from the muddy and/or poisonous waters of fake skepticism. (I have the impression he is loyal to his son which is understandable.)
The article at https://www.theguardian.com/environment/2024/feb/09/atlantic-ocean-circulation-nearing-devastating-tipping-point-study-finds recommended as high-quality science by Karsten V. Johansen 10 FEB 2024 AT 5:05 AM has a graphic of AMOC showing deep water formation at latitude 82N well north of Svalbard and a place 200 km SSE of Ireland. This graphic attributed or fake-pretense-attributed as “Guardian graphic. Source: Noaa, S Rahmstorf et al from the Potsdam Institute for Climate Impact Research (PIK)” is ENTIRELY DIFFERENT from most other graphics of AMOC deep water formation that I’ve been seeing, most of which are different from the others. This absurd BONE-IDLE LAZY Dog’s Breakfast is NOT GOOD (well, unless the topic is a trivial, unimportant one. Somebody inform me, is it that the topic is a trivial, unimportant one and hence crap disseminated to the Public is of no importance ?).
https://www.eurekalert.org/news-releases/1038917 – Newly uncovered history of a key ocean current carries a warning on climate: The Antarctic Circumpolar Current is speeding up―and now we know it’s done so before
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023GL106088
Here are some summary threads on the readily accessible Threadreader, at least one of which I found exceedingly helpful. Your dripping with contempt characterizations do your ’cause’ no good.
https://threadreaderapp.com/user/rahmstorf
Yes, the headline is over the top (a problem everywhere).
Insults are more likely to make people ignore you than heed what you have to say. Please do better.
> There is never only one legitimate scientific position.
The Earth could be or could not be the center of the universe.
There could be or could not be a greenhouse effect.
We could or could not be in a warming trend.
This current warming could or could not be anthropogenic.
Victor could or could not be a vanilla contrarian.
+ [brevity, wit’s soul]
Vanilla libelz!
“The Earth could be or could not be the center of the universe”
The notion that the Earth was the center of the universe has been falsified.
“There could be or could not be a greenhouse effect.”
Depends on how you define “greenhouse effect.”
“We could or could not be in a warming trend.”
The notion that we are in the midst of a warming trend is most certainly falsifiable. Time will tell.
“This current warming could or could not be anthropogenic.”
The theory that this current warming is anthropogenic is most certainly falsifiable. But proponents of this theory refuse to accept that. A theory that isn’t falsifiable is not a scientific theory, according to Karl Popper’s widely accepted interpretation of scientific method.
> Karl Popper’s widely accepted accepted interpretation of scientific method
You might like the Popper Ratio, Victor:
https://andthentheresphysics.wordpress.com/2019/08/03/the-popper-ratio/
Also, what you’re portraying as the “scientific method” is actually a solution to the demarcation problem. It has its shares problems. In fact it is not widely accepted at all!
Please keep the rest of your quote fest to yourself.
“The notion that the Earth was the center of the universe has been falsified.”
Nope. It has been falsified GIVEN a list of assumptions.
” according to Karl Popper’s widely accepted interpretation of scientific method.”
Apparently, unlike you,Popper realized in The Logic of Scientific Discovery that science involves INDUCTIVE reasoning which can never be 100% falsified when he said:
1. “Every test of a theory, whether resulting in its corroboration or falsification, must stop at some basic statement or other which we decide to accept. If we do not come to any decision, and do not accept some basic statement or other, then the test will have led nowhere.” .
2. “Experiences can motivate a decision, and hence an acceptance or a rejection of a statement, but a basic statement cannot be justified by them—no more than by thumping the table.”
3. He then goes on to make a jury analogy to the research community in any particular area saying: “The piles […of the chain of reasoning…] are driven down from above into the swamp, but not down to any natural or “given” base; and if we stop driving the piles deeper, it is not because we have reached firm ground. We simply stop when we are satisfied that the piles are firm enough to carry the structure, at least for the time being.”
I know Popper. You sir are no Karl Popper.
Victor,
A display of pop philosophy in all its glory. Quite popular these days in the United States amongst parts of the AGW deniers/skeptics crowd, particularly with some of my fellow conservatives.
Lacking much in the way of verifiable evidence against the ever growing mountain of data that anthropogenic activities are affecting the Earth’s climate, why not trot out the Popper chestnut?
“… why not trot out the Popper chestnut”
And quite improperly. I mean it’s not like Popper didn’t understand the limits of inductive reasoning. That said, I personally find Pepper’s notions of structural and multiplicative corroboration and contextualism more attuned to modern science than those of Popper.. (We used to engage in Pepper/Popper debates back in the day in seminars and the lounge, even!) Both, however, understood science at a rather deeper level than vic.
Vic seems to think that Popper posited some particularly sophomoric of logical positivism as the foundation of his views. He did not and in quite opposite fact, he viewed LP as completely insufficient for scientific explanation. Vic appears unaware of this just as he appears unaware of many science and philosophy of science topics…or at least any more advanced than pre-introductory levels.
I simply quoted Popper, whose position is well known and widely accepted.
> whose position is well known and widely accepted.
Most contrarians who appeal to teh Pop have not really read him, and no, Victor, his positions (note the plural) are not widely accepted!
More on Pop:
https://neverendingaudit.tumblr.com/tagged/PopperForBloggers
My favorite:
https://neverendingaudit.tumblr.com/post/23481303516
Oh, and you’re increasing your P-ratio.
No. You misunderstood and bastardized Popper, who you don’t understand in the slightest.
Yes, Popper’s positions are in fact well known among those who actually understand his ideas. And no they are not “widely accepted” among those people. They are in fact basically considered as an important intro in high school science and even some undergrad science areas.
First off, they are a century old and are not really considered current these days. In any case, you seem to think Popper can help you to infer things. Like that a “hiatus” in warming occurred in a particular point in time. Interestingly you follow precisely zero of Popper’s hypethetico-deductive reasoning steps in coming to this “conclusion” and utterly violate other steps as in your use of post hoc “inference”.
Popper, you may be surprised to know in this regard posited that induction itself was a myth. So no, you have not shown there was an hiatus. You have merely shown a short period of non-significant trend. Nonsignificance is not proof of anything at all.
What Popper basically tried to do was to finesse the whole notion of induction by bypassing it. That is not the view most in philosophy or in science hold. Or in real, everyday life for that matter.
Finally, as I mentioned above, Popper clearly believed in the notion of irreducible principles for which there could never be proof, only acceptance. Which basically means he never did fully finesse induction away at all.
Currently notions like Bayes (as well as _many_ other variants of pragmatism), contextualism (Pepper), fuzzy/probabilistic logic, etc. have generally superseded Popperian ideas in . Popper is basically used to teach the scientific method at the high school level by going through his hypothetico-deductive sequence at that pre-sophomoric level (which if you’d ever actually worked in science, you’d know basically no scientist has ever actually followed anyway).
I have suggested you read the Stanford Encyclopedia of Philosophy entry on the induction problem before as you so totally screw up handling inference all the time. Clearly you still have not read it as your notions of the subject remain incredibly high schoolish-to-sophomoric. The link remains: https://plato.stanford.edu/entries/induction-problem
V. Popper would not accept your misrepresentations. Stop pretending. The beginning of wisdom is admitting what you don’t know.
We’re willing to look at any evidence, Weaktor. It’s just that you wouldn’t recognize evidence if it bit your nose off.
Why do you insist on playing the fool, Ray, by making absurd accusations such as this?
It’s a nitpick, but I don’t believe it has. The cosmologically well-read are invited to correct me on this, but my understanding is that the shape of the universe is not known. While the currently favored idea is that “center” is probably a meaningless term in relation to our universe, which is hypothesized to be “homogeneous [and] isotropic,” that is, as it says on the label, hypothesis–and not substantiated knowledge.
Ah, yes–the old Humpty Dumpty argument:
I breathlessly await the accepted definition of “greenhouse effect” satisfying the non-existence requirement.
Ah, but how much time will suffice? And why? Personally, I find the warming trend observed since the mid-1970s damned convincing. Others, less so.
There’s also some vexing questions of definition: it’s quite possible to be warming over one time scale, and ‘simultaneously’ cooling over another. (For example, the “Southeast warming hole,” which last I know still showed cooling over the instrumental record, but which has nevertheless been warming during the modern (post ’70s) era.) Which span ought to be ‘prioritized?’
“There could be or could not be a greenhouse effect.”
Depends on how you define “greenhouse effect.”
Ah, yes–the old Humpty Dumpty argument:
V: If your claim is limited to what happens in a greenhouse then I’d agree that the greenhouse effect is an established fact. If by “greenhouse effect” you mean the power of greenhouse gases such as CO2 to drastically alter the climate then I would have to insist that such a theory is certainly falsifiable. And as you know, imo it’s already been falsified.
Kevin: (quoting V) “The notion that we are in the midst of a warming trend is most certainly falsifiable. Time will tell.”
Ah, but how much time will suffice? And why? Personally, I find the warming trend observed since the mid-1970s damned convincing.
V: As I’ve said before it all comes down to what you think about the “hiatus” from 1998-1916. I’ve already quoted the paper authored by several prominent climate scientists asserting that the hiatus was real. The lack of any warming trend during this period is evident from the two satellite surveys: https://skepticalscience.com//pics/RSS-UAH-2016-02.png As evident from the graph there was NO warming trend from 1998 to early 2016, a period of 18 years. While climate change advocates prefer to criticize the satellite results, they are definitely preferable to the land-based results since they cover the entire earth and don’t require a long set of adjustments to account for anomalies.
If you are willing to accept the opinion of the experts, reinforced by the satellite data, then you have to admit that there is no basis for claiming a long-term warming trend since 1979. But of course you are unwilling to do that. I understand.
Victor,
Would you please provide a link or explanation which SkS article you pulled your graphic from in your reply to Kevin? As you no doubt know, there are hundreds (thousands?) of graphics at the Skeptical Science site and you didn’t annotate the one you are using to buttress your argument. I have other questions regarding the graphic, but first I need to know where I can find the article it was a part of and then go from there.
I also have questions regarding your statement to Kevin “…you have to admit that there is no basis for claiming a long-term warming trend since 1979.” What part of the system are you referring to with this statement? Atmosphere (if so which layer), land surface, ocean surface or all? Regarding timeframe, do you mean 1979-2016 or 1979-2023?
Lastly, if I may, one question regarding your preference to use satellite data over surface data due to the latter in your words “require a long set of adjustments to account for anomalies.” Do you have a basis for favoring the number of adjustments made to one set of source data over the other? What is your basis to underpin your contention that adjustments to surface measurements are a “long set” but adjustments to satellite data are not?
Thank you,
V: “And as you know, imo [the greenhouse effect] already been falsified.”
Me: A worthless opinion, because it is based on willful ignorance.
V: “The lack of any warming trend during this period is evident from the two satellite surveys: https://skepticalscience.com//pics/RSS-UAH-2016-02.png”
Me: Half right. You can’t tell from that image, as it doesn’t isolate the putative ‘pause.’ But that’s easily remedied using the woodfortrees site, which lets you plot trends over any period you like. Here’s UAH and RSS for 1998-2016.
end/plot/rss/from:1998/to:2016/mean:13/plot/uah6/from:1998/to:2016/mean:13/plot/uah6/from:1998/to:2016/trend/plot/uah6/from:1999/to:2016/trend
UAH (v.6) not only doesn’t show warming, there’s a neglible cooling trend of 0.006 C/decade. On the other hand, RSS clocks in with a warming trend of 0.11 C/decade.
Illustrating the lack of robustness in the claimed ‘pause’, if you pick the span 1999-2016, even UAH v. 6 gives you a warming trend once again, albeit a very small one, of just 0.07 C/decade. As with V’s previously-claimed “cooling period” starting in the 40s, the trend is the product, not of a lack of warming, but rather of a warming spike–in this case, the very large El Nino of ’98–being cherry-picked as starting point for the analysis.
It’s a pretty obvious thumb on the scales, but V will never admit to it–thus does bad faith conceal itself from itself.
Somehow I managed to truncate the URl for the Woodfortrees plot referred to below (I think, based on what I recall of threading on the site!)
So, here’s the illustration I thought I was making easily available:
https://woodfortrees.org/plot/rss/from:1998/to:2016/mean:13/plot/uah6/from:1998/to:2016/mean:13/plot/uah6/from:1998/to:2016/trend/plot/uah6/from:1999/to:2016/trend
For the umpteenth time, you show you have absolutely no clue whatsoever about the scientific method. Let alone your blatant lies about science and your insecurity about admitting to be so wrong all the time. Epic critical thinking and learning failure, sport. Truly epic.
Please by all means be specific. Exactly what lies about science have I been guilty of? And please share anything you’ve found in anything I’ve written that’s “so wrong.” I’d love to learn your views.
You’ve claimed that the consensus model is unfalsifiable religious repeatedly, despite being shown you are wrong…repeatedly. That is a lie. One of many. Mostly, though, you are so obtuse that I think you must live on the surface of a sphere.
There really is only one legitimate scientific position — https://medium.com/@puk_54065/the-triple-crown-in-geophysics-db24eef26300
Willard says: You might like the Popper Ratio, Victor:
https://andthentheresphysics.wordpress.com/2019/08/03/the-popper-ratio/
V: From the above cited source:
“Many quotes could be presented to illuminate the concept of falsifiability. Since it may boost our ratio let’s stick to one, from the Logic of Scientific Discovery:
It might be said that even if the asymmetry [between verification and falsification] is admitted, it is still impossible, for various reasons, that any theoretical system should ever be conclusively falsified. For it is always possible to find some way of evading falsification, for example by introducing ad hoc an auxiliary hypothesis, or by changing ad hoc a definition. It is even possible without logical inconsistency to adopt the position of simply refusing to acknowledge any falsifying experience whatsoever.”
V: But this is exactly the point I’ve been making. As I see it, the importance of Occam’s Razor is to discourage such attempts to dodge falsification by “introducing ad hoc an auxiliary hypothesis, or by changing ad hoc a definition.” The refusal of “climate change” advocates to accept even the possibility that their theory could ever be falsified is an excellent example.
> the importance of Occam’s Razor is to discourage such attempts to dodge falsification
Are you referring to Gavin’s moderation, Victor?
If you’re just using my comments as a springboard, I’ll do the same.
Still awaiting one single example of someone embodying this claim:
“The refusal of “climate change” advocates to accept even the possibility that their theory could ever be falsified is an excellent example.”
You realize, Ray, that, by challenging me to provide solid evidence by some recognized expert or other, you are dodging the question I raised: To wit:
“Classic cult-speak. There is never only one legitimate scientific position. By adopting such an attitude, you are in effect refusing to accept that the theory you’re defending could be falsifiable,”
I haven’t the time or the inclination to track down every “peer-reviewed” publication of the sort you’re demanding. I did provide you with a list of recognized scientists who doubt the mainstream view and have written extensively on this topic. However, the real point is that, by insisting that there is only one legitimate scientific position re climate change, you are, as I wrote, “in effect refusing to accept that the theory you’re defending could be falsifiable,”
As Popper has written:
“. . . it is always possible to find some way of evading falsification, for example by introducing ad hoc an auxiliary hypothesis, or by changing ad hoc a definition. It is even possible without logical inconsistency to adopt the position of simply refusing to acknowledge any falsifying experience whatsoever.”
Which is exactly what you are doing.
> It is even possible without logical inconsistency to adopt the position of simply refusing to acknowledge any falsifying experience whatsoever.
Which is exactly what Einstein did the first time he saw empirical results that undermined his theory. And it just so happened that he was right. Sometimes evidence isn’t that falsifying. There is no experimentum crucis.
So it’s nice of you to quote where Karl concedes that falsificationnism is wrong and holism wins, Victor!
So, in other words, you don’t have time to find any actual evidence that supports your position, but you are sure you’re right? That about got it.
And Occam’s Razor is merely a heuristic. There are actual quantifiable measures that allow one to assess whether a more complex statistical model is justified over a simpler one–e.g. Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC).
In the case of physical models, there is the criterion of predictive power. If you make the model more complicated, adding more forcings, it should improve its predictive power.
Falsifying the consensus model for climate is easy in principle: just produce a model that is simpler and/or explains the data better–and that is ALL the data, not just the very noisy surface temperature data.
Ray, your insistence that there is only one legitimate scientific position on the cause of “climate change” is in itself equivalent to a denial that the position you’re defending could be falsifiable. This has nothing to do with Occam’s Razor.
> is in itself equivalent to a denial that the position you’re defending could be falsifiable
No, Victor. Falsifiability is only the idea that there could be in principle a falsifier.
By your logic, water’s boiling point would be infalsifiable!
Fine Weaktor, cite the peer-reviewed publication and tell us how many times it has itself been cited in peer-reviewed work.
You do realize that if there were a better theory to explain the variability in temperature that it would be BIG news. It would merit publication in a top-tier journal, such as science, Nature…
Go ahead. We’ll wait.
Do you also maintain that there alternative theories to electromagnetism or evolution–because the understanding of the greenhouse effect is just as old and just as well established?
V: channeling ‘science’ is not the same thing as understanding it. If you’d only stop pretending you might actually learn something. Faking it does not work here, where dedicated people share their real understanding gained through patience, intelligence, and hard work.
Victor. No. Falsifiability and legitimacy are different things. Get a dictionary.
“As Popper has written:
“. . . it is always possible to find some way of evading falsification, for example by introducing ad hoc an auxiliary hypothesis, or by changing ad hoc a definition. It is even possible without logical inconsistency to adopt the position of simply refusing to acknowledge any falsifying experience whatsoever.”
Which is exactly what you are doing.”
Methinks you haven’t looked into a single mirror lately. But you obviously do reside in a projection booth.
I was able to locate the Skeptical Science article Victor pulled the image from regarding 1998-2016. After reading the article, I think I now realize why Victor chooses to ignore my admittedly novice questions.
The article at SkS is titled: Tracking the 2°C Limit – February 2016
Posted 16 March 2016 by Rob Honeycutt
Thank you Kevin McKinney for the woodfortrees site info. Neat site.
My thanks to the commenters here and my gratitude to the group who run this site! As a frequent visitor I’ve admired RC from afar, but until quite recently resisted the urge to comment. I’ll try to not drag down the collective IQ too much !
Atmosphere Dynamics in a Nutshell –
including Brewer-Dobson circulation and coupling with AMOC (have written this ultra-short note for Raymond Pierrehumbert):
1) During atmospheric flow, between two instants of time, both absolute vorticity (relative vorticity + Coriolis parameter) and potential vorticity (ratio of absolute vorticity to layer thickness) are conserved.
2) As a consequence, both relative vorticity and thickness must change, as follows:
3) The Coriolis parameter changes gradually, depending from flow direction.
4) In the pressure field, the change of isobar curvature creates convergence (CON) or divergence (DIV), through mass continuity, between two instants of time.
5) A self-organizing process, based on transverse gravity drift with zero kinetic energy, adjuststs the direction of trajectories in the flow field, concurrently with transverse drift of isobars in the pressure field.
6) During meridional flow, conservation of potential vorticity (PV) requires CON/DIV, which in turn requires latent heating or radiative cooling, increasing/decreasing geopotential energy accordingly.
7) The process of self-organization is under the constraint of stable stratification and guidance by the first and second laws of thermodynamics, which includes heating and cooling, that allows CON/DIV to adjust the geopotential as required by PV conservation.
8) Observational evidence, provided by vertical soundings and satellites, allows to explain and understand atmosphere dynamics, forming an alternative to numerical simulations with mathematical models.
:
Ray Ladbury: You do realize that if there were a better theory to explain the variability in temperature that it would be BIG news.
V: Temperatures have always varied in the past as well as in recent years. Natural variation is assumed to be the cause in the past and I see no reason why it couldn’t be responsible for more recent changes in today’s climate history.
Humans are part of nature. They are a natural variation in nature. They are varying nature’s climate. They are naturally varying the natural environment by dumping giga tons of nature’s carbon that had naturally been sequestered in the ground, and as the natural great apes that we are, we’re putting it into the atmosphere naturally.
We know from nature’s past natural variations, that when nature’s natural carbon is variably pumped into the natural air, the planet naturally heats up. Naturally we’re doing that.
It’s all perfectly natural; Natural, but not good. Sometimes natural things are not good.
Do
You
Understand?