Striking study finds a climate tipping point in clouds

From ARS Technica

We aren’t likely to see it happen, but it’s still sobering.

Scott K. Johnson – 2/25/2019, 6:13 PM

Stratocumulus clouds, like those in the lower two-thirds of this image, are common over the oceans.

Stratocumulus clouds, like those in the lower two-thirds of this image, are common over the oceans.

NASA Earth Observatory

The word “hysteresis” doesn’t immediately seem threatening; it hints at a portmanteau of “history” and “thesis”—a dense read, perhaps, but those never killed anyone. But that’s not what the word means. Hysteresis is a profound behavior some systems can display, crossing a sort of point-of-no-return. Dial things up just one notch, and you can push the system through a radical change. To get back to normal, you might have to dial it down five or six notches.

Earth’s climate system can provide examples. Take the conveyor-belt-like circulation of water in the Atlantic Ocean. Looking back at the past, you can see times that the circulation seems to have flipped into an alternate pattern regarding climatic consequences around the North Atlantic. Switching from one pattern to the other takes a significant nudge, but reversing it is hard—like driving up to the top of a ridge and rolling down into the next valley.

A new study led by Caltech’s Tapio Schneider may have identified a disturbing hysteresis in Earth’s climate—a shift in cloud patterns in response to warming that could quickly heat the planet much further. If we were to continue emitting more and more greenhouse gas, we’d eventually end up running this experiment for real. (Let’s not, please.)

Cloud services

The center of this drama is a particular type of cloud. Stratocumulus clouds typically blanket about a fifth of the low-latitude ocean. Most clouds are formed because air warmed by the Earth’s surface (or forced over mountains) cools as it rises, condensing water vapor to cloud droplets.

Stratocumulus clouds are a little different. The convection that lifts their moisture isn’t driven by warming at the bottom but by cooling at the top.

The water in this cloud deck absorbs much of the infrared radiation emitted upward from the warm surface. The cloud deck re-emits some radiation back downward and some into outer space. The air above these clouds is drier and absorbs much less of the outgoing energy passing through it. That means you can think of these clouds like the cooling fins of a radiator. They shed more heat upward than they receive from the atmosphere above them, allowing them to cool off from the top down. The cold air at the top of the clouds sinks, setting up a convection loop that brings water vapor up from the sea surface to the cloud deck.

So, what happens to this unique process in a warmer world?

Nothing but blue skies

To tackle this, Schneider and his colleagues flipped things around. They utilized a model that can simulate these clouds in a small patch of atmosphere—given a simplified version of the world around them. Specifically, they simulated a patch of the subtropical ocean with stratocumulus clouds above and a neighboring patch of tropical ocean responding to global warming. They did this for varying concentrations of greenhouse gas equivalent to 400 parts per million of CO2 (similar to today) on up to 1,600 parts per million.

Up to about 1,000 parts per million, there were no major surprises. Things got around 4°C warmer and numbers changed for things like water vapor and cloud altitude. But the cloud deck generally looked familiar.

At about 1,200 parts per million, however, the simulated clouds suddenly dissipated. And without that shade reflecting sunlight, the world warmed another 8°C.

Processes responsible for the cloud deck breaking up around 1,200 ppm CO2 in the model. Temperatures shown in units of kelvins.

Processes responsible for the cloud deck breaking up around 1,200 ppm CO2 in the model. Temperatures shown in units of kelvins.

Schneider et al./Nature Geoscience

How is CO2 flipping the switch on these clouds? The researchers found a pair of simple processes working together in their simulation. First, warmer air carries more water vapor up from the sea surface, and when that water vapor condenses, it releases a lot of latent heat. That extra latent heat gives the air a little buoyancy boost, increasing the turbulent movement that can mix dry air from above into the cloud layer. This dries out the cloud deck and makes cloud formation less likely.

Read the full article here.

Advertisements

164 thoughts on “Striking study finds a climate tipping point in clouds

    • What is the ECS of the model they used? Additionally, I’m unaware of any scenario that result in CO2 concentrations at or above 1,000 ppm.

        • Oolitic limestone in the rock record is testament to spontaneous precipitation of calcite oolites when the CO2 level in the atmosphere is high enough. This occurs in shallow continental shelves. It only occurs in 3 places in the world today, Barhia Lagoon, Baja, in Qatar, and one more site I cannot recall. So there is an atmospheric stopping point of CO2 when oolites begin to form and pull CO2 out of sea water, and hence the atmosphere. What that stopping point level is, I have not seen published. Infinite CO2 level in the atmosphere is not possible by that geologic model.

          • So at 1200 ppm clouds dissipate, the top ocean warms, and calcite oolites precipitate. This takes CO2 out of the atmosphere and no feedback further occurs. Okay. Sort of like runaway hysteresis but then a square wave filter for the gain is applied.

          • Oolitic limestone is currently forming on the Bahamas Banks. Andros Island is one of the best modern analogs.

          • Oolites form on many tropical islands and atolls, wherever water is warmed in the shallows. Every beach I have visited in the Bahamas (dozens) has spherical oolite sand. Raising atmospheric CO2 reduces the supersaturation of CaCO3, making formation of oolites less likely, not more.

      • I’m unaware of any empirical evidence in support of the hypothetical effect of CO2 on temperature having ever occurred, so to me the ECS is just BS anyway, no matter where they choose to “set it” in their ASSUMPTIONS.

    • Never. Since they have no means to collect real experimental data to investigate the amount of warming from CO2 and the concomitant downstream climate effects, they have to fabricate the data in some fashion, and using computers to do the dirty work gives that data fabrication a false veneer of credibility.

    • ” The cloud deck re-emits some radiation back downward and some into outer space. ”

      The IR radiation downward is irrelevant as the surface, land or water will always be warmer than the IR from adiabatically cooled clouds. The IR would be reflected back upward because the similar energy levels of the warmer surface are already full. A cool object cannot warm a warmer object.

      Even if we were warming, there would still be this immutable Law of Thermodynamics.

        • I will too and it doesn’t.

          The temperature difference between matter emitting a photon and matter receiving that photon doesn’t affect whether the receiving matter absorbs or reflects it unless the reflectivity is temperature dependent.

          The law of thermodynamics being cited only applies to the relative temperatures of matter in physical contact with other matter. The transfer of energy by photons is fundamentally different from the transfer of energy by matter in contact with other matter.

          • Photons are a kindergarten myth. Learn something about EMR and Poynting vector.

            Matter at low potential (as measured by temperature) cannot transfer energy to higher potential through the electric field and magnetic field that it exists in.

          • RW, watching the debate about whether cooler CO2 does, or does not, warm a hotter earth via IR reminds me of watching Christians debate the trinity. In that discussion there’s this certain nebulous triggering point that if you inadvertently activate trying to get to the truth behind the matter, you are anathematized by the orthodoxy. Not that long ago people were burned at the stake for crossing that line.

            In this discussion that triggering point seems to be whether a cooler substance can warm a hotter substace via IR. I have yet to read a convincing explanation of exactly how that happens.

          • Tim,

            It doesn’t defy SB, but is exactly what SB describes as a gray body whose emissivity, e, is the ratio between the average emissions of the planet and the average emissions of the surface and is equal to about 0.62. The net absorption of surface emissions is then 2*(1-e) = 76%. Half of this is returned to the surface as photons and the remaining half is emitted into space, also as photons.

            Currently, the surface emits about 1.62 W/m^2 per W/m^2 of solar forcing. In the steady state, the first W/m^2 of the surface emissions is replenished by the solar forcing. The extra 620 mw of surface emissions per W/m^2 of forcing is being replenished by energy emitted by the surface absorbed by the atmosphere and returned to the surface at a later time. The delay is crucial to understanding how this all works. It’s not 620 mw of ‘feedback’ power, but is 620 mw of feed forward power which is among the many errors by the consensus that precludes applying Bode’s feedback analysis.

            Additionally, the atmosphere is emitting another 620 mw per W/m^2 of forcing into space. The surface emits about 390 W/m^2 at its average temperature of about 288K. 76% of this is absorbed by the atmosphere (296 W/m^2) and the remaining 24% (94 W/m^2) directly reaches space. To be in equilibrium, the planet must emit 240 W/m^2 which is 146 W/m^2 more than the 94 W/m^2 coming directly from the surface. The 620 mw per W/m^2 emitted by the atmosphere into space is .62*240 = 149 W/m^2. and is a little more than the 146 W/m^2 required owing to rounding.

            This all leads to a trivial falsification of the entire range of ECS presumed by the IPCC. If the atmosphere absorbed 100% of what the surface emits, half of this ultimately leaves the planet while the remaining half is returned to the surface, limiting the emissions sensitivity to 2 W/m^2 of surface emissions per W/m^2 of forcing. Starting from 288K, this corresponds to a theoretical maximum temperature sensitivity of about 0.37 C per W/m^2 which is below the IPCC’s presumed lower limit of 0.4C per W/m^2.

            Another of the many erroneous assumptions made by the consensus is that nearly all of what the atmosphere absorbs from the surface is returned to the surface. This incorrect assumption defies both the physics, the data and basic geometry.

            And yes, a cold body can not heat a warm body by contact and in fact, the atmosphere is primarily warmed by the surface, but the atmosphere does not warm the surface by contact and instead warms it in the same way that the Sun does, which is by photons. These photons originate from cloud emissions and GHG’s returning to the ground state, rather than from the Sun. It couldn’t be any simpler.

          • Rick,

            What experiment do you propose falsifies the existence of photons?
            Do you understand that the Poynting Vector is a macroscopic property of an EM wave?
            Do you also understand that a photon is a particle of EM energy?

            You’re coming from a point of view restricted to planar EMR. There’s a demonstrable equivalence between planar EMR and photons and its called the particle-wave duality. This Quantum Mechanical property is somewhat counter-intuitive, so it’s easy to see how anyone lacking a strong background in Quantum Mechanics can be confused and this includes most climate scientists.

            You might have a better case if you claimed that planar EMR emitted by a radio antenna, while equivalent to a collection of photons is not a collection of photons, but this doesn’t falsify the existence of photons and the Sun, GHG’s and clouds do not emit planar EMR, but emit photons, which paradoxically can also be quantified as a wave. You are going down a very wrong path if you think denying the existence of photons is the answer.

          • Learn about the maximum speed EMR can move and those vectors can build up and down and how fast that can be detected elsewhere.

      • Even if the Earth did absorb the IR it would just re-radiate it. Almost all of the energy balance discussions you find on the net assumes that the Earth just absorbs all that “back radiation” which causes it to heat up but it never re-radiates any of that heat. That’s how the “greenhouse” effect apparently is supposed to work. It’s a violation of the Stefan-Boltzmann equation. As temperature goes up the amount of radiation is supposed to go up as well!

        • Not correct. The assumptions is that the residence time of escaping every is increased by redirecting it back towards the surface. Bit incoming radiation from the sun is constant, thus more net energy.

          Think of it like traffic on a freeway. A certain number of cars get on and off.
          Decrease the cars exiting ( increased residence time ) and there are now more cars on the freeway.

      • As a non-scientist reading this sub-thread, I am mightily confused with the statement, often heard, that the ‘science is settled’.

      • Looks like I could have saved myself the trouble of reading all the way to them mentioning the above if I had first seen it was from ARS.

        • Ars is an AGW echo chamber, bunch of ultra-liberal techies.

          If you try and argue with them, providing links to real data, they will shout you down, swear at you until you say it is not worth the trouble.

          No honest debates, no chance for dialog, just the party line.

          • Yes, I found out many a moon ago not to even bother with any sites run or populated with majority warmistas. Even ten years ago, trying to comment on sites like Sci Am was a waste of time. The comments just vanish.

            I have recently been spending a lot of time on twitter, and that place…dang!
            It is like a prison yard up in that biatch.
            The difference is, there are plenty there from our side, and lots of them are tireless, just like warmista trolls.
            Another even bigger difference about Twitter…you can just block someone. I have finally learned not to even wait…autoblock anyone that starts out rude. Especially if they do not use real name and/or have an actual photo.
            I use my real name there.
            I would here now too, I no longer work for an employer who I have to worry about.

      • For some things you can only do a model

        https://www.youtube.com/watch?v=vzInIjD6nKw

        Of course some people will see the word model and doubt the answer?

        So, when you watched this video above and saw that the guy used a model

        Did you

        A) think ” They lost me at “utilized a model”.”
        B) accept the model
        C) demand that we run an actual experiment with new buildings

        They used a model

        must be a conspiracy

        • Stephen Mosher – If you can accept one model then all models are valid.

          Is that your argument?

          The model you referenced is modeling the Laws the physics. There are no Laws under the Greenhouse Gas Theory, why is that? That’s why it can’t be modeled, it hasn’t been measured yet.

          Perhaps you haven’t seen my comparison of the Theory of Gravity and the Theory of CAGW.

          With the Theory of Gravity, we are still defining how it works, but mankind has been able to measure how it behaves with such precision that the planet Neptune was known to exist before it was ever seen. Man has derived a set of Laws and formulae under the Theory of Gravity which have been applied to land a spacecraft on an asteroid.

          With the Theory of CAGW, detailed explanations are provided to explain how it works, but mankind has not been able to measure anything of significance. Since nothing has been measured, there are no Laws, Axioms, Postulates, nor formulae. There is no science to apply, we cannot even measure how CO2 manifests itself as a Greenhouse Gas on Mars where it makes up 95% of the atmosphere.

          • Nor, when you measure at the altitude where the atmospheric pressure is the same as Earth’s, is there any difference between the temperature of Venus (95.5% CO2 atmosphere) and Earth (0.041% CO2 atmosphere) that can’t be explained by a single difference – the distance from the Sun.

          • Homer to Mosher: If you can accept one model then all models are valid.

            Touché

            i don’t think the gravity is an analog to the CAGW complexity in this debate – but the point made still seems valid

        • They lose us at “used a [CLIMATE] model,” because there IS no “model” that can accurately resemble something which is so poorly understood. That “revelation” simply lets anyone who is conscious know that this “study” is nothing more that a reflection of the unsupported ASSUMPTIONS made by the “modelers.”

        • Steven,

          A broken model must not override first principles physics, yet climate models do this as a matter of course. How else can they support 4.4 W/m^2 of surface emissions (0.8C) per W/m^2 for the next W/m^2 of forcing. while all the other W/m^2 from the Sun only contribute 1.62 W/m^2 to the surface emissions?

          If you think this is wrong, they explain how the planet can tell the next Joule from all the others so it can be amplified up to 4.4 W/m^2 of surface emissions, while all the others are amplified up to only 1.62 W/m^2 of surface emissions?

          If you cite ‘feedback’, then you don’t understand the concept. The only effect of ‘feedback’ is the steady state 0.62 W/m^2 more surface emissions per W/m^2 of forcing, so again, how can the planet tell the next Joule from all the others, so it can be amplified by 3.4 W/m^2 of ‘feedback’ while all the others are amplified by only 0.62 W/m^2 of feedback?

          Perhaps you don’t understand one or more of these basic facts:

          1) 1 Watt is 1 Joule per second
          2) Joules are a measure of work
          3) all Joules can do the same amount of work
          4) it takes work to warm the surface

      • They lost me when they told me I wouldn’t know what ‘hysteresis’ means. And I don’t have a science qualification to my name.

      • “They utilized a model that can simulate these clouds in a small patch of atmosphere—given a simplified version of the world around them.”

        “Up to about 1,000 parts per million, there were no major surprises. Things got around 4°C warmer and numbers changed for things like water vapor and cloud altitude.”

        Selective use of alarmist supportive model components with cherry picked world inputs.
        Coupled with maximum temperature impacts from CO₂ increases.

        Surprise!
        The model results indicate a reachable tipping point!
        But only in tailored simplified models using excessive CO₂ temperature responses.

        Yawn! Just more Santer “Gold standard” “Five Sigma” prestidigitation results.
        i.e. a flim flam.

      • yup
        saw this on science alert last night aus time and was so annoyed i turned the pc off.
        theory and modelling said it all
        wait for the media to fall over themselves to promote this as gospel truth to the faithfully gullible sheepies

    • The solution to the climate problem may be as simple as creating a simplified model which removes CO2 to any desired level which takes advantage of a favorable hysteresis which counteracts their model. Thus, run the two models side by side with the favorable one feeding the unfavorable one and the CO2 problem simple vanishes. Then we can all go back to our day jobs, holidays, vacations and living.

  1. I got lost when I read “The cold air at the top of the clouds sinks, setting up a convection loop that brings water vapor up from the sea surface to the cloud deck.”
    I thought we were talking about strato cumulus – ie very high. How does moisture from the sea SURFACE enter that picture?
    In addition, the part about the CO2 trigger doesn’t explain at all just how CO2 is involved.

    • “… In addition, the part about the CO2 trigger doesn’t explain at all just how CO2 is involved”.
      It’s slick how the article glides seamlessly from CO2 concentrations to degrees C.

    • CO2, AS USUAL, is simply ASSUMED to “drive” temperature, despite NO empirical evidence in support of that assumption, and plenty that refutes the notion.

  2. Oh, fer crise sakes. If this were a possibility it would have happened during the many times in the earth’s past when CO2, and temps, were much higher than today’s.

    More alarmist BS.

    • This is yet another proof that warmistas are allergic to Earth history.
      Hence runaway greenhouse effects, ocean acidification, higher CO2 killing/dissolving coral and shellfish, etc.
      They never take into account the past because they ignore it like it never happened.
      They are History Deniers.

      • No. Actually they state that this can explain previous past climates when the temperatures
        were significantly higher than current levels. This utility of paper is that it can help explain
        past climates rather than what might happen in the future since the CO2 levels at which this might happen are significantly higher than what is predicted under any realist scenario.

        • Yes, it has never been possible to get realistic Eocene climates by current climate models. So this is just a fudge mechnism, to avoid having to take into account of the very different geography and the consequent completely different ocean circulation in the past. Because climate models don’t do oceans realistically, like they don’t do convection-

        • @Percy;
          I don’t see how that works. We have past episodes when CO2 has been higher than today and temperatures have been both higher and lower than today. This mechanism doesn’t cover both cases.

          • Of course not. It’s just more Eco-Fascist speculation to support the “Cause.”

            Menicholas is right. The pseudo-scientists pushing this crap are History Deniers.

            Didn’t Mann say that “you can’t trust proxies older than…” you know, the ones HE likes. You see, there’s just WAY too much “inconvenient” information in the Earth’s climate history once you dig too far back.

            The reason the propaganda pushers want to deride the distant past is, as Jim Carrey said in “Liar Liar,” “Because it’s DEVASTATING to my case!”

  3. Seems like this process is happening over the warmest sections of the ocean right now. They are 3-4°C warmer than many other areas of the ocean, which would be the conditions of the study with increased CO2. Any evidence for reduced clouds above them?

    • Very little, if any, evidence of reduced clouds above at the hottest part of the tropics. I believe Will has shown that the tropics can change little. As the water T reaches a certain level the evaporation thundercloud feedback amplifies very quickly.

      My understanding is that the “study” uses the highest IPCC feedback scenario to reach this level.

      I cannot resist another round of this…
      To the tune of Joni Mitchell’s. Both Sides Now

      Both Sides Now
      Woes and blows to warmist scares
      Excise schemes now in cross hairs
      And weather claxons now despair
      I’ve looked at clouds that way

      We all know that they block the sun
      And rain and snowjobs on everyone
      So many frauds have been done
      But clouds got in their way

      We’ve looked at clouds from both sides now
      From cool and warm, and still somehow it’s
      Warmist delusions I recall
      They really don’t know clouds at all

      Loons and goons with feckless deals
      Are busy advancing their ideal
      And so their fairytales reveal
      We’ve heard them yack away

      But now it’s not supposed to snow
      So we’re laughing as they eat crow
      And polar bears, their numbers grow
      Their fairytales now all show.

      We’ve looked for signs of high tides now
      From near and far, and still no rise
      Somehow its still
      Warmist delusions we recall
      They really don’t know squat at all

      Tears and fears and feeling proud
      To say “It’s bullshit!” right out loud
      Dreams and schemes of circus clowns
      The crooks’ in disarray

      This now transcends just acting strange
      We shake our heads, they’re so deranged
      They’re data’s lost, still
      unexplained
      They make up more, it will ever change

      We’ve heard their crap, from their government grants
      From Ivory towers and brainwashed children all, its
      still somehow Mann’s delusions I recall
      He really doesn’t know clouds at all.

      I’ve looked at clouds from both sides now
      From cool and warm, and taxes they take
      Those warmists really are dirt balls
      They really don’t know clouds at all.

    • Evidence of reduced clouds.
      Not that I know anywhere in the tropics. I remember Willis did a post on how the tropical water cannot go above a certain T due to the amount of evaporation and thunder heads growing exponentially at about 90 degree water.

      Also consider that the tropics are not warming at that rate at all. The major warming, IF it occurs at the extreme high ECS used in this study
      ( very unlikely) will be mostly in the higher latitudes- towards the poles.
      And it will be mostly at night.

      I cannot resist – sung to the tune of Joni Mitchell’s “Both Sides Now” lyrics ?? Some mine
      Both Sides Now
      Woes and blows to warmist scares
      Excise schemes now in cross hairs
      And weather claxons now despair
      I’ve looked at clouds that way

      We all know that they block the sun
      And rain and snow on everyone
      So many frauds have been done
      But clouds got in their way

      We’ve looked at clouds from both sides now
      From cool and warm, and still somehow it’s
      Warmist delusions I recall
      They really don’t know clouds at all

      Loons and goons with feckless deals
      Are busy advancing their ideal
      And so their fairytales reveal
      We’ve heard them yack away

      But now it’s not supposed to snow
      So we’re laughing as they eat crow
      And polar bears, their numbers grow
      Their scams now all show

      We’ve looked for signs of high tides now
      From near and far, and still no rise
      Somehow its still
      Warmist delusions we recall
      They really don’t know squat at all

      Tears and fears and feeling proud
      To say “It’s bullshit!” right out loud
      Dreams and schemes of circus clowns
      The crooks’ in disarray

      This now transcends just acting strange
      We shake our heads, they’re so deranged
      They’re data’s lost, still
      unexplained
      They make up more, it will ever change

      We’ve heard their crap, from their government grants
      From Ivory towers and brainwashed children all, its
      still somehow Mann’s delusions I recall
      He really doesn’t know clouds at all.

      I’ve looked at clouds from both sides now
      From cool and warm, and taxes they take
      Those warmists really are dirt balls
      They really don’t know clouds at all.

  4. “They utilized a model that can simulate these clouds in a small patch of atmosphere—given a simplified version of the world around them. ”

    This is playing computer games, not a scientific activity. It does not porvide us with information about how the planet really functions.

    It is mathematical onanism, and the most likely result is that the authors are going to grow hair on their palms.

  5. So if their computer games reflected reality, why wasn’t there any sort of runaway warming during periods when CO2 was several thousand PPM?

  6. Isn’t it impressive how Climate Crisis Central can blanket the world with a scary message, with enough variety in titles to disguise the robotic repetition? Yet just reading the headlines already suggests to anyone with critical intelligence what is false about this alarm. Let me list some of the obvious flaws before digging into this issue.

    1. It’s a projection from a climate model, not a finding from observations.

    2. It is based on highly uncertain supposed mechanisms.

    3. It presupposes CO2 concentrations 3 times the present level.

    4. The possible effect will occur after almost all readers will be dead of natural causes.

    5. It claims a runaway warming “tipping point” which the earth has suppressed until now.

    6. It contradicts the logic of a warmer world increasing the hydrology cycle with more clouds and precipitation.

    7. It stokes fear of “hothouse earth” when presently we are slowly emerging from “severe icehouse earth.”

    https://rclutz.wordpress.com/2019/02/26/clouding-the-climate-issue/

    • You missed the big one – It ASSUMES that CO2 levels drive temperature. NO empirical evidence supports THAT – the supposed “effect” is purely hypothetical.

  7. And in a computer simulation fantasy, Superma can fly around the Earth and turn time backwards.

    After 600+ million years of no runaway hot house or ice house (snowball earth) with CO2 levels much higher than anything conceivable under fossil fuel burning, and the fact the Earth is still in the Pleistocene, I see little reason to take a positive feedback runaway amplification scenario as anything but a model fantasy.

    The Earth’s climate is robustly stable to strong forcings. That is the only logical conclusion we can draw based on the evidence, not the computer fantasy.

    And the reason for that robust stability is not to be found in the clouds, where these researchers’ heads obviously are (or up their arse). It is because we live on a water planet with vast deep oceans.

  8. “First, warmer air carries more water vapor up from the sea surface, and when that water vapor condenses, it releases a lot of latent heat. That extra latent heat gives the air a little buoyancy boost, increasing the turbulent movement that can mix dry air from above into the cloud layer. This dries out the cloud deck and makes cloud formation less likely.”

    Wait a minute! What happened to the “more water vapor from the sea surface”? Does it all of a sudden just disappear? If it keeps coming up from the ocean then how does the cloud deck dry out? The water vapor coming up from the ocean will just re-hydrate it!

    Something fishy here. Either this is a poor explanation of the actual model methodology or the model has a major hole in it! In either case how did this manage to pass any kind of peer review or editing?

    • “… That extra latent heat gives the air a little buoyancy boost, increasing the turbulent movement that can mix dry air from above into the cloud layer. This dries out the cloud deck and makes cloud formation less likely. …”

      Exactly. The paper is paywalled, sure as eff not paying for it.

      And when that cloud type is gone the humidity will rise again and other cloud types will form.

      And the model they used, did it have day and night? Did it have diurnal change in T and P and humidity plus wind direction changes plus effects of land masses?

      I bet it didn’t as they’ve simplified the model to remove all the other variables to CO2 changing.

      i.e. GIGO

      The humidity will not go away in the natural world.

  9. I believe the use of the word “hysteresis” is incorrect in this article. Wikipedia and other web sites define hysteresis most simply as: “Hysteresis is the dependence of the state of a system on its history.” I believe a more appropriate technical term–consistent with the concept of a “tipping point” as used in the article’s title and “switching” as used in the article’s text–is “metastability”.

    Beyond that, when a mathematical model of a dynamic system suddenly diverges in a metastable manner, one should immediately suspect the accuracy of the model’s mathematics and programmed feedback loops, and not the background physics.

      • “Strike-out study finds a climate tipping point in clouds”

        There, title fixed. You’re welcome.

    • Also the lag observed in some well known cause and effect phenomena – such as (if you look further down in the search results), the lag between an increase in a magnetic field and the magnetization of a chunk of iron. That is what they are using, apparently. The upper atmosphere turbulence happens at a certain temperature, but subsides only at a much lower temperature.

      However, and it is a big however, if the turbulence is real (possibly), they stopped their simulation as soon as they had the results they wanted (i.e., the basis for their next grant). “Drying out” the stratocumulus cloud layer (which is up about to 2,000 meters) will increase outgoing radiation (they are quite correct that less water vapor concentration allows higher outgoing IR). So, I would be willing to bet that, if they were to continue cranking up their model, they would indeed hit a tipping point. Right into the next ice age.

      All hypothetical, of course. As noted by many, empirical evidence says that this does not happen.

    • Gordon,
      If you read the article you will see that hysteresis is correct. They predict that the climate has
      two states and the switch up to the higher temperature low cloud state occurs at >1200 ppm of
      CO2 while the switch down doesn’t occur until the CO2 level drops to below 300 ppm. Both states
      appear to be stable and the climate is bi-stable.

      And again clearly the climate has at least several stable points — ice ages and interglacial being two.
      This paper suggests that there are more and again that is not surprising given that the climate is a
      nonlinear driven dynamical system. If you don’t want a bistable system then you need to argue that the
      climate is linear.

      • Percy, as I tried to point out, the physical occurrence of hysteresis in any cycling system, by itself, does not CAUSE the occurrence of metastable states or “switching” events or “tipping points”, which were the main assertions of the above article’s assertions of happens to clouds as a function of varying atmospheric CO2 concentrations.

        Furthermore, hysteresis describes the state-vector path variation on the beginning half of a closed cycle (“going up”) compared to the state-vector path variation on the ending half of a closed cycle (“going down”). Hysteresis does not, per se, address/analyze the degree of stability of a dynamic system as it changes over a cycle.

        • Gordon,
          You can’t have a hysteresis cycle without switching events or “tipping points”. The cycle
          can only exist if for a range of the control parameter there are two different stable states
          and the only way you can get from one stable state to the other is to drive the system past the
          bistability region at which point it will switch to the other state. And while hysteresis does not address the stability of the two states by definition both states need to be stable for a hysteresis cycle to exist. Typically in such a system there are three possible states — two stable and one unstable one which connects the two. The unstable state is never observed but must exist by continuity.

          • There ARE NO “unstable” states caused by CO2 levels. The paleoclimate record shows temperature is unaffected by the CO2 level, and that no “unstable” climate state could be induced by CO2 levels up to 7,000 ppm, much less 1200 ppm.

          • Sorry, Percy, but you appear to have a total misunderstanding of the physical term “hysteresis”, and I can only gently suggest you read up on it and consult some x-y plots that show the phenomenon for different scenarios.

            One easy-to-see-and-understand example is the hysteresis curve for a piece of rubber that is stretched in pure tension and then relaxed. If one uses a instrumented mechanical tension testing machine, one can plot total tension load versus total displacement (stretch) of the material CONTINUOUSLY over, say, an elongation of 300%. In doing this, if one pauses just a few minutes at any time under any significant load, almost any rubber chosen for this experiment will have a load vs. displacement curve when the tension is being increased that is distinctly different from the load vs. displacement curve when the tension is being relaxed back to zero. There is only one “stable” point for the rubber coupon, and that is when it is not under any applied load. There are NO “tipping points” or “switching events” (as used in the context of the above article re: clouds and CO2) in the total, continuous hysteresis curve from first application of load to final removal of load.

            Reaching a point of maximum displacement and staying there with the tension tester holding fixed elongation is NOT a stable point because the tension is continuously (but asymptotically) decreasing due to the long-term relaxation of the molecular chains comprising the rubber material. And, actually, any rubber that does not suffer a permanent “set” after being stretched to this degree will take seconds to hours (or even days) to have its length return to the starting dimension, even with no applied tension (a characteristic known as the rubber’s “recovery time”, which itself if a function of applied elongation).

            You can simulation the above example, qualitatively, with a simple rubber band.

            Good luck to you.

    • No, they failed right from the start by not even understanding and misrepresenting hysteresis. This is the level of stupid we are dealing with. Arseheadica is the epitome of sophistry.

  10. If there WERE such a thing as run-away warming, or run-away cooling, then the Earth would currently be trapped in hell-like-Venus or Snowball-Earth. It isn’t, so there is no such thing as a run-away anything in our climate system. 3+ billion years of real-live testing demonstrate this. The climate system is stable.

    It has had more than 1,200 parts per million CO2 before. It will likely again. It’s still stable. It may warm some, or cool some, but as long as the sun does not change the input into the system, we live on a stable planet with a stable climate.

    There are a few unstable things. Their model – it’s not stable. Their thinking must not be stable either.

    • Actually, given the apparent periodicity of relatively-long glacial climates interspersed with relatively-long interglacial climates, Earth’s climate is really not stable, but instead varies in a non-smooth, metastable fashion between two general state points: globally cool and globally warm.

      Rarely, the Earth can change from ~100,000 year (was ~41,000 year prior to about 1 million years ago) glacial-interglacial periodicity to intervals lasting 10’s to 100’s of million of years of sustained cold, the true Ice Ages.

  11. I find the author’s perception of the word “hysteresis” a little off. To me, it hints more towards a portmanteau of the words “hysteria” and “uresis” – as in the uncontrollable pissing of oneself while in a state of panic. This version seems to fit more with the general theme of “Climate Change®” articles than the author’s.

    (Sarc off) I’m aware that neither version is anywhere near what the word actually means so, my version is an equally valid interpretation of what the word is “hinting”.

  12. So, what happens to this unique process in a warmer world?

    Judging by the Holocene Optimum, far less El Nino, so a reduced water vapour supply.

  13. Take the conveyor-belt-like circulation of water in the Atlantic Ocean.

    What conveyor belt? M. S. Lozier: Deconstructing the Conveyor Belt. That paper (Science 328(5985), 1507-1511) summarizes experimental evidence that pretty much refutes the conveyor idea.

    Floating buoys at depth have been unable to detect a conveyor belt. See especially Figure 5 in 2002 Carl Wunsch Ocean observations and the climate forecast problem here.

    That figure shows deep water floating buoys off the coast of Brazil jagging around in gyres, rather than embarking uniformly southward, as the conveyor belt model predicts.

    Here’s Wunsch’s abstract: “The widely disseminated and accepted view of the ocean as a nearly-steady, nearly-laminar system is primarily a consequence of the great difficulty of observing it, and of the intense computational cost of modelling it. Uncritical use of the steady/laminar framework has led to a gross distortion of the science, particularly the study of climate change, partly manifested by the belief that a comparatively small number of simple observations suffices to describe the system, and by the inference that oceanic behavior under changed external forcing can be deduced by pure thought without integration of the equations of motion. All of the evidence of the last 25 years shows that the behavior is much more interesting and complex than this distorted view would imply.

    “Real progress will involve confronting the actual system, not the fictitious one.

    Start off with a very wrong physical model, what is the meaning of the simulation?

    That, apart from the fact that climate models cannot model clouds with enough accuracy to resolve any CO2 effect.

  14. You wonder how many models they had to try before they hit on one that gives them this interesting and paper-worthy result. Which of course is the big problem with massively simplified models of complex phenomena – they usually end up saying exactly what you want them to say…

    • All models say exactly what the modelers want them to say. IIRC, UN IPCC modelers are on record as saying they adjust parameters, etc. until they get something that “looks right.” Ya picks your ECS and ya gets what you want.

      On top of that, models tuned to the late 20th Century do poorly in both hindcasts and forecasts. All of the hand-waving in the world by model apologists and data manglers can’t change those facts.

    • It is impossible to “learn” anything from a computer model. The model represents only what the modelers already know, or think they know, or want to pretend they know. No important discovery will ever be made by a computer model. A computer model can never prove anything to be true. I wonder how the authors were able to validate their contention that their model “can simulate these clouds in a small patch of atmosphere”?

  15. In electronics you would use a voltage divider to bias a transistor just below the crossing point (threshold) on the curve, that way you could simply add a small voltage to nudge it over the crossing point.

    Without this biasing you could not “nudge” it anywhere.

    It would seem to me people believe there is a natural biasing at play keeping the climate just below the crossing (threshold) and CO2 is doing the nudging.

    Personally i think the hysteresis analogy like all analogies is BS, even if it was relevant i suspect the climate is way down the bottom of the curve, ergo we dont have the initial voltage to bias the climate and large swings in “forcings” (another B terminology) have no effect.

  16. Is that a graphic from the paper? I note the cloud deck in the left hand frame is pretty high.

    Up to about 1,000 parts per million, there were no major surprises. Things got around 4°C warmer and numbers changed for things like water vapor and cloud altitude. But the cloud deck generally looked familiar.

    At about 1,200 parts per million, however, the simulated clouds suddenly dissipated. And without that shade reflecting sunlight, the world warmed another 8°C.

    …and then what?

    As Feynman once said, if you start an explanation at some point and don’t take it all the way to completion you can prove all sorts of things that are wrong.

  17. ARS Technica is totally in the tank for hysterical Global Warming. Nothing they put out on the topic is worth reading. Certainly nothing worth a comment.

    Tim Gorman:
    Hat Tip for the quick, effective take down of their ridiculous “theory”.

    Interested Observer:
    A Tip O’ The Hat for the ridicule of that most insulting gimmick they used to open.

  18. This study is just a crock of Beeee Esssss! Of course it exist in the virtual world of models. Well, I have a model that turns the earth into a snowball as the concentration of CO2 rises. Any takers? Ya think I can get a few hundred thousand for a grant?

    This shist gets tiring!

  19. Tapio Schneider says: “Stratocumulus clouds are a little different. The convection that lifts their moisture isn’t driven by warming at the bottom but by cooling at the top.”

    An extraordinary statement coming from someone with his qualifications. Does he not know that the clouds get where they are because water vapor is lighter than dry air ( see the respective molecular weights). It is this resulting buoyancy that drives the water up through the atmosphere NOT in any way due to temperature differentials creating convection.

    Is he not aware that the Hydro Cycle behaves as a Rankine cycle? If not then he should go back and mug up on basic thermodynamics and the properties of water, before next pontificating nonsense on the media.

    Having read this bit I’m afraid I switched off reading the rest with any interest.

    • Convective energy comes from two sources. The temperature difference between the rising parcel and its surrounding, as well as the density difference due to water vapor between the parcel and the ambient air. This is accounted for by using a virtual temperature which is the dry air temperature with a correction for moisture. The virtual temperature can make a big difference in the early stages of convective development when the convective energy is small. It has much less effect when the convective energy becomes large with well developed towering cumulus cloud.

    • That’s the first egregious mistake I saw too, Alasdair. I forged on, however, and found all the other unscientific crap.

  20. As Tim Gorman pointed out earlier, what happens to all that water vapour from increased ocean evaporation in their warmer world? I submit that they haven’t gone far enough in their modelling because they don’t talk of ……………………. tropical thunderstorms! (which we’ve heard all about from Willis. Thank you Willis for all that.) Masses of towering cumulo-nimbus transporting heat high into the atmosphere and sending down cold rain every afternoon.

    There’s no rain in their model!

    Their sub-tropical surface temperature of 305°K = 32°C is going to make the sub-tropics just like the tropics are now, and their tropical surface temperature of 315°K = 42°C is almost certainly impossible because there would be so much evaporation when the surface temp started going over 30°C, there would be constant 100 percent cloud cover (projected temperatures are at the bottom of their cartoon).

    It’s just not believable. Like so much of climate science.

    • Very first off, I had a skim through the equations in the model and it does appear they try to account for precipitation in some manner.

      Your other point is good, what about thunderstorm formation when the stratocumulous dissipates. More heat will reach the surface resulting in more evaporation and more convection.
      This process is evident in the summer over the land. Often, in the morning, there is a deck of stratocumulus formed by the overnight cooling of the air to the form the cloud. Then when the sun comes out the lower levels begin heating up and the stratocumulus gradually dissipates due to the heating and turbulent mixing in of drier air. Once the stratocumulus dissipates the convective clouds will form quite rapidly and eventually thunderstorms may result.
      This can be a very tricky forecasting problem as to when/if the stratocumulus will dissipate and thunderstorms form up. I have been caught more than once by persistent stratocumulus that did not want to dissipate and the thunderstorm forecast did not occur.

      • I believe Willis postulated that many parts of the tropics reach their maximum ocean T now. At about 90 degrees F ? the evaporation increase is exponential and thundercloud formation happens rapidly.

        Also this study is based on the highest IPCC ECS scenario. ( The world is disproving that scenario today) Additionally the day time tropical T has hardly changed at all, so is most certain to never reach their hypothetical.

        ” They really don’t know clouds at all.”

  21. Back in the day, before computer models were the be-all, end-all of “science”, we had a saying about computer models: GIGO. At the very least the authors should publish the actual code of their model so the experiment can be replicated. Come to think of it, maybe the IPCC could do that, too…

    • Oh. I see EdH is way ahead of me. Thanks for the link to their code! I haven’t looked at it in detail, but since we’re dealing with clouds, is there room in there to model cosmic rays and sunspot activity? Or other parameters? For example, if the oceans warm up as “predicted” wouldn’t vertical circulation in the seas bring more organic material from depth to surface, vastly increasing the life forms in the ocean, which feed the sea birds, who will multiply in an exponential way, and whose white wings will reflect enough sunlight to increase the albedo of the planet and introduce cooling to moderate the deadly warming? Just a thought, but any government sponsored Ph.D. student is welcome to it…

    • I tell my friends that all of the time. Especially one of my former clients (who happened to be a Director of Environmental Quality for a prominent city government where I come from), who when she mentioned the models she had seen as the proof of what was happening to the climate. It’s all garbage in, garbage out.

  22. This is an obvious example of gigo — model blows up when driven out of bounds of normal atmospheric physics indicating the model is wrong and the researcher needs to go back and debug.

  23. Gordon

    I agree, this is not an example of hysteresis. Typically the word is used to describe an efficiency loss to phenomena inherent in the properties if a system. Consider why AC transformers get warm. As the magnetic field reverses, the core tries to remain in its present state. It gets warm.

    Pb = η * Bmax^n * f * V

    Pb = hysteresis loss (Watts)

    A tipping point is quite different. That would be like having a material that heats up, a certain flux density, then suddenly stops doing that, and cools as the rate of change in magnetization increased. Good luck finding that material.

    What they describe is claimed to happen in the model above some CO2 concentration. That might be an emergent phenomenon, not a hysteresis.

    “Stratocumulus clouds are a little different. The convection that lifts their moisture isn’t driven by warming at the bottom but by cooling at the top.”

    Balderdash. Convection is driven by exactly two things; density difference caused by the average molecular weight of gases or density difference caused by temperature. It is also known as the buoyancy effect.

    Show me a cloud that doesn’t cool at the top! A white cloud in IR is “black” and radiates with an emissivity of almost 1.0. High nines at least. Same for water vapour.

    They argue for a different kind of thermosiphon based on the cloud height/type. By what mechanism can a vaporous cloud top suck up gases from below? The evanescent cloud top beckons with its little cloudy fingers?

    Even the concept that water vapour condenses and dumps heat into the air raising the temperature …this is ridiculous. It condenses because it is cold or super-cooled and immediately, as it condenses, radiates the energy into space or back to the atmosphere and ground. Remember it is black in IR. If you only see IR radiation, all water would be black like crude oil.

    The idea that heating the oceans in the tropics 4 C would cause clouds of this type to disappear shows the model is defective. Suppose it were true: other types of cloud would form and block the sun, and that would happen long before 4 degrees was reached. Willis has shown (and published the paper) that it is very difficult to get an ocean above 31 C at the surface because it shades itself with huge clouds above 30.

    They propose that a rising temperature and evaporation rate would reduce cloud cover to zero. Good luck with that.

    Consider the opposite. A hot Earth with hot oceans and no such clouds, in equilibrium. Cool the oceans, reducing the evaporation rate, and suddenly clouds appear? A cooling ocean with reduced evaporation creates the emergent phenomenon of cloud formation? Whereas before the evaporation rate was so high, clouds couldn’t form? And being so warm they couldn’t radiate into space? From the moment water leaves the ocean as vapour, it is radiating IR.

    Good grief. How did this get past peer review? It is thermodynamic gibberish.

  24. There’s no way to verify this model against actual data. If even one negative feedback in a complex model is ignored or underestimated the conclusion is erroneous.

  25. If the waters are getting warmer, wouldn’t there be more hurricanes to transport that heat to the upper atmosphere?

    I would like to see a list of their assumptions.

  26. A significant problem with this study is that the models they used claimed a 4C temperature increase from only 1000 ppm. Clearly, the model is broken as 1000 ppm is less than 2 doublings, the first of which will cause at most a 1.1C increase and the second will cause even less. It’s likely that the same flaw is causing the clouds to disappear at 1200 ppm.

    The disappearance of clouds at higher ocean temperatures is obviously wrong. If anything, what we see is that ocean temperatures clamp at a little over 300K (about 80F) as the latent heat of evaporation becomes enough to offset incident solar energy. With this much water vapor entering in the atmosphere, clouds are inevitable as water vapor rises and cools.

    One problem with their mechanism is that the release of latent heat is into the cloud water being condensed upon and not the surrounding air molecules. Also, the only way to ‘dry out’ the cloud deck is for it to rain and that also requires clouds. If what they claim is true, why is the average cloud coverage across the inter-tropical convergence zone larger than the average cloud coverage elsewhere?

    It sure looks like confirmation bias got in the way here …

    • Confirmation bias renders the whole thing junk science the moment they ASSUME that CO2 levels “drive” temperature, when there is NO empirical evidence in support of that.

  27. The basic finding here is that CO2 above a certain level will cause a rise in temp sufficient to prevent clouds from forming. But they seem to be only talking about one sort of cloud-strato cumulus.
    Besides for that head scratcher, they are ignoring several findings from long accepted values from the paleo record: That for most of the earth history, CO2 was far above the level they specify as critical. And for most of the Earth’s history, the Earth was stuck at about 10 C warmer than present. Far more than the 4 degrees they claim will cause the end of clouds.
    But those periods of time/ with Earth at about 22C, the planet was very wet.
    Geologists have long known that warmer periods of Earth’s history were far more “humid” as geology texts refer to these wet periods.
    Carboniferous, when vast forests covered the Earth for tens of millions of years. Jurassic, Triassic, Cretaceous?
    Wet. Wet Wet.
    Wet wet wet.
    And rainy.

    The obvious conclusion is that these turkeys are just making this crap up.
    Like everything else they would have everyone believe.

  28. https://www.nature.com/articles/s41561-019-0310-1.epdf?author_access_token=0KiqRkFsS6qEi37dkGz8X9RgN0jAjWel9jnR3ZoTv0Nq8LfnDsfOJgJee7VyE1P3etD8357qMjqyq2BVVSP5V9bFmsDkWYfYyGV7gtmSgJncc5u_hUNNfMaYS7BFcu8_tWNipaYj6kz2PMZ8OXu5CQ%3D%3D

    The above is actual link to study but Nature Geoscience won’t let you print it. Ron Clutz nailed most of the criticisms above. I will add a couple of comments.
    No. 1 What they did was run 2 different types of climate models a) a model that dealt with clouds only with simplified global physics and b) the regular complicated physics model with the usual global cloud parameterizations. They inputted the results of the cloud model into the general model. THIS HAS A MAJOR FLAW. By running the cloud model with a simplified version of the global physics, you end up with variables that affect the clouds that come from the general model but are dealt with at a vastly simplified scale. So even though your cloud resolution is good in the cloud model, its findings are not. Then when you input these findings into your general model, you cant be sure whether the error bars are lower or higher than if you just ran the general model without the findings from the cloud model. If this wasnt true, we could model a raindrop and then model a cluster of raindrops, and work our way up the ladder until the whole globe was modeled. It might involve having a 1000 different staged models. The problem is we wouldn’t know what the error factor was. I predict that if climate scientists attempted that, the 173 year predictions would be so ridiculous, that the climate scientists would go back to the way that it is done now ; just 1 big simulation run 100’s of times with different inputs.
    No.2 Not only are the mechanisms uncertain but they don’t take into account; super saturation because it can’t be measured at the present time. They assume a climate sensitivity number . Also they varied a parameter called Instability. This parameter was based on an equation that needed variables like latent heat flux at the surface which can’t be measured. Also turbulent entrainment of dry and warm air cannot be measured. Also they played around with temperature inversion (subsidence) and varied it by 1 to 3% / Kelvin .
    That means the models have no way of calculating when or by how much temperature inversions happen. They freely admit that subsidence weakens under warming and counteracts the whole process.

    No. 3 This follows from no. 4.
    No.4 is certainly apropos. if you solve the Keeling CO2 curve for 1200 ppm you get 173 years from now.

    The Keeling net CO2 in atmosphere curve is approximated mathematically by the formula:

    ppm = 0.013 t^2 + 0.518 t + 310.44 where t = the time in years since 1950

    setting the equation = 1200 and using the quadratic formula of (-b +/- ( (b^2 -4ac)^ 1/2)) / 2a

    gives t= 242. Adding that to 1950 gives the year 2192. That is 173 years from now. Solving it for 5000 ppm (UK and US workplace safety limit) gives 511 years from now where we potentially choke to death, assuming we find and burn enough FF to emit that much CO2. The alarmists will not let this go after their warming theory completely falls apart. This does bother me because the thought of mankind choking on his/her prosperity is a worry even if it is 511 years away. However some skeptics say that we will never be able to burn that much fossil fuels because we will run out way before then. I am not so sure.

    However I still have a feeling in my gut that the CO2 numbers will either level off or they are fraudulent in the 1st place. Why arent more organizations/ agencies measuring the CO2 in the atmosphere?

    No. 5 Tony Heller has pointed out that the only way to have no clouds is to have no oceans.

  29. The article contains the common fallacy of CO2 as the one and only “control knob”: “For example, the Arctic was frost-free during the early Eocene, around 50 million years ago. However, current GCMs only reproduce a frost-free Arctic at CO2 levels above 4,000 ppm”

    But (citing https://ucmp.berkeley.edu/tertiary/eoc/eoctect.html):

    «In the middle Eocene, the separation of Antarctica and Australia created a deep water passage between those two continents, creating the circum-Antarctic Current. This changed oceanic circulation patterns and global heat transport, resulting in a global cooling event observed at the end of the Eocene.»

  30. “Hysteresis is a profound behavior some systems can display, crossing a sort of point-of-no-return.”

    That isn’t what hysteresis is at all. From Wikipedia, “Hysteresis is the dependence of the state of a system on its history.” Hysteresis means the return path isn’t the same as the outgoing path, creating this characteristic magnetic field strength diagram, which shows the fundamental principle used by magnetic storage media of all types.

    https://en.wikipedia.org/wiki/Hysteresis#/media/File:Ehysteresis.PNG

    Not scary at all.

  31. Take the conveyor-belt-like circulation of water in the Atlantic Ocean. Looking back at the past, you can see times that the circulation seems to have flipped

    There you . Opening statement and we are already in speculation mode

  32. Tipping point in the clouds, what more rubbish can they come up with?

    The droughts that are coming soon now are going to be a problem,
    starting round and about this year. It happens every 87 years or so.
    Europe had a dry summer 2018 already. USA will be next.
    Click on my name to read my report on that.

    • Well, according to the IPCC reports, clouds are, you know, “poorly understood.” So they must be a great place to twaddle about in their latest attempt to keep THE CAUSE going when searching for “tipping points” and “missing heat” and all those other mysteries they have no REAL evidence to support their endless assertions of the existence of.

  33. To tackle this, Schneider and his colleagues flipped things around. They utilized a model that can simulate these clouds in a small patch of atmosphere—given a simplified version of the world around them.

    Clouds aren’t based on physics. They’re parameterised entities and their formation is based on rules such as the humidity level, temperature and pressure.

    At about 1,200 parts per million, however, the simulated clouds suddenly dissipated. And without that shade reflecting sunlight, the world warmed another 8°C.

    So when they’re taken way, *way* out of their expected ranges all bets are off as to how they behave.

    This paper is some scientists having some lulz. The problem is people actually take this stuff seriously.

  34. “That extra latent heat gives the air a little buoyancy boost, increasing the turbulent movement that can mix dry air from above into the cloud layer. This dries out the cloud deck and makes cloud formation less likely.”

    So where does all that evaporated water go then? Does it just disappear into nothing? This seems to be just another proof that climate models can’t handle convection realistically. Which is not news.

  35. I think you are all wrong!

    Look at this quote from one of their reference papers: ” The simulations validate this framework for studies of MBL clouds and establish its usefulness for studies of how the clouds respond to climate change”!

    Its been proven by simulation!

    Do I need a /sarc ?

  36. Stratocu normally forms, in my observation, from wind turbulence. That’s why it tends to lurk at around two to three thousand feet– ideal to hide under if you’re a maritime strike aircraft. The rising air currents take the CCNs up to the condensation level.

    If they want to play with computer models, might I suggest that the team studies what happens if for some reason there are fewer CCNs. Possible scenarios: reduced plankton-produced DMS; oil-smoothed surface producing fewer breaking waves and thus less spray.

    It’s the condensation particles. Fewer CCNs, less cloud cover, more warming. Google ‘ship tracks nasa’.

    Sheesh.

    JF

  37. “Hysteresis” isn’t some terrible “profound behavior … crossing a sort of point-of-no-return.” It’s common in many (if not most) natural systems and is nothing more than a situation where future conditiond=s depend at least partially on past conditions. It is certainly not any sort of “point ofm no return”. It is usually possible to return to some original state, just not along the original path. In fact, the phrase “hysteresis loop” refers to a path that repeatedly cysles through a sequence of states.

    The article attempts to paint hysteresis as related to hysteria when they have completely different derivations and a similar only in sound and spelling.

    • You nailed it! In a magnetic material when an H field is applied the B field moves to a certain point in the H,B coordinates. When H is removed, i.e. goes to zero, B doesn’t go back to zero. To get B to go to zero you must apply a negative H field. If the field is of the same magnitude as the original field then B will go through zero and to a negative value, an antipode of the original starting point if you will. If H is then taken to zero B remains at the negative value.

      To get B to zero a positive H field needs to be applied again and removed before B goes positive again. Or, just apply the original positive H field and let the B field go back to its starting point. That’s why it is called a hysterisis “loop”.

      What this study does is assume that water vapor is at a certain value on the vertical axis because of some physical process and then some other process removes all the water. I.e. Water vapor goes to zero. It never seems to consider that the original forces will move the water vapor back to its original level. A hysterisis LOOP. In other words they only modeled part of the hysterisis loop and made a conclusion they had found a tipping point! Partial models that don’t consider the entirety of a hysterisis loop can be made to show almost anything, e.g. perpetual motion.

  38. And yet there have been several times when CO2 was above 1200 ppm (some during ice ages), and the dreaded problem apparently didn’t happen. Hmmm.

  39. I would appreciate it if one of the mathematicians who comment here could briefly address the constant references to “tipping points.” My understanding is that, in chaos theory these are usually called phase changes. Furthermore, my understanding is that chaos theory indicates two important things or properties about these “tipping points”: 1) their timing is not predictable; and 2) their SIGN is not predictable. If this is true, any talk of “tipping points” that implies predictability for either of these two properties is nonsense.

    Thanks again for any brief explanation for this engineer. I even dug up Lorentz seminal paper “Deterministic Nonperiodic Flow.” Quite a slog for me but if I understood it correctly is seems to imply my idea about “tipping point” predictability is pretty close.

  40. When you look at their graphic, the proposed mechanism for damping convection is the elimination of the lapse of temperature with altitude. One might fairly ask why the surface is not commensurately warmed, maintaining the lapse and convection.

    The answer seems to be that this study is a reincarnation of the “mid tropospheric hot spot”. This hot spot has been routinely predicted for increasing atmospheric CO2 by generations of models, but it has never been seen in satellite or balloon measurements.

    Correct the model so it does not show a mid level hot spot and so it does not run hotter at the surface than observations at current CO2.

    Run the experiment again.

    • Actually the “hot spot” is (suppsed to be) caused by a decreasing lapse rate in turn caused by increasing water vapor. Air with more water vapor has greater heat capacity and lower average molecule weight and therefore cools less when rising a specific distance. The absence of a hot spot proves that there is no “water vapor feedback”, at least in the tropics.

      The lapse rate can never be eliminated in an atmosphere containing greenhouse gases as long as the sun is hining.

  41. “Striking study finds a climate tipping point in clouds” –> Should more accurately read:

    “Predictable psuedo-science “study” finds “tipping point” in climate models that assume the real climate has any “tipping point” with regard to something that has never caused such a “tipping point” in the past.”

  42. Alan Tomalty February 26, 2019 at 10:34 pm
    I guess I’m a simpler mathematician.
    1958 – Co2 310ppm, 2019 – Co2 412ppm = an additional 102ppm / 61 years = 1.67ppm/yr.
    1,200ppm Co2 – 412ppm = 788ppm. 788ppm / 1.67 = 472 years…
    So in the year 2491 all of this one type of cloud will disappear.
    Damn, there goes all the good sunset pictures….

  43. “Up to about 1,000 parts per million, there were no major surprises. Things got around 4°C warmer and numbers changed for things like water vapor and cloud altitude. But the cloud deck generally looked familiar.
    At about 1,200 parts per million, however, the simulated clouds suddenly dissipated. And without that shade reflecting sunlight, the world warmed another 8°C.”

    Nonsense, but with a model you can make anything up you want.

    Firstly, 1,000 ppm CO2 can never cause water (ocean) to warm 4c, not even close.

    Secondly, 1,200 ppm C02 causing a further 8c rise would lead to the warmest period in Earth’s history ever known with life, beating warm oceans circulating over the poles with no polar ice caps or glaciers.

    Thirdly, there has been zero evidence of this occurring any time before, when CO2 levels were higher than 1200ppm CO2.

    Fourthly, this initial warming is similar to what occurs with ENSO over the Tropical ocean where it warms more than 3c with a strong El Nino.

    Fifthly, the warmest climates over the past hundreds of millions years ago were due to different continental land and ocean positioning with different ocean currents changing albedo hugely.

    ENSO occasionally causes rises in Tropical ocean temperatures above 3c and the result is more cloud formation and heavier rains/thunderstorms.

    “Stratocumulus clouds are a little different. The convection that lifts their moisture isn’t driven by warming at the bottom but by cooling at the top.”

    Stratocumulus clouds usually form from a layer of stratus cloud breaking up. They are indicators of a change in the weather and are usually present near a warm, cold or occluded front.

    Stratus clouds form in calm, stable conditions when gentle breezes raise cool, moist air over colder land or ocean surfaces. These clouds can exist in a variety of thicknesses and are sometimes opaque enough to darken days allowing for little light to pass through.

    Cooler moist air in the lower troposphere below and around the cloud levels cause Stratus clouds to form. Generally if they were formed only by cooling at the top they would only form at night and how would they form near a warm front with advancing warmer air rising up above the dense cold air below?

    • Yes. Stratus clouds are very typical over cool oceans offshore of dry, hot land. For example on the coasts of Peru or Namibia or around the Galapagos.

      In such areas they are so persistent that a special vegetation belt forms at the level where they usually lie, that is sustained solely by the fog, while lower levels are arid, because it almost never rains from such clouds.

  44. 1000 or 1200ppm carbon dioxide does not seem so bad…

    “”As plant communities expanded onto land to form the first forests, they depleted the carbon dioxide (CO2) that was in the atmosphere,” Waters said. “CO2 levels dropped to 400 ppm toward the end of the Devonian. It got colder. There were glaciation events and the rapid change in the climate caused severe extinction in the tropics and the existing coral reefs became extinct.” By comparison, the world’s current CO2 level is very close to 400 ppm.”

    from….https://www.sciencedaily.com/releases/2013/12/131213092841.htm

  45. “That extra latent heat gives the air a little buoyancy boost, increasing the turbulent movement that can mix dry air from above into the cloud layer. This dries out the cloud deck and makes cloud formation less likely.”
    ___________________________________________________

    And because the energy balance must be balanced for well-known reasons, the oceans have to contribute slightly to warming the atmosphere – a Zero-sum game.

Comments are closed.