Ned Nikolov: Dispelling the Milankovitch Myth

Posted: January 3, 2022 by tallbloke in climate, Critique, Cycles, data, Ice ages, Natural Variation, solar system dynamics, Uncertainty

Ned Nikolov, Ph.D.
Dec 30, 2021

There has been a long-standing belief in Paleoclimatology that orbital variations (a.k.a. Milankovitch cycles) have been responsible for the initiation and/or duration of glacial cycles (Ice Ages) over the past 800 Ky. Milankovitch cycles are often referred to as a pacemaker of the Ice Ages. This myth dates back to 1970s, when sediment cores revealed a weak correlation in the frequency domain between Earth’s 41-ky obliquity (axial-tilt) cycle and the periodicity of Ice Ages during the early Pleistocene (Quaternary). However, in the late Pleistocene, the frequency of glacial cycles better match the Earth’s 100-ky eccentricity cycle, which further fueled the confusion. Yet, no one has been able to demonstrate a meaningful relationship between glacial cycles and any of the Earth’s 3 orbital parameters obliquity, eccentricity and precession or combination thereof on a linear time scale. A physical causation requires a strong correlation between parameters in the time domain, not the frequency domain!

Using recent data describing the dynamics of global surface air temperature inferred from geological proxies and variations of Earth’s orbital parameters computed by the best available orbital models, we show here the lack of a physically meaningful relationship in the time domain between Milankovitch cycles and Ice Ages for the past 784 ky. Orbital data came from the state-of-the-art model by Laskar et al. (2004 and 2011) and were downloaded from a page on the official website of the Virtual Observatory Paris Data Center in France. The top-of-the-atmosphere (TOA) solar insolation on summer solstice at 65o N latitude was obtained from the Milankovitch Orbital Data Viewer of Colorado State University. A time series of global surface air temperature for the late Pleistocene (past 784 ky) was constructed from published reconstructions by Snyder (2016) and Friedrich et al. (2016). All data series used in the analysis share the same temporal resolution of 1,000 years. Standard Score (a.k.a. Z-Score) is used in some graphs to plot time series having different measurement units on the same axis.

Figure 1.

Changes in Earth’s mean annual distance to the Sun (measured in Astronomical Units, AU) resulting from variations of planet’s orbital eccentricity have been minuscule for the past 800 ky (Fig.1) causing only a ± 0.05 W m-2 variation in the Earth’s baseline TOA Total Solar Irradiance (TSI) (Fig. 2). According to recent solar reconstructions (e.g., Egorova et al. 2018), this variation is 50 – 100 smaller than the TSI fluctuations caused by Sun’s magnetic activity on centennial to millennial time scales. 

Figure 2.

Hence, orbitally induced TSI changes are bound to have an immeasurably small effect on Earth’s global surface temperature. The latter shows practically no correlation to TSI variations induced by the Milankovitch cycles (Fig. 3a and 3b).

Figure 3a

Figure 3b


Earth’s obliquity (axial tilt) varied narrowly between 22.3o and 24.5o for the past 800 ky (Fig. 4) while showing no relationship to global surface temperature over this time period (Fig. 5a and 5b). The linear correlation between obliquity and the global surface temperature is R2 = 0.053 (Fig. 5b).

Figure 4.

Figure 5a.

Figure 5b.

Earth’s orbital eccentricity also varied over a narrow range (from 0.004 to 0.05) during the past 800 ky (Fig. 6). Note a pronounced 400-ky cycle in the eccentricity time series, which is not found in the global temperature record (Fig. 7a). The correlation between global temperature and eccentricity is rather weak (R2 = 0.235) (Fig. 7b) albeit a bit better than the correlation between temperature and TSI or temperature and obliquity discussed earlier.

Figure 6.

Figure 7a.

Figure 7b.

Figures 8a and 8b depict the relationship between rates of change of global temperature and Earth’s orbital eccentricity. These time-derivatives are correlated with a coefficient R2 = 0.341, which is the strongest relationship found between global temperature and any orbital parameter of Earth! However, this correlation does not imply a physical causation, because eccentricity changes have a negligibly small effect on TOA TSI and surface temperature.

Figure 8a.

Figure 8b.


Paleoclimatologists claim that Milankovitch cycles affect Earth’s climate chiefly through changes in the solar flux reaching the top of the atmosphere at 65o N latitude on the day of June summer solstice. According to this concept, a decreased summer isolation at 65o N due to a specific configuration of obliquity, precession, and eccentricity impedes the summer melting of snow at high latitudes and promotes ice accumulation, which over time allows glaciers to grow, thus initiating an Ice Age. The reverse process is believed to take place, when the summer isolation anomaly at 65o N is above its long-term mean (baseline value). During such periods, more snow/ice is expected to melt in the summer, which is thought to initiate deglaciation… However, the data reveal a complete lack of a relationship between summer insolation at 65o N and the global surface temperature for the past 784 Ky (see Figs. 9a and 9b). The correlation coefficient between these time series is a meager R2 = 0.031 (Fig 9b).

Figure 9a.

Figure 9b.

Roe (2006) claims to have found a strong correlation between the rate of change of Earth’s ice volume and the TOA June insolation anomaly at 65o N latitude. However, in his study, the ice volume (measured in “arbitrary units”) was estimated by models relying on oxygen isotopes. Noticeably one of the models (SPECMAP) dating back to 1984 assumed a-priori that ice volume and orbital forcing were related. Hence, the ice volume estimates utilized by Roe (2006) appear to be biased toward orbital cycles and much less reliable than modern proxy-based reconstructions of global temperature. Also, planetary-level climate change is physically much better defined through variations of the absolute global surface temperature rather than fluctuations of some unitless ice-volume estimates. This is because temperature is a fundamental metric controlling the dynamics of icesheets and sea ice. In an effort to “mimic” Roe’s approach as closely as possible, we compared the rate of change of global surface temperature to the TOA June insolation anomaly at 65o N latitude for the past 784 Ky (Fig. 10a & 10b). The correlation coefficient between these time series is R2 = 0.254 (Fig. 10b), which suggests an effective lack of control by the orbitally driven high-latitude summer insolation changes on the global surface temperature of Earth.

Figure 10a.

Figure 10b.

CONCLUSION: The available data indicate that, in the time domain, the Milankovitch orbital cycles are poorly correlated (if at all) to changes of global surface temperature inferred from sediment- and ice-core proxies for the past 784 Ky. Hence, the geological record provides no evidence that Ice Ages of the past one million years were controlled or even influenced by known variations of Earth’s orbital parameters. Putting to rest the Milankovitch orbital hypothesis of climate change as an unsupported conjecture seems to be an important and necessary step toward developing a new and physically robust Paradigm of paleoclimate drivers as discussed in this video: https://www.youtube.com/watch?v=DpUkPPtkPVc

Comments
  1. Graeme No.3 says:

    Thank you Ned,
    I have always been baffled by my failure to match Milankovitch cycles with global temperature by backtracking in time, compared with the near correlation of the graphs shown as ‘proof’.
    When I examined those graphs more closely I realised that they were based on variable times, with “values” for the 3 cycles used were (17, 19, 21, 22, 23, and 25), (40, 41), and (95, 100, 105, 110 and 125).
    While Milankovitch cycles exist and can be measured by astronomers – Hipparchus noting the first around 150 B.C. (based on the precession of the equinox) my thought is that those variations are nothing but fudging to make the theory match the data.
    Best regards and a Happy New Year to you.

  2. Ned Nikolov says:

    I fully agree with you, Graeme! 🙂

    Happy New Year to you too!

  3. Phil Salmon says:

    Thanks for the nice compilation of data.
    I would draw a different conclusion, that figure 5a actually makes it clear that all the post-MPR interglacials are initiated by obliquity peaks lagged with a delay of a few thousand years. Every second or third obliquity peak initiates an interglacial when it combines maximally with eccentricity and precession to give the largest warming input. This is all well known and clearly understandable, and it’s strange that Milankovitch denial is still ongoing.

    Prior to the mid Pleistocene revolution/transition, every obliquity peak initiated an interglacial. But the earth is gradually getting colder and the climate less responsive to being pushed toward the interglacial attractor by Milankovitch forcing. So obliquity alone was no longer enough, all three cycles post-MPR had to peak together to achieve initiation of an interglacial.

    I mentioned “attractor” in the hope, no doubt a forlorn one, that people would know what this means. But OK, it should be explained that attractors are states that are preferred and more stable than surrounding states in what is called the multidimensional “landscape” of states in which each parameter is a dimension.

    If people knew about chaos related phenomena such as periodically forced nonlinear oscillators, there would be no discussion about Milankovitch cycles since it is so obvious what they are. But no-one gets taught anything about chaos and nonlinear dynamics, and this is a major reason why we have climate alarmist pseudoscience. That’s why we have so many people thinking that periodic forcing needs to have the thermal energy to bring about the entire change of temperature, so dismiss Milankovitch forcing as too weak. This is just ignorance of chaotic-nonlinear systems. Such systems are “excitable”. The real power of the system transitions comes from internal dynamic cycling driven by feedbacks. Both the spread of glacial ice and its catastrophic recession and withdrawal are feedback driven excursions.

    Alternation between glacials and interglacials is inter-attractor flicker. It’s hard to understand why this is not obvious. This flicker occurs at the transitional stage between non glacial and deep uninterrupted glacial (eg “snowball earth”) into which the earth is likely headed within a million or so years. Accurate palaeo stratigraphy of former deep glaciations such as the Cryogenian has found they they too had interglacial flicker at the transitional periods at their start and end.

    https://ptolemy2.wordpress.com/2020/08/11/flicker-an-explanation-for-the-d-o-events-rapid-climate-fluctuations-of-the-last-glacial-period/

  4. tallbloke says:

    Fig 10a is super-interesting. Would it be worth comparing some of the more localised paleo T reconstruction records such as GISP2 rate of change to 65N Summer insolation?

  5. Ned Nikolov says:

    Phil,

    Your convoluted explanation makes no physical sense! Real physical forcing does not act as you describe it. Watch the video presentation at the bottom of the blog to see what the real driver of Ice Ages is… Our analysis of modern NASA planetary data clearly showed that obliquity has NO effect on a planet’s global average temperature. That’s a pattern across the Solar System! Yet, during the Ice Ages we have a substantial variation of Earth’s global average surface temperature. Only 2 factors can significantly change the long-term (baseline) global temperature of a planetary body: distance to the Sun and total atmospheric pressure. That’s it!

  6. daveburton says:

    There’s a clear mechanism by which Milankovitch cycles drive glaciation cycles: Ice / albedo integral feedback.

    In most contexts, ice / albedo climate feedbacks are minor. (For instance, open water in the Arctic Ocean increases the rate at which heat escapes from the sea more than it increases sunlight absorption.)

    But in the context of North American and Eurasian ice sheets, ice / albedo effects are the mechanism for natural “positive integral feedback,” because the effect accumulates/increases as the ice sheets grow or shrink. Over thousands of years this feedback mechanism becomes very important.

    Any systems scientist or electrical engineer can tell you that large positive feedback, or even small positive integral feedback, tends to cause a system to be “bistable,” meaning that it can “latch” (stabilize) in either of two states. We see that bistability in the Earth’s glaciation cycles.

    A common misconception is that the Earth’s dramatic glaciation/deglaciation cycles are evidence that the planet’s climate is very unstable, suggesting that climate sensitivity is high. They aren’t. There are two apparent reasons that Milankovitch cycles have a large effect on glaciation, and neither of them implies that climate sensitivity to GHG forcings must be high. The two reasons are:

    1. Milankovitch cycles change the breadth of seasonal temperature swings at the latitudes where it matters for glaciation: mainly northern North America and northern Eurasia.

    When those seasonal swings increase it increases ice melt in the summers and decreases snowfall in the winters. (When temperatures are very low snowfall is greatly reduced, because the cold air cannot carry much moisture; it is said, not quite accurately, to be “too cold to snow.”) That causes ice sheets to shrink.

    When the seasonal swings are reduced it decreases ice melt in the summers and increases snowfall in the winters. That causes ice sheets to grow.

    Note that it is not total solar insolation at 65°N latitude which drives those cycles, it is the seasonal distribution of that insolation: large seasonal swings cause the ice sheets to shrink, and small seasonal swings cause the ice sheets to grow.

    2. Milankovitch cycles last for tens of thousands of years, which enables them to overcome the extreme damping of the slow feedback mechanism.

    When, due to Milankovitch cycles, the Earth’s seasonal swings are reduced to the point that the great northern ice sheets grow a little bit each year, by adding more snow in the winters than they lose in the summers, after thousands of years of ice sheet growth it adds up to a large increase in planetary albedo. Conversely, when the Earth’s seasonal swings are increased to the point that the great northern ice sheets shrink a little bit each year, as the ice sheets dwindle it eventually adds up to a large reduction in planetary albedo.

    3. One known additional positive feedback mechanism also contributes to the bistability of the Earth’s climate. Glaciation cycles are also associated with swings of about 90 ppmv in atmospheric CO2 level (probably through a combination of water temperature and and ice sheet burial of organic matter). So in the glaciated state, the lower CO2 level reduces “greenhouse”[sic] warming, and helps keep the ice sheets frozen, but in the deglaciated state the higher CO2 level increases greenhouse warming and helps keep the ice sheets at bay during interglacials.

    That is an important positive integral feedback mechanism, but only on timescales of thousands of years, and it is highly non-linear, because it only works when the extent of the great northern ice sheets can significantly increase or decrease.

    Those ice sheets are gone, now. The only remnant is Greenland, so ice sheet albedo feedback could only become important in a warming climate if enough of the Greenland Ice Sheet were to melt to significantly increase the exposed land area, which is not in prospect.

    So Milankovitch cycle-driven glaciation cycles are evidence of very large natural long-period climate variability, but they are not evidence of high climate sensitivity to anthropogenic GHG forcings.

  7. daveburton says:

    Aw, crud. I hate it when my typos invert my meaning!

    I wrote:

    “Note that it is total solar insolation at 65°N latitude which drives those cycles, it is the seasonal distribution of that insolation…”

    But I meant:

    “Note that it is not total solar insolation at 65°N latitude which drives those cycles, it is the seasonal distribution of that insolation…”

    [mod] earlier comment amended

  8. Paul Vaughan says:

    baits fish hook

    dance with
    2 + 2 = 5

    understood perfectly

  9. Stephen Wilde says:

    I can accept that the baseline temperature is set only by distance from the sun and the mass of the atmosphere but I see no reason why chaos theory should not apply to variations around that baseline.

  10. Ned Nikolov says:

    Stephen,

    Global temperature variation around the baseline are possible, and do occur, but these are due to Sun’s effect on cloud cover/albedo. Such variations are small, though (+/-1 K), because of stabilizing negative feedbacks operating within the system affecting evapotranspiration & cloud formation… This is part of our model and the new concept. Watch this video about the role of albedo in climate for physical details and the math of it:

  11. Graeme No.3 says:

    The Vostok graphs show warm peaks at 11, 128, 210, 238, 325 and 420 thousand years ago.
    Taking the simple 26,000, 40,000 and 110,000 Milankovitch cycles back from 11,000 the only one of these peaks that corresponds with the 3 cycles is the previous one (allowing 125 to 131,000). To my simple mind that is coincidence not proof, although I note that the 40,000 cycle (Milankovitch’s choice) does roughly correspond with 4 of the previous 5 peak warms.
    Perhaps it is time to revisit Reid Bryson’s idea that a cooler period results in drier conditions and increasing dust reduces the received solar and that acts as a feedback, but when the dust level reaches a higher level it starts to fall on the ice fields reducing their reflectance and/or increasing heat absorption, ending the ice age.
    I can see the fangs bared so will exit ‘as if pursued by a bear’.

  12. Ned Nikolov says:

    DaveBurton,

    I was thinking of including a discussion about the ice-albedo feedback and other so-called “positive” feedbacks in the blog article, but then decided against it to keep the narrative short. Thus, I was expecting a comment like yours… 🙂

    Did you know that the positive ice-albedo feedback comes from the work of Arrhenius in the late 19th Century? He proposed it (just like the greenhouse hypothesis) as a thought experiment, a seemingly logical mechanism that made sense to him in the absence of observed global data. The purported feedback was later incorporated into math models by the Russian climatologist Mikhail Budyko, and became part of the standard “climate theory”, which is a narrative mostly based on conjectures from the 19th and beginning of the 20th Century rather than on data!

    However, modern satellite observations provide no support to this feedback concept! Take a look at these 2 papers published by different teams:

    Stephens et al. (2015) The albedo of Earth. Rev. Geophys.,53,141–163, doi:10.1002/2014RG000449.
    https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2014RG000449

    Datseris G and Stevens B (2021) Earth’s albedo and its symmetry. AGU Advances, 2, e2021AV000440. DOI: 10.1029/2021AV000440. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2021AV000440

    It turns out that the surface albedo plays little role in the overall planetary albedo, because clouds have the ability to override differences in surface albedo almost perfectly. This is apparent in the observed amazing symmetry of total albedo between Northern and Southern Hemisphere. Despite the fact that the surface albedo of SH is 11% lower than the surface albedo of NH, the top-of-the-atmosphere (TOA) reflected solar radiation only differs by 0.1 – 0.2 W m-2 between the two Hemispheres (provided that the total reflection is about 100 W m-2)! Climate models cannot reproduce this almost perfect albedo symmetry.

    So, making conclusions about regional changes in the TOA albedo based on the presence or absence of surface ice is likely to be quite wrong! Also, there are no observational data confirming the physical reality of the putative positive ice-albedo feedback as a temperature-change enhancing mechanism. The current climate theory and global projections heavily depend on positive feedbacks, but these are model-generated fictions. The real system is governed by negative feedbacks such as those stabilizing the cloud albedo variations forced by Sun’s magnetic activity so that the global temperature can only vary +/-1 K in response to cloud-cover changes.

    It’s time to separate mythical beliefs proposed decades to over a century ago from data-supported phenomena…

  13. tallbloke says:

    Clive Best took a look at Milankovitch in 2016. Worth a read.
    http://clivebest.com/blog/?p=7368

  14. Ned Nikolov says:

    This blog article by Clive Best from 2016 is similar to many other analyses of the Ice Ages undertaken in the past. The focus of attention is on trying explain Ice Ages via changes in insolation, i.e. through variations in solar radiation. However, radiation is not the causative driver of the Ice Ages in any shape or form! The real driver, according to our research, is adiabatic cooling and warming caused by changes in total atmospheric mass and surface air pressure. This adiabatic forcing is principally different from the radiative forcing. For more details, watch the video at the end of our blog article…

  15. Pablo says:

    Graeme,

    No fangs here.

    See also:

    “We present here a simple and novel proposal for the modulation and rhythm of ice-ages and interglacials during the late Pleistocene. While the standard Milankovitch-precession theory fails to explain the long intervals between interglacials, these can be accounted for by a novel forcing and feedback system involving CO2, dust and albedo. During the glacial period, the high albedo of the northern ice sheets drives down global temperatures and CO2 concentrations, despite subsequent precessional forcing maxima. Over the following millennia more CO2 is sequestered in the oceans and atmospheric concentrations eventually reach a critical minima of about 200 ppm, which combined with arid conditions, causes a die-back of temperate and boreal forests and grasslands, especially at high altitude. The ensuing soil erosion generates dust storms, resulting in increased dust deposition and lower albedo on the northern ice sheets. As northern hemisphere insolation increases during the next Milankovitch cycle, the dust-laden ice-sheets absorb considerably more insolation and undergo rapid melting, which forces the climate into an interglacial period. The proposed mechanism is simple, robust, and comprehensive in its scope, and its key elements are well supported by empirical evidence.”

    https://www.researchgate.net/publication/303535559_Modulation_of_ice_ages_via_precession_and_dust-albedo_feedbacks

  16. Phoenix44 says:

    Complex, non-linear, chaotic phenomena cannot be disproved with simple linear correlations. Is there any doubt that climate is a complex, non-linear, chaotic system?

  17. Graeme No.3 says:

    Thanks Pablo:
    I think that there are several (multiple?) factors in play with the climate. The influence of the Milankovitch cycles is probably a factor, but I am thinking that volcanic eruptions are a bigger factor.
    Pinatubo in 1991 supposedly cooled the Earth by 0.5℃ with the effect lasting for nearly 2 years. Mt.?
    (now Lake) Toba about 73,000 years ago caused about 5℃ cooling and lots of ice formation (and sea levels drop). Mt. Tambora in 1815 gave the northern hemisphere in 1816 “The Year without Summer”.
    Very obviously climatologists are aware of airborne particles but where do they go once gone from the atmosphere?

  18. Phil Salmon says:

    Ned
    Your convoluted explanation makes no physical sense!

    Periodically forced nonlinear oscillators, with both strong and weak forcing, are well established phenomena. Their absence from the narrative of climate science doesn’t detract in any way from their physical reality. There’s a literature on them, albeit largely in chemical engineering.

  19. Pablo says:

    Graeme,

    Toba is new to me…fascinating.

    Explosive volcanic for short term cooling. https://en.wikipedia.org/wiki/Toba_catastrophe_theory

    Submarine basaltic extrusion for longer term oceanic warming. https://ozonedepletiontheory.info/volcanoes-and-climate/

    I think ultimately, it is deep ocean warming via saltier warm waters sinking from shallow tropical seas and position of continents that keeps us out of an ice age.
    Today we have no shallow tropical seas of any size and a huge continent over the south pole. Those
    are two of the reasons why we have been in our present ice age for 2.6 million years.

  20. Ned Nikolov says:

    Fellows,

    Before continuing with speculations about “nonlinear oscillators” and “ice-albedo feedbacks”, would you please watch the videos on paleoclimate drivers I listed at the end the blog article and “the role of albedo in climate“, which I posted above?

    That’s because theoretical speculations unsupported by data combined with the omission and/or misunderstanding of fundamental mechanisms have brought us to the current dismal state of affairs in climate science. Thank you!

    BTW, I already addressed the “ice-albedo feedback” concept in one of my comments above, and showed that it’s refuted by satellite observations:
    https://tallbloke.wordpress.com/2022/01/03/ned-nikolov-dispelling-the-milankovitch-myth/#comment-174633

  21. Pete Rogers says:

    Dear Ned, You are right about planetary temperature being determined by pressure and incoming solar energy of course. It is worrying that “97% of All Scientists” were ever confused about that.
    May I therefore ask if you agree that, specifically, it is Charles’ Law that explains the Atmospheric Thermal Enhancement (ATE), because if pressure was lower the Atmosphere would be more voluminous and therefore contain less thermal energy per unit volume and cooler accordingly, which means that Gravity, not any Greenhouse Effect (GE), is responsible for the ATE by dint of the volume lost to it by compression.
    We should not conflate or confuse the GE with Charles Law because they are mutually alien.
    The failure of the Milankovitch explanations means that the main candidate for big-time temperature changes are self-reinforcing, and therefore runaway, Albedo effects in either direction.

  22. Phil Salmon says:

    Ned

    I watched the video.
    Two questions emerge,
    (1) you assert that atmospheric pressure can be “the only” factor influencing temperatures and glacial cycles. This seems hard to justify as well as arrogant. What about the ocean? The CO2-only proponents also ignore the ocean. In the figure you showed of global cooling since the Cretaceous, the distinct cooling events at 33 and 16 million years ago when Antarctic glaciation started are associated with well defined events of tectonic movement and continental rearrangement. Specifically, the isolation of Antarctica and the opening up of the latitudinally continuous deep Southern Ocean. These events stopped the previous currents bringing warm water from Africa toward the South Pole. Tectonic continental rearrangement and consequent changes to the ocean circulation are the main mechanisms of climate change over millions of years. (Warmists ignore ocean currents and talk only of CO2 release or drawdown.)

    2. If we are “explaining” temperature by pressure, it seems impossible to avoid cause-effect confusion. You claim the calculation of pressure is independent of temperature but this surely is impossible? Temperature and pressure are inseparable by the gas laws. So correlation of temperature with pressure is inevitably – in part at least – a correlation of temperature with itself.

  23. Phil Salmon says:

    Tallbloke

    Thanks for sharing Clive Best’s article on this topic, which is excellent as usual.

  24. Paul Vaughan says:

    no time for videos longer than 7 min
    link to summary in some other form please

  25. Ned Nikolov says:

    Paul,

    New paradigms cannot be explained in 7 min especially when the minds of those seeking an explanation have been indoctrinated with the wrong concepts for decades. It requires time and lengthy narrative to shift perspective in one’s understanding. It took me several years to realize what I’m now trying to explain in an hour long video… 🙂

    Start with this latest video of ours:
    Demystifying the Atmospheric Greenhouse Effect

  26. daveburton says:

    Ned wrote, “…modern satellite observations provide no support to [the positive ice-albedo feedback] concept! Take a look at these 2 papers published by different teams…”

    Thank you for the interesting links!

    Ned wrote, “It turns out that the surface albedo plays little role in the overall planetary albedo, because clouds have the ability to override differences in surface albedo almost perfectly. This is apparent in the observed amazing symmetry of total albedo between Northern and Southern Hemisphere.”

    That is incorrect, in this context.

    The Datseris paper says, “We show that the surface albedo asymmetry is compensated by asymmetries between clouds over extra-tropical oceans, with southern hemispheric storm-tracks being 11% cloudier than their northern hemisphere counterparts.”

    They’re talking about oceans. SH surface albedo is lower than NH albedo because much more of the SH is water. But open water also causes more evaporation and clouds, thereby compensating for the lower surface albedo of dark open ocean.

    As I wrote in my previous comment, “In most contexts, ice / albedo climate feedbacks are minor. (For instance, open water in the Arctic Ocean increases the rate at which heat escapes from the sea more than it increases sunlight absorption.)”

    Based on Nimbus-5 observations, Zwally, et al. 1983 reported that:

    “…the release of heat to the atmosphere from the open water is up to 100 times greater than the heat conducted through the ice.”

    Open water causes evaporation, thereby increasing clouds formation (and lake/ocean-effect snowfall). Sublimation of ice is much slower than evaporation from the open ocean, so when the same water is covered with a layer ice it releases far less moisture, and causes fewer clouds to form.

    But that’s not what we’re talking about. We’re talking about the ice / albedo feedback which drives the advance and retreat of the great northern ice sheets, which define the Earth’s glaciation cycles. The great Laurentide, Fennoscandian & Cordilleran ice sheets were on land.

    Exposed dry land does not generate clouds like exposed open water does. So when land is covered with ice and snow, the albedo really does increase, even when viewed from orbit. So the positive integral feedback loop that I described is real:

    Milankovitch cycles change the breadth of seasonal temperature swings at the latitudes where it matters for glaciation: mainly northern North America and northern Eurasia.

    When those NH seasonal swings are larger, it means that summers are hotter, and winters are colder. The hotter summers increase summertime ice melt and evaporation from the ice sheets. The colder winters decrease snowfall accumulation on the ice sheets. The combination of those two facts means that large NH seasonal swings cause the great northern ice sheets to retreat.

    Conversely, when NH seasonal swings are smaller, summers are cooler, and winters are milder. The cooler summers decrease ice loss from the ice sheets in summertime. The milder winters increase snowfall accumulation on the ice sheets in wintertime. The combination of those two facts means that small NH seasonal swings cause the great northern ice sheets to advance.

    It doesn’t much of a change in ice sheet extent each year to add up to a very large change after thousands of years. That’s the “integration” (or summation, if you prefer) which makes this a positive integral feedback mechanism.

    Ned wrote, “Also, there are no observational data confirming the physical reality of the putative positive ice-albedo feedback as a temperature-change enhancing mechanism.”

    Yes, satellite coverage was poor during past glaciations and deglaciations.

    Ned wrote, “The real system is governed by negative feedbacks…”

    Well, there are fewer identifiable positive feedbacks than negative feedbacks. I count seventeen identifiable negative feedbacks, and only eight identifiable positive feedbacks, here (plus a few of unknown sign). But both negative and positive climate feedbacks are real.

    Ned wrote, “…such as those [negative feedbacks] stabilizing the cloud albedo variations forced by Sun’s magnetic activity so that the global temperature can only vary +/-1 K in response to cloud-cover changes.”

    Which negative feedbacks are you talking about?

  27. Paul Vaughan says:

    I’m open to concise summaries not requiring video.

  28. tallbloke says:

    2+2=5 is a bit too concise for me.

  29. Paul Vaughan says:

    calculated ambiguity?
    monsoon indeed…

  30. tallbloke says:

    Phil S, Clive’s article is good but limited in scope. He only deals with the last three interglacials and ignores prior data. The observationally derived ‘rules’ he develops only apply correctly in 2 out of the 3 cases. This is basically saying, “my rules work, except for when they don’t.” 😉

    I’m willing to listen to and think about your ‘chaos with bi-stable attractors’ hypothesis, but I need more flesh on the bones please.

  31. Paul Vaughan says:

    Spoken very politely: If a non-video case exists (whether concise, convincing, or otherwise), could someone (anyone – doesn’t matter who) please link to it? If so: thank you.

  32. Ned Nikolov says:

    Paul,

    I really don’t undestand your vigorous (and irrational) opposition to getting information and new insights from a video. What’s up with that? 🙂

  33. Ned Nikolov says:

    To: Pete Rogers @ January 4, 2022 at 2:05 pm

    Yes, planetary atmospheres obey Charle’s Law, which states that, under constant pressure, the gas volume is proportional to temperature. That’s because the average surface pressure is independent of temperature and it’s only a function of atmospheric mass above a unit surface area and gravity.

    However, Charle’s Law does not explain the Atmospheric Thermal Effect (ATE). The latter is a function of surface air pressure and incoming solar radiation (see our 2017 paper: https://www.omicsonline.org/open-access/New-Insights-on-the-Physical-Nature-of-the-Atmospheric-Greenhouse-Effect-Deduced-from-an-Empirical-Planetary-Temperature-Model.pdf).

    Also, decreasing atmospheric pressure causes a reduction of the gas volume as well for the same amount of solar radiation reaching the top of the atmosphere. I explain this conceptually and mathematically in my video (atmospheric depth/height increases nonlinearly with surface air pressure):
    Demystifying the Atmospheric greenhouse Effect

  34. Ned Nikolov says:

    Here is the bottom line:

    The available quantitative evidence from geological records and our contemporary understanding of the Milankovitch orbital cycles indicates that Ice Ages were NOT caused (driven) by radiative factors!

    Glacial cycles are the result of changes in the adiabatic (pressure-induced) forcing of the climate system.

    This profound insight emerges from our discovery based on modern NASA planetary data that the Atmospheric Thermal Effect (ATE) is a form of adiabatic (compression) heating that is independent of atmospheric composition (see Nikolov & Zeller 2017: https://www.omicsonline.org/open-access/New-Insights-on-the-Physical-Nature-of-the-Atmospheric-Greenhouse-Effect-Deduced-from-an-Empirical-Planetary-Temperature-Model.pdf)! This is a completely new concept for current climate science dominated by the faulty radiative “greenhouse” theory, but one that firmly has its roots in standard Gas Thermodynamics.

    To understand the adiabatic forcing and the geological evidence supporting its control of the glacial cycles, please watch (preferably more than one time) this video:

  35. Phil Salmon says:

    Tallbloke

    I’m willing to listen to and think about your ‘chaos with bi-stable attractors’ hypothesis, but I need more flesh on the bones please.

    I can only offer the linked article below, which contains my arguments about flicker between basins of attraction. I’ll admit it’s a bit rambling and unstructured but contains the scientific basis for this argument. It starts not with glacial cycles (it gets to them later) but with the extraordinarily DO events (Dansgaard-Oeschger). As a payoff for making it to the end there’s published evidence that other much earlier glacial periods (Cryogenian, etc.) also contained intervals during which Milankovitch forced glacial-interglacial flicker took place. For the same reasons that it does now.

    https://ptolemy2.wordpress.com/2020/08/11/flicker-an-explanation-for-the-d-o-events-rapid-climate-fluctuations-of-the-last-glacial-period/

  36. Paul Vaughan says:

    last time I watched TV? like 20 years ago

    monsoons supplementary

  37. tallbloke says:

    Phil S: it’s a bit rambling and unstructured but contains the scientific basis for this argument. …
    The large scale timing of glacials and interglacials is under the controlling influence of the Milankovitch orbital cycles, of precession, obliquity and eccentricity. Interglacials happen (at least over the last million years) when all three of these cycles coincide to give the maximal climate warming effect.

    OK, read that, thanks. Words are important. Your post contains the *conceptual* basis for the argument. To be scientific, you’ll need to quantify the way the three orbital cycles interact and relate to temperature change. I haven’t found any papers which show definitively and quantitively how “these cycles coincide to give the maximal climate warming effect” in a consistent way over the last 800kyr. Hopefully, you have.

  38. Phil Salmon says:

    I’ve an open mind to atmosphere pressure and mass changes. Some more background would be welcome. What are the normal input and output paths for the main gasses? What factors affect the input and output rates? How does atmospheric mass increase and decrease? Why would this appear to correlate with Milankovitch cycles? Thanks.

  39. Ned Nikolov says:

    Phil,

    The proposed changes in atmospheric mass and total pressure do NOT correlate with Milankovitch cycles. Nor does the global temperaures as I’ve demonstrated in the above blog article. The lack of a meaningful correlation between global temperature and the Milankovitch cycles over the past 800 ky is explained by the fact that glacial cycles are NOT caused by radiative forcing as you and many others have assume. Ice Ages are caused by adiabatic forcing.

  40. daveburton says:

    Paul Vaughan wrote, “no time for videos longer than 7 min. link to summary in some other form please”

    On YouTube (and, these days, on most other platforms) you can adjust the playback speed. That helps. A lot of tedious presentations are a lot less tedious at 175% speed.

    However, text still has major advantages over videos. Most obviously, pausing and reviewing text is effortless, and pacing is determined by the reader, rather than the presenter.

    Also, if you want to discuss part of a video, in order to cite it you’ll have to back up to find the time index of the start of the section, and in order to quote it you have to transcribe it, hopefully without too many mistakes. It is very tedious.

    With text, you just copy & paste, and there will be no mistakes.

    If it’s HTML you can even use a “Chrome text fragment link” to link directly to the text in question. With the “link to text fragment” extension it’s about a three second process.

    If it is PDF, you can at least cite the page number, at a glance (and link to the page, if the PDF has a URL).

    It is a frequent annoyance to me that people respond to what they imagine that I really meant, rather than quoting what I actually wrote. With text documents there’s really no excuse for that. But if they were responding to a video it could easily be an understandable mistake.

    Lastly, someone with poor hearing, with difficulty understanding some English accents, or even with poor vision, can use special software to read a text document, but a video might be unusable to him.
     

    Paul Vaughan wrote, “last time I watched TV? like 20 years ago”

    Bravo!

    I don’t own a working TV, but I do occasionally see one elsewhere. Watching TV when away from home seems a little like it must feel for an ex-smoker to sneak an occasional cigarette. (Or opoid.)
     

    Paul also wrote, “I’ve an open mind to atmosphere pressure and mass changes. Some more background would be welcome. What are the normal input and output paths for the main gasses? What factors affect the input and output rates? How does atmospheric mass increase and decrease? Why would this appear to correlate with Milankovitch cycles?”

    Good questions, and I doubt that there are good answers to them (in the context of the last million years or so). I have no reason to suspect that there’ve been significant changes in the mass of the Earth’s atmosphere over that time period.
     

    Ned replied to Phil, “The proposed changes in atmospheric mass and total pressure do NOT correlate with Milankovitch cycles.”

    That’s a problem. The glaciation cycles do seem to be quite obviously correlated with Milankovitch cycles, which is the main reason most people assume there’s a causal relationship between them. So if something else (anything else!) is uncorrelated with Milankovitch cycles it is hard to see how it could be causing the glaciation cycles.
     

    Paul wrote, “monsoon indeed…”

    I don’t understand those graphs. What is the source? What is the significance of Stalagmite O2 isotope ratio, and where is it shown? Where are those monsoons, and where does the ancient monsoon data come from?
     

    Paul wrote, monsoons supplementary…”

    If I didn’t understand the simple monsoon graphs, I surely have no hope of understanding these!

  41. Ned Nikolov says:

    DevBurton,

    You’ve got a comprehension issues, my friend. You seem to only see and understand statements that reflect your belief system rather than patterns revealed by the actual data.

    Where is the correlation between Milankovitch cycles and the Ice Ages? Do you see any physically meaningful correlation in all the 10 Figures I presented in the above blog article?

    How can not even get the main point of a blog that you are commenting on?

  42. Paul Vaughan says:

    If important graphs of observations appear in some of these videos, I invite anyone to link to the graphs.

    There seems to be an effort underway recently to create the appearance of disagreement where it possibly doesn’t even exist.

  43. Paul Vaughan says:

    If anyone can link to graphs & concise text supporting this claim I’ll give it consideration:
    “adiabatic forcing and the geological evidence supporting its control of the glacial cycles”

  44. daveburton says:

    Paul Vaughan wrote, “I never said…That was: Phil Salmon…”

    You’re right, and I apologize, to both of you.

  45. Ned Nikolov says:

    Paul,

    All graphs and explanations about how the geological records supports the hypothesis that pressure changes have been responsible for the observed climate change on geological time scales are presented in the video I linked at the end of this blog post… Man up and watch that video. It won’t bite you… 🙂

  46. tallbloke says:

    Dave B: The glaciation cycles do seem to be quite obviously correlated with Milankovitch cycles,

    People keep saying this, but no-one ever seems to want to do a thorough job of demonstrating those correlations. Ned’s data plots and calculated R values contradict the claim, quantitively and scientifically.

    which is the main reason most people assume there’s a causal relationship between them.

    Assumption is the mother of all f*ck ups. And correlation is not proof of causation. (Not that anyone has shown any decent correlations anyway).

    Personally, I would *like to believe* that orbital factors control the glacial/interglacial timings. And I would *like to believe* that Phil Salmon is onto something with his ideas about coupled non-linear oscillating chaos theory. BUT…. liking and believing,,, IS NOT SCIENCE.

    SO… can Milankovitch proponents please do something more than post multiplots with wiggles all over them with vague vertical grey lines with horizontal steps in supposedly linking them in some undefined way and provide something more substantial. Thank you.

  47. daveburton says:

    Ned asked, “Where is the correlation between Milankovitch cycles and the Ice Ages?”

    By “Ice Ages” I assume you mean glaciations, right? (Geologists say that we’re still currently in an ice age.)

    Here’s a paper which plots calculated June 65°N latitude insolation vs. two estimates of ice sheet mass in Fig.1, and against the first derivatives of those estimates (i.e., rate of change of ice sheet mass) in Fig. 2:

    Roe, G (2006) In defense of Milankovitch. doi:10.1029/2006GL027817 (preprint)

    The most well-defined transition in the glaciation cycles is usually on the warming side: the relatively abrupt onset of interglacials. Descents back into a glaciated state tend to be more gradual, so the timing is less well-defined. If we look at the timing of those glacial-to-interglacial transitions, they generally occur when June 65°N latitude insolation is high and (although nobody ever plots it) when December 65°N latitude insolation is low.

    In other words, when high latitude northern summers are relatively hot, and winters are very cold, the great northern ice sheets retreat.

    Here’s Roe’s Fig. 1:

    Here’s Roe’s Fig. 2:

    I do wish these plots were for lower latitudes. 65°N is nearly the Arctic Circle! 50°N (just north of the U.S. / Canadian border) would be more pertinent to the start of the ice sheets‘ retreat:

    Correlation does not necessarily imply causation, and Roe worked hard to tweak the scales and lags to maximize the of the correlation. That said, it certainly seems that he succeeded. I doubt that the correlation he identified was entirely coincidental. Don’t you agree?

  48. Pablo says:

    Going back a bit further to the Carboniferous ice age:

    “Cyclical Permo-Carboniferous sea level fluctuations have long been linked to glacial-interglacial fluctuations on Gondwanaland. Similar to the Pleistocene, such fluctuations may in turn have been driven by variations in orbital insolation forcing. Herein we report results from climate model simulations that examine the effect of Milankovitch insolation variations on the climate of the Gondwanan supercontinent. Utilizing maximum summer insolation values typical of interglacials, we simulate completely snow-free conditions, with summer temperatures at the South Pole >20°C. Modifying orbital configuration to minimum summer insolation receipt results in a large area of below freezing temperatures. Comparison of model-generated summer snow cover for the latter run with reconstructions of glacial ice extent indicates a good first-order agreement. These calculations support the cyclothem model and suggest that the entire glacial-interglacial couplet for the Carboniferous can be simulated with a minimum number of adjustable parameters.”

    https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/93GL01119

  49. Paul Vaughan says:

    Ice scene either disagree mean T nor need 4D-bait.
    Left us a proxy misinterpretation. So write orthogonal to geographically aware:


    image credit: Bill Illis

    Phil: Left to look back at what physicists (a decade ago) never had boundary conditions right.

  50. tallbloke says:

    Thanks Pablo. The paper is paywalled, so we can’t see the parameters, but with Crowley as co-author, we can be sure the models referred to will have a big fat non-existent CO2 forcing in them.

    Next!

  51. tallbloke says:

    Ned’s figure 8a is very interesting and suggestive of a link between rate of change of orbital eccentricity and glacial cycles. Notice the same sawtooth pattern as the temperature which rises suddenly to interglacial warmth and decays more slowly to glacial maximum.

    I wonder what it is about the patterns of motion of the other planets that causes this asymmetry in the rate of change of Earth’s orbital eccentricity. It’s suggestive of a periodic shorter term orbital forcing followed by a long period where its absence allows Earth’s orbit to ‘freewheel’ back towards circularity.

  52. oldbrew says:

    TB: the ‘model and boundary conditions’ of Pablo’s linked paper can be viewed here…

    https://www.deepdyve.com/lp/wiley/milankovitch-cycles-and-carboniferous-climate-AW3IkeZH7F

  53. oldbrew says:

    The NASA-JPL view…

    February 27, 2020
    Milankovitch (Orbital) Cycles and Their Role in Earth’s Climate
    By Alan Buis,
    NASA’s Jet Propulsion Laboratory

    https://climate.nasa.gov/news/2948/milankovitch-orbital-cycles-and-their-role-in-earths-climate/

    Quoting a couple of things at random:
    When Earth’s orbit is at its most elliptic, about 23 percent more incoming solar radiation reaches Earth at our planet’s closest approach to the Sun each year than does at its farthest departure from the Sun. Currently, Earth’s eccentricity is near its least elliptic (most circular) and is very slowly decreasing, in a cycle that spans about 100,000 years.
    . . .
    He calculated that Ice Ages occur approximately every 41,000 years. Subsequent research confirms that they did occur at 41,000-year intervals between one and three million years ago. But about 800,000 years ago, the cycle of Ice Ages lengthened to 100,000 years, matching Earth’s eccentricity cycle. While various theories have been proposed to explain this transition, scientists do not yet have a clear answer.
    – – –
    Also worth a look:

    The 41 kyr world: Milankovitch’s other unsolved mystery
    Maureen E. Raymo, Kerim H. Nisancioglu
    First published: 06 March 2003

    For most of the Northern Hemisphere Ice Ages, from ∼3.0 to 0.8 m.y., global ice volume varied predominantly at the 41,000 year period of Earth’s orbital obliquity. However, summer (or summer caloric half year) insolation at high latitudes, which is widely believed to be the major influence on high-latitude climate and ice volume, is dominated by the 23,000 year precessional period. Thus the geologic record poses a challenge to our understanding of climate dynamics.

    https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2002PA000791

  54. Ned Nikolov says:

    A word of caution: the Carboniferous glaciation was some 300 My ago. We only know the temperature distribution on Earth with a decent level of certainty for the past 110 My or so. In fact, the proxy temperature record start becoming fuzzy beyond 83 My ago. So, conclusions made about Carboniferous Ice Ages and their drivers based on a standard CO2-driven climate model should not be taken seriously, IMO!

  55. Pablo says:

    More on the Carboniferous:

    “The record of eccentricity and precession by the Mauch Chunk Formation sediments is consistent with its 23°S paleolatitude (Bilardello and Kodama, 2010) where the strength of the monsoon is driven by eccentricity and precession.”

    “The astronomically forced, Milankovitch-scale climate cycles were probably encoded by variations in erosion of the source area supplying varying amounts of depositional hematite into a background of paramagnetic clay minerals or diamagnetic quartz sand in the depositional basin.”

    https://www.frontiersin.org/articles/10.3389/feart.2019.00285/full

  56. Ned Nikolov says:

    Oldbrew,

    Thanks for the links. Yes, using Milankovitch orbital variations to explain Ice Ages of the past 3 My present major challenges in several respects. The root cause of these challenges is the erroneous a-priori assumption that Ice Ages were caused by radiative forcing. This assumption stems from the lack of understanding about the adiabatic forcing operating in the climate system. Our research corrected this situation by showing that key features of the glacial cycles such as the “polar amplification” phenomenon are only consistent with an adiabatic forcing being in control. Here are the details:

  57. tallbloke says:

    Those already familiar with Ned and Karl’s pressure-temperature theory could jump into the video at 19 mins to see their newer findings on how polar amplification predicted by their latitudinal model match paleo records from glacial/interglacial epochs well, and why only an adiabatic forcing, not a radiative forcing can be responsible for the glacial cycles.

    That would reduce viewing time to 14 minutes, which isn’t such a big ask. Paul V could manage it in two sittings within his 7 minute rule for example.

  58. oldbrew says:

    Looking for Milankovitch…

    From the Raymo 2003 paper, section 2 Ice Age Record:

    Figure 1

    Caption: Benthic δ18O record from DSDP Site 607 in the North Atlantic (solid line) plotted to a paleomagnetic timescale. The magnetic field reversals are marked, as well as the transition from a dominant 41 kyr to a 100 kyr world. B, Brunhes; M, Matuyama; J, Jaramillo; TOld, top of Olduvai; G, Gauss. Also shown is orbital obliquity (red dashed line).
    – – –
    The vertical red bars are interpretations of the data. The red dashes don’t seem to have a lot in common with the black solid line other than (possibly) part of the middle section, but it’s hard to tell on such a small graphic.

    The paper says: One must conclude that summer insolation at high northern latitudes does not exert a dominant (linear) influence on climate over most of the northern hemisphere Ice Ages.

  59. Paul Vaughan says:

    A misunderstanding may have resulted because of the disappearance of 2 comments I submitted.

  60. tallbloke says:

    Well they’re not coming back so get over it and discuss Milankovitch cycles instead.

  61. oldbrew says:

    I found this paper shortly before Ned N’s post appeared. Some ideas in it may be of interest.

    A Modified Milankovitch theory that reconciles contradictions with the paleoclimate record
    https://cp.copernicus.org/preprints/cp-2021-10/cp-2021-10.pdf

    From the abstract:
    In particular, two elements of the theory need modification. One is the limitation of eccentricity’s role and the other assuming that glaciation results only from cool summer conditions. By applying the Solar Energy Invariance law to define e-seasons, how eccentricity provides conditions for glaciation is demonstrated.

    My comment — See Figure 1 to get the general idea. The caption to it reads:

    The four e-seasons in a 100 kyr eccentricity cycle. The chart depicts the Earth orbit changing from an eccentricity (e) of 0.0 (circular orbit) to 0.05 (elliptical) and back. The Earth moves counter clockwise in the orbits. The aphelion Earth-Sun distance increases while the perihelion distance decreases as e expands but the sum remains constant. Applying the Solar Energy Invariance law and Kepler’s second law, the change will result in ap season cooling (dark blue) and peri season warming in (dark orange). The cooling and warming are global. ν is the true anomaly

  62. Ned Nikolov says:

    Oldbrew,

    Thank you for this new reference:
    https://cp.copernicus.org/preprints/cp-2021-10/cp-2021-10.pdf

    This 2021 paper reflects the continuing conundrum arising from trying to explain Ice Ages through radiative forcing. However, this approach simply does not work! The author comes up with a new scheme using eccentricity variations to artificially create seasonal cooling and warming as Earth moves between aphelion and perihelion within a single year of rotation around the Sun. The paper offers no quantitative assessment of the newly invented eccentricity-driven radiative forcing on the long-term global temperature through a physical model. In the absence of such an assessment, the paper remains another “hand-waving” exercise unsupported by physics just like so other studies before it.

    A hallmark of the glacial cycles is a phenomenon called polar amplification, which must be reproduced by any model claiming to explain Ice Ages. Polar amplification refers to a much larger change of Polar temperatures compared to the Equatorial temperature observed in the geological records during the glacial cycles of the past 800 ky. This paper does not even mention this phenomenon. Also, the author’s concept relies heavily on unphysical processes such as the fictitious positive ice-albedo feedback. He states in the Conclusions section:

    Global temperature reduction takes place from the sustained snow growth and creation of ice sheets as well as other feedbacks.

    This is physically absurd, because ice sheets are the result (consequence) of low temperatures. Ice sheets by themselves do not and cannot lower the global temperature any further!

  63. Aequitas says:

    This is a radical proposition of Ned’s and below I think I have captured the sense of it in four graphs.
    Below is the calculated air pressure over 83 million years. The pressure drops by about a factor of 3.

    Below is the money shot of this proposal by Ned. The temperature changes by latitude showing that ice did not exist on the earth prior to 43 million years ago.

    Now getting to the Milankovitch problem; the scale switches from millions of years to the last 780,000 and Ned calculates what the pressure change had to be to produce the temperatures over that time period. The pressures are shown below.

    The lowest pressure is about 70 KPA or 10psia. This is the equivalent to the entire planet living at 3000 meters elevation today. The graph of pressure vs elevation is below.

    The only problem I have with this theory is: how does the pressure on earth oscillate that much in these time periods? Million of years I can buy into. The shorter time frames of 40 to 50 thousand years is much harder to understand.

  64. tallbloke says:

    Ned, I think the author is implying positive feedback due to ice surface albedo?

  65. Aequitas says:

    I sent a larger post which has not appeared however my difficulty with this theory is: the 780K years graphic of calculated earth atmospheric pressure shows it falling to a low of 70kpa and then rising again to 100kpa many times in 40 to 50 thousand years. 70kpa, is the earth’s atmospheric pressure equivalent to being at 3000 meter elevation today. How is this possible in such a short time frame?

  66. Pablo says:

    Aequitas,

    I have that same problem with the theory and would be very interested to see the missing post.

  67. Ned Nikolov says:

    Aequitas,

    Yes, the calculated change in total surface atmospheric pressure between the Last Glacial Maximum (LGM) some 21 ky ago and the present is about 30 kPa. This means that during LGM, sea-level pressure had a value that we now find at about 3100 m altitude… These modelled pressure changes correctly and accurately explain the observed polar amplification in the geological record. Keep in mind that our model equations relating surface temperaures to air pressure & density are derived from modern NASA observations across a wid range of planetary conditions in the Solar System. Applying relationships derived from observed spatial patterns to study temporal climate dynamics on Earth and obtaining accurate estimates for changes in Polar and Equatorial temperatures over nearly 800 ky is a powerful indication that our approach is physically correct.

  68. Ned Nikolov says:

    Remember what Arthur Conan Doyle said:

    Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth.

    Also note that the calculated pressure changes only seem large on the background of a false a-priori assumption made in Paleoclimatology that surface air pressure had been constant for 10s of millions of years… We simply need to start thinking that the Earth’s atmospheric mass is in reality much more dynamics than thought before… 🙂

  69. Aequitas says:

    Ned, I appreciate the Sherlock Holmes. Yours is a radical theory and I was very impressed that it captures the different changes in temperature over the spread in earth latitudes and it also puts a date on the existence of ice on this planet. A drop in the total earth atmospheric pressure over 83 million years by 2.5 times is not frightening. A forty percent increase in the total earth’s atmospheric pressure in 40 to 50 thousand years is something else again. 😮

  70. tallbloke says:

    Aequitas; earlier comment now restored, sorry it got spamcanned. I’m sure videophobes here will be grateful for the trouble you took to screenshot and reproduce key plots from Ned’s AMS presentation. You only need to post the direct links to the images without the markup language, but I’ve edited your comment so the images now work.

  71. Phil Salmon says:

    Tallbloke

    I haven’t found any papers which show definitively and quantitively how “these cycles coincide to give the maximal climate warming effect” in a consistent way over the last 800kyr

    Periodically externally forced nonlinear oscillators come in two varieties, those with strong and weak forcing.

    With strong forcing, then yes – the oscillation frequency in the forced system should match closely that of the external forcing agent. But not so with weak forcing, where the forced system oscillation is weakly and intermittently related to the forcing frequency. The relationship between the forcing and emergent forced oscillation dynamics can be complex. For example the very complex tides arising in a coastal embayment with a narrow neck.

    https://link.springer.com/article/10.1007/s10236-011-0479-3

    And if there’s one thing we’re all agreed on, Milankovitch forcing is weak.

    The answer is clearly there to see if you allow yourself to consider the phenomenon of the internally excitable and externally periodically forced nonlinear oscillator. Deny them all you like, but the universe is full of them. One of them is your heart.

  72. tallbloke says:

    Ned: We simply need to start thinking that the Earth’s atmospheric mass is in reality much more dynamics than thought before

    Images of the Earth’s atmosphere from space always look worryingly thin to me.

  73. tallbloke says:

    Phil S: the phenomenon of the internally excitable and externally periodically forced nonlinear oscillator. Deny them all you like, but the universe is full of them. One of them is your heart.

    I’m delighted to hear the Universe is full of them Phil. That means astrophysicists will have got around to properly quantifying some of them, or at least formally observing and recording them,,, right? So, links to papers… or at least posts with some actual physics with measurements, please. Otherwise, it’s just conceptual speculation isn’t it?

    I mean, look at Ned here. He’s produced a couple of seriously good papers, with more in the pipeline judging by what he’s revealing in his videos. And he does the math. And even makes nice easy to understand graphs.

  74. Ned Nikolov says:

    Thanks, Roger (tallbloke)!

    Yes, quantification of processes and concepts along with verification of numerical predictions made by such quantifications is key to real science. Otherwise, it’s just a beer talk! 🙂

  75. Ned Nikolov says:

    Phil,

    In physics, nebulous concepts coming from general systems theory such as the Chaos Theory are not very useful without showing numerically how exactly the claimed drivers are supposed to work in a particular case such as the Ice Ages. The purported Milankovitch forcing is not just weak (e.g. the eccentricity-induced changes in Earth’s annual distance to the Sun), but it also shows no physically meaningful relationship with glacial cycles in the time domain.

    It’s beyond me, how and why scientists in the past could not realize that matching cycles in the frequency domain mean NOTHING with respect to establishing a proper causation. The key for causation is a strong & consistent correlation in the time domain accompanied by a corresponding lag of the effect process with respect to the causative driver. This is totally missing in he relationship between global temperature variations and orbital cycles over the past 800 ky.

  76. Ned Nikolov says:

    Aequitas, thank you for posting the graphs from my AMS video presentation:

    https://tallbloke.wordpress.com/2022/01/03/ned-nikolov-dispelling-the-milankovitch-myth/comment-page-1/#comment-174701

    Note that the timing of the predicted initial glaciation of the Poles by our model matches perfectly the observed timing of initial Arctic glaciation some 43 My ago inferred from measurements of ice-rafted debris:

    Tripati & Darby (2018) Evidence for ephemeral middle Eocene to early Oligocene Greenland glacial ice and pan-Arctic sea ice. Nat Commun. 9, 1038
    https://www.nature.com/articles/s41467-018-03180-5

    The correctly predicted changes of polar temperatures are a direct consequence of the assumption that changes of total air pressure has been the driver of Earth’s paleoclimate!

  77. Phil Salmon says:

    There is a large literature on chaos, chaotic dynamics and nonlinear oscillators. I’m not going to start from scratch trying to persuade you of their existence.

    This article explains why the denial of chaos lies behind the dysfunctional state of climate science and the phenomenon of climate alarmism. It contains citations on the subject.

    https://ptolemy2.wordpress.com/2021/11/13/climate-pandemonium/

  78. Phil Salmon says:

    Talking about astrophysics, it turns out that the filamentous structure of galaxy concentrations on the universe’s largest scale is a Turing reaction between gravity and dark energy, resulting in an architecture that suspiciously resembles biological structures. Because the same chaos-linked pattern formation process lies behind both.

    https://ptolemy2.wordpress.com/2021/12/26/is-cosmic-texture-a-result-of-turing-reaction-diffusion-emergent-pattern/

  79. Phil Salmon says:

    One aspect of periodically forced nonlinear oscillators is phase locking. Tziperman and colleagues have applied this to ENSO, and here it is applied to the Milankovitch cycles:

    https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2005PA001241

    This article addresses some of the criticisms of my arguments in this thread.

  80. Phil Salmon says:

    Final comment:

    This statement from Tziperman’s abstract:

    Nonlinear phase locking can determine the timing of the major deglaciations, nearly independently of the specific mechanism or model that is responsible for these cycles as long as this mechanism is suitably nonlinear.

    Shows that nonlinear phase locking to (e.g.) obliquity and Ned’s pressure hypothesis are NOT necessarily mutually exclusive.

  81. daveburton says:

    Aequitas wrote, “…the 780K years graphic of calculated earth atmospheric pressure shows it falling to a low of 70kpa and then rising again to 100kpa many times in 40 to 50 thousand years… How is this possible in such a short time frame?”

    Pablo replied, “Aequitas, I have that same problem with the theory…”

    So do I (though you apparently meant 400 to 500 thousand years).

    Thank you, Aequitas, for those screenshots.

    According to Ned’s 780K yr graph, at LGM (20K years ago) the Earth’s sea-level atmospheric pressure was just 2/3 of today’s sea-level atmospheric pressure.

    I think the simple answer to your question (and Pablo’s) is that it is not possible.

    Air pressure at the bottom of the atmosphere is simply the weight of the air above it. A 33% decrease in air pressure at the bottom would mean a 33% reduction in the total mass of the atmosphere.

    If the ratios</b of the major gases in the atmosphere (N2, O2 & Ar) had changed appreciably in the last 400K years, then someone surely would have noticed that fact, because of the frequently-analyzed preserved samples of that air which we have in ice cores.

    So, for Ned’s graph to be correct, 1/3 of the nitrogen, 1/3 of the oxygen, and 1/3 of the Argon currently in the atmosphere was simply missing 20K years ago.

    As Phil previously wrote, “What are the normal input and output paths for the main gasses? What factors affect the input and output rates? How does atmospheric mass increase and decrease?”

    Where do you think all that air goes to and comes from, Ned, during the glaciations and deglaciations, respectively?

  82. tallbloke says:

    Phil S: nonlinear phase locking to (e.g.) obliquity and Ned’s pressure hypothesis are NOT necessarily mutually exclusive.

    Agreed. And I do intuitively agree with your conjecture about non-linear coupled oscillators. I think it’s evident in Ned’s figure 10a plot. But I also agree with Ned, that we need less arm waving and better physics.

  83. Aequitas says:

    Ned is painfully close to the answer. The earth is different in that its atmosphere contains a condenseable strongly radiation absorbing gas, Water varies from 4 to 0.02 percent of the atmosphere from the equator to the poles. The pressure applied by the non condensing gas sets a floor for temperature but I believe water vapour can strongly modulate the temperature above that floor. The amount of radiation striking the earth changes with the solar cycles and the earth orbit.
    Take all the water off the earth today and this would be a much colder planet. The answer is close but a little messy.

  84. Ned Nikolov says:

    Aequitas,

    I’m aware that many people believe water vapor controls the Earth’s climate, but consider the following:

    1. Water is ubiquitous throughout the Solar System, i.e. every planetary body contains water (including Mercury and the Moon). However, only Earth has liquid water that forms vast oceans on the surface. Why? It’s because the near-surface conditions on Earth in terms of atmospheric pressure and temperature allow water to occur in all 3 phases: liquid, solid and vapor. So, liquid water is a consequence of the Atmospheric Thermal Effect (ATE), not a driver of it.

    2. The above conclusion is also supported by the fact that Earth is a part of the pressure-temperature continuum spanning the breadth of the Solar System described by our semi-empirical model, and no special provision involving the presence of water is needed to accurately predict the long-term global temperature of Earth:

    The only way that water affects Earth’s climate (in terms of global surface temperature) is through clouds (which are an aerosolized form of liquid water). That’s because clouds reflect back solar radiation and can modulate the amount of solar energy reaching the surface.

  85. Ned Nikolov says:

    DaveBurton,

    For your scientific enlightenment, the Earth’s atmosphere is constantly being lost to Space. Current estimates of the rate of this loss is about 90 tonnes per day but this rate likely varies:

    https://phys.org/news/2016-07-curious-case-earth-leaking-atmosphere.html

    Atmospheric gases (CO2, N2, and others) are also being emitted from the mantle. This is called mantle degassing:

    https://cpb-us-e1.wpmucdn.com/sites.northwestern.edu/dist/c/1849/files/2018/07/Role_of_Earth_s_Mantle_in_Water_and_Gases_in_the_Environment-1qxrupd.pdf

    http://news.unm.edu/news/new-findings-link-relationship-between-earths-mantle-and-its-atmosphere

    When the rate of atmospheric loss to Space (likely controlled by Solar wind) exceeds the rate of mantle degassing, the atmospheric mass and total pressure decrease. Conversely, when the rate of degassing exceeds the rate of loss, atmospheric mass and total pressure increase.

  86. Ned Nikolov says:

    A new analytic method that distinguish degassed N2 by the mantle from atmospheric N2 is being developed by a team of scientists at University of New Mexico in USA:

    http://news.unm.edu/news/new-findings-link-relationship-between-earths-mantle-and-its-atmosphere

    This method is being applied to measure mantle nitrogen in volcanic emissions. Results revealed that “nitrogen in the mantle has most likely been there from the beginning of our planet“. In other words, Earth’s atmosphere is likely supplied with nitrogen through mantle degassing.

  87. daveburton says:

    Ned wrote, “the Earth’s atmosphere is constantly being lost to Space. Current estimates of the rate of this loss is about 90 tonnes per day but this rate likely varies…”

    How much do you think it varies?

    This paper puts the mass of the Earth’s atmosphere at 5.1480 × 10^18 kg.

    90 tonns/day = 9.0 × 10^4 kg / day

    There are 365.24 days / year, so that’s 365.24 × 9.0 × 10^4 kg / yr
    = 3.28716 × 10^7 kg / yr.

    So to lose 33% of the atmosphere would take:

    (5.1480 × 10^18 kg) × 0.33 / (3.28716 × 10^7 kg / yr)

    = (5.1480/3.28716) × 10^11 yr

    = 1.5661 × 10^11 yr

    = 156.61 billion years.

    = 11.35 times the age of the universe.

    (Even longer if some of that loss is balanced by outgassing from the Earth’s mantle via volcanoes.)

  88. Pablo says:

    Oxygen is 20% of atmospheric mass and took a long time to get there.

    “Why is there oxygen in the atmosphere? The high school explanation is ‘photosynthesis.’ But we’ve known for a long time … that building up oxygen requires the formation of rocks like black shale.”
    https://news.wisc.edu/fossil-fuel-formation-key-to-atmospheres-oxygen/

    “Here we show that the earliest plants, which colonized the land surface from ∼470 Ma onward, were responsible for this mid-Paleozoic oxygenation event, through greatly increasing global organic carbon burial—the net long-term source of O2.”
    https://www.pnas.org/content/113/35/9704

  89. oldbrew says:

    Where does the nitrogen in the air come from?
    BBC Science Focus Magazine

    Living things and volcanic activity are an essential part of the Earth’s ‘nitrogen cycle.’

    https://www.sciencefocus.com/planet-earth/where-does-the-nitrogen-in-the-air-come-from/

    Contains this graphic…

  90. Phil Salmon says:

    Tallbloke
    Agreed. And I do intuitively agree with your conjecture about non-linear coupled oscillators. I think it’s evident in Ned’s figure 10a plot. But I also agree with Ned, that we need less arm waving and better physics.

    Tzipermann et al. 2006 is not arm-waving:

    https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2005PA001241

  91. Philip Mulholland says:

    “nitrogen in the mantle has most likely been there from the beginning of our planet”. In other words, Earth’s atmosphere is likely supplied with nitrogen through mantle degassing.

    Quite so Ned, and here’s why. This work by Ian Miller provides a valid chemical mechanism by which nitrogen can be incorporated into the solid particles which form the process of planetary accretion :-

    “There is, however, a further mechanism for accreting nitrogen. If the stellar nebula reaches the 2000 K, at that temperature nitrogen reacts with most metals to form nitrides, which, being solids, will be able to accrete, and will subsequently react hydrothermally to form ammonia able to be released during degassing.”

    Miller, Ian, Early Martian Atmosphere and Biogenesis (April 2001). Chemistry Preprint Archive Vol. 2001, Issue 4, pp 126-140. Available at SSRN:

  92. tallbloke says:

    Phil S, thanks for the interesting paper. I liked this in the discussion:

    “The edifice of particular physical mechanisms, while interesting, obscure the simpler point that the models actually fit the proxy record because they are phase locked to the Milankovitch forcing. Figuring out the correct glacial mechanism will require more than just a good fit to ice volume record.”

    Which seems to leave the field wide open for different competing mechanisms. However, Ned’s point regarding polar amplification is yet to be addressed.

  93. oldmanK says:

    Reading this far, I would agree that questioning the dogma is more productive than asserting it.

    At the top of the page, at the top of the series of graphs, is one that has never been proven. Maybe it is time to look again at what GF Dodwell said on the matter near 80 yrs ago.

    In the paper indicated by Ned, it says “The “100 thousand year problem” has been 47 the subject of extensive research since a 100 thousand year cycle that matches the Earth 48 orbit eccentricity period dominates the frequencies found in paleoclimate records. Yet, 49 eccentricity produces an insignificant variation in annual solar energy.” That in effect means it is not variation of the heat source but the mechanism of the Earth’s heat engine.

    Ned’s video, at 22:00 shows on left a comparison of latitude temperatures as per today’s and in the Eocene. I do not think that variation can be explained by [PV=MRT^g], but it may be explained by Dodwell’s theory. It is, or may be, a simple question of configuring the earth’s heat engine (in mechanical terms, from direct heat supply-rejection to indirect via heat transfer interstages. And it would explain also polar amplification.

  94. Pablo says:

    “It is remarkable that the hypothesis claiming a quantitatively important AGW has survived for more than 100 years. Svante Ahrrenius first proposed it 1896 (ref. 1). His hypothesis was correctly questioned by contemporary scientists on the basis that it omitted important convective vertical energy fluxes.”

    https://journals.sagepub.com/doi/10.1260/095830503765184655

  95. oldmanK says:

    Adding a piece:
    At the top of the page, at the bottom of the graphs, the two saw tooths indicate an unstable system. A fast rise and a slow return to the two extreme tipping points. (read: from direct to indirect heat through the engine).

    Also rise and fall are littered with stop-start points (friction) with what seems chaotic occurrence (chaotic in ‘strength’ -and resulting effect- , but not in ‘time’).

  96. tallbloke says:

    OldmanK: I do not think that variation can be explained by [PV=MRT^g]

    Got anything more than a gut feeling to back that opinion with? Ned provides a model derived from conditions across the solar system, and also the data shows that the higher the pressure is, the less variation you get across the latitudinal gradient. No doubt the way that works in the actual atmosphere involves the configuration of the heat engine (e.g. separate hadley and ferrell cells, rather than a single supercell), but those details themselves are a result of pressure and insolation.

  97. oldbrew says:

    eccentricity produces an insignificant variation in annual solar energy

    Are there variations in the distribution of that energy over Earth’s surface arising from eccentricity variation and that of the other orbital parameters?

  98. tallbloke says:

    OB, for sure. Big variations that last thousands of years. Just look at the Y axis of fig 10a for example.
    Swings of up to 120W/m^2 over the course of half the equinoctal precession cycle at 65N midsummer.

    That’s going to affect regional climates. The question Ned is asking, is whether, given the poor overall correlation, these can be what is causing the big longer term swing between glacial and interglacial states. He thinks not, and so pressure variation is the only viable possibility. Others here see things differently.

  99. Phil Salmon says:

    Tallbloke
    Figuring out the correct glacial mechanism will require more than just a good fit to ice volume record.

    This makes the important point that the mechanism of glacial to interglacial transition and vice versa (one having enough energy for this) and an external e.g. astrophysical periodic forcing (with attendant phase-locking), can be two different things.

  100. brianrlcatt says:

    Roger , perhaps mistakenly, kindly suggested I joined this discussion. So here I am.

    Not quite, Dr. Nikolov, . I suggest there is a problem with the limited scope of the Milankovitch effects that is considered in this science, the inverse square variability of electromagnetic radiation of the incoming light..

    There is another (effect). Not considered at all. Actual orbital forcing of the Earth itself. Planetary twerking.

    Also, as regards the variability of the cycles, at the most basic level of multi cyclic effects, and as regards the rate and range variability of ice age periods, the MIlankovitch correlation is very close if you convolve all three cycles, as is done rather neatly in the link below. This effect is a chord, not a pure note, so the range, rate and period varies according to the way the main cycles convolve. For an interesting visualisation try the UoM, Wisconsin toolf, adding in the cycles and comparing to the the Vostock temperature profile.

    https://cimss.ssec.wisc.edu/wxfest/Milankovitch/earthorbit.html

    However, I suggest the fundamental problem with the above approach is the blinkered focus on the variability of TSI hence insolation at ground level. It becomes immediately clear that the relatively instant warming of an interglacial event, a continual 7Ka warming producing an Ocean rise of 130m, cannot be from the rather obvious neo net zero effect of eccentricity on radiative emissions. What else, then?

    In this case “follow the money” does not work but “follow the physics” should. So I asked myself, what other effect could cause this? Answer? There is only gravity. But how? The suggested answer is solid tides. Paper is WIP here:

    http://dx.doi.org/10.2139/ssrn.3259379

    I was also studying climate change at this time and wondering about the true effect of volcanic action that was dismissed as ineffectual in any long term impactful way – as small and invariate. Which appeared overt academic BS at the most basic scrutiny. L As daft as “no natural change”. Dogma not science. Very obviously wrongly, they only considered the relatively small and short lived aerosols and dust effects on the surface, with magma heat quickly lost to space and iceanic feedback losing clouds to raise temperatures.

    It was obvious that most of the activity occurs unseen beneath the oceans, where most of the volcanoes and divergent plates are, and the major surface heat sink is, that can retains volcanic heat (and CO2 but that doesn’t matter in this). So how were these assumptions supportable? They weren’t.

    And how much is this effect, is it variable at a consolidated macro level, , and if so, how?

    To begin with, although eccentricity clearly affected gravity, I could not add in the effects of obliquity and precession, until I realised, after a year and finding the work of John Wahr, about the true nature of these effects. Both are caused by gravitational forcing, AKA orbital. et Voila! Solid tides came as a bonus, soon the the papers showing submarine emission levels by White and the MIlankovitch variability by Kutterolf. But none of these recent authors were joining the dots that John Wahr and MIchael House at least had already done qualitatively, so I did.

    To validate the basic premise that there was a real and significant effect, all that was left was to better estimate the volume of magma entering the ocean and its variability. Difficult? Not so difficult with the multidisciplinary macro level engineering approach my rather basic science background facilitates (I’m too thick to specialise in clever over complex mathematical theories that probably are unreal in nature but support a lot of pointless papers by academics of limited ability – and also disappear up their own backsides of academic speculation, by ignoring the larger general, natural environments impact on their partial system considerations. Probably.

    Nature does not come in separate boxes of academic specialisation. it’s joined up.

    My final final point , there may be more, is that TSI changes are largely neutralised by oceanic evaporative feedback, cooling the surface and increasing low level cloud albedo to keep the SST’s stable. Maintaining the heat balance at the surface but changing the TOA heat balance to adapt to new levels of TSI, or indeed to a small perturbation in the atmospheric lapse rate like GHE All under control w/o a significant change in SST or surface heat balance. A highly controlled system with a self stabilising set point.

    BUt NOT when the causes are internal heat or solar winds affecting cloud formation rates, that are effectively outside the control system. Oceanic feedback response cannot fix return to the prior equilibrium SST and heat balance, because solar winds and internal heat release/solid gravitational tides are not causes it can negate.

    Such effects require a new equilibrium heat balance and thus a new SST at the surface, and at the TOA. Obs.. It’s just a control system problem. To me. You?

    HENCE: I suggest he ice age cycle range of temperatures simply reflects the oceanic SST required to stabilise the variability caused by the gravitational effects of MIlankovitch cycles, not the TSI, which is strongly controlled by the oceanic feedback mechanism.

    nb: Of interest in evidence is the dodgy cyclic vandalism of the Younger Dryas. Obviously ice melting is one of a number of positive feedbacks once the primary interglacial warming occurs, and the heat required to thaw 130m ocean level volume of ice is huge, 0.4×10^25 Joules. Presumably the mechanics are that the ice sheets on land are thawed by summer rains from the warmer circulating oceans.

    BUT Note in particular that the ocean rise is not boverred by young Jack Dryas freezing interglacial warming back to glacial conditions on land for over 1Ka. The ocean keeps on thawing the land ice and rising without any reversal. Why? Where is the heat coming from to keep the ocean levels rising rising? etc.

    Go figure, I thought. That was when version 2 got re written, also with a reduced number of submarine “average volcanoes”, each at White’s 28 x10^6 m^3 pa magma output.

    CAVEAT: THis is still WIP. I think there is a lot more volcanic heat entering the deep oceans by other means than sea-mounts and conduction (note that conduction does not vary with MIlankovitch cycles). The 74k km of divergent ridges di emit heat but are not included in the estimates for a start.

    But the ideas are clearly expressed …………… I think.

    Your climate may vary. So this may be a good place to float this serious paper, created over several years of literally systematic thought of the planet as a control system, and constant repetition and challenge to my own BS of “yes, but how does it do that, and by what cause and effect?”

    I suggest the answers as regards cause and effect are fairly unique, physically supportable, and ignored by the specialisations because Universities do less and less joined up science now so are stuck in reinforcing the catechisms of their specialisations and their worthy great and good Departmental opinion leaders. Not science, an academic state funded industry proving itself right..

    The ideas above form the now well read pre-pub paper on SSRN.

    But I have had no questions or feedback. I do have a prospective publisher, since I reduced my total average submarine volcanic heat levels to a tolerable fraction of total internal heat, but need to get this as good as I can, and properly considered so it can gain some traction and be developed – if it has merit.

    So comments are welcome. Not alternative ideas, but, as Eugene Parker said when his papers on solar winds were decried as anti consensual rubbish “what’s wrong with my numbers?”.

    Proof/numbers? They also turned out to be recently available, after a year of DIY. It’s all in my paper.

    Needs more work to refine, and shorten, but I have done all the hard work. And my numbers are proudly accessible at High School maths level, so some of you can follow and even check them, unlike the new consensual science where such presumptuous requests for the data and maths to check are called science denial by self serving experts”, who consider requests for the basic evidence as heresy. No one publishing new science expects the Academic Inquisition. Discoveries have become career limiting rather than empowering.

    WARNING: All calculations done on my Casio Scientific calculator. Contains only pure deterministic physics and mathematics. No computers or models were used or abused in the writing of this paper. Contains thought experiments and basic extrapolation.

    To paraphrase Morecombe, E. “I’m using all the Milankovitch effects, but not necessarily in the old order”

    Hope I got this good enough. Dishwasher to mend, bathroom to paint and car to restore and sell. I believe its called Honey-do in the USA?

  101. tallbloke says:

    From Ned’s link: “Earth’s atmosphere weighs in at around five quadrillion (5 × 10^15) tonnes.”

    If Ned is right about the long term baseline being set by pressure, and his model correctly has the PETM around 2.6 ATM, then Earth has lost ~7.5 x 10^15 tonnes of atmosphere over the last 56Myr.

    If I did my sums right, no guarantee, that’s ~367,000 tonnes a day for 56 million years.

    If Earth loses around 30% of its atmosphere over 90kyr between interglacial and glacial that would be 45.6 million tonnes a day which would be 124 times faster rate of loss.

  102. Ned Nikolov says:

    I think the crux of the Ice-Age problem and why it has not been resolved thus far is that it’s been approached exclusively from a standpoint of radiative forcing, i.e. 65 N insolation, ice-albedo feedback, CO2 “radiative” effects, or a combination of these. The reason for this biased “radiative” approach is the lack of understanding in the current climate science about the atmospheric adiabatic heating/cooling and its differential latitudinal effects… As the saying goes: if the only tool you’ve got is a hammer, you tend to view every problem as a nail. Approaching a problem with the wrong tool is never going to solve it satisfactorily.

    The empirical evidence clearly indicates that glacial cycles are not caused by radiative forcing. Here is why:

    1. There is practically no change in the average annual solar flux reaching the top-of-the atmosphere during the past 800 ky.

    2. A maximum summer insolation at 65 deg N implies a minimum summer insolation at 65 deg S. If changes in this insolation were driving glacial cycles, there should be a phase difference in glacial maxima and interglacial periods between Northern and Southern Hemisphere, but the geological record shows full synchronicity of glacial cycles between NH and SH.

    3. Seasonal variations in the 65 deg N TOA insolation cannot explain the observed 4-5 K change in Equatorial annual temperature during glacial cycles, because the Equator never had any ice sheets, and the TOA insolation over the tropics has virtually been constant for the past 800 ky.

    4. The CO2 “radiative forcing” used by climate models to explain Equatorial temperature changes during the Ice Ages is a mathematical fiction, because the Atmospheric Thermal Effect (ATE) is caused by total pressure and does not depend on atmospheric composition. Atmospheric LW radiation is simply a byproduct of atmospheric temperatures, and not a driver of climate!

  103. daveburton says:

    tallbloke wrote, “Phil S, thanks for the interesting paper. I liked this in the discussion:
    “The edifice of particular physical mechanisms, while interesting, obscure the simpler point that the models actually fit the proxy record because they are phase locked to the Milankovitch forcing. Figuring out the correct glacial mechanism will require more than just a good fit to ice volume record.”
    Which seems to leave the field wide open for different competing mechanisms.”

    Good point! As Larry Niven noted, “Any damn fool can predict the past.” Correct “hindcasting” is not strong evidence that the mechanisms are correctly modeled or even understood.
     

    tallbloke continued, “Ned’s point regarding polar amplification is yet to be addressed.”

    It turns out that polar amplification is primarily Arctic amplification.

    In the context of recent warming, it’s probably mostly a function of ice coverage. When there is less ice on the ocean, there is far more heat transfer from the ocean to the air.

    That acts as a thermostat, regulating water temperature. It’s a negative feedback loop:

      warmer water temp → less sea ice coverage → more evaporation → cooler water temp

    However, by cooling the water, reduced ice coverage warms & moistens the air. Thus the air temperature increases: Arctic amplification.

    The Gulf Stream / AMOC carries a great deal of energy from the tropics to the North Atlantic, with the warm surface water cooling and evaporating as it goes. At the northern end of its trip, the cooler, saltier water sinks and begins its return trip to the tropics. It’s a slow trip, but a very big boat. Without it, much of northern Europe would be much less habitable.

    The ice coverage “thermostat” helps prevent surface water warmth from making it into the ocean depths, so in the context of water temperatures it could be called “Arctic attenuation” rather than “Arctic amplification.” But it makes the air warmer.

    A second factor contributing to Arctic Amplification is that polar air is much drier than air at lower latitudes. That means that additional GHGs added to the air have a bigger relative impact. At high latitudes a higher percentage of radiation which reaches the surface is downwelling LW IR from the air and clouds, and a lower percentage is from solar radiation — especially in winter. So increased levels of radiatively active gases (CO2 & H2O), and increased cloud coverage, help reduce cooling during frigid winter nights. (Climate alarmists rarely mention that “global” warming and Arctic Amplification disproportionately make brutal winter nights at high latitudes slightly milder, which is certainly a Good Thing.)

    An additional minor factor is the overlap between CO2 and H2O vapor on the long-wavelength side of CO2’s 15µm absorption band. This spectrum was measured at low latitude, over water:

    Water vapor thus masks some of CO2’s effect. Since there’s less water vapor at high latitudes, there’s less masking of CO2’s effect, and additional CO2 thus has a greater effect on the Earth’s radiative emission spectrum than it does at low latitudes. However, IIRC, Happer & van Wijngaarden (who’ve done the most complete line-by-line analysis to date) found that this has a small impact.

  104. Aequitas says:

    Water is not a trace compound on this planet and being a polar molecule it is not an ideal gas especially when it goes through a double phase change. The energy used or released during waters phase changes is a thousand times the heat capacity of air. Adiabatic gas compression or expansion is not enough to cause the changes occurring in an ice age. Once the adiabatic air compression or expansion is done the air’s temperature changes and there is no energy left to do anything else.
    There are other drivers and we can also not ignore the whiteness or snow and ice. Looking out my windows this morning is a stark reminder that we live on the water planet and the falling snow was not caused by the adiabatic expansion of the air.

  105. brianrlcatt says:

    This seems too obvious BUT the two key factors in the North are that the Arctic has a small shallow ocean, surrounded by incontinents with even less heat capaciity, and is mostly ice covered in winter so with a lot of albedo, which changes dramatically when the ocean surface freezes.

    Thats means it takes very little heat to make a given change versus oceanic Antarctica. Antarcrtica is a continent surrounded by the World’s largest and deepest oceans witha global current circulating it. So brutally stable and has been since measurement began. No change at the Scott Amundsen weather station.

    Just physics. Obs.

    PS The Arctic extremes during the glacial phase/D-O effects are dramatically larger than the Antarctic, also than the 2 degree cycles of the Arctic interglacial record. Because its still under the control of the liquid oceans. Count the degrees of range superimposed on the main cycles of the three MIlankovicth frequencies, whose presence is a bit obvious – if you know the periods.

    Arctic 50Ka

    Antarctic: EDC:

    https://www.dropbox.com/s/11efbkhvdr7q27p/EDC%20All%20800K%20Data.xlsx?dl=0

  106. brianrlcatt says:

    The models don’t fit the MIlankovitch cycles to the effects. Untrue. The multi frequency nature of the ice age cycles is determined by the frequency analysis of the actual ice core date, and maps directly onto the observations of the Milankovitch cycles. So that presumption is completely false in fact. It is not modelled, it is from the data. We clearly need references to the sources supporting such assertions. Here’s a slide from one of my talks, it’s easy to validate.

  107. Ned Nikolov says:

    Aequitas:

    Your understanding about the effect of pressure on temperature in the atmosphere is incorrect! Dynamic pumping (continuous compression) is NOT necessary to maintain a pressure thermal effect as you’ve assumed. It’s a knowledge fact in atmospheric Thermodynamics that the vertical drop of temperature in the troposphere is due to the temperature dependence on pressure and the pressure decrease with altitude. In other words, the vertical static pressure gradient in the troposphere creates a vertical thermal gradient. I explain the math behind this phenomenon in my video “Demystifying the Atmospheric Greenhouse Effect“. Watch the segment “Enhanced Greenhouse Effect” starting at 19:56 min. Also, the thermal effect of Earth’s atmosphere is about 90 K and it’s 100% explained by total pressure and TOA solar irradiance:

  108. Ned Nikolov says:

    brianrlcatt,

    You came late to this discussion and it sounds like you did not even read my blog article above: The phase overlap of two phenomena in the frequency domain does NOT establish a chain of causation! In fact, the match of frequencies is irrelevant with respect to a cause-effect relationship. Causation can only be established by a strong correlation between phenomena in the time domain and the presence of a proper lag between the effect and the driving force. There is no physically meaningful correlation in the time domain between Milankovitch cycles and Earth’s global temperature for the past 800 ky. That’s the main point of this blog article!

  109. oldbrew says:

    Standard Atmosphere graphs, as used by commercial aviation. Temp/pressure/density correlation obvious at tropospheric heights.

    https://www.digitaldutch.com/atmoscalc/graphs.htm

  110. tallbloke says:

    Brian C, welcome to the talkshop. You and Ned are natural allies in this exploration. You’ve got plenty of hot magma in your theory and Ned needs lots (and lots) of volcanic and other mantle gases during deglaciation. Somewhere in the region of 400,000,000 tonnes a day for 10,000 years.

  111. oldmanK says:

    tb: look at this, from 1954 https://cds.cern.ch/record/96414/files/CERN-ARCH-PMC-06-355.pdf

    This point was mentioned in another thread. Yr 173CE is interesting for other things, including the occurrence of tsunamis, the first recorded. See last page, last para. A minor excursion of obliquity but quite revealing.

    In 1979 Axel Wittmann expressed same opinion.

  112. Ned Nikolov says:

    I’d like to highlight a key point regarding the amount of mantle degassing needed to support our hypothesis that Ice Ages were caused by a variation of total atmospheric mass and surface pressure:

    We need first to focus on the evidence pointing toward pressure changes being the driver of Ice Ages, and not be concerned too much with explaining the causes of such changes. That’s because these are separate science questions. The inability to explain variations of atmospheric mass with our current knowledge should not be viewed as a reason to dismiss the strong evidence that atmospheric mass and surface air pressure have varied significantly on geological time scale.

  113. Aequitas says:

    Ned, the reason the thermal atmospheric gradient persists is because of the heat energy input by the sun and a little from radioactive heat from the earth. Remove the suns energy and the atmosphere would collapse. The air molecules need an energy source to keep them apart or as they radiate energy to space the atmosphere will cool and gravitation will pull the atmosphere in and it will snow nitrogen and oxygen etc. I will give you the last kick at the can. I’m done. Regards.

  114. brianrlcatt says:

    I agree. TOA TSI wise, eccentricity cannot be the dominant cycle because it is net zero annually BS.

    So its obs another effect of orbital forcing that eccentricity is good at. What is left? Gravity perhaps? That also causes obliquity and precession.

    So much so I wrote a paper suggesting it is the gravitational solid tidal effect of Orbital forcing that creates the primary driver of interglacial perturbations to the steady ice age glacial phase. After I found out what they were, that is.

    Suggested effects of gravitational tides here: http://dx.doi.org/10.2139/ssrn.3259379

    PS It may be that I am more confused that I thought, and that obliquity and precession are not the causes of the effects we attribute to them, but rather they are simply the consequences of the gravitational forces acting on the Earth that create those cyclic effects. If that makes sense to you. Chicken or egg? Cause or effect? Doesn’t matter to my proposition but is important none the less. Is our tilted twerking wobble causing gravitational changes, or vice versa. Never thought to ask before…. I suspect the latter.

  115. Ned Nikolov says:

    Aequitas,

    Yes, without solar radiation, the Earth’s atmosphere will freeze and collapse solid on the ground. No question about that! This is because the effect of gas pressure on temperature is relative as pointed out on p. 14 of our 2017 paper (https://www.omicsonline.org/open-access/New-Insights-on-the-Physical-Nature-of-the-Atmospheric-Greenhouse-Effect-Deduced-from-an-Empirical-Planetary-Temperature-Model.pdf). The Earth’s Atmospheric Thermal Effect (ATE) in term of pressure alone is about a 45% enhancement or 1.45. It’s the TOA solar irradiance of 1,361 W m-2 that makes this relative thermal effect equal to about 90 K in absolute terms. If Earth is moved to the orbit of Titan while preserving the same surface air pressure, the relative ATE will still be 1.45, but the absolute thermal effect will drop to about 29 K, because Titan only gets about 1.1% of the solar radiation received by present Earth.

  116. Colin Barton says:

    Very interesting and good work.
    The figure of “The Rate of Change of Orbital Eccentricity and Global Surface Temperature” does show a corellation that matches the 4 most recent ice ages. Wurm, Riss, Mindel and Guntz. Correlation is not causation but 4 matches like this enhances the possibility. The whole matter is so complex and little understood that we remai uncertain.

  117. Philip Mulholland says:

    I was also studying climate change at this time and wondering about the true effect of volcanic action that was dismissed as ineffectual in any long term impactful way – as small and invariate.

    Brian
    Have a look at the work of Professor Wyss W.-S. Yim on Research Gate.

  118. oldmanK says:

    brianrlcatt asked “Is our tilted twerking wobble causing gravitational changes, or vice versa. Never thought to ask before…. I suspect the latter.”

    Myth (and math!) has it that when the sun and moon are together, and the planets are in-line, the stars in the firmament change their positions. So, if I get the question right, its the latter, but the reason, and the full story, may not be so clear.

  119. I may have missed some comments in the discussion but it appears no one has mentioned that both CO2 and SO2 are soluble in water and that the solubility is higher with lower temperature. Further both CO2 and SO2 are reactive in water giving in soluble CaCO3 and slightly soluble CaSO4. It should be noted that the huge chalk deposits in Europe (eg white cliffs of Dover) were laid down in 145-65 million years ago. At the present time CO2 in the oceans are being removed by the growth of various algaes and the formation of corals and shells. CO2 and SDO2 have a greater mass than O2 and N2. Neither gas has by radiation absorption (which is tiny) can warm the surface due to the second law of thermodynamics but with Ned’s new theory could be partly responsible to changes in atmospheric mass.

  120. Jim Steele says:

    I believe the Milankovitch cycles, especially obliquity, are key drivers of the glacial and interglacials, and it would be a mistake to suggest there should be a linear correlation.

    First, Obliquity refers to the changing tilt of the earth’s axis, and it is the axis tilt that determines the earth’s seasons. The current seasonal effects of axis tilt on Arctic ice demonstrate obliquity’s effects.

    Northern hemisphere summer happens when the tilt of the axis’s north pole points towards the sun. This seasonal tilt moves the ITCZ poleward, as well as the Hadley high pressure systems. This increases cross-equatorial ocean heat transport and transport into the Arctic. The greatest Arctic sea ice melt, occurs around the Barents Sea where warm Atlantic water intrusions create open waters deep inside the Arctic Circle. The combined maximum tilt of obliquity, and extra insolation contributed by precession caused summer coinciding with perihelion at the end of the glacial maximum caused a greater transport of warm Atlantic water into the Arctic . Several studies have shown melting Arctic sea ice and glaciers during the Holocene Optimum coincide with the greatest inflows of Atlantic water, and the cooling trend of the last 5000 years coincides with less inflows as the tilt is reduced and precession cause summer to happen during aphelion,

    Today the peak cross-equatorial flows happen in September despite the sun’s most direct rays having returned southward to the equatorial equinox. (There are many published papers but I offer Johns (2015) Continuous, Array-Based Estimates of Atlantic Ocean Heat Transport at 26.58N as one example) The inertia of the strengthened gyres and Atlantic subtropical pressure system during summer continue to carry heated water northward. Those circulation dynamics are largely why the sun’s position and heat transport do not coincide, and is one reason why we should not expect obliquity and glacial-interglacials to exhibit linear correlations.

    Second, considering only correlations with 41,000 and 100,000 year cycles is a mistake that overlooks a driving dynamic of ocean heat transport. In that regard Dansgaard-Oeschger events provide better insights.

    Spolaor (2016) shows a graphic (https://www.nature.com/articles/srep33925/figures/1) wiith the 65°N summer solstice insolation (green) over the past 120,000 years due to combined Milankovitch cycles which varied by as much as 60 W/m2. The peak determined from delta O18 are the Dansgaard-Oeschger events during which ventilated heat typically caused sudden Greenland warming of 10–15 °C within several decades and persisted for about 500 to more than 2000 years. Thus far, 25 events have been identified with an apparent 1600-year periodicity. Greenland was warmer than present by 2 to 3 °C during the Holocene Climatic Optimum, broadly assigned to the period 6–9 ky ago, when summer insolation at high northern latitudes was at a maximum.

    Dansgaard-Oeschger events represent the sudden release of heat from an ice-covered Arctic. Clearly the 1600 year periodicity does not directly correlate with Milankovich cycles, but is driven by the accumulation of heat and its ability of melt the ice and vent. Three major dynamics are involved.

    1) Insulating effects of sea ice causes Arctic Ocean temperatures to increase while air temperatures decrease. 2) Changes in transport of ocean heat would be driven by Obliquity and precession. During the greatest tilt, the greatest poleward transport happens, just as it does seasonally today. Precession can either intensify obliquity effects or dampen them. 3) Drop in sea level reduced the inflows of fresher water from Arctic through the Bering Strait. The Pacific waters insulate sea ice from the warmer and denser Atlantic water.

    I blogged about some of this in an article Natural Cycles of Polar Sea Ice: The Arctic Iris Effect with supporting links at https://perhapsallnatural.blogspot.com/search?q=dansgaard

    My argument is the earth has been getting colder and the shift from 41,000 year glacial/interglacial cycles to ~100,000 year cycles is not due to Eccentricity, but the increasing thickness Arctic sea ice. There is no exact 100,000 year cycles, but cycles approximating 80,000 and 120,000 that are multiples of the Obliquity cycles. The combined effects of Obliquity and Precession can transport maximum heat into the Arctic. As the earth continues to cool forming thicker Arctic sea ice, an increasing glacier volume was needed to lower sea levels and eliminate insulating inflows from the Pacific through the Bering Strait in order for the warm Atlantic water to melt the overlying ice and warm the atmosphere enough to begin an interglacial

  121. Ned Nikolov says:

    Dear Jim Steele,

    It sounds like you need to carefully read the above blog article once again and pay close attention to the graphs, which use REAL data. I’m not claiming that the relationship between Milankovitch cycles and glacial cycles measured in terms of changes in the global surface temperature must be linear. I’m showing that there is NO relationship between these quantities over the span of 800 ky, period!

    Read this comment I posted today and try to think objectively:
    https://tallbloke.wordpress.com/2022/01/03/ned-nikolov-dispelling-the-milankovitch-myth/#comment-174750

    Also, one cannot make conclusions about drivers of the Ice Ages by only considering the last 120 – 300 ky. We must consider the entire record (which extents to over 1 My) or a large portion of it. On the time scale of the past 800 ky, Milankovitch cycles show NO relationship to Ice Ages!

  122. daveburton says:

    Jim, thank you for a most enlightening lesson on the ocean dynamics during these cycles!

    One question: you wrote, “the Dansgaard-Oeschger events during which ventilated heat typically caused sudden Greenland warming of 10–15 °C within several decades and persisted for about 500 to more than 2000 years. Thus far, 25 events have been identified with an apparent 1600-year periodicity…”

    Can you please expand upon the “ventilated heat?”

    It is my understanding that the current majority opinion is that D-O oscillations were characterized by increased AMOC / Gulf Stream flow during the warm events, and decreased AMOC flow the rest of the time. Is the energy carried north by the AMOC the “ventilated heat” that you’re referring to?

    The AMOC variations, in turn, might have been caused by variation in the balance of freshwater flows into the Atlantic: greater flows down the Mississippi into the Gulf of Mexico would drive a stronger AMOC. Reduced flow down the Mississippi, and increased flow out the Saint Lawrence Seaway and from northern Europe would cause a weaker AMOC. But the 1600 year periodicity is mysterious, at least to me.

  123. Jim Steele says:

    Dear Ned,

    I simply presented how I see the Milankovitch Cycles connected to the glacial/interglacials. I have not yet watched your video to judge, but when I carefully read your post you did write “no one has been able to demonstrate a meaningful relationship between glacial cycles and any of the Earth’s 3 orbital parameters obliquity, eccentricity and precession or combination thereof on a linear time scale.”

    You sort of implied it should be linear. You call it a myth, but I showed you a connection, and added the impact of ocean heat transport, that you did not refute

    You also wrote, “A physical causation requires a strong correlation between parameters in the time domain, not the frequency domain!”

    So I replied objectively how I see the physical causations linked to glacial/interglacial. Your reply certainly did not seem very objective or honest. You say I have not considered the ice ages for the entire period, but I have, not just in this first post.

    So for you to objectively understand my views watch my video or read the transcript
    How Antarctica Caused Global Cooling or Why Earth Remains in Ice Age Mode for Next 200 Million Years

    https://perhapsallnatural.blogspot.com/search?q=refrigeration

  124. Jim Steele says:

    Hi Dave,

    Yes, the energy carried north by the AMOC is the “ventilated heat” . The Arctic ocean has a layer of warm Atlantic water that resides at about a 100 to 900 meter depth, containing enough heat to easily melt all the Arctic ice.

    The so-called 1600 year cycle is indeed a mystery, and likely due to a conflation of many things, but I think the answer lies in how much heat must accumulate in order to melt the sea ice and maintain open waters for centuries.

  125. Ned Nikolov says:

    Jim,

    When I used the phrase “on a linear time scale”, I mean in the time domain. Sorry for the confusion. Causation can only be claimed if 2 time series show a close relationship mediated by a proper lag when feasible in the time domain, not the frequency domain as has been done with Milankovitch cycles and temperature variations inferred from the geological record…

    Let’s resume this discussion after you got a chance to watch the video linked to the bottom of the blog article. Another video that might help you better understand our new concept is this:

    Demystifying the Atmospheric Greenhouse Effect“: https://vimeo.com/manage/videos/602819278

    Thank you!

  126. daveburton says:

    Ned, it is not possible that the mass of the oxygen, the nitrogen, and the argon in the Earth’s atmosphere could all have increased by 33% in 10,000 years.

    Oxygen and nitrogen are involved in biological processes, which could, in theory, very slightly change the quantities of those gases in the atmosphere, though certainly not by 33% in 10K years. Argon isn’t involved in any biological processes at all.

    Where do you imagine all that air could have come from, so quickly??

  127. daveburton says:

    Correction:
    67 kPa → 100 kPa is a 49% increase in atmospheric mass, not just 33%.

  128. Paul Vaughan says:

    Carefully Note

    tropical ocean temperatures over the past 3.5 million years

    carefully note small word “Peak” (i.e. maximum, NOT to be confused with mean)

  129. Paul Vaughan says:

    misunderstanding/misinterpretation/misrepresentation alert:
    Plot by day-of-year to vanish calendar-month aliasing.
    (online calculator aggregated by month)

  130. Ned Nikolov says:

    Dave,

    I provided references above, which show that the mantle degasses all kind of gases including noble gases. There is a HUGE inventory of nitrogen in the mantle. Molecular oxygen is probably the only gas that’s unlikely to be degassed from the mantle in sufficient quantities although there is TONS of O2 tied in minerals in the mantle. Oxygen is the most abundant element in Earth’s crust and mantle, but molecular oxygen is rare…

    Like I said earlier, we don’t need to have all the answers regarding where the gasses are coming from at this point. We need first to agree on the evidence that atmospheric pressure has indeed been changing significantly during glacial cycles. IMO, the geological record provides strong (albeit indirect) evidence supporting this hypothesis.

    You stated earlier that the polar amplification is only observed at the North Pole. This is completely incorrect! The Antarctica ice cores show a temperature variation of 9-11 K between glacial maxima and interglacial periods for the past 800 ky, while Equatorial temperature only varied 4-5 K.

  131. Jim Steele says:

    Ned, Having partially read your article “New Insights on the Physical Nature of the Atmospheric Greenhouse Effect Deduced from an Empirical Planetary Temperature Model” it seems clear that your theory is based on planets without an ocean and thus your theory has not accounted for changes in the storage and ventilation of ocean heat.

    So while I wade through the rest of your article, I would again advise you to read my arrticle How Antarctica Caused Global Cooling or Why Earth Remains in Ice Age Mode for Next 200 Million Years

    https://perhapsallnatural.blogspot.com/search?q=refrigeration

    as a return courtesy

    So far it seems you ignore the ocean dynamics I bring up to explain the earth’s transition from a hot house equable climate to the current ice house.

    In a nutshell, it is well documented that the tropics transport “excess” heat to the polar regions making polar regions warmer than they would be based on solar radiation. Ocean currents carry heat into the Arctic as well as to the Antarctic coast before the formation of the Antarctic Circumpolar Current (ACC)about 35 million years ago, when plate tectonics separated Antarctica from South America and Australia/Tasmania. Once the ACC formed, it prevented adequate meridional advection of tropical heat, so Antarctica transitioned from a subtropical climate to an ice house and this began cooling the global oceans. Before the ACC, the bottom waters were at least 10C warmer than today. The source of warm water was due to the evaporation of shallow seas that formed dense salty and warm water that sank to the bottom, much like the Mediterranean outflow provides warm salty waters to Atlantic’s depths.

    But as sea ice formed around a cooling Antarctica, bottom waters were now fed by cold salty waters formed by brine ejection. As the those cold salty waters filled the abyss, the warmer waters were displaced. The upwelling of once warmer waters at the equator and along the coasts, were eventually replaced by cooler waters originating from Antarctic waters, much like the Antarctic Intermediate waters do today. It appears this transition happened about 2.5 to 3 million years ago cooling the earth enough to allow a permanent ice cap to begin forming on Greenland and the ice house conditions that allowed the ice ages.

    I dont see how your pressure theory explains the time series of those dynamics

  132. Chaeremon says:

    @oldmanK, howdy 🙂
    .
    There are null scholars who have ever measured 1 perihelion precession over its whole cycle, null who have ever measured 1 equinoctial precession over its whole cycle, and the same null for 1 eccentricity precession over its whole cycle.
    .
    In particular, the latter could exhibit the form of a stadium, but only for a non-existent mathematically symmetric [!] ellipse is there an applicable magic formula.
    .
    So how were the cycles invented?: by correlation of proxies … Yet in comments above, proxies are correlated and commentators argue about their preferred application of cyclic reasoning.

  133. oldmanK says:

    @ Chaeremon, Hello, pleased to hear from you again. I hope all is well over there – considering the circumstances.

    Yes, quite so. The ancient past is never quite what it seems.

    Take care and stay safe. And if conditions leave you with more free time, and you are interested, year 173CE looks to be a revealing time. Two links to start with:
    ‘https://adsabs.harvard.edu/full/1979A%26A….73..129W’

    regards cr

  134. brianrlcatt says:

    And anuvver ‘fing. A supplement to my full length submission above.

    You claim “Yet, no one has been able to demonstrate a meaningful relationship between glacial cycles and any of the Earth’s 3 orbital parameters obliquity, eccentricity and precession or combination thereof on a linear time scale. A physical causation requires a strong correlation between parameters in the time domain, not the frequency domain!”

    I beg to differ. Fundamentally if the frequencies are derived from the time series, not imposed upon it.

    And I did demonstrate correlation in both domains, which is implicit if the theory is correct BTW.

    Probably. Volcanic activity in terms of evemts in the deposition record as recorded by Kutterolf and temperature as recorded by multiple ice cores. Did you read my paper yet? Too soon?

    I suggest I have indeed correlated the changes in temperature with peaks of volcanic activity in the time domain and also hard correlated in the frequency domain, with each other and the Milankovitch frequencies, all three of which must have actual time domain maximums and minimums of gravitational solid tidal effects on the planetary structure. Perhaps that’s why you’re ignoring me?

    THis is not the latest version but it’s the one in Pre Pub right now. Been there two years with a few hundred reads and one major update. Can’t believe you haven’t found it…..

    Submarine volcanism denier? 😉

    http://dx.doi.org/10.2139/ssrn.3259379

    Best

  135. tallbloke says:

    OldmanK, WordPress seems to struggle with Harvard links
    Please would you see if you can get an alternative URL by copying the link you have that works into one of the short URL generators such as tinyurl.com and post it here.
    Thanks

  136. tallbloke says:

    Jim S, welcome here, and thanks for the interesting and enjoyable video at

  137. Paul Vaughan says:

    100ka: equatorial SST
    precession: monsoons
    (side-effects polar)
    …and graphing June insolation at the equator is an old joke (some know)

  138. oldmanK says:

    Tried something new here (as suggested; it worked for me) Link tinyurl.com/yy62hydj

  139. tallbloke says:

    OldmanK, excellent, it works. Thanks for that.

    Paul V, yes, equinoctal precession is what produces the big swings in 65N summer insolation over ~11kyr when the Earth’s orbit is near max eccentricity.

  140. tallbloke says:

    Ned: We need first to agree on the evidence that atmospheric pressure has indeed been changing significantly during glacial cycles. IMO, the geological record provides strong (albeit indirect) evidence supporting this hypothesis.

    As always with climate questions, there’s a lot going on at the same time, and it’s not easy to disentangle what matters from what doesn’t, and what’s feasible from what isn’t. I think part of the reason the air in the polar regions changes in T much more than the equator over the glacial/interglacial cycle is due to the presence of ice, which insulates the ocean and prevents it losing energy to the atmosphere.

    We need better data on temperatures throughout the water column during the glacial period. If heat can’t escape, it must build up beneath the ice. The circumstantial evidence that it does is provided by the asymmetry of the cycle. Slow glaciation followed by rapid deglaciation. Once that water gets warm enough to melt the ice from below, a lot of heat and water vapour is going to be released to atmosphere and induce a positive feedback.

    Maybe the less extreme regime of insolation change at low eccentricity, coupled with DO excursions is enough to initiate the deglaciation and thats why eccentricity correlates reasonably well with global T in phase if not amplitude. It’s a low energy trigger opening up a conduit for energy release from a high heat capacity energy store.

  141. Paul Vaughan says:

    not just paleoclimatologists
    “The tropics have been long neglected by paleoclimatologists […]” — Berger, Loutre, & Melice (2006)

  142. Paul Vaughan says:

    note carefully that the monsoons alternate north / south

  143. Chaeremon says:

    @oldmanK thanks for the links; Wittmann made another shot in 1984 (put 1984MitAG..62..201W behind adsabs.harvard.edu/pdf/) with details on how he selected [mathematically adjusted] from the pre-examined observations.
    P.S. what’s the context of your 173CE thing?
    P.P.S. 99.987% of things are fine here; we do not participate in the politically-invented health experiment.

  144. oldmanK says:

    @ Chaeremon. Had seen 1984 paper, but in consideration I think the raw data is more factual.

    In another thread (Orbital resonance —) on a hunch I looked at the actual distribution of the Wittmann raw data for whatever pattern there could be in the apparent disturbances, and possible matches time-wise.
    Apparent match here in fig 6 https://www.researchgate.net/publication/270293211_Arctic_Holocene_glacier_fluctuations_reconstructed_from_lake_sediments_at_Mitrahalvoya_Spitsbergen (effect of insolation change within the span of a century)

    Also planetary alignment. Tsunamis at new moon (Hindu associate moon + sun = destruction). But main is October 24th 173ce and here I still draw a blank (possible dating problem from old Chinese to universal time; or —).
    Which all appear to indicate obliquity is readily influenced,,, which indicate the megalithic readings are reliable (where I started from some years ago).

  145. tallbloke says:

    Apologies to Ned for the thread drift, but I noticed this and thought it worth a mention.

    OldmanK;

    If, as I suspect, obliquity is affected by the relative orbital plane angles of the other planets, via a gyroscopic effect, the 41kyr cycle won’t be a smooth sinusoid. There will be wrinkles along the way when unusual planetary configurations give Earth’s axis a kick.

    On Oct 24 173CE there was a rare 5-way conjunction of Jupiter, Saturn and Uranus, Earth and Venus

    It’s possible that the geo-effective action started earlier in the year when the big three gas giants were exactly aligned as Earth came to right angles to them.

  146. daveburton says:

    Tallbloke wrote, “Ned needs lots (and lots) of volcanic and other mantle gases during deglaciation. Somewhere in the region of 400,000,000 tonnes a day for 10,000 years.”

    Yes, that matches my arithmetic pretty closely, and that’s the big, big problem with Ned’s hypothesis.

    If we take the mass of the Earth’s atmosphere as 5.1480 × 10^18 kg, and if (as Ned contends) about 33% of it (1.7 × 10^18 kg = 1.7 × 10^6 Gt) was added over about 10K years (an average rate of about 170 Gt/year!) — somehow without ever altering the ratio of N2 to O2 to Ar — that would mean an average rate of addition to the atmosphere equal to (5.1480 × 10^18 kg) × 0.33 × (10^-3 tonnes/kg) / (365.24 × 10^4 days) = 465,000,000 tonnes/day = 0.465 Gt/day.

    For comparison, anthropogenic CO2 emissions are only about 35-40 Gt/year.

    Glaciations are slower than deglaciations, so from Eemian peak to LGM minimum there was, according to Ned’s theory, a loss of 130% as much atmospheric mass, over a period roughly ten times as long, which works out to “only” an average rate of atmospheric loss of about 60 million tonnes/day for 100K years. Ned mentioned a process which could account for 0.00015% of that rate of loss. What about the other 99.99985%?

    There are no known processes which could produce such enormous changes in atmospheric mass, and there is no evidence that the mass of the Earth’s atmosphere has changed significantly in the last million years.

    Note that biological processes could not do it. We know from ice cores that the ratios of the three major non-condensing gases, N2, O2 & Ar, have not changed significantly from their current values (78%:21%:1%) in the last 400K years. Biological processes could not cause large changes in atmospheric mass without changing the ratio of N2 to O2 to Ar, because, although such processes do affect atmospheric O2 & N2 concentrations (though certainly not by ±33%!), there is no biological “argon cycle.”
     

    Ned wrote, “We need first to agree on the evidence that atmospheric pressure has indeed been changing significantly during glacial cycles.”

    The evidence is compelling that atmospheric pressure and mass have not changed much during glacial cycles.
     

    Ned, in his OP, wrote, “Changes in Earth’s mean annual distance to the Sun… resulting from variations of planet’s orbital eccentricity have been minuscule for the past 800 ky… Hence, orbitally induced TSI changes are bound to have an immeasurably small effect on Earth’s global surface temperature.” and “eccentricity changes have a negligibly small effect on TOA TSI and surface temperature.”

    That does not follow, because it’s not total or average TSI which mainly affects the advance and retreat of the great Laurentide, Fennoscandian & Cordilleran ice sheets. It is driven by seasonal differences.

    Specifically, it is due to persistent changes in the magnitude of the difference between summer and winter insolation between about 40°N and 70°N latitude (where the ice sheets were). Large seasonal variations at those northern latitudes (hot summers and very cold winters) cause the ice sheets to retreat, because of increased melting in summer, and reduced snowfall in winter. Small seasonal variations at those latitudes (cooler summers and milder winters) cause the ice sheets to advance, because of reduced melting in summer, and increased snowfall in winter.

  147. daveburton says:

    P.S. — a clarification:

    I wrote, “For comparison, anthropogenic CO2 emissions are only about 35-40 Gt/year.”

    That’s about right, but >70% of that CO2 is oxygen which was removed from the atmosphere to fuel combustion, so it isn’t actually added mass, in the atmosphere. (Some CO2 comes from calcination, during cement-making, which doesn’t take O2 from the atmosphere.) So anthropogenic CO2 emissions actually add only about 10-12 Gt/year of mass to the atmosphere.

  148. Ned Nikolov says:

    Dave,

    My hypothesis is backed by calculations produced by a model derived from NASA planetary data. So, I have strong quantitative evidence for my assertion about pressure being the driver of Ice Ages (see the paleoclimate video at the bottom of the blog article). I also showed above using the best available data that summer insolation changes at 65 deg N have no meaningful relationship to global temperature variations over the past 800 ky.

    What do you have? Adopted beliefs & hand-waiving?

    You do not have a physics-based math model to demonstrate that difference between summer & winder insolation at high northern latitudes can produce the observed changes in global and Equatorial surface temperatures for the past 800 Ky. What about temperature changes in Antarctica, which are synchronous with Equatorial temperature variations? Are they also magically caused by the seasonal temperature variations at 65 deg N? And how do you explain the observed Polar amplification (where Polar temperatures vary 11-13 K while tropical temperatures only fluctuate 3-5 K)?

    It’s this lack of rational thinking that has brought climate science to its current dismal state of affairs! 🙂

  149. oldmanK says:

    tallbloke: That is exactly what seems to take place.

    Furthermore, 24th October has the alignment near perfect, including the moon (a new moon). [but I have no hint from Chinese annals on that day/night – no access to sources]

    The earlier two tsunamis mentioned in the log (first link) occur also on new moon – and near solstice earth orientation (a matter of gravitational torques). October is more equinoctial.

    If earth’s obliquity has the tendency to shift under the effect of gravitational torques (and that is what the megalithic sites indicate; and substantial shift) then the matter of solar insolation with latitude changes greatly. But more solid proof is (I) preferred.

    The matter does/may not detract from Ned’s work on adiabatic warming, and may even reduce the need to invoke mass change.

    Year 173ce is also a peak Eddy (still confused on that, – Eddy is a major timing mechanism)

  150. Chaeremon says:

    @oldmanK what tsunami? there are several rivers/deltas (incl. shorelines) with spring tide situations (iFF constellations permit), e.g. youtube.com/watch?v=8R6Ipsl2VJ0 , youtube.com/watch?v=1y_0qnJGo8U …
    .
    I haven’t checked but surmise that these phenomena [should] occur markedly around equinox (Lunestices [declination] included, Re astroclimateconnection).
    .
    Rule of thumb: if an eclipse is very near, then ±max abs lunar declination is very near regardless of month (sorry, as yet no such rule for lunar anomaly).

  151. oldbrew says:

    TB – 1306 might have been interesting 🤔

  152. tallbloke says:

    OldmanK: If earth’s obliquity has the tendency to shift under the effect of gravitational torques (and that is what the megalithic sites indicate; and substantial shift) then the matter of solar insolation with latitude changes greatly.

    Well I’m not sure about this. I can’t remember how big the shift was from your megalithic estimates, but obliquity is a change of not so many degrees, whereas the changes in summer Arctic insolation due to equinoctal precession are very large (over 100W/m^2 when eccentricity is at max)

  153. tallbloke says:

    Ned, although you’re only getting R^2 = 0.254 in Fig 10b, the 33 peaks in summer insolation at 65N in Fig 10a are matched by increases of +ve global T rate of change in 29 of those 33 peaks.

    So although the amplitudes are a bit hit and miss, the phasing looks pretty good. So it would appear that there are teleconnections between higher northern latitudes insolation change and tropical Ts.

    The other plot showing good phase agreement is rate of change of eccentricity, fig 8a. When we look at 8a and 10a together, we can see that warm interglacials occur around the time that a rapid rise to higher eccentricity coincides with or is soon followed by northern hemisphere summer occurring at perihelion.

    My takeaway from all that is that looking at the Milankovitch cycles in isolation from each other isn’t really the best way to assess their effect on the glacial/interglacial cycle.

  154. oldmanK says:

    Chaeremon: It is a question of moon+planetary alignment. The Chinese record ( see at oldmanK says: January 7, 2022 at 1:54 pm ) tsunamis in 173CE. A year of planetary alignment. They also record a ‘small’ deviation in the obliquity. Different from the normal tidal phenomena.

    The important factor is that the obliquity measurement in that year is a small but substantial ‘outlier’ from the 3k yr trend.

    Attached links: From tinyurl.com/2p8f92wp see fig 6, and para 5.5.4 part quote “–and it remains possible that the advance of Karlbreen around 1900 cal. yr. BP occurred as a response to a regional climatic shift along the western coast of Svalbard.”

    Fig 6 is compared to the obliquity ‘wobbles’ here: https://www.facebook.com/melitamegalithic/photos/a.433731873468290/2093466177494843/
    The sedimentation rates in the centuries before and after Yr 173ce seem to match the wobbles of the obliquity measurements.

  155. Philip Mulholland says:

    While I support the hypothesis of Ned and Karl that atmospheric pressure and solar irradiance are the controlling variables of global average surface temperature (GAST), I have severe doubts about assigning the temperature variations seen in the glacial cycles to variations in atmospheric pressure.

    I agree with Dave Burton that the change in atmospheric mass required for this hypothesis to be valid is too large and the issue of the long-term stability of the ratio of Argon to Nitrogen is compelling evidence in favour of long-term pressure stasis.

    In addition to this we have the clear geological evidence of changes in ocean circulation as being the major component in creating tipping points that flip Earth’s planetary climate. For example:
    1. The destruction of the Cretaceous Tropical Zonal Tethys Ocean and the formation of the Meridional Atlantic Ocean system.
    2. The creation of the Ferrel Cell located Zonal Southern Ocean with its circumpolar gyre associated with the Tertiary separation of Australia from Antarctica.
    3. The formation of the Isthmus of Panama blocking zonal oceanic circulation
    4. More recently the opening and closing of the Bering Strait associated with eustatic sea level variations caused by the current glacial cycles.

    Next on my list is daily planetary rotation rate and its impact on the latitudinal reach of the Hadley cell. There are two modelling studies that are relevant here, both show that the latitudinal reach of the Hadley cell is a function of daily rotation rate with its critical feature of forced mid-latitude tropospheric air descent: Hunt, B.G. (1979) and Del Genio, A.D. and Suozzo, R.J., (1987). From these papers we can establish why Venus and Titan, which are slow daily rotators have a hemisphere encompassing Hadley cell pair that reaches from the equatorial zone of solar zenith directly to the rotational Polar Vortex. By contrast Earth and Mars, which are both rapid rotators have a triple cell structure of Hadley, Ferrel and Polar cells per hemisphere.

    On Earth the mid latitude zone of the Hadley Cell in the Horse Latitudes creates an atmospheric window of clear dry descending air that forms a thermal radiant energy leak point that allows for global surface heat shedding to space. Note the importance here of the global surface area involved and also the nature of that surface in the special case of water dominated planet Earth. If the surface under the descending limb of the Hadley cell is land, then the surface heat storage capacity by day is low and the thermal radiant capability is always high. However, if the surface is ocean water, then the surface heat storage capacity by day is high and the thermal radiant capability is always low. So, for example during the Cretaceous with its mid latitude Tethys Ocean we can expect that the GAST will be high; whereas now with the presence of the Sahara Desert and the Tibetan Plateau as solid surface thermal radiant leak points then the GAST will be lowered.

    Next, we come to the issue of albedo and its clear impact on GAST. One of the unexpected results of the development of our Dynamic-Atmosphere Energy-Transport Climate Model (DAET) is the relationship between the freezing point of the dominant atmospheric condensing volatile, water for the Earth and concentrated Sulphuric acid for Venus and the upper limit of these two planets respective troposphere. Solid atmospheric particles are always more efficient thermal emitters than polyatomic molecular gases and the point in the troposphere at which the relevant condensing volatile freezes has two impacts:
    1. There is no more latent heat energy to be released and so atmospheric air mass ascent must cease.
    2. The formation of an atmospheric veil of solid particulates enhances radiant energy loss to space.

    In the case of the Earth the relevant temperature is the flash freeze point of super-cooled water droplets and the formation of cirrus cloud, clouds which are then cleared in the forced air descent of the Horse latitudes. In the case of Venus, because there is no mid-latitude forced air descent, the sulphuric acid veil persists to the Polar Vortex. Consequently, energy shedding to space from the atmosphere of Venus is totally dependent on the planet encompassing high level cloud veil of frozen particles with no possibility of surface energy loss to space, unlike the rapidly rotating Earth.

    Finally returning to Earth and the formation of continental ice caps. I have personally found it very instructive to study the wind patterns shown on Ventusky weather maps. In particular the way that surface winds over the sea follow the path of least resistance and will try and track along straits between land masses until forced inland. The presence of the Cheshire Gap for example was always mentioned as a geographic feature guiding the path of storms coming off the Irish Sea and tracking down to the Midlands. With this in mind it is clear that the formation of 3,000-metre-high continental ice masses will have a permanent impact on planetary surface air flow, guiding the northern hemisphere storms of the Ferrel cell south of their current inter-glacial track and into the Mediterranean region (for example).

    In addition to guiding the tracks of storms these continental ice caps provide an additional high elevation solid surface thermal energy leak point to space and in doing so create cold dense gravity winds that further enhance and spread surface cooling, sea-ice formation and maintain ice surface high albedo.

    In conclusion I suspect that it is albedo variations, both geologic caused and atmospheric induced that are the primary driver of GAST changes.

  156. Ned Nikolov says:

    Roger (tallbloke),

    As we’ve discussed before, these vague matches between the rate of global temperature change and 65 N insolation anomaly and/or eccentricity change do not suggest that orbital variations are the direct cause of glacial cycles through radiative forcing. There is no indication in the geological temperature record that changes in incoming radiation in any shape or form have been driving the Ice Ages! However, there is indication provided by the sodium deposition in Antarctic ice that air density was substantially lower during glacial maxima suggesting a lower air pressure as well. On the other hand, our model clearly indicates that changes in the adiabatic forcing can fully explain the observed polar amplifications (which cannot satisfactorily be explained through other mechanisms) and the geological evidence for enhanced poleward air transport due to lower air density.

    The combination of enhanced wind speed towards Antarctica and reduced heat transport from the Equator during glacial maxima suggested by the sodium deposition record and the polar temperature amplification respectively is a tell-tale sign that atmospheric density was much lower during peak Ice Ages compared to interglacial periods.

    So, the vague Milankovitch-temperature correlations are likely the result of other processes controlling both orbital variations and changes in atmospheric mass & surface air pressure on Earth.

  157. Ned Nikolov says:

    Phillip,

    Your reasoning is physically inconsistent!

    If pressure and solar irradiance determine the long-term (baseline) global temperature of a planet as revealed by modern NASA observations, then changes in this baseline temperature as observed during the glacial cycles and over the past 83 My must be due to either changes in incoming radiation or surface air pressure or both. Our modern understanding of orbital variations suggests that the Earth-Sun distance has been quite stable for the past 100 My, and that Sun’s luminosity has only slightly increased during this time in a nearly linear fashion. Therefore, changes in solar irradiance cannot account for observed temperature changes in the geological record. The only other possible driver of baseline planetary temperature is pressure! Furthermore, assuming pressure as a driver numerically fully explains polar amplifications observed during the early Eocene (51 My ago) and the Quaternary (past 800 ky). Hence, what more proof do you need?

    Also, as I pointed out earlier, the sodium deposition record in Antarctic ice combined with the observed polar amplification over the past 800 ky indicates the existence of a much lower air density during glacial maxima compared to interglacial warm periods.

  158. Philip Mulholland says:

    The only other possible driver of baseline planetary temperature is pressure!

    Ned,
    You are assuming a constant planetary albedo. I assume it varies.

  159. Ned Nikolov says:

    Phillip,

    Nope, I do not assume a constant albedo! However, the albedo corresponding to a planet’s baseline temperature is a byproduct (an emergent property) of the climate system itself set by pressure and solar irradiance, and as such this albedo does not control the surface temperature. We call it a baseline albedo. It represents the bulk of the albedo of a planet. Variations around the baseline albedo induced by solar magnetic activity are responsible for the observed fluctuations of global temperature around its baseline value on decadal to centennial time scale. However, these albedo variations are very small compared to the baseline abedo and, on Earth, they can only cause -/+1 K change in global temperature around a baseline. Bottom line is that the albedo is NOT a free variable controlling surface temperature. This is all explained numerically in our AMS video about the role of albedo in climate:

  160. brianrlcatt says:

    Agree the albedo bit on the evidence. As to you like temporal data, a guy called James Covington created this interglacial overlay for 4 cycles, from the ice cores. You can see the Younger Dryas in our interglacial warming and how similar these events are.. ALSO can clearly see the short term solar wind effects and the dominant short term cycle of around 1 deg K every 1Ka, with the 500a and 200a periods also well seen. Whatever you believe, this is what happens in nature.

    The MIlankovitch effects, in particular the interglacial warming, and larger, much slower and more sustained, 7deg in 7Ka roughly, vs. 1 deg in 500a each way for the shorter term.

  161. Philip Mulholland says:

    Ned,
    You still fail to acknowledge that daily rotation rate is a controlling variable on the latitudinal reach of a planet’s Hadley cell. Atmospheric albedo is caused by the freezing point of the relevant condensing atmospheric volatile. This is temperature dependent effect and as such is a function of GAST and lapse rate (lapse rate being a function of gravity and specific heat). Venus is hot because it is a slow rotator, has a sulphuric acid condensing volatile that determines it atmospheric albedo and so requires a deep atmosphere to achieve that low temperature level at altitude.

  162. Paul Vaughan says:

    so quick
    briefing

    peripheral discussion highlight
    off-topic, so briefly noting

    oldmanK wrote:
    “173CE […] They also record a ‘small’ deviation in the obliquity.”
    “The important factor is that the obliquity measurement in that year is a small but substantial ‘outlier’ from the 3k yr trend.”

    The brief spike is the largest of all observed outliers (swell noted comments no. 173804).

  163. Ned Nikolov says:

    Phillip,

    The NASA planetary data reveal NO effect of a body’ spin rate on its global surface temperature! If the rotation speed were a factor affecting global temperaures, then the pressure-temperature relationship we discovered across planetary bodies would have been impossible, because the 6 planetary bodies participating in our regression analysis have different rotation speeds and our model does not account for those differences… The claim that the spin rate affects global surface temperature of a planet comes from math models, not real data!

    Besides, what does rotation speed have to do with Ice Ages?

  164. Philip Mulholland says:

    Ned,

    The rotation rate of a planet determines the latitudinal reach of the Hadley cell.
    On Earth the forced Coriolis descent of air in the Horse Latitudes guarantees clear skies which allows for clearance of the cirrus cloud veil, this reduces planetary atmospheric albedo and increases the surface albedo component of energy capture while also increasing the surface to space thermal radiant by-pass window from solid land surfaces.

    On Venus and also Titan the slow rotation means that these bodies have no rotation induced forced air descent mechanism to clear the upper atmosphere veil. The only place that air can descend on these bodies is in the polar vortex. This has profound meteorological implications, a high cloud veil of solid particles is an inefficient thermal emitter compared to a solid surface. So, slow rotating planets with pole-to-pole unbroken cloud veils run hot. In the case of the Earth the more high level surface, either mountain plateau or continental ice caps, the more thermal radiant energy is loss to space and so the lower the GAST

    During the Cretaceous there were no major mountain ranges and so we have here yet another reason for the hot Cretaceous world, in addition to the lower surface albedo of a planet Earth with no icecaps.

  165. Ned Nikolov says:

    Phillip,

    This is a “story” of yours with no physical reality to it! We now know well that the net effect of cloud albedo is to cause surface COOLING, not warming as you imply. This is a well-established fact that is verified by most accurate albedo measurements from the CERES platform we have to date. I show this in my albedo video above! So, more clouds and higher cloud albedo reduce the surface temperature by blocking a portion of the incoming solar energy… The surface temperature is controlled by the absorbed solar radiation, not the emission of LW radiation back to Space. Radiative cooling to Space is a trivial matter and always occurs on any planet, which is reflected in the balance between incoming solar flux and outgoing LW radiation found at the top of the atmosphere on all planets.

    If you think that clouds somehow block the outgoing LW radiation and cause warming, you are in the delusional camp of climate alarmists, who believe that an open, convective atmosphere can “trap” heat, which is physically ridiculous! 🙂

  166. Ned Nikolov says:

    Phillip,

    The surface of Venus is hot because of its 93 bar atmospheric pressure and proximity to the Sun, not because of its slow rotation and thick cloud cover. Let’s not be confused about such a basic fact!

  167. Pablo says:

    Ned,

    “Radiative cooling to Space is a trivial matter ”

    Without water vapour to slow down surface radiative cooling at night, killing ground frosts would occur most nights in summer.

  168. Ned Nikolov says:

    Jim Steele @ January 7, 2022 at 6:54 am

    I’ve read your online article describing your hypothesis about how Antarctic glaciation caused global cooling over the past 35 My and I watched carefully your video on the same topic:

    I have numerous comments regarding your hypothesis, which does not agree well with recent geological findings, but I’d like to start a discussion after you had a chance to carefully watch my videos in this order:

    Demystifying the Atmospheric Greenhouse Effect: https://vimeo.com/602819278

    Drivers of Earth’s Paleoclimate: https://www.youtube.com/watch?v=DpUkPPtkPVc

    Role of Albedo in Climate: https://www.youtube.com/watch?v=Gv66_mpJz-c

    These videos provide a lot of necessary background info for our discussion. Bear in mind that this is a New Quantitative Paradigm based on vetted NASA observations, and not a contrived theory such as the 19th-Century “greenhouse” concept. 🙂

    Thank you!

  169. Pablo says:

    “Clear night cooling occurs at about 1.9 0C per hour, and overcast night cooling about 0.3 0C per hour.”

    Click to access tut37-Radiative-Cooling.pdf

  170. Ned Nikolov says:

    Pablo,

    The net effect of clouds over a 24-h period is COOLING, not warming. That’s a well-established fact. Clouds can reduce the diurnal temperature amplitude, but their presence during the day and night results in a cooler surface on average, because their blocking effect with respect to solar radiation is greater than their LW radiative effect at night. Furthermore, clouds are water aerosols that got in the atmosphere thanks to evaporation from the surface, which caused cooling at some other location.

    We are discussing here surface temperatures on a planetary scale, not the temperature in your backyard. There is a big difference… 🙂

  171. Pablo says:

    “The net effect of clouds over a 24-h period is COOLING, not warming.”

    Agreed, but you cannot dismiss rates of night time radiative cooling as trivial. Life depends on it.

  172. Philip Mulholland says:

    Ned,
    This conversation is useful for me, it is helping me to clarify my ideas.
    Albedo is by definition a daytime phenomenon and is self-evidently a property of the day-lit hemisphere. However, I am interested in the physical and chemical properties of the cloud layer that creates the albedo effect. I am trying to address the bigger picture of the energy transfer mechanisms associated with outgoing thermal radiation. In the case of Venus, the atmospheric veil is continuously present and we see that on the surface the diurnal temperature range is about 1 degree Celsius. This is an astonishing feature of that planet’s climate which requires an explanation.

    There is meteorological data which shows that in the Earth’s troposphere advected upper-level cirrus ice clouds can cause night time surface warming on land. A possible mechanism for this is by reflection of surface thermal energy from adjacent warm water bodies (this is NOT a cold atmosphere heats the warmer ground story). In addition to providing a thermal radiation cap to the troposphere, top of the atmosphere thermal radiation to space occurs most efficiently from solid particles and not from gases. So, in the presence of a thermally opaque atmosphere the temperature and elevation of the tropopause cloud veil will have an impact on GAST.

    I view planetary atmospheres as a gigantic chemistry experiment in which the surface is heated by solar radiation and the properties of the molecular materials retained within the atmosphere are a function of molecular mass, escape velocity and stability to ionising radiation.

    “The surface of Venus is hot because of its 93 bar atmospheric pressure and proximity to the Sun,”
    The intercepted insolation power for the Venus atmosphere is lower than that of the Earth.

  173. tallbloke says:

    Philip M: “intercepted insolation power”

    What is this and how/where is it measured?

  174. Philip Mulholland says:

    tallbloke

    The Venusian Solar Irradiance is 2,601.3 W/m^2
    The Earth’s Solar Irradiance is 1,361 W/m^2
    This reduction in power is the distance effect.

    However the Venusian Albedo is 0.77 so the power flux available to the planet reduces to 2601.3*(1-0.77) = 598.3 W/m^2

    The Earth’s Albedo is 0.306 so the power flux available to the planet reduces to 1361*(1-0.306) = 944.5 W/m^2

    The Earth’s climate receives more power than that of Venus.
    This is the Albedo Effect on intercepted insolation power.

  175. Ned Nikolov says:

    Phillip,

    Your numbers are bit off:

    – Venus’ spherical albedo is 0.9, not 0.77. See Mallama et al. (2006): https://www.sciencedirect.com/science/article/abs/pii/S0019103505005105

    – Earth’s spherical albedo is 0.29 at the moment according to CERES measurements, not 0.306. Earth’s baseline albedo is 0.3. This is the long-term average albedo, which is a byproduct of the climate system and does not control surface temperature.

  176. Ned Nikolov says:

    Phillip,

    Just FYI, the sensitivity of Earth’s global temperature to albedo deviations from the baseline value is -1 K per 1% albedo change. So, if Earth’s albedo were 0.306, this means that our global surface temperature should have been about 1.6 K cooler than it is. That’s the entire warming since the end of the Little Ice Age! So, it’s important to use the correct albedo figure… 🙂

  177. Philip Mulholland says:

    This is the long-term average albedo, which is a byproduct of the climate system and does not control surface temperature

    Ned,
    You keep saying this but offer no mechanism. Planetary brightness varies due to the real physical cause of change in material substances, it is not a “byproduct of the climate system”, that is just “and here a miracle occurs” hand-waving.
    See for example Fenton, L.K., Geissler, P.E. and Haberle, R.M., 2007. Global warming and climate forcing by recent albedo changes on Mars. Nature, 446(7136), pp.646-649.

    I am using recognised numbers for illustrative purposes. Let me know when NASA update their Venus/Earth Comparison factsheet.

  178. oldbrew says:

    If albedo is not a byproduct of the climate system, that implies it causes itself. How would that work?

    Re the Venus/Earth Comparison factsheet, where does NASA gets its Venus ‘blackbody temperature’ figure from?

  179. Philip Mulholland says:

    oldbrew.
    The new James Webb space telescope is now cooling down to its operating temperature of 48 Kelvin.
    I wonder how that happened?

    “where does NASA gets its Venus ‘blackbody temperature’ figure from?”

    I suggest you ask Dr. David R. Williams, his email is published on the information sheet.

  180. oldbrew says:

    We don’t need Dr. Williams, the answer is here.

    https://en.wikipedia.org/wiki/Black-body_radiation#Temperature_relation_between_a_planet_and_its_star

    One of the factors said to be determining the temperature of a planet is given as ‘The greenhouse effect for planets with an atmosphere’. Another is albedo. A planet is not a black body anyway, so it’s an odd concoction.
    – – –
    Why mention the JWST?

  181. Paul Vaughan says:

    2019: surface temperature of Europa

  182. tallbloke says:

    OB, Philip mentions the JWST because he’s noting the cooling effect of the heat shield that has just been deployed beneath it. It creates a high ‘albedo’ for the instrument by reflecting away heat from the Sun, Earth and Moon.

  183. Ned Nikolov says:

    Phillip,

    The conclusion that the bulk of the planetary albedo is an intrinsic property (byproduct) of the climate system comes straight from our analysis of NASA data. I explain this in the “role-of-albedo” video. Of course, this only applies to bodies with tangible atmospheres. Airless bodies such as Mercury, the Moon, Europa, Callisto etc. have albedos set by the optical characteristics of their surface minerals.

    The albedo of planets & moons with tangible atmospheres is primarily determined by the cloud cover, haze or dust produced by atmospheric processes. It’s this intrinsic (climate-controlled) nature of the albedo that explains its observed stability for individual planetary bodies. Albedo stability is a feature that climate models still cannot explain/reproduce well, which is why it’s been puzzling scientists for decades. There are negative feedbacks operating within the climate system, which we do not fully understand that maintain a planet’s albedo. A good example in this regard is the amazing hemispherical symmetry of Earth’s TOA albedo. Despite a large difference in surface albedos between NH and SH, the difference in reflected radiation between the Hemispheres at the top of the atmosphere is only 0.1 W m-2. The clouds totally mask differences in surface albedos (see Datseris & Stevens 2021: https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021AV000440).

    The NASA planetary factsheet (https://nssdc.gsfc.nasa.gov/planetary/factsheet/) contains wrong values for some parameters of certain planetary bodies such as the global surface temperaures of Mercury and the Moon and some albedo values. I sent an email about this to Dr. David Williams years ago, but nothing changed. I guess it’s just sloppiness… 🙂

  184. daveburton says:

    The JWST sunshield uses a very refined version of what is called multi-layer insulation (“MLI”). MLI is a nice “real world” application of the mechanism by which the reflective coating on a “space blanket” makes it insulate slightly better than clear Mylar would (though a “space blanket” isn’t multi-layer). A “space blanket” would work even in the vacuum of space.

    MLI is also analogous to the mechanism through which radiatively active gases in the atmosphere cause the tropospheric “lapse rate” of decreasing temperature with altitude. Prof. Robert G. Brown explained that a few years age (as I related in the linked WUWT comment).

  185. tallbloke says:

    From Ned’s link:
    ” reflection decreases over time with a significant trend”

    There’s the real cause of ‘global warming’ then…

  186. tallbloke says:

    Heh, Dave B’s resorted to trolling now.
    Hey Dave, if the lapse rate is due to radiatively active gases, why is it defined by -g/Cp ?

    Oh, and while space blankets will work in space ‘radiatively’, almost all their benefit down here in the atmosphere is due to their reducing convective heat loss, just like the ‘greenhouse effect’ of greenhouses. 😉

  187. daveburton says:

    Ned wrote, “My hypothesis is backed by calculations produced by a model derived from NASA planetary data.”

    Just what climatology needs: another model based on someone’s unproven assumptions. As if we didn’t have enough of those, already.
     

    Ned asked, “What about temperature changes in Antarctica, which are synchronous with Equatorial temperature variations? Are they also magically caused by the seasonal temperature variations at 65 deg N?”

    I discussed that, Ned. I wrote:

    “When, due to Milankovitch cycles, the Earth’s seasonal swings are reduced to the point that the great northern ice sheets grow a little bit each year, by adding more snow in the winters than they lose in the summers, after thousands of years of ice sheet growth it adds up to a large increase in planetary albedo. Conversely, when the Earth’s seasonal swings are increased to the point that the great northern ice sheets shrink a little bit each year, as the ice sheets dwindle it eventually adds up to a large reduction in planetary albedo.”

    A large change in planetary albedo has global effects, obviously.

    100 meter changes in global sea-level and 90 ppmv CO2 level changes might affect the southern hemisphere a bit, too.
     

    Ned, I asked you a question, which you have ignored. Will you please respond to it? I asked you this:

    “…from Eemian peak to LGM minimum there was, according to Ned’s theory… an average rate of atmospheric loss of about 60 million tonnes/day for 100K years. Ned mentioned a process which could account for 0.00015% of that rate of loss. What about the other 99.99985%?”

    It takes only one insurmountable objection to a hypothesis to disprove it. So, what about the other 99.99985%?

    What process do you think could have removed 39% of the nitrogen, 39% of the oxygen, and 39% of the argon from the Earth’s atmosphere in just 100K years?

    The mark of a conscientious scientist is his willingness — eagerness, even! — to revise his assumptions and conclusions, when confronted by conflicting information.

  188. daveburton says:

    The lapse rate is the result of multiple factors, which vary in importance with location and altitude, which is why the lapse rate is a lot more complicated that merely -g/Cp.

  189. Ned Nikolov says:

    Dave,

    The temperature lapse rate in the troposphere is NOT caused by a “multi-layer insulation mechanism” provided by “greenhouse gases”! It’s caused by temperature dependence on pressure and the pressure decrease with altitude. The latter is a result of the hydrostatic-equilibrium requirement. This is standard atmospheric Thermodynamics, which I describe using classical math equations in my video Demystifying the Atmospheric Greenhouse Effect (starting at about 30:00 min):

    https://vimeo.com/manage/videos/602819278

    Therefore, the lapse rate has nothing to do with IR radiative properties of gases!

  190. daveburton says:

    Ned, if you think that “the lapse rate has nothing to do with IR radiative properties of gases” then why is it positive at some altitudes and negative at others?

  191. Ned Nikolov says:

    Dave,

    Your reasoning is all broken. You confuse our current lack of knowledge about the mechanisms controlling mantle degassing and the loss of atmosphere to Space with geological and numerical evidence that pressure has been varying significantly through time. These are different science questions. As I said many times before, we must first examine the evidence pointing toward large pressure variations, and then launch research to find out how such variations could have happened.

    If you follow a sound logic based on the available evidence regarding Milankovitch cycles coming and the geological record, your would have realized that Ice Ages could not possibly have been caused by a radiative forcing. Only an adiabatic forcing can explain the polar amplification as well as the fact that global temperature variations of the past 800 ky show NO relationship with Milankovitch cycles. I pointed this out in one of my comments above:

    https://tallbloke.wordpress.com/2022/01/03/ned-nikolov-dispelling-the-milankovitch-myth/#comment-174750

  192. tallbloke says:

    Ned: Therefore, the lapse rate has nothing to do with IR radiative properties of gases!

    They have plenty to do with the lapse rate above the tropopause, but very little to do with the lapse rate where we live in the troposphere.

  193. Ned Nikolov says:

    About “space blankets” – these work by reflecting LW radiation emitted from the body under the blanket. This reflection traps radiant heat between the body and the blanket, which is why “space blankets” provide thermal insulation in the vacuum of Space, where there is no convective cooling.

    Since gases do not reflect IR radiation, there is no physical analogy between the working of space blankets and the purported trapping of heat by “greenhouse” gases. Atmospheric gasses cannot and do not trap radiant heat because they do not reflect IR radiation.

  194. Ned Nikolov says:

    Here is something interesting:

    A 2019 paper by Ashkenazy (https://www.sciencedirect.com/science/article/pii/S2405844018357724) used an elaborate thermo-physical model to assess the surface temperature of Jupiter’s moon Europa. The author calculated the following surface temperatures that are somewhat lower than previous estimates:

    Mean annual global temperature: 90 K
    Mean annual Equatorial temperature: 96 K
    Mean annual polar temperature: 46 K

    Using updated values for the ice-covered long-wave emissivity of the surface (0.94) and the rate of internal heating (0.05 W m-2) on Europa quoted by Ashkenazy, the much simpler NZ model produced the following estimates:

    Mean annual global temperature: 89.9 K
    Mean annual Equatorial temperature: 96.9 K
    Mean annual polar temperature: 41.4 K

    The lower Polar temperature yielded by the NZ model is due to the fact that internal heating rate is assumed to be uniformly distributed throughout the surface, while Ashkenazy reports a higher subsurface heating at the Poles. Overall, our NZ model did pretty good against a much more detailed thermo-physical model!

  195. tallbloke says:

    That’s an outstanding result for your model Ned! Well done to you and Karl.
    I’m looking forward to the results from upcoming NASA missions. Especially to Mercury. It would be a fantastic validation for you if you have nailed that one.

    Credit to Paul V who posted the link to the Europa paper earlier.

  196. tallbloke says:

    Dave B: the lapse rate is a lot more complicated that merely -g/Cp.

    Well at least the gas laws get the tropopause temperature correct at around -60C, whereas your radiatively inspired diagram runs about 20C too hot (like all the CMIP radiative models which don’t correctly couple convection).

  197. Paul Vaughan says:

    found it while tracing citations of the author — fine opportunity to review

    fantastic sea-kayaking in the snow yesterday
    now time for a hike (taking crampons…)

  198. tallbloke says:

    Thanks Paul, interesting insolation-100kyr SST link.

    Speaking of hiking in the snow, I got sent this photo today by an old friend. That’s me on the left, in 1979.

  199. daveburton says:

    Ned wrote, “our current lack of knowledge about the mechanisms controlling… loss of atmosphere to Space… we must first examine the evidence pointing toward large pressure variations…”

    There is no such evidence (on timescale of mere tens & hundreds of thousands of years).

    We cannot ignore the fact that the Earth’s atmosphere could not have lost 39% of its nitrogen, 39% of its oxygen, and 39% of its argon, in just 100K years (and then gained back 3/4 of those lost gases in just 10K years). It simply is not possible.

    If you dispute that, then explain how it could have happened. Explain what could have caused a “loss of atmosphere to Space” at more than 600,000 times the current estimated rate?

    Then explain how the Earth could have recovered 3/4 of that lost atmosphere, in just 10K years.

    So many people have their pet theories about a singular “control knob” for climate! Well, we can rule out air pressure / atmospheric mass.
     

    Ned wrote, “Ice Ages could not possibly have been caused by a radiative forcing.”

    I’ve twice explained to you how it works, Ned.

    Glaciations are characterized by ICE. Lots of ice! What causes glaciations is year-by-year growth of the great northern ice sheets, over thousands of years. What causes deglaciations is year-by-year retreat of those ice sheets, over thousands of years.

    Whether the great northern ice sheets advance or retreat it mainly governed by the magnitude of the difference between summer and winter insolation between about 40°N and 70°N latitude (where the ice sheets were). Large seasonal variations at those northern latitudes (hot summers and very cold winters) cause the ice sheets to retreat, because of increased melting in summer, and reduced snowfall in winter. Small seasonal variations at those latitudes (cooler summers and milder winters) cause the ice sheets to advance, because of reduced melting in summer, and increased snowfall in winter.

    Note that neither of those conditions is due to a change in average insolation, at any latitude.
     

    Ned wrote, “Therefore, the lapse rate has nothing to do with IR radiative properties of gases!”

    Tallbloke replied, “They have plenty to do with the lapse rate above the tropopause, but very little to do with the lapse rate where we live in the troposphere.”

    I mostly agree, Tallbloke, but I think “very little” is an overstatement. I would say they have less to do with the lapse rate in the troposphere.

    For an illustrative example, consider Antarctica. Even at ground level above the Antarctic Plateau, the lapse rate is typically negative. That is, temperature usually increases with altitude, there. Do you know why?
     

    Ned wrote, “Since gases do not reflect IR radiation, there is no physical analogy between the working of space blankets and the purported trapping of heat by “greenhouse” gases…”

    Fair enough, but the analogy was with multi-layer insulation.

    If the reflectivity of the first layer of the JWST MLI sunshield were perfect, it wouldn’t heat up at all, and there’d be no need for four more layers. The radiation which the second layer blocks is the the radiation which was re-radiated by the first layer (or which somehow penetrated it, because it’s not completely opaque, plus radiation which could have passed though a hole). The reason for multiple layers in MLI is that everything above absolute zero radiates, and that includes the first/outer/sun-side layer of the MLI.
     

    Ned continued, “Atmospheric gasses cannot and do not trap radiant heat because they do not reflect IR radiation.”

    Radiatively active gases in the atmosphere absorb and emit IR radiation. For instance, CO2 causes the big, green notch in this satellite-measured emission spectrum, and that notch certainly affects the Earth’s temperatures:

    But changes in the amount of CO2 in the atmosphere have only a small effect on the Earth’s radiation balance, and, hence, a modest effect on temperatures. You can see that in this graph is from van Wijingaarden and Happer (2021), which is derived from line-by-line spectral calculations. The black trace is the emission curve for CO2 = 400 ppmv. The red trace is for CO2 = 800 ppmv. (I added the flashing purple ovals.)

    The difference between the red and black traces is the calculated effect at the mesopause of a doubling of CO2 concentration. As you can see, the difference is only about 277 – 274 = 3 W/m². They give a more precise figure of 2.97 W/m² in their Table 2:

    To put that radiative forcing into perspective, it is calculated that a uniform global temperature increase of 1°C would increase radiant heat loss from the surface of the Earth by about 1.4% (variously estimated to be 3.1 to 3.7 W/m² or 3.1 to 3.3 W/m² in the CMIP5 models (the 8th column) — it’s complicated).

  200. daveburton says:

    BTW, good point about that wrong tropopause temperature in that lapse rate diagram, Tallbloke! I hadn’t noticed that, until you pointed it out.

    Space.com credits the National Weather Service for the diagram, which is a bit disturbing.

  201. tallbloke says:

    Dave B: What causes glaciations is year-by-year growth of the great northern ice sheets

    Of course, ice ages are caused by ice. Simples. Doh! 😉

    the difference between summer and winter insolation between about 40°N and 70°N latitude

    Not just insolation changes there but in the tropics too.

  202. tallbloke says:

    Dave B: BTW, good point about that wrong tropopause temperature in that lapse rate diagram

    Yeah, well never mind the NWS’ incorrect diagram, take a closer look at the PV/nR=T relationships on the right hand side of my correct diagram. No LW fluxes required! (They are another by-product of the system which Ned correctly tells us is controlled by pressure and insolation). As you were taught in primary school, everything radiates according to its temperature; not the other way round!

  203. Ned Nikolov says:

    Dave B,

    You lack elementary physics reasoning: Ice accumulation is caused by LOW temperaures. Ice does not cause the low temperaures! The purported ice-albedo feedback needed for your “explanation” to work is a fiction that can be traced back to Arrhenius’ mediocre work in the 19th Century… The fact that temperature controls the formation of snowfall and ice accumulation is demonstrated in Earth’s history by the early Eocene (56 – 48 My ago), when there was NO glaciers and NO ice anywhere on this planet. Milankovitch cycles were still operating back then as they are now, but the variation of insolation at high northern latitude did NOT produce any Ice Ages. Not only that, but Polar temperaures were 33 K – 37 K higher than today. How do you explain these facts?

    So, you basically have verbal “story” not numerically supported by any physical model or the geological record.

  204. Ned Nikolov says:

    It’s frustrating to see people like Dave Burton repeat the same nonsense over and over again… 🙂

  205. tallbloke says:

    Ned and I agree that high Eocene temps were due to higher pressure.
    But we disagree about the glacial/interglacial cycles.
    Just because Milankovitch cycles couldn’t induce them under a much higher pressure-temperature Eocene climate regime, doesn’t mean they can’t once the long term pressure baseline has dropped.

  206. Ned Nikolov says:

    Roger (tallbloke),

    If atmospheric pressure caused the hot equable climate of the early Eocene and the drop of pressure (loss of atmospheric mass or adiabatic forcing) was the reason for the observed giant cooling of Earth from 50 My to 1.5 My ago, then adiabatic forcing must also be responsible for the glacial cycles, because these are a part of the same temperature continuum through time! Furthermore, we have clear evidence that:

    – Milankovitch cycles determining the 65 N insolation show no relationship to global temperature variations for the past 800 ky;

    – The average annual amount of solar radiation reaching Earth have practically not changed for the past 800 ky;

    – Pressure changes (adiabatic forcing) fully explain the polar amplifications observed in the geological record during the glacial cycles. No other mechanism comes even close to explaining this;

    – The sea-salt sodium deposition record in Antarctic ice along with the observed polar amplification strongly indicates the existence of a much lower near-surface air density, hence pressure, during glacial maxima over the past 800 ky.

    What else do you need to get convinced about what drove Ice Ages? And why should we continue to cling to the idea that Milankovitch cycles caused the Ice Ages without any supporting data? Is it just to keep a “science tradition” alive? Or is it because we cannot comprehend at the moment, how atmospheric mass and total pressure could fluctuate so much on a time scale of thousand of years?

  207. tallbloke says:

    Too late at night here to respond now Ned. More tomorrow.
    Cheers

  208. daveburton says:

    Ned wrote, “Ice accumulation is caused by LOW temperaures. Ice does not cause the low temperaures!

    That is a common misconception. Most climate alarmists are convinced of it. They think warmer temperatures necessarily cause melting, and thus accelerate ice mass loss from glaciers and ice sheets, and thus necessarily accelerate sea-level rise. They build those assumptions into the models which predict catastrophic sea-level rise, and they have a hard time believing the measurement data which shows very little acceleration in global sea-level rise in response to rising CO2 levels and global warming:

    https://sealevel.info/MSL_weighted.php?id=Honolulu,%20San%20Francisco,%20Harlingen,%20Battery,%20Sydney&c_date=1925/1-2024/12

    Warming doesn’t necessarily cause melting. For example, Antarctica averages more than 40° below zero. I hope it is obvious that a few degrees of warming cannot melt it!

    Of course warming does cause melting, in some places, in the right circumstances. But the most important factor affecting annual changes in ice mass, for the Antarctic and Greenland ice sheets, is NOT melting.

    Nor is it iceberg calving, nor sublimation.

    The most important factor affecting the annual ice mass balance of ice sheets and glaciers is snowfall.

    Snowfall is the most important factor affecting net ice mass flux for both the Greenland and Antarctic ice sheets, and snowfall was also certainly a very important factor affecting the advance and retreat of the great Laurentide, Fennoscandian & Cordilleran ice sheets.

    A warming climate accelerates snowfall accumulation on ice sheets and glaciers, through 2 distinct mechanisms:

    #1. Warmer air carries more moisture. Below freezing, it’s 8-12% more moisture per 1°C of warming. (That’s why heaviest blizzards occur when temperatures are only moderately below freezing.)
    https://web.archive.org/web/20190928155425/https://web.gccaz.edu/~lnewman/gph111/topic_units/labs_all/water%20vapor%20capacity%20of%20air.pdf
    https://www.google.com/search?q=%22too+cold+to+snow%22

    #2. Reduced sea ice coverage = more open water, increasing ocean evaporation and thus “lake/ocean-effect snowfall” (LOES) on downwind land.
    http://archive.is/vp9eP#selection-1257.0-1257.450
    https://google.com/search?q=%22lake%2Focean-effect+snowfall%22

    The importance of LOES is illustrated by the story of Glacier Girl, a P-38 warbird which made a forced landing on the Greenland Ice Sheet during WWII. It was buried by snowfall which averaged ≈70 feet/yr (no, that’s not a typo!), and recovered 50 years later.

    That snow represents evaporated water, mostly removed from the North Atlantic and Arctic Oceans, which then fell as ocean-effect snow on the Greenland Ice Sheet.

    The story of Glacier Girl is fascinating. You can read more about it here:
    https://www.airspacemag.com/history-of-flight/glacier-girl-the-back-story-19218360/?all
    https://p38assn.org/glaciergirl/recovery.htm

    The near-linearity of sea-level trends over then last nine decades, despite a warming climate, prove that accelerations in ice mass loss in some places are being roughly balanced by accelerations in ice mass gain in others, through increased snowfall accumulation. Here’s a list of a half-dozen papers (and a few articles), published over a span of about thirty years, about accelerating snowfall accumulation in Antarctica:

    https://sealevel.info/feedbacks.html#antarcticsnowcitations

    It is remarkable how slow the climate modelers sometimes are to incorporate the influence of measured reality into their models. It took about thirty years (counting from this 1991 paper) for the modelers to discover that warmer temperatures increase snowfall accumulation on Antarctic ice sheets, largely offsetting ice loss from melting and iceberg calving, and to incorporate that fact into their “new generation of climate models.”
     

    Ned wrote, “Ice does not cause the low temperaures! The purported ice-albedo feedback needed for your “explanation” to work is a fiction”

    That’s a very strange statement. There’s nothing fictional about the fact that light-colored snow reflects more sunlight than darker dirt (and plants).

    Of course, snow and ice can only reflect more sunlight in daytime. A lot of climate alarmists think reduced albedo from less ice coverage is why the Arctic is warming in winter, when there is little or no sunlight. That really is remarkably silly.

  209. oldbrew says:

    tallbloke says: January 9, 2022 at 4:02 pm

    Earth’s albedo isn’t manufactured by humans, it arises from the climate system itself. Surely that’s an important difference compared to a heat shield.

    Obviously changes in Earth’s albedo can’t be caused solely by changes in Earth’s albedo!

  210. tallbloke says:

    Ned: adiabatic forcing must also be responsible for the glacial cycles, because these are a part of the same temperature continuum through time!

    What’s a temperature continuum, and why can it only be caused by one thing?

    Milankovitch cycles determining the 65 N insolation show no relationship to global temperature variations for the past 800 ky

    I made a graph yesterday which shows otherwise. Paul V has linked graphs which show otherwise for the tropics and equatorial insolation and SST as well.

    The average annual amount of solar radiation reaching Earth have practically not changed for the past 800 ky

    I’ve learned to beware of averages over the years. They hide all sorts of interesting stuff.

    Pressure changes (adiabatic forcing) fully explain the polar amplifications observed in the geological record during the glacial cycles. No other mechanism comes even close to explaining this

    That’s a big plus for your hypothesis. What else could cause the temperature to drop further near the poles during the glacial part of the cycle than it does nearer the equator? I would suggest that the ice cover preventing energy release from the ocean beneath would be a factor.

    The sea-salt sodium deposition record in Antarctic ice along with the observed polar amplification strongly indicates the existence of a much lower near-surface air density, hence pressure, during glacial maxima over the past 800 ky

    I think you need to do more research on the sodium deposition line of investigation. Precipitation is lower during glacial periods and that will affect the concentration of wind blown particles in ice cores.

    why should we continue to cling to the idea that Milankovitch cycles caused the Ice Ages without any supporting data? Is it just to keep a “science tradition” alive? Or is it because we cannot comprehend at the moment, how atmospheric mass and total pressure could fluctuate so much on a time scale of thousand of years?

    Well you say there’s no supporting evidence for Milankovitch cycles affecting T, but looking at the plots you and others have made, I think there is.

    Your hypothetical requirement for the mass of the Earth’s atmosphere to increase by 30% or more in 10,000 years is a huge stumbling block in my opinion. I don’t see how that could have happened every 100kyr for the last 800kyr without it leaving huge piles of geological evidence.

  211. oldbrew says:

    TB says: What else could cause the temperature to drop further near the poles during the glacial part of the cycle? I would suggest that the ice cover preventing energy release from the ocean beneath would be a factor.

    I think Ned is saying you can’t have the effect before the cause, i.e. the increasing ice cover is a result of the temperature drop?

  212. Philip Mulholland says:

    oldbrew,

    Start with basic meteorology and a study of the climate of Antarctica. The Antarctic icecap is the world’s highest average surface elevation landmass. Central Antarctica south of latitude 80 degrees experiences months of zero sunlight energy input during the austral winter. The high-level efficient surface to space radiative cooling creates copious volumes of cold dense air. This cold air descends from the icecap as a gravity wind with temperatures of down to minus 50 Celsius. These katabatic winds flash freeze the Southern Ocean and extend the winter ice limit up to 800 miles offshore from the Weddell and Ross Seas drainage funnels.
    So, an established land icecap creates sea ice, not by albedo (it’s dark winter) but by wind flow.

    And how do we grow a land icecap? The answer is ocean-effect snow. Here is an example of a cold front concentrating the deposition of snow on the coastal mountains of southeast Greenland on the 4th January 2022.

  213. tallbloke says:

    OB: Obviously changes in Earth’s albedo can’t be caused solely by changes in Earth’s albedo!
    …I think Ned is saying you can’t have the effect before the cause, i.e. the increasing ice cover is a result of the temperature drop?

    Systems, by definition, contain feedbacks. There isn’t simple cause and effect in complex systems. If the initial temperature drop has one cause, the continuation and amplification of it may have several more.

  214. Philip Mulholland says:

    Obviously changes in Earth’s albedo can’t be caused solely by changes in Earth’s albedo!

    Oldbrew,
    I think that we are struggling here with a conflation of ideas. First albedo is a property of any illuminated body in space, hence my comment about the cooling of the space telescope now that it is in the shadow of its highly reflective (high albedo) sun shield.

    Ned holds the view that albedo is a property of climate, I hold the view that albedo is a property of materials. Take the example of the Moon, a vacuum planet with an albedo of 0.11, in other words the moon has a very dark surface, and we can observe this by looking at the distribution of the dark basalt Mare on the visible face of the Moon. Now we can simply measure the Moon’s albedo directly by observation or more usefully attempt a calculation from first principles, namely the relative areas of the Moon’s different regolith surfaces and the illumination angle. Not easy but it is possible to do this.

    We can easily speculate that if we suddenly turned our Moon into an ice moon of Jupiter, Io or Europa for example, then it might have a similar highly reflective Visual Geometric Albedo of 0.62 to 0.68 (NASA data) but still remain as a vacuum world with no atmosphere (at least in the short term until the ice sublimes in to space).

    Next let us look at Mars. The albedo of Mars is clearly dependent on its surface properties and unlike the Moon, but like our Earth, rapidly rotating Mars has reflective surface polar icecaps. I keep mentioning daily rotation rate for a very important reason. The Coriolis effect by inducing forced air descent in the mid-latitudes of both Earth and also Mars acts as an upper atmospheric air cleaner. Why is this important? Well studies of Mars show that at times of global dust storms the planet becomes more reflective as its albedo rises. The atmospheric dust then clears by deposition in the zones of descending air and the surface albedo eventually returns to its former value.

    Venus and Titan have permanent high level cloud veils (bright concentrated sulphuric acid particles and dark Tholins respectively) and I ascribe this permanent cloud cover to the impact of slow rotation and the consequent lack of a Ferrel cell on these worlds. So, both of these worlds have a permanent total atmospheric albedo with no surface component.

    Earth however is an interesting combination of features. Earth has a high-level reflective ice cloud environment at its tropopause, like Venus does. Surface reflective polar ice caps that are visible from space, like Mars does. A unique dominant surface of liquid water with a very high absorptivity (only Titan has liquid methane on its surface and these lakes are only in polar regions). Earth, like Mars but unlike Venus and Titan, has solid dark land surfaces visible from space under the descending limb of the Horse Latitudes.

    So, to calculate Earth’s albedo from first principles we need to establish the area of the ice cloud veil, that is the area of the ITCZ, tropical cyclones and cold cored Ferrel Cell storms, the area of cold sea surface fogs and apply this as a mask to the underlying surface which can be either, ocean water, surface ice, land vegetation or dry surface desert.

    Now what can we vary to make the Earth’s albedo change? First the area of Ferrel cell cloud cover is a function of Rossby wave sinuosity. During the Zonal phase of the natural 65-year climate cycle the Ferrel cell storm paths are shorter (less waviness) than during the wavier Meridional phase of the climate cycle. Next and this in geologic terms is the big one, remove the Antarctic ice cap and replace it with a vegetated landscape. Oh, but what about the clouds? Well, the summer climate of polar Antarctica will be convective cumulus storms as we also see in the polar regions of Titan and for the same reason. The descending high-pressure limb of the Earth’s polar vortex will still be in charge of the climate of Antarctica.

    Next remove all sea ice, remove all land ice, flood the continents, denude the mountains, create epeiric seas in the Horse latitudes and transport the extra captured solar energy to the poles by ocean gyres. Welcome to the low-albedo Cretaceous Earth.

    Golovneva, L.B., 2000. The Maastrichtian (Late Cretaceous) climate in the northern hemisphere. Geological Society, London, Special Publications, 181(1), pp.43-54.

  215. Philip Mulholland says:

    Ice accumulation is caused by LOW temperatures. Ice does not cause the low temperatures!

    Ned,
    You are quite correct and as meteorology shows us, mountain peaks are colder on average than sea level locations due to the adiabatic lapse rate. The real light bulb moment for me in the development of the Antarctic polar ice cap was the realization of the fundamental role of the Transantarctic Mountains (TAM) that separate East from West Antarctica. This now ice buried range has solid rock elevations of summits and dry valleys some of which rise more than 4,500 metres above sea level and the range reaches as far south as 85 degrees in the Queen Maud Mountains.

    Both the elevation and polar location of this range is critical to the development and maintenance of the East Antarctic icecap. Their elevation is such that snow can be expected to fall and accumulate all year round even under conditions of a warm polar climate even during the Eocene. Consequently the accumulation of snow and ice at a permanent high elevation rock surface provides not only a thermal radiant leak point to space, but also the locus for katabatic winds that in the continuous months-long night of the austral polar winter will chill the surrounding land mass and coastal waters of the Ross and Weddell Seas and so initiate, grow and ultimately maintain a permanent icecap on Antarctica by the meteorological process of cold air katabatic wind feedback.

  216. tallbloke says:

    I’d like to know more about how far the weight of continental ice sheets push the land mass under them downwards.

    I’m not getting anything sensible from the National Geographic website though…

    https://www.nationalgeographic.org/encyclopedia/ice-sheet/

    The Antarctic ice sheet is about 2 kilometers (1.2 miles) thick.

    Both the Antarctic and Greenland ice sheets have caused the land under them to sink. Eastern Antarctica is about 2.5 kilometers (1.6 miles) below sea level because of the colossal weight of the ice sheet above it.

  217. Philip Mulholland says:

    I’d like to know more about how far the weight of continental ice sheets push the land mass under them downwards.

    tallbloke,
    If you’re looking for hard rock numbers try this paper:
    Stern, T.A. and ten Brink, U.S., 1989. Flexural uplift of the Transantarctic Mountains. Journal of Geophysical Research: Solid Earth, 94(B8), pp.10315-10330.

  218. tallbloke says:

    Thanks Philip. Looks like the answer is… complicated. Lol.

  219. Philip Mulholland says:

    No problem.

    The Antarctic ice sheet is about 2 kilometers (1.2 miles) thick.

    I think that number is a tad low. More like 3 plus.
    Have a look at this paper:

    Sugden, D.E., Marchant, D.R. and Denton, G.H., 1993. The case for a stable East Antarctic ice sheet: the background. Geografiska Annaler: Series A, Physical Geography, 75(4), pp.151-154.

  220. tallbloke says:

    Thanks again. Ned has been saying the Arctic froze a lot more than 2.5Mya too. Hopefully, he’ll tell us more about that.

  221. Ned Nikolov says:

    What DaveBurton describes above about higher snowfall & accumulation occurring at places such as Greenland and Antarctica when the Planet has warmed is a trivial matter, and it’s NOT what I tried to convey with my statement “Ice accumulation is caused by LOW temperatures. Ice does not cause the low temperatures!“.

    Here is what I meant: A warmer Erath (as at present) causes more evaporation and has a higher atmospheric moisture content on average than a cooler Earth (as during the Ice Ages). Because of that, as long as there are places on Earth (such as the Poles) that have subfreezing temperatures for most of the year, the moist air carried by currents from warmer (above-freezing) regions will produce more snowfall and cause more ice accumulation in subfreezing regions. However, if the temperature of these cooler regions (like the Poles) is raised above freezing by a forcing such as high air pressure, the increased amount of moisture carried by currents will fall down as rain and there will be NO ice accumulation. The Antarctic Dome C record shows that the rate of ice accumulation was 2.4 to 3 times higher during interglacial warm periods compared to glacial maxima. That’s because glacial maxima were globally much cooler and as a result, had a much drier atmosphere due to a globally reduced rate of evapo-transpiration than the interglacials. Yet, despite an overall reduced snowfall during glacial times, we had a huge accumulation of ice in continental ice sheets like Laurentide in Canada that do not exit today. These ice sheet grew as snowfall was decreasing. Why? Because the temperatures in those regions fell and the length of time in a year with subfreezing weather increased significantly! Conversely, when the temperature increased above freezing for most of the year in during the deglaciation period, the Laurentide ice sheet started to melt and totally disappeared within 10,000 years:

  222. Ned Nikolov says:

    So, this is how the temperature controls ice accumulation & ice-sheet formation. For example, there was plenty of moisture in the early-Eocene atmosphere (56 – 48 My ago), much more than in our current atmosphere! Yet, there was no snowfall and no ice accumulation anywhere on Erath during those times, because temperatures were way above freezing year-around everywhere.

  223. Pablo says:

    Jim Steel on migration of ITCZ :

  224. Ned Nikolov says:

    Roger (tallbloke),

    Here is the reference to the study, which found based ice-rafted debris that Greenland/Arctic glaciation began some 44 – 41 My:

    Tripati, A., Darby, D. (2018) Evidence for ephemeral middle Eocene to early Oligocene Greenland glacial ice and pan-Arctic sea ice. Nat. Commun. 9, 1038.
    https://www.nature.com/articles/s41467-018-03180-5

    This is exactly the time period, where our model predicted that the annual Polar temperatures should have fallen below the freezing point (273 K) while assuming a decreasing pressure being the driver of the giant cooling for the past 50 My. See this portion of our video:

  225. Philip Mulholland says:

    because temperatures were way above freezing year-around everywhere.

    Ned, Once mountain building commenced during the Tertiary after the Cretaceous hiatus, then with the standard environmental lapse rate of 6.5 K/km any polar land mass e.g. Antarctica with an average lowland summer surface temperature of +26 Celsius will have a freezing point elevation of 4,000 metres. So once mountain building in Antarctica exceeds this height south of 80 degrees latitude where the winter night is longest, then permanent perennial snowfields with their high albedo surface that can survive the 24 hour long summer day become possible. Great Ice sheets from little glaciers grow 🙂

  226. Philip Mulholland says:
  227. Ned Nikolov says:

    Phillip,

    Yes! Terrain elevation causes the air temperature to drop. However, a higher overall pressure moves the freezing point to a higher altitude. Any mountain that’s taller than the freezing altitude set by total pressure will experience snow fall and a potential ice accumulation. During the early Eocene, the existing high atmospheric pressure (due to a much larger total atmospheric mass then) lifted the freezing point to an altitude that was higher than any mountain on Earth. Hence, there was no snow and ice at any place on the Planet at that time.

  228. Philip Mulholland says:

    During the early Eocene, the existing high atmospheric pressure (due to a much larger total atmospheric mass then) lifted the freezing point to an altitude that was higher than any mountain on Earth. Hence, there was no snow and ice at any place on the Planet at that time.

    Ned,
    Thermal lapse rate is NOT a function of pressure.

  229. Stephen Wilde says:

    Ned,

    Can you link changes in total atmospheric mass to ice ages ?

    I agree with you as regards distance from sun and atmospheric mass (leading to a decline in density and pressure with height) as setting the baseline surface temperature for any planet with a gaseous atmosphere but I don’t have any problem with variations above and below that number becoming quite substantial as a result of orbital changes combined with internal system variability.

    Apart from distance from sun and atmospheric mass, one has the issue of albedo to consider because albedo changes mimic the effect of changing distance from sun by altering the proportion of incoming energy actually absorbed.

    Ice is very reflective so that characteristic would have significant effects on albedo and would exaggerate the effects of chaotic internal system variability.

    Note that the thermal lapse rate slope is a a result of declining density with height with the decline in pressure a secondary feature.

    It is actually the decline in density with height that creates the thermal lapse rate because the reduction in density allows more conversion of KE to PE as one moves upwards. That conversion occurs in parallel with the reduction of pressure because reduced pressure is an indication of more space available for the molecules to occupy which allows more PE to be created from KE when they move further apart. It is the moving apart that reduces KE to create the thermal lapse rate slope’.

    You are observing a correct relationship but it is not one of causation.

    The decline in density with height is in turn created by the way gravity organises the mass of the atmosphere into lowest density at the top and highest density at the bottom.

  230. Ned Nikolov says:

    Phillip,

    I did NOT say that the lapse rate was a function of pressure! What I meant (and thought you’d get without me explaining it) is that a higher pressure (i.e. more atmospheric mass) increases the altitude of the tropopause and the total atmospheric depth. This lifts the freezing point toward a higher altitude without changing the lapse rate…

    Why do I have to spell out every little detail in this discussion?? 🙂

  231. brianrlcatt says:

    Barometric Equation of the Barometric formulae says it is.

    Climatology 101. Ned taught me that. but its is absolutely solid climate physics, unlike UN IPCC virtual reality models.

    BUt I suggest submarine volcanoes are the primary variable cause of the Milankovitch climate cycles, because of orbital forcings other effect, Gravitational cyclic changes that create variable solid rides and much increased ocean warming from submarine volcanoes at this time, as observed by Kutterolf et al., Not a qualitative idea, quantified in my paper, and Ian Plimer has just written a book discussing this possibility amongst other subjects.

    Not to detract from Ned’s other work on what determines, and what controls, SST, TSI and gravity plus the oceans, GHE of CO2 is a tiny and easily neutralised perturbation to the lapse rate..etc.

  232. Ned Nikolov says:

    Stephen Wilde,

    Yes, we have linked directly changes in atmospheric mass to the Ice Ages, because changes in surface air pressure (which we’ve shown to explain the polar amplifications observed in the geological during glacial cycles) is basically equivalent to changes in total atmospheric mass. That’s because surface pressure P is a function of total atmospheric mass M, planet’s surface area (A), and gravitational acceleration (g): P = (M/A)*g. If A and g are constants, then P is only a function of changes in M. Watch our paleoclimate video for details:

    Regarding the thermal lapse rate in the troposphere, it is NOT caused by change in air density but by change of pressure with height. This is basic atmospheric thermodynamics not disputed in science. I provide the math explanation of the tropospheric lapse rate in my video:

    Demystifying the Atmospheric Greenhouse Effect: https://vimeo.com/602819278

  233. Stephen Wilde says:

    Ned,

    One can use the decrease in pressure in the equations because the decline in pressure exactly follows the decline in density. That is why the relationship is not disputed but here I am considering causation.
    To work out what is really going on it is more useful to link the lapse rate to the decline in density.
    The reason it is more useful is that density variations govern convection which is the process that leads to the enhanced surface temperature within higher pressure environments.
    If there were no convection the surface temperature would be the same as the top of atmosphere temperature and that temperature would be predicted from the S-B equation. The atmosphere would behave like an isothermal, transparent solid and there would be no lapse rate because conduction upwards from the surface would eliminate it.
    One only sees a lapse rate develop when convection begins and it is that convection which warms the surface above S-B.
    Convection converts KE lower down to PE higher up which produces the lapse rate slope because PE does not register as heat.
    The lapse rate slope marks the changing balance from KE to PE as one moves upwards.

    Separately I would be interested in a link to data showing that atmospheric mass varied with the onset and cessation of ice ages. I know that atmospheric mass declined over geological time but not that it increased periodically.

  234. Stephen Wilde says:

    Ned,

    I have now watched your video.
    I accept that atmospheric mass has declined over the aeons and that the surface temperature has dropped as result.
    I note that eventually the temperature dropped to a point where ice ages became possible.
    I also note your idea of ‘polar amplification’ by which I think you mean that higher pressures at the poles are indicative of increased total atmospheric mass.
    It is that point which I have difficulty with.
    Higher polar pressures can result from more vigorous global convective overturning with correspondingly lower pressures at the equator but no significant change in total atmospheric mass.
    I think it more likely that the ice ages do not necessarily result from a change in total atmospheric mass but rather a redistribution of the available mass following Milankovitch variations in insolation amplified by internal system variability which involves chaos theory as well as albedo effects from ice cover changes.
    You do have a new climate paradigm linking atmospheric pressure to the so called greenhouse effect but I doubt that it helps us with ice ages.
    However, without convection resulting from pressure differentials in the horizontal plane your hypothesis does not appear to explain the surface temperature enhancement.
    In my humble opinion I think you have a valid observation of the effect of atmospheric mass leading to the ATE but not the explanation.
    Philip Mulholland and I have submitted the underlying explanation.

  235. Pablo says:

    SW,

    ‘One only sees a lapse rate develop when convection begins and it is that convection which warms the surface above S-B.”

    Gravity gives a lapse rate of 10°C/km.
    Thorough mixing of air gives that lapse rate.
    Latent heat reduces it.
    Theoretical radiative transfer in the absence of convection gives super adiabatic lapse rates which create instability for convection to begin.

  236. Philip Mulholland says:

    “the altitude of the tropopause and the total atmospheric depth. This lifts the freezing point toward a higher altitude without changing the lapse rate”

    Ned,
    I am not trying to be difficult, I really do not understand this point.
    In its basic form a thermal lapse rate is a ΔT divided by a physical distance (it is a gradient).
    So, if we measure temperature at the ground and increase the height of the troposphere, but maintain the tropopause at the same temperature, then the lapse rate must change because the gradient has changed by definition.
    If on the other hand as you raise the height of the tropopause and its temperature falls because mass is rising against gravity then the lapse rate gradient remains constant and the elevation of the freezing level is also constant for a given surface temperature.
    The point Stephen and I are trying to make is that the troposphere is a “boiling pot” of ascending and descending air with a lid at 100mb.
    It is the motion and interplay of kinetic and potential energy that defines the thermal lapse rate of this system.
    Robinson, T.D. and Catling, D.C., 2014. Common 0.1 bar tropopause in thick atmospheres set by pressure-dependent infrared transparency. Nature Geoscience, 7(1), pp.12-15.

  237. Ned Nikolov says:

    Stephen Wilde @ January 10, 2022 at 10:11 pm

    I’ll be frank with you and tell you that what you said above totally lost me! Where did you get the crazy idea from that by “polar amplification” I meant “higher pressures at the poles are indicative of increased total atmospheric mass“, when I never said anything of the sort in my video??!!

    Polar amplification simply refers to an observation in the geological records that variations of Polar temperaures have always been larger in amplitude than variations of Equatorial temperaures during past climatic transitions such as the glacial cycles of the last 800 ky. Our model equations derived from NASA planetary data accurately reproduce independently measured polar amplifications in the geological record upon assuming that changes of total atmospheric mass and surface pressure were the driver of the global average surface temperature during the Ice Ages. This successful reproduction of observed polar amplifications is evidence that pressure was indeed the driver of the Ice Ages… How could anyone get confused about such a basic fact discussed in my video??

  238. Ned Nikolov says:

    Phillip, to answer your question, please watch “Demystifying the Atmospheric Thermal Effect” again starting at 30:00 min mark, and pay attention to the equation describing the height of a pressure/temperature layer in the troposphere as a function of surface temperature To and surface pressure Po. Keep in mind that changing surface pressure Po causes a change in the surface temperature To as well:

  239. Philip Mulholland says:

    “You only need to post the direct links to the images without the markup language,”

    Like this?

  240. Philip Mulholland says:

    Ned,
    With respect I have watched your video and I still don’t understand why you say that my example is wrong.
    If the summer temperature at the South Pole in the Eocene at sea level is 26 Celsius and the environmental lapse rate is 6.5 K/km then the freezing point elevation is 4,000 metres. The Transantartcic Mountains grew in elevation during this period so at some point their elevation reached the summer frost level. The point I want you to acknowledge is that adiabatic lapse rate is a gravity controlled feature of a planetary atmosphere (-g/Cp = 9 K/km).

    p.s. I noticed that your image of Titan in your montage is the composite surface image. The image above shows the true nature of the featureless shroud of Titan.

  241. tallbloke says:

    Yes, like that. Lovely image by the way.

    Reduction in cloud responsible for most of the warming since 2000, as revealed by CERES data analysed by my friend Fritz Vahrenholt and his colleague Hans-Rolf Dübal.

    https://www.mdpi.com/2073-4433/12/10/1297

  242. Ned Nikolov says:

    Phillip,

    You misinterpreted my comments above as if I claimed that a higher pressure would change the tropospheric lapse rate. It will not, and I never said or implicitly claimed anything like this.

    It you increase the surface pressure Po by adding more mass to the atmosphere, this will also increase the surface temperature To. Increasing To or Po or both will cause all temperature/pressure levels to move up in altitude including the tropopause, because the atmospheric volume will expand in response to such changes. The altitude of a pressure level Z depends linearly on To and non-linearly on Po, and is described by the 3rd equation at the bottom of the slide shown at the 37:19 min mark in the video.

    So, the conclusion from all this is that a higher pressure during the early Eocene has shifted the freezing (0.0 C temperature) level to a higher elevation than any existing mountain peaks, which is why there was no ice anywhere on Earth at that time, although I’m not sure how tall the highest peak in Antarctica was at that time.

    I hope you understand now… 🙂

  243. Ned Nikolov says:

    Roger,

    The reduction of cloud albedo since year 2000 visible in the CERES data record explains not most but all of the warming observed over the past 20 years. I’ve shown this numerically in my video “Role of Albedo in Climate“:

  244. Ned Nikolov says:

    Something really cool: the BedMachine Antarctica Project University of California (Irvine) produced the first hi-res topography map of Antarctica under the ice. We can now see the Southern Continent as it looked when it was roamed by dinosaurs some 90 – 100 My ago:
    https://scitechdaily.com/high-precision-map-shows-what-the-land-looks-like-under-antarcticas-ice-sheet/

  245. Ned Nikolov says:

    Antarctica without ice:

  246. Ned Nikolov says:

    2020 Paper: Temperate rainforests near the South Pole during peak Cretaceous warmth (some 90 My ago at paleolatitude 82 deg S). Note that climate models require way more CO2 to produce this warmth than inferred from the geological record:
    https://www.nature.com/articles/s41586-020-2148-5.epdf

    According to our estimates, it was an atmospheric pressure of 3.0 – 3.2 bar (300 – 320 kPa) that caused this Polar warmth during that Cretaceous period.

  247. tallbloke says:

    Ned: Antarctica without ice

    Is that before or after post-glacial uplift?

    The reduction of cloud albedo since year 2000 visible in the CERES data record explains not most but all of the warming observed over the past 20 years. I’ve shown this numerically in my video “Role of Albedo in Climate“:

    I’ve watched your Albedo video twice now. It’s excellent. I just flagged up Fritz’ paper as it mostly agrees with your assessment.

  248. Philip Mulholland says:

    Ned,
    That is a great map, thanks for posting. It is a representation of Antarctica in the Cretaceous with a high sea level, flooded continents, low 1,000 metres tall TAM peaks and No Ice. Absolutely no problem, that is what I expect for the Cretaceous!

    However I am talking about the Miocene ice initiation event when the BAM mountains had grown significantly taller due to Tertiary orogeny. My simple arithmetic of thermal gradient and vertical distance says that if the peaks grow to a height of 4,000 metres then there will be a cold enough environment at the summits for perennial snow near the South Pole.

    My concept is Mount Kilimanjaro at the South Pole 25 million years ago, that’s all.

  249. Ned Nikolov says:

    Fellows,

    The Antarctica map without ice I posted, was created using modern radar data. This is how the topography of Antarctica looks like now under the ice! I only mentioned the Cretaceous (100 – 90 My ago), because Antarctica had no ice back then. The sea-level was probably 100 m or so higher than today, so during the Cretaceous, there were probably a bit less land exposed above the ocean than at present. Read the article: https://scitechdaily.com/high-precision-map-shows-what-the-land-looks-like-under-antarcticas-ice-sheet/

  250. Ned Nikolov says:

    Phillip,

    I get what your are saying and I agree. However, it’s likely that the glaciation of both Arctic and Antarctica started during the Eocene some 40 My ago according to new evidence from ice-rafted debris and our model calculations. See my comment above:

    https://tallbloke.wordpress.com/2022/01/03/ned-nikolov-dispelling-the-milankovitch-myth/comment-page-1/#comment-174927

  251. Stephen Wilde says:

    Ned,

    Thank you for this clarification:

    ‘Polar amplification simply refers to an observation in the geological records that variations of Polar temperaures have always been larger in amplitude than variations of Equatorial temperaures during past climatic transitions such as the glacial cycles of the last 800 ky. Our model equations derived from NASA planetary data accurately reproduce independently measured polar amplifications in the geological record upon assuming that changes of total atmospheric mass and surface pressure were the driver of the global average surface temperature during the Ice Ages. This successful reproduction of observed polar amplifications is evidence that pressure was indeed the driver of the Ice Ages ‘

    But variations of Polar temperatures would be larger than variations of Equatorial temperatures simply because the area receiving energy from the equator is much smaller than the area near the Equator sending energy to the Poles.
    There is no need to assume a change of total atmospheric mass to account for it.

  252. Stephen Wilde says:

    Roger,

    I was interested to note that apparently there was a drop in cloudiness after 2000.
    I had previously noted that there was a drop during the 80s and 90s but that there had been a partial recovery around 2000 or so.
    Do you have a link to the whole record from say 1980 to 2020 ?
    This is important because it may signify that the solar effect on lengthening jet stream tracks has not yet produced enough of an increase in albedo to start a cooling trend.

  253. Ned Nikolov says:

    Stephen Wilde,

    Your comment about Polar Amplification made me laugh really hard… 🙂

  254. Aequitas says:

    Ned, I am going to give you a wild hypothesis on where one third of the atmosphere went during and ice age.
    Let’s say the atmospheric pressure over the earth is relatively uniform, and the density of air using the ideal gas law is:

    Density = Pressure/ (Gas constant R times Absolute Temperature)

    Let’s also say the temperature at the poles in an ice age is -100C or 173K and at the equator 20C or 293K. So the ratio in density between the two at constant pressure due to the temperature is 173/293=0.59 . So if enough air at the poles is compacted densely then the pressure over the entire earth will drop but the density ratio will stay the same. The air composition does not change. It’s crazy and says nothing about how such a condition could occur or sustain itself over time. But the air is still on the earth in the same composition, it just is compacted near to the poles. When the earth heats up everything goes back to our normal. Like I said “wild”.

  255. tallbloke says:

    StephenW: Do you have a link to the whole record from say 1980 to 2020 ?

    See fig 14 in https://www.mdpi.com/2073-4433/12/10/1297

  256. Stephen Wilde says:

    Ned,

    Happy to amuse you but not sure why.
    Do you not see that since the poles are receiving descending air that originally lifted off around the equator then the thermal consequence of the descent per unit area at the poles will exceed the thermal consequence of the ascent per unit area at the equator ?

  257. Stephen Wilde says:

    Roger,

    Thanks for that.
    Fig 14 seems to show a big drop in cloudiness ending around 2002 or so and a modest recovery from 2002 to 2020 unless I have misread it. Have I misread it ?
    It is that recovery that coincides with the increase in jet stream meridionality around 2000.
    It is still well below the 1980s level which is why cooling has not yet become established but the warming trend seems to have almost faded away.

  258. Ned Nikolov says:

    Aequitas,

    The degree of compaction of air has no effect on surface pressure (P), because the latter depends on the atmospheric mass over a unit area (M/A) and gravity (g), i.e. P = (M/A)*g. So, it makes no difference for the surface pressure, how dense the air is as long as the M/A ratio remains unchanged. Total pressure can only be changed by either increasing or decreasing total atmospheric mass. That’s it!

  259. Ned Nikolov says:

    Aequitas,

    Also, it’s physically impossible to “compact” 30 kPa worth of air mass in one spot like the Poles while the rest of the Planet is deprived of air mass! That’s because the atmosphere is interconnected fluid. This means that any increase of pressure in one region at the expense of another will create a pressure gradient that will cause winds (airflow) from the high-pressure region to the low-pressure one. This happens in the atmosphere all the time…

  260. tallbloke says:

    Stephen W; That’s also what the Palle et al Earthshine Project found too. A drop followed by a slow recovery but still below 80s levels.

    I do think you’ve misunderstood this though:
    Do you not see that since the poles are receiving descending air that originally lifted off around the equator then the thermal consequence….

    The air that lifts off at the equator descends all dry and hot at the Horse latitudes and in the Sahara desert, at the Hadley cell boundaries.

  261. Philip Mulholland says:

    The air that lifts off at the equator descends all dry and hot at the Horse latitudes and in the Sahara desert, at the Hadley cell boundaries.

    Tallbloke,
    Absolutely true for fast rotating planet Earth. However the mechanical Ferrel cell provides a second zone of uplift in the cold cored cyclones of the Temperate Zone. Stephen’s area of uplift versus area of down-draft relationship still holds true.
    In a very real sense the Polar Vortex with its descending air is an “upside down cyclone” It drains dry air from the TOA and heats it by adiabatic auto-compression during forced air descent.

    We see this example of descending air energy delivery to the polar surface in my record of temperature profiles made at Dome Argus.

  262. tallbloke says:

    Ned: any increase of pressure in one region at the expense of another will create a pressure gradient that will cause winds (airflow) from the high-pressure region to the low-pressure one. This happens in the atmosphere all the time…

    It’s also why the tropopause is at a much greater altitude over the warm tropics where air density is lower, than it is over the cold poles where the density of air is higher. Pressure equalises at the surface so there has to be a greater column depth where the air is less dense.

  263. tallbloke says:

    PhilipM: We see this example of descending air energy delivery to the polar surface in my record of temperature profiles made at Dome Argus.

    The other fascinating detail from your Dome Argus records is the 10m subsurface temperature, which closely matches the temperature at the tropopause. It makes me wonder if there might be some reason why they are in approximate balance, or whether it’s merely a random coincidence.

  264. Philip Mulholland says:

    The other fascinating detail from your Dome Argus records is the 10m subsurface temperature, which closely matches the temperature at the tropopause. It makes me wonder if there might be some reason why they are in approximate balance, or whether it’s merely a random coincidence.

    tallbloke,

    Good catch and I think the relationship is real. I keep mentioning the role of the lowest flash-freeze temperature point of super-cooled water in the formation of the upper veil cirrus ice cloud albedo, but there is also the issue of latent heat of crystallization. Once all of the condensing volatile in the atmosphere is solidified then there is no more energy for latent heat fueled convection. Consequently there is an upper lint to convective lift and this means that there is also an upper limit to ice cap surface elevation growth. It is no accident that the 4,000 metre elevation surface of Dome Argus is one of the driest (i.e low humidity) environments on planet Earth.

  265. Stephen Wilde says:

    Roger

    After descending at the Hadley cell boundary it then goes through the Ferrel cell and to the Polar cell. I was keeping it simple.

  266. Stephen Wilde says:

    Anyway, the point is that the idea from Ned that there is a periodical change in total atmospheric mass from ice age to interglacial and back again does not seem to be evidenced but merely assumed and as I pointed out above that assumption is not necessary.
    It is correct that there has been a fall in atmospheric mass since the Cretaceous but that is on an entirely different timescale.

  267. Pablo says:

    This is interesting.

    “Conclusions
    This Hadley cell analysis shows us that most of the latent heat that is transported upwards in the tropics, is radiated into space in the subtropics, from an altitude of 1,5 to 5 km. Only for a minor part it is radiated into space from the tropopause, while floating to the subtropics.

    This means that the standard greenhouse gas effect explanation is wrong.

    The analysis does not prove the existance of a thermostat in the Hadley cell.
    On the other hand, it is consistent with the presence of the tropical thunderstorm thermostat as described in the hypothesis of Eschenbach.”

    https://climatetheory.net/10-the-standard-greenhouse-theory-reconsidered-the-hadley-cycle/

  268. Ned Nikolov says:

    Stephen Wilde,

    In my paleoclimate video, I presented a numerical proof based on physics and nonlinear relationships derived from NASA planrtary data that pressure variations MUST be the driver of the Ice Ages. I also showed numerically that Milankovitch cycles and the resulting changes of solar insolation have no relationship to global temperature variations during the last 800 ky. You and others, on the other hand, presented verbal stories not backed by any physics-based calculations while naively believing that, whatever “makes sense” to you from a standpoint of your limited understanding about drivers of atmospheric mass, must be true… This is a classical example of “hand-waiving” in science, which as an argument has no real weight as far as evidence is concerned!

    I’m amazed at the inability of some people to let go of preconceived old notions in the face of numerically indisputable new evidence! But then again, this is one of the reasons, why the ridiculously silly “Greenhouse theory” has survived for over 120 years! 🙂

  269. Philip Mulholland says:

    Ned,
    Milankovitch astronomical climate cycles occur throughout Geologic time;

    Abstract
    Periodic changes in depositional environments due to Milankovitch astronomical climate cycles can cause cyclic patterns in sedimentation properties as recorded by logging data. Ocean Drilling Program Site 801 recovered Callovian (upper Middle Jurassic) through Valanginian (Lower Cretaceous) clayey radiolarites, originally deposited in a near-equatorial setting. Cycles of variable concentration of radiolarians and clay, and associated changes in degree of silicification were apparent in the geophysical logs, especially in the gamma-ray signal and the Formation MicroScanner. Three-dimensional spectral analysis was performed on the gamma-ray log signal using a 40-m sliding window. The dominant spectral peaks maintain the same relative ratios in frequency as the 413-k.y., 123-k.y., and 95-k.y. Milankovitch periods of eccentricity. The wavelengths of these eccentricity-modulated cycles were used to determine rates and discontinuities in sedimentation with depth.
    Two sharp discontinuities in sedimentation rate were inferred: (1) Callovian alternations of red radiolarite and claystone, with a sedimentation rate of approximately 14.5 m.y., is terminated by a Callovian/Oxfordian boundary hiatus, and the overlying upper Oxfordian through lowest Tithonian clay-rich radiolarites and the lower Tithonian banded chert have an average sedimentation rate of 7 m/m.y.; (2) a discontinuity of probable late Tithonian-early Berriasian age terminates the Tithonian banded chert; the overlying Berriasian through Valanginian radiolarite has a mean sedimentation rate of 11.5 m/m.y. These computed sedimentation rates and interpreted discontinuities are consistent with the stratigraphy of the recovered sediments and the uncertainties in the geological time scale.
    Eccentricity cycles identified in the gamma-ray signal were matched to corresponding features on the Formation MicroScanner high-resolution imagery of clay content and degree of silicification. Eccentricity cycles are manifested as groupings of beds of higher radiolarian content and silicification. Milankovitch climate cycles may affect the intensity of equatorial Pacific upwelling, hence the surface productivity of radiolarians, and the amount of eolian dust and clay contributed to the sediments

    Molinie, A.J. and Ogg, J.G., 1992. 30. Milankovitch Cycles in Upper Jurassic and Lower Cretaceous Radiolarites of the Equatorial Pacific: Spectral Analysis and Sedimentation Rate Curves1.

  270. oldbrew says:

    2009 study:
    Now, Drysdale et al. (p. 1527, published online 13 August) offer firmer constraints on the timing of the penultimate deglaciation, by correlating a difficult-to-date marine record of ocean volume to a precisely datable nearby speleothem (terrestrial stalagmite). Ocean volume began to increase about 141,000 years ago, thousands of years before the rise in 65°N summer insolation. [bold added]

    DOI: 10.1126/science.1170371

  271. Ned Nikolov says:

    Phillip,

    I know very well that Milankovitch cycles have operated throughout the geological history. No one disputes this! The orbital model by Laskar et al. (2011) reconstructs these cycles going back 250 My ago… However, the issue is that there is NO evidence showing a physically meaningful relationship between Milankovitch cycles and changes of Earth’s global temperature throughout the geological past on any time scale!

    The paper you quoted above (like many other studies before) only reports an approximate match of frequencies between eccentricity variations and the sedimentation rate of some minerals. However, frequency (spectral) analyses cannot prove causation! We live in a World, where everything moves in cycles. Hence, finding matching frequencies between fluctuating time series is not surprising, and does not imply that one oscillating series controls/drives the other. Only analyses performed in the time domain can address causation.

  272. Philip Mulholland says:

    Ned,

    I believe that you are focused on air temperature as a fundamental variable to the exclusion of all other possible causes of planetary environmental change.
    In the paper I cite a possible link is made to ocean current variations of the Equatorial Pacific Ocean.

    In another paper by Lena Golovneva she suggests that up-welling of warm water in the Arctic Ocean explains the high latitude heat of the Cretaceous polar region.
    We have good geologic evidence that in the Cretaceous the bottom water temperature of the abyssal ocean throughout the world was 16 Celsius, this explains the occurrence of anoxic bottom water and oil shale formation in the Arctic Ocean during the Lower Cretaceous.
    The presence of the Tethys Ocean throughout the Cretaceous created this warm dense global bottom water.

    I am not averse to the idea that air pressure was higher in the Cretaceous, the issue I have is the rapidity of the pressure fluctuations required in the Pleistocene. The issue of the Argon/ Nitrogen Ratio and the rate of pressure change with the requirement for a replenishment gas reservoir is the biggest no go for me.

  273. tallbloke says:

    Ned: there is NO evidence showing a physically meaningful relationship between Milankovitch cycles and changes of Earth’s global temperature

    The two plots you made below, in the time domain, taken together, show that interglacial warmth comes about when eccentricity is high AND northern hemisphere summer occurs near Earth perihelion.

  274. Ned Nikolov says:

    Phillip,

    Temperature change is the hallmark of climate change, because temperature is an intensive property directly related to the energy content of the climate system. It’s the energy content that controls countess other processes determining the rate and type of environmental change. Ocean currents cannot exit without air currents (winds), and air currents are a direct function of thermal-pressure gradients. A high surface pressure creates a more equable climate with less winds, yet much warmer Poles (because the thermal energy is not just transported by winds, but by convection-induced infrasound waves as well). Venus is an extreme example of the effect of high pressure on surface temperatures and winds (isothermal surface with virtually no surface winds). A low pressure causes larger thermal gradients and stronger winds leading to more vigorous ocean currents.

    The idea that, during the Cretaceous, ocean currents were somehow carrying enormous amounts of Equatorial heat to the Poles to make them 36-38 C warmer than today in the absence of a higher pressure is simply ridiculous from a physics standpoint of view.

    Having a disbelief that pressure could vary significantly on time scales of 10s of thousands of years is NOT an evidence that such pressure changes are not possible or did not occur. The key to a successful science is to always follow the numerical evidence, no matter where it leads!

  275. Ned Nikolov says:

    Roger,

    Look at these graphs again: they show the rate of change (that is the time differentials) of temperature and eccentricity, not warm or cold periods! Also, can you count how many times the insolation peaks at 65 deg N do NOT correspond to warm periods and vice versa how many times warm periods occurred during low insolation? Here is the graph that shows this:

  276. Philip Mulholland says:

    Ned,

    The bottom waters that exit the Red Sea through the Gulf of Aden and into India Ocean are the densest deep water in the modern world ocean, these waters are also the warmest. They occur because of the high insolation of the Red Sea under the clear skies of the descending limb of Hadley cell. The generation of warm waters is independent of the ocean gyre transport mechanism. This is basic Oceanography.

  277. Ned Nikolov says:

    Phillip,

    Without enough pressure to create a high Atmospheric Thermal Effect, there will be no liquid ocean, and no deep warm waters. Cretaceous ocean was 10-12 C warmer at the bottom than our current ocean because of the high ATE on the surface caused by 2.8 – 3.2 bar of pressure.

  278. Philip Mulholland says:

    caused by 2.8 – 3.2 bar of pressure

    Ned,
    At 2.8 bara the boiling point of water is 131.2 Celsius. I am not sure what the relevance of this is for a dynamic system of saline water that is being evaporated by sunlight.
    Boiling points of water at absolute pressures ranging from 1 to 70 bara

  279. Stephen Wilde says:

    Ned,

    You said:

    ‘In my paleoclimate video, I presented a numerical proof based on physics and nonlinear relationships derived from NASA planrtary data that pressure variations MUST be the driver of the Ice Ages’

    Didn’t you also say that the numerical proof depended on an assumption that pressure variations were the driver ?

    I have pointed out that the assumption is not necessarily correct because your observation that, from ice ages to interglacials and back, again pressure varies more at the poles than at the equator (your polar amplification) could simply be the inevitable consequence of three dimensional physics around a sphere. Any thermal effect will naturally be dispersed across a larger area at the equator than at the poles so that the poles must vary more than the equator.

    So what actual evidence (rather than an assumption) do you have that total atmospheric mass varies significantly from a glacial peak to an interglacial and back again ?

    I know of no mechanism that could affect total atmospheric mass on such a short timescale. Do you have one ?

    It is one thing to assume that something must be so. It is another thing to show that it is so.

  280. Stephen Wilde says:

    Ned and Philip,

    It is correct that the weight of the atmosphere affects the energy capacity of the oceans but it is best not to get into discussing the water cycle because if you say that has an effect on surface temperatures then where does that leave our agreed proposition that surface temperature is set only by incoming insolation and the downward pressure exerted by the mass of an atmosphere ?

    The surface temperature has to be the same for both a wet and a dry world does it not ?

    My solution for that was to suggest that the water cycle simply makes it easier for energy to be shifted up and down and around so that as a consequence the vigour of atmospheric overturning need not be so intense for a water planet as it would be for a dry planet.

    It is the rate of atmospheric overturning that adjusts to equalise energy in with energy out and thereby maintain long term hydrostatic equilibrium.

    Variations in that rate inevitably manifest themselves in changes in the intensity and extent of the Hadley Ferrel and Polar cells which affects the locations of the primary climate zones.

    So you do get climate zone shifts from an increase in radiative gases but for CO2 at 0.04% of the atmosphere one would never notice any effect compared to natural internal system variability.

  281. Philip Mulholland says:

    The key to a successful science is to always follow the numerical evidence, no matter where it leads!

    That is the problem with climate science.

  282. daveburton says:

    Stephen Wilde wrote, “variations of Polar temperatures would be larger than variations of Equatorial temperatures simply because the area receiving energy from the equator is much smaller than the area near the Equator sending energy to the Poles…” and, “…since the poles are receiving descending air that originally lifted off around the equator then the thermal consequence of the descent per unit area at the poles will exceed the thermal consequence of the ascent per unit area at the equator”

    That’s an interesting hypothesis, however I can think of a couple of possible “buts.”

    1. But if the latitudinal range over which air descends near the poles is greater than the latitudinal range over which it rose, then the area over which the warmth is distributed near the poles might not really be smaller; also,

    2. But the high-altitude air which circulates northward at the top of the polar cells radiates to space along the way, and loses some of the heat it was carrying when it rose.

    I certainly agree with you that, “the idea from Ned that there is a periodical change in total atmospheric mass from ice age to interglacial and back again does not seem to be evidenced but merely assumed and as I pointed out above that assumption is not necessary.”

    The atmospheric mass change that Ned hypothesizes is not merely unnecessary, it is also impossible. The only mechanism he has identified for the Earth to lose atmosphere (e.g., from Eemian peak to LGM) is about six orders of magnitude too slow. Even among astronomers that’s a problem.

    I also agree with you that Ned’s hypothesis isn’t necessary to explain polar (mostly Arctic) “amplification” of temperature changes. In and near the Arctic, the recent warming seen as Arctic Ocean and North Atlantic ice coverage decreases is mostly due to heat and water vapor released from the ocean. It acts as a sort of thermostat, reducing the temperature of the water before it sinks for the AMOC return trip south, and preventing warming of the deep ocean, but simultaneously warming the air, and adding to cloud coverage. The additional water vapor and clouds increase downwelling LWIR, and slow cooling at the surface, especially at night/winter.

    Additionally (at both poles), since polar air is both colder and drier than air at low latitudes, additional GHGs added to the atmosphere (CO2 & H2O vapor) have a larger relative effect. Colder air loses heat more slowly (per Stefan-Boltzman), so heat added by any means has a more lasting effect on temperatures at high latitudes. Also, where the air is dry there’s less masking of the radiative effects of CO2, on the long-wavelength side of CO2’s 15µm absorption band.

  283. Stephen Wilde says:

    daveburton
    Engaging on your two ‘buts’ would derail this thread so I’ll leave out a detailed comment.
    Suffice it to point our that the polar cells are a whole lot smaller than the Hadley cells and that potential energy in uplifted air is not heat and cannot radiate to space along the way.

  284. Philip Mulholland says:

    Ned,

    I am going to sign out here.
    I believe that by trying to apply your pressure hypothesis to the implausibly short time scale of the ice age cycles you are damaging your fundamentally correct concept.

  285. Aequitas says:

    Ned, your assumption is that the height of the atmosphere is uniform across the planet. This is not the case. It is lower at the poles and greatest at the equator keeping the pressure relatively constant. The temperature density relationship can not be ignored. The temperature does drop for reasons other than pressure. The earth is closer to a steady state system than it is to a thermodynamic equilibrium. The Coriolis effect also tends to keep air masses into various latitudes and prevents total mixing. I was giving you a possible partial solution that did not throw out your entire hypothesis but if you are going to stick to the disappearing reappearing mass of unvarying composition theory then good luck with that.

  286. Ned Nikolov says:

    Stephen Wilde @ January 12, 2022 at 7:00 pm

    You said “I have pointed out that the assumption is not necessarily correct because your observation that, from ice ages to interglacials and back, again pressure varies more at the poles than at the equator (your polar amplification) could simply be the inevitable consequence of three dimensional physics around a sphere.

    Stephen, where in the hell did I claim in my paleoclimate video that pressure varies more at the Poles than at the Equator?? This is absurd! I explained to you in plain English what the Polar Amplification is:

    https://tallbloke.wordpress.com/2022/01/03/ned-nikolov-dispelling-the-milankovitch-myth/#comment-174943

    Why are you twisting my explanation in such a ridiculous manner? Or do you have comprehension issues? 🙂

  287. Ned Nikolov says:

    Aequitas,

    Where did I claim that “the height of the atmosphere is uniform across the planet.”. I’ve NEVER said that, and never assumed it in my calculations, because it’s not true! In my video “Demystifying the Atmospheric Greenhouse Effect” I specifically discuss at one point the fact that the tropopause is higher at the Equator and lower at the Poles due to a differential solar heating, and I do say that the height of the tropopause is an indication of atmospheric volume… I’m really baffled why are you making stuff up about what I’ve actually said. Can you explain?

    Furthermore, what evidence do you have that 21 ky ago the atmospheric composition was the same as it is today?

  288. Ned Nikolov says:

    It sounds like this discussion started drifting in the direction of irrational thought and wildly unphysical hypotheses. Also, some of you began badly distorting what I’ve repeatedly stated here and in my videos. Not sure what’s the reason for this, but it’s becoming unproductive for me stay on this thread any longer. So, I’m going to sign off.

  289. oldbrew says:

    Philip Mulholland says: January 12, 2022 at 3:09 pm

    Molinie, A.J. and Ogg, J.G., 1992. 30. Milankovitch Cycles in Upper Jurassic and Lower Cretaceous Radiolarites of the Equatorial Pacific: Spectral Analysis and Sedimentation Rate Curves.
    – – –
    That’s an interesting paper. Full pdf here:

    Click to access sr129_30.pdf

  290. tallbloke says:

    Ned: can you count how many times the insolation peaks at 65 deg N do NOT correspond to warm periods and vice versa how many times warm periods occurred during low insolation? Here is the graph that shows this:

    As I said earlier, looking at the Milankovitch cycles in isolation from each other isn’t really the best way to assess their effect on Temperature change. I’ve overlaid your eccentricity plot (blue curve) onto your 65N insolation vs Temperature plot so we now have time domain rather than rate of change illustrated.

    Also as I said earlier, interglacial warmth comes about when eccentricity is peaking AND northern hemisphere summer occurs near Earth perihelion (creating the peaks in 65N insolation). You can also see that during troughs in eccentricity the shape and phasing correlation of the Temperature response to 65N insolation is still quite apparent, although of much lower amplitude.

    Thanks for taking part in the lively debate you engendered with your provocative and interesting post. It’s certainly got people thinking harder about this question, and I agree we need to better quantify and elucidate the relationships apparent in the data. Climatic change isn’t caused by single factors, because there are always feedbacks involved in complex systems. It could well be a combination of pressure and orbitally induced insolation changes that are responsible for glacial cycles. Given the 500-2500 year lag period, I think we can be pretty sure the much maligned carbon dioxide molecules have little to do with it.

  291. Ned Nikolov says:

    Roger,

    I saw this “relationship” in the data when I was working on the blog article, which is why I decided to plot the rate of change of eccentricity vs. the rate of change of temperature (my Fig. 8 a & b). But one has to realize these key points:

    1. There is NO real radiative forcing in these matching cycles that can physically explain the observed global temperature variations. Also, the correlation between temperature and these cycles is rather weak as illustrated in my Figures 8b and 10b.

    2. The pattern of “matching” cycles between temperature, eccentricity, and 65 N insolation falls apart for glacial-interglacial periods prior to 800 ky.

    3. The matching cycles cannot explain the observed polar amplification in the geological record.

    4. Assuming pressure was the driver of Earth’s climate on geological time scales perfectly explains the observed polar amplifications not only during the Pleistocene, but also in the early Eocene as demonstrated in my paleoclimate video. This fact tells you that the Pleistocene climate was not driven by radiation, but by an adiabatic forcing.

    Bottom line: The matching patterns between global temperature, eccentricity, and 65 N insolation you pointed out above is “interesting”, but immaterial in regard to the physical causation of the Ice Ages. Point 2 suggests that it might just be a coincidence…

  292. tallbloke says:

    Ned, your points are well made and I’m happy to let you have the final word here. Thanks again for the time you’ve given to this discussion, and all power to you in your research, seeking more empirical evidence to support your hypothesis.

  293. Ned Nikolov says:

    Thank you, Roger!

  294. Stephen Wilde says:

    Ned, you said:

    ‘Our model equations derived from NASA planetary data accurately reproduce independently measured polar amplifications in the geological record upon assuming that changes of total atmospheric mass and surface pressure were the driver of the global average surface temperature during the Ice Ages. ‘

    The polar amplifications were of temperature and you say they were caused by a change of atmospheric mass so I took it that you meant that the higher polar temperature variability was due to higher pressure over the poles from increased total atmospheric mass.
    I pointed out that it was not necessary to assume greater atmospheric mass and explained why.
    Anyway, what empirical support to you have for changes in atmospheric mass on the relatively short timescale of ice ages and interglacials.
    How could it happen?

  295. Ned Nikolov says:

    Stephen Wilde,

    If you watch my paleoclimate video carefully, you’ll understand that the NASA planetary data reveal a nonlinear decrease of meridional temperature gradients (such as between Equatorial and Polar temperatures) with increasing near-surface globally average air density. Since, in planetary atmospheres, the near-surface density depends on total pressure and global temperature, the meridional temperature gradients become ultimately nonlinear functions of global temperature and surface air pressure. In my video, I show the equation describing the nonlinear response surface of the Equator-to-Pole temperature gradient to global temperature and total pressure along with a 3-D graph illustrating that response surface.

    So, according to this relationship derived from NASA data, increasing total air pressure on a planet, shrinks (reduces) nonlinearly the meridional temperature gradients. Conversely, decreasing the total pressure, increases the meridional temperature gradients. Variations in meridional temperature gradients is the the reason for the observed Polar Amplifications, and NASA data indicate that such variations can only be caused by a variable total surface air pressure. I hope you get it now… Watch the paleoclimate video again!

    As for your “explanation” of polar amplifications, it’s simply a conjecture (numerically unsupported story) based on no data, no quantitative model, and really no physics. “Hand waiving” is NOT how you do science, Stephen! I’ve read some of your posts from several years ago on this blog and elsewhere, and it appears that all your concepts are nothing more than unquantified “hand waiving”. Some are physically dead wrong even from a standpoint of standard atmospheric thermodynamics. ​

    Again, here is the link to the paleoclimate video:

  296. Stephen Wilde says:

    All I will say is that my so called ‘handwaving’ as you put it is based on established meteorological principles and observations.
    Meteorology is the study of the way physics plays out within an actual atmosphere and the thing that has always fascinated me about meteorology is that many of the phenomena observed are counter intuitive being out of line with what one would normally expect from the underlying physics.
    We agree on the pressure based description of the ATE but I think you are unwise to extend it to the shorter timescales of glacials and interglacials.
    I do appreciate your efforts in this field and your engagement here.

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