Study gives first proof that the Earth has a natural thermostat


I was taught in high school in the 70’s that clouds and the phases of water perform this function.   Read about it in Scientific American as well sometime in the 80’s or 90’s.  But we now have first proof!~ctm


August 15, 2017

New data provides the first proof that the Earth has a natural thermostat which enables the planet to recover from extremes of climate change – but the recovery timescales are significant. This work is presented today at the Goldschmidt conference in Paris, and has just been published in the peer-reviewed journal Geochemical Perspectives Letters.

The idea of a natural temperature thermostat was first proposed in 1981, but until now no-one has been able to provide data to show that the recovery from the hot and cold temperature fluctuations were associated with a specific mechanism.

Now a group of British scientists has shown that recovery from global cooling events is associated with changes in the rate of weathering of rocks, which is the main mechanism of removing CO2 from the atmosphere. In weathering, rocks are dissolved by rain and river water; the process removes CO2 from the atmosphere, which is then transported to the seas by rivers to be locked up in carbon-rich rocks such as limestone. The more weathering, the more CO2 is removed from the atmosphere.

The team had previously found evidence supporting the role of weathering in cooling the Earth in times of high temperature. This current work confirms that a slow-down of weathering takes place in cold periods, and so supports the concept of an “Earth thermostat”.

The researchers were able to use the Lithium isotope ratios in rocks as a measure of weathering. They examined rocks from the period of the Hirnantian glaciation – around 445 million years ago – which correspond with the second greatest extinction of life in history, when around 85% of marine species were wiped out, due to the cooling and a dramatic drop in sea levels (estimated at around 80m) as water was locked into ice fields and glaciers.

The samples, which came from Anticosti Island (Quebec, Canada), and Dob’s Linn (near Moffat, Scotland), show that global chemical weathering rate declined by a factor of four temporarily during the 5°C cooling that caused the glaciation, removing less CO2, allowing the climate to recover from the cooling.

Lead scientist, Dr Philip Pogge von Strandmann (University College London and Birkbeck, University of London) said:

“From looking at the relative abundance of lithium isotopes in ocean-derived rocks, we were able to confirm that chemical weathering is the driver of the Earth’s natural thermostat. When there is a warmer climate, there is more weathering, and when it is cooler there is less weathering: this is what you would expect, given that chemical reactions go faster with increasing temperature. So more weathering removes CO2 from the atmosphere and puts a break on global warming. However, when the temperature cools, the reverse is true, and less CO2 is removed from the atmosphere in cold periods. This is the process that has allowed life to survive on Earth for around 4 billion years, and is what we are reporting in Paris”.

Nevertheless, we need to be clear that the changes in temperature are gradual, and that recovery can take hundreds of thousands of years. Given the rapid increase in the rate of global warming at present, this kind of wait is not an option for us”.

Read the full story here.


150 thoughts on “Study gives first proof that the Earth has a natural thermostat

    • No YAY!!! This article just supports that CO2 is the thermostat of the earth. Without ‘weathering’ CO2 would get out of control and we’d be flaming-ball earth. Add more than weathering can remove we’re all dead (oops). The earth has had a somewhat stable climate for billions of years, sorry to say, CO2 did not have a major part in this. My vote is on the trillions of swimming pools that surrounds us.

      • I would hardly call the earth’s climate over billions of years stable. I would not call it stable over millions of years. We are in a relatively cool period right now, but it was much hotter at the beginning of the Holocene, a mere thousands of years back. In between those periods there were times when it was cold and unstable enough to cause mass starvation of human beings.

      • Ernest, stable planet enough that life formed ~4.5 billion years ago and it is still going, hugely diverse. Not saying it was easy. Human beings are fragile creatures, we need umbrellas in a rain fall as we do not have fur coats. Cold or not, humans are so successful, mass starvation or not, we’ve adapted over hundreds of thousands of years, we’ll make it (just like the dinosaur’s did).

      • Absolutely correct. No gas of any kind at any proportion can detectably warm the Earth’s surface. This junk science model says that the upper tropical troposphere (the “hotspot”) at -17 deg C traps IR and sends it down to the surface at 15 deg C. As the surface is always warmer than the IR source (particularly because the computer models are sunlight 24/7), the equivalent energy levels are full and the IR is reflected back upward; no net warming.
        Because their “science” failed so miserably, as the “hotspot” was never found and that region of the atmosphere has been gently cooling for the last 40 years (NASA), the warmists tacitly let people think that CO2 and water vapor near the surface causes the claimed warming. However, these gases are “radiative gases” and are saturated in sunlight as they convert IR to heat and heat to IR; they have no net effect.
        It is during night-time, which is not included in any of the computer global climate models, that these gases convert heat to IR unopposed by solar input. They are why the air chills so quickly after sunset and why local breezes kick up so quickly in the shadows of clouds on a sunny day with scudding clouds. These gases work quite quickly and serve to cool the planet whenever sunlight ceases.

      • The only good thing about this is that finally they are prepared to accept that there are corrective measures ( negative feedbacks ) which stabilise climate.
        Rowing back on three decades of activists driven antiscience is going to be hard and long.
        They are NEVER going to admit they were wrong.

      • The article claims that rain and river weather the rocks – given that cloud & rain therefrom weathers the rocks and is dependent on climate, why not draw the conclusion that clouds/rainfall are the feedback mechanism. They just had to mention CO2, their funding & publishing probably depended on it…

      • I agree. The theory that CO2 as a “greenhouse gas” is a key or even measurable driver of global temperature is still just a theory with little direct corroborating evidence and a considerable amount of evidence going the other way to suggest that temperature drives CO2. It may or may not be important to temperature trends but the above study assumes it is central.

      • Hum, if SL was a couple if hundred feet higher in the really warm periods, would there not be far less shoreline to weather?

    • Well why don’t they be honest and just admit that THEY only just discovered that the earth has a natural thermostat.
      The rest of us figured it out a long time ago.
      You can come at it a couple of ways.
      #1 imagine that every last H2O molecule is removed from the Earth’s atmosphere, and dumped into the oceans and lakes.
      Well we can be sure that we will have the mother of all positive forcings, with ZERO clouds in the sky to reflect 35% of the sun’s energy back into space. Surface irradiance will be much closer to 1362 W/m^2, than to 1,000.
      Stand by for massive evaporation from the oceans.
      Well Peter Humbug already did that model on his X-box, and he got all the water back in just three months. With all that evaporation and precipitation the clouds will be back in full force and it will be cooling down.
      #2 imagine the sky full of clouds and 100% relative humidity from the surface to 45,000 feet.
      Good luck on getting any measurable ground level solar energy. You are gonna freeze your arse off !
      Well with all of that cold frigistication, it is going to rain and snow like you wouldn’t believe, which will remove a whole lot of that water from the atmosphere which will start to let some sunlight reach the ground, so it WILL warm up from that freezing cold, as the clouds dissipate.
      So you start from zero and boiling hot sun, and it cools down, but if you start from massive solid clouds, and freezing conditions, it will precipitate and warm up.
      So obviously we will end up in either case, at one of two Temperatures. One where it stops on the return of the clouds case, and one when it returns from the perpetual darkness of thick cloudiness.
      So which one of those two Temperatures are we at now; the high one or the low one.
      Well if they aren’t the same Temperature, then there is a space between the low Temperature and the high Temperature, and it is easy to prove that if we were in between those two temperatures the condition is unstable and it will drive the system to one or the other of those two Temperatures.
      Well of course there could be more than two stable Temperatures. If there are, they must come in pairs, and in between each pair it must be unstable so the system moves to one end or the other of whichever one of those pairs we are in.
      Well I’m not ‘splaining it very well, but you get the idea; there’s not a shred of evidence that we are being forced on one direction or the other.
      The end points of the two experiments have to be the very same Temperature.
      Yes massive changes in the system like orbital parameter shifts, would move the goal posts.
      But for the last 650 million years it has stayed between +12 deg. C and + 24 deg. C, neither of which is very uncomfortable, and in any ordinary week it changes by that much or more in Downtown Silicon valley in no more than 24 hours.
      So these guys are late to the party.
      So was Peter Humbug !

      • Greg, there is ONE thing YOU can be assured of, and that is whenever I write Temperature, instead of temperature; that I darn well intended to write that.
        So buzz off !!
        And G is NOT g; only sometimes when I say so are they the same.
        So what’s the diff ??
        When I write Temperature greg, I am referring to the international SI absolute scale measured in kelvin.
        If’n I write temperature, you can just do what you feel like, and use funny farm units, or Celsius, or even use ” anomalies ” which aren’t even any kind of temperature.

    • They only so a correlation, not causality. Mthey have the CO2 tsil wagging yhe clinate dog, again…
      There’s a thermostat, but it works in days at the hot end… thunderstorms and hurricanes…

      • My first thoughts as well. I would be surprised if the resolution of their evidence allowed them to say weathering caused temperature change. I have no doubt they can detect periods of greater or lesser weathering, but I notice they didn’t specify ppm. The claim is that 280ppm is fine and 400ppm is dangerous. Are they claiming they can distinguish this range of CO2 with any precision during a period from over 400 million years ago?

      • Auto, mate, I’m sorry, but you really have to get with the program here.
        Of course CO2 can predict the winner of a horse race.
        It will be wrong, along with all the other predictions made on it’s behalf, but a prediction will be made.

      • …and all convection and conduction below thunderstorms and hurricanes.
        The additional energy is exponentially used up, accelerating the hydrological cycle.

      • Whoops, wrong place!
        Auto, mate, I’m sorry, but you really have to get with the program here.
        Of course CO2 can predict the winner of a horse race.
        It will be wrong, along with all the other predictions made on it’s behalf, but a prediction will be made.

    • Their theory assumes up front that it IS CO2 in the atmosphere that makes the earth warm. In places without water, the CO2 is remarkably inept when it comes to warming things up.
      NO !! It is the sun that makes the earth warm; an the amount of sun energy that reaches the condensed surfaces. depends on the amount of water in the atmosphere, and that increases by 7% for each 1 deg. C increase in the global mean (surface/lower tropo) Temperature.
      It’s the CLOUDS that regulate that solar energy input.

    • They have proven nothing! Simply another correlation and this one supposes accurate dating from 445 million years ago. It appears they went looking for evidence that would support their preconceived ideas. What else happened 445 million years ago that may have been relevant?
      Modern climate science. Make something sticky and throw it against the wall! See! It sticks!

    • …and assuming CO2 as a natural thermostat had not been proposed before 1981.
      A general ‘governor’ of global temperature as an analogy to homeostasis (but with with no thermostat) was proposed by Lovelock in his Gaia theory in the late 1970s.
      The CO2 thermostat was proposed in the foreword to a NAS ‘Energy and Climate’ report in 1977
      But then there is the Swede, Nils Ekholm, 117 years ago:

      …we must expect that secular variations of the quantity of carbonic acid in the atmosphere will occur and cause climatic variations of the same kind as those revealed by geological science. Thus a future Ice Age might possibly occur [due to CO2 thermostic control]. But here we find a remarkable circumstance that has hitherto been unexampled in the history of the earth. This is the influence of Man on climate.

      Ekholm followed Arrhenius in the agument for CO2-driven ice age cycles, but Ekholm’s vision of CO2 thermostat control gave recognition to several aspects of the carbon cycle in temperature control:

      In fact, we have seen that the present burning of pit-coal is so great that in one year it gives back to the atmosphere about 1/1000 of its present store of carbonic acid. If this continues for some thousand years it will undoubtedly cause a very obvious rise of the mean temperature of the earth. Also Man will no doubt be able to increase the supply of carbonic acid also by digging of deep fountains pouring out carbonic acid. Further, it might perhaps be possible for Man to diminish or regulate the consumption of carbonic acid by protecting the weathering layers of silicates from the influence of the air and by ruling the growth of plants according to his wants and purposes. Thus it seems possible that Man will be able efficaciously to regulate the future climate of the earth and consequently prevent the arrival of a new Ice Age… (Nils Ekholm 1900)

      • Well stated. Note that Lovelock now admits that the warmists are wrong.Earth’s atmosphere has evolved from abiotic processes to the present where the entire atmosphere is of biological origin. The hydrosphere and radiative physics continue to operate in parallel.
        Any biologist knows that planet Earth is now responding to biological evolution.

      • It is a pity for them that the evidence is contrary to their ‘beautiful’ hypothesis. CO2 concentrations in the atmosphere lag changes in ‘global temperatures’ by centuries. The lag means CO2 cannot be the cause of the change but one indication of the change in temperatures.

    • “Assuming that CO2 is a significant driver of temperatures” and that increased weathering somehow “removes” CO2 from the atmosphere, which then cools the planet, shouldn’t the increase in storms like Harvey be a welcome relief to these warmists? Look at all that “weathering” going on in Texas right now! (sarc)

  1. I think there are a few more things providing temperature stability than just CO2 weathering cycles. Given the low correlation of CO2 and temperature in both the instrumental and proxy histories, there are other things going on that are more important.

  2. So this weathering, when warm, reduces the co2 at a higher rate than the oceans release. This causes CO2 in the atmosphere to be reduced causing cooling. Does not fit what I have learned on this site.

    • ” at a higher rate than the oceans release”
      It’s on a longer timescale than that. The key thing is what volcanoes release. That’s the cycle – magma expels CO2, leaving more basic material behind. Some of that comes to the surface, gets weathered eventually, and takes the CO2 back, by acid-base reaction.

      • NS,
        That is an interesting take on volcanism! I didn’t know that you had a background in geology. Clearly, the more volatile components such as CO2 tend to be released early in the life of a volcano. However, the typical evolution is to go from what geologists call a mafic composition (rich in iron and magnesium) to one rich in silicates that melt at lower temperatures and what have traditionally been called ‘acidic’ or sialic. However, the composition of the magmas tend to be quite different whether they erupt at spreading centers (mafic and ultramafic), or at continental margins above subducting plates. The magmas at continental margins can vary considerably depending on the rocks the plate is made of. If limestone is abundant, then there is plenty of CO2. However, it the plate is made of granitic rocks, or sediments derived from granitic rocks, CO2 will be scarce. Also, the weathering rate, under attack from carbonic acid, will be higher for the mafic rocks rich in calcium feldspars. Just like climate or the carbon cycle, the rock cycle is very complex and can’t be described in one sentence.

      • Clyde,
        “the rock cycle is very complex and can’t be described in one sentence”
        True. But there is some basic chemistry of acid-base reaction that has to be followed. If you expel acidic CO2, the material behind has to be more basic. Limestone leaves behind CaO. And that stays as part of the rock composition until, if it comes to the surface, it is exposed to the air by weathering. Then the CaO can react again with CO2 to restore the carbonate.
        This is where the Lewis acid concept from chemistry helps. CO2 in rock carbonate was sharing an electron pair. When it leaves, it leaves that behind, unshared. It’s looking for another one – that’s why it is acidic. Eventually, after millions of years, some of those electron pairs left behind will surface (basic rocks). Some acid, probably CO2, will find them (after weathering).
        That’s why burning carbon has such a long term effect. We create an acid (CO2) by redox. And while it may dissolve in water and participate in carbonate equilibria, it won’t find a permanent solid state (CaCO3 etc) until it finds that electron pair, and there just isn’t a massive source of them around, except for basic rocks. But they are only available after weathering.

      • So why is atmospheric CO2 at almost the lowest level in the planet’s history? Is that a good thing? How did life manage all those millions of years with CO2 at much, much higher levels? Why wouldn’t CO2 levels follow temperature as it is absorbed or outgassed from ocean water in to maintain a direct relationship with temperature?

      • NS,
        CO2 by itself is not acidic; it is neutral. It has to be dissolved in water to create carbonic acid.
        Typically, the amount of CO2 found in magmas is negligible, except for rare rock types like carbonatites. The normal concepts of acidity and basicity apply to dissociation into ions in an aqueous solution and are not applicable to the molten state. For example, you cannot have crystalline precipitation in a magma — driving a reaction by removal of an insoluble product — as a result of the introduction of some ion. Precipitation can only occur when the temperature is lowered below the melting point of one or more potential silicates, sulfides, oxides, or elements whose atoms are to be found in the magma. At that point, those early products can react with the magma as the temperature continues to drop to create new minerals, essentially by what might be called ‘corrosion,’ as illustrated by Bowen’s Reaction Series for the silicates. It has nothing to do whatsoever with any acid-base reaction! It is a result of the crystalline stability at the particular temperature and pressure the mineral is subjected to. Although, some early geologists thought that there was a theoretical acid, based on the silicate anion, and thus it became common to refer to silicate-rich magmas as being ‘acidic.’ Similarly, silicate-poor magmas are called ‘basic.’
        When limestones dissolve, under the influence of both carbonic and humic acids, calcium oxide is not left behind as in calcining. Both the calcium and carbonate/bicarbonate go into solution and are carried away by what is then called ‘hard’ water.
        I have a suggestion for you: Take a trip to Hawaii, find an active lava flow, put a piece of litmus paper in it, and get back to me and tell me what the indicated pH is. I strongly suspect that the paper will turn black, which doesn’t correspond to any particular pH.
        I’m afraid that you are out of your depth here and are just trying to BS your way though with your fixation on the Lewis acid concept. Why don’t you stick to things that you have more experience with?

      • Clyde,
        “The normal concepts of acidity and basicity apply to dissociation into ions in an aqueous solution”
        To quote you from above
        “what have traditionally been called ‘acidic’ or sialic.”
        The Lewis concept is perfectly normal to chemists, and is approaching its centenary. It allows you to track what is invariant beyond the current aqueous state.
        Yes, crystallization in magma is not usefully regarded as acid-base. Driving off CO₂ from magma is not caused by acidity either (heat and lower pressure), but it leaves a more basic rock behind. And the reaction is reversible if the heat goes away and the products are brought back together.

      • NS,
        You said, “…, but it leaves a more BASIC rock behind.” Alright, what is the pH change (or if you prefer, the hydrogen ion concentration change) of the magma before and after your CO2 is driven off?

      • NS.
        Alright once again! From Encyclopedia Britannica:
        Although the Brønsted–Lowry concept of acids and bases as donors and acceptors of protons IS STILL THE MOST GENERALLY ACCEPTED ONE, other definitions are often encountered. Certain of these are adapted for special situations only, but the most important of these other definitions is in some respects more general than the Brønsted–Lowry definition. This definition was first proposed by the American chemist Gilbert N. Lewis in 1923…
        Numerous lengthy polemical exchanges have taken place regarding the relative merits of the Brønsted–Lowry and Lewis definitions. The difference is essentially one of nomenclature and has little scientific content. In the remainder of this article the term acid is used to denote a proton donor (following the Brønsted–Lowry terminology), whereas the term Lewis acid is employed exclusively to refer to electron-pair acceptors. This choice is based partly on the logical difficulties mentioned in the last paragraph and partly on the fact (see below Acid–base equilibria) that THE QUANTITATIVE DESCRIPTION OF ACID-BASE REACTIONS IS MUCH SIMPLER WHEN IT IS CONFINED TO PROTON ACIDS. IT ALSO REPRESENTS THE COMMONEST USAGE OF THE TERMS.

      • Clyde,
        From your quote
        “Numerous lengthy polemical exchanges have taken place regarding the relative merits of the Brønsted–Lowry and Lewis definitions. “
        Nice to be part of a tradition.
        ” the most important [Lewis] of these other definitions is in some respects more general than the Brønsted–Lowry definition”
        That’s the part I would have highlighted. And it’s the part that is relevant whenever you talk about basic or acidic rocks (as you just did). It’s not a reference to any pH or protons. It refers to the silica content. Silica has no protons but is a (weak) Lewis acid.
        “Alright, what is the pH change (or if you prefer, the hydrogen ion concentration change) of the magma before and after your CO2 is driven off?”
        That is the point – Lewis liberates you from talking about pH. What is the pH of sialic magma? Driving off CO₂ is reversible. It is reversible in a calcining kiln, so you have to remove the CO₂ before cooling. And it is reversible in geology, as when the mafic rocks weather and absorb CO₂.

      • NS,
        You said, “That is the point – Lewis liberates you from talking about pH.” This sounds like pseudoscience hand-waving where one is ‘liberated’ from making quantitative measurements and calculations.
        And therein is the major weakness of the Lewis theory. It may help explain qualitatively what goes on in non-aqueous solutions, but in the real world of weathering rocks, water is essential. And, to not be able to quantitatively describe what is happening sets science back a couple hundred years.

      • NS,
        You asked, “What is the pH of sialic magma?” That is a nonsensical question akin to asking “Why is a mouse?” I already stated that the concept of acidity and pH really only has validity in the context of aqueous solutions because the disassociation constant of water is critical.

      • Clyde,
        “I don’t think that your Lewis Theory will be of any help”
        It is. CO₂ is held in solution (as carb or bicarb) because it is sharing an electron pair. It is displaced and evolved when a stronger acid comes and takes that pair. But if that acid is CO₂, no progress can be made. It could only replace one CO₂ with another.
        “That [pH] is a nonsensical question”
        That is my point. Acidic and basic have long been used in talking about lava, but no protons are present. Protons as an acid species are handy because they give a familiar quantifier – pH. But nature doesn’t care about that. It makes sense to call SiO₂ acidic, even though it is insoluble. You can heat it up with alkali to make glass. That is an important acid-base reaction, not happening in aqueous solution.
        Protons are of course Lewis acids. And Lowry-B acids can transfer protons to water, and that gives a measure of their acidity. But other Lewis acids (eg SO₃) can displace protons from water, with the same net effect. They can also react directly with Lewis bases without water as an intermediary. Water is a distraction here.
        The Lewis POV comes into its own with bicarb equilibria in seawater. People get hung up on trhe difficulties of measuring pH. But that is because protons are a trace intermediary. The key reaction is between acid CO₂ and base CO₃⁻⁻. And the way to quantify it is by measuring those species directly.

      • “What is the pH of sialic magma?”
        What a damfool question.
        Hydrogen ion concentration aka pH is only relevant to aqueous solution, magma of any variety is about as far from an aqueous solution as you can possibly get.

    • Nope.
      Warmer=more weathering, but it’s because warmer air, causes more evaporation, which causes more clouds, which bring RAIN. RAIN is the chief remover of CO2 from the atmosphere. Water must be combined with CO2 to form the weak acid that erodes rocks.
      Ironically, many of the vast stretches of rock in the world are nowhere near a river, so the water+CO2 dissolves a little bit of rock, and then evaporates back into the atmosphere.
      They didn’t say weathering CAUSES warming, or that lack of weathering CAUSES cooling. They just showed a correlation and made a HUGE, and unproven leap to their conclusion.
      P.S. This site discusses science…good…bad…ugly…and sometimes hilarious. Keep reading. Keep learning.

      • Macusn, don’t be confused, Anthony/Charles do post all sorts of info, not all are right or wrong – it’s a blog after all. You as a intelligent person, should absorb all and make rational decisions. It’s shades of grey. The one thing keeps people coming back, yes we’re mostly non-AGW but it’s a good community, we even like Nick but argue with him nonetheless (and he can be very good at it).

      • “Rain, rain, rain…” Yes. But both you and the authors of the paper and most of the commentators here omitted plants, which can erode rock fast in geological time.
        You can hammer at a piece of granite and get a few crumbs of rock. But the mosses and lichens can make the rock crumble just by the action of the acids produced by their roots. The kaolin washes out into streams and the silicates tumble downhill to form piles of coarse sharp sand.

    • Well just think; we no longer have to watch the grass grow, to while away the time
      The new gig is watching rocks disintegrate !
      Now I know what the hell happened to my pet rock; it died warming up the planet.

  3. I too was taught that the combination of of water and the energy from the Sun was what regulated the worlds temperature, but in view of the 17th century minimun I would expect the thermostat to be working all of the time and not just over some millions of years.
    The basics even excluding the possibility of cosmic rays would have to be more sunshine, warmer air so more evaporation, so more clouds lesss sunshine so cooler. Very simple of course and very polpitically incorrect.

  4. This seems to assume CO2 is The Mechanism that controls global temperatures and weathering is the control knob. Considering CO2 has been much higher during a previous glacial period, I doubt that.

  5. “Nevertheless, we need to be clear that the changes in temperature are gradual, and that recovery can take hundreds of thousands of years. Given the rapid increase in the rate of global warming at present, this kind of wait is not an option for us”……….So send us more money now!
    Read the full story here.

    • Yeah, what rapid warming? Where? When?
      Assuming things not in evidence is unscientific, and that’s what it seems the authors of this study are doing.

  6. 600 Gtons of CO2 goes through bio systems each year and 70% of the earth is an ocean-atmosphere interface and they claim dissolving rocks is a detectable signal in the CO2 cycle. Extraordinary claim.

    • “they claim dissolving rocks is a detectable signal in the CO2 cycle”
      Where? They are writing about a study of lithium isotopes from a period 445 million years ago. That is their evidence for saying that weathering slows during cold periods, which is the thermostat effect. But it is on a timescale of millions of years. Not detectable on any scale that we measure CO2 in the air.

      • While you are at it, perhaps you could explain how during the Snowball Earth episodes, when there was minimal exposure of rocks, any weathering took place. Where did the CO2 come from? Don’t tell me it was volcanos all the way down. In the case of silicates, weathering will extract CO2. However, when carbonic acid falls on limestone, more CO2 is released into the atmosphere. I haven’t read the original article, but this proposal seems a little short on details.

      • “Where did the CO2 come from?”
        The more usual question os, where did the O2 come from. CO2 was there first. We started with a big excess of acidity. Photosynthesis reduced CO2, emitting O2 and burying carbon, until we got to our present state of near neutrality. Digging up and burning carbon is part-reversing that.

      • Nick,
        I suspect you’re preaching to the converted here. It doesn’t look like many on this site have much faith in this paper either.

      • That weathering slows during cold periods should be a given. When ice covers the ground, the rocks cannot be “weathered”, and if the “rain” that would normally erode the rocks lands frozen on the ground, it doesn’t melt and reach rivers, or make it’s way to the oceans, and rocks cannot be “weathered” by it until it melts….during a warm period.
        Those two things are an effect caused by the cold period, but they certainly do NOT act AS the “thermostat”. A thermostat controls temperature. Something is clearly controlling the temperature of Earth, but it’s beyond insane to think that because the amount of weathering occurring is correlated to the temperature of the globe, that “weathering” that is causing the temperature change. Only a belief in the CO2 god can cause such irrational conclusions.

      • NS,
        You responded, “The more usual question os, where did the O2 come from.” But, that isn’t the question I asked! I didn’t ask about the primordial composition of the atmosphere, I asked where the CO2 came from that presumably ended the Snowball Earth episodes.
        CO2 in the atmosphere is not acidic! It has to react with water to dissociate into hydrogen and carbonate ions to have an excess of hydrogen ions, thereby creating acidity.
        I haven’t a clue what you mean talking about “…our present state of near neutrality.” It is the nature of acid-base reactions to neutralize each other to create neutrality. Again, your view of alchemy is not applicable to the way things work.

      • Clyde,
        Your chemistry is shaky.
        “However, when carbonic acid falls on limestone, more CO2 is released into the atmosphere.”
        No, it doesn’t. the reaction is
        CaCO₃+CO₂+H₂O → Ca⁺⁺+2HCO₃⁻
        There is no way that CO₂ can liberate CO₂.
        “CO2 in the atmosphere is not acidic!”
        That’s the point of the Lewis acidity. It doesn’t change with hydration status. You can use it to track and balance over long periods. CO2 is a Lewis acid. If you expose CaO to dry air, the acid-base reaction is
        CaO+CO₂→ CaCO₃
        “It is the nature of acid-base reactions to neutralize each other”
        Provided you have equal amounts of each. At the moment we are creating acid by burning C, and there just isn’t enough base anywhere to neutralize it, and allow it to sequester as CaCO₃. The only adequate long term source is contained in basic rocks, but that needs weathering.
        As to ending Snowball Earth episodes, we’re talking about very long time periods. Tens, hundreds of millions of years. Continents move. Volcanic activity varies hugely. Even the Sun’s output varies. It’s not like a recent glacial period ending in millenia.

      • Nick Stokes says: “We started with a big excess of acidity. Photosynthesis reduced CO2, emitting O2 and burying carbon, until we got to our present state of near neutrality. Digging up and burning carbon is part-reversing that.” You are a pretty smart fellow, the hero of Griffs everywhere, but please tell us where in this formulation the temperature of the earth was too hot to inhabit. Was it during the “big excess acidity” epoch? If so, the “unprecedented global warming” is not unprecedented at all, wouldn’t you agree? If we are simply reversing (part-reversing) the process, we are going back to global conditions that existed before, the contrary of “unprecedented,” no? Conditions the earth self-corrected, not just in part but all the way to “neutrality”? Your formulation is that we are “part-reversing”, that is, reverting to pre-existing conditions. You have de-bunked “unprecedented” CAGW in just a few sentences. I congratulate you, but the Griffs out there will be let down.

      • NS,
        You said, “No, it doesn’t. the reaction is CaCO₃+CO₂+H₂O → Ca⁺⁺+2HCO₃⁻
        There is no way that CO₂ can liberate CO₂.”
        With the application of a strong acid, the effervescence of calcite is generally quite evident. Things are more subtle with a weak acid such as carbonic, particularly when you have competing carbonate species. The key to what is happening is the solubility of the CO2 and bicarbonate species with varying pH. The equilibrium equation that you give above is fundamentally a neutralization reaction where all the carbonic acid is used up. If more carbonic acid (rain) is added to the bicarbonate in solution, then the pH is lowered to where the bicarbonate is less soluble and CO2 will be evolved when it becomes saturated with carbonic acid. I don’t think that your Lewis Theory will be of any help in determining at what concentrations those things will happen.

      • Clyde,
        “I don’t think that your Lewis Theory will be of any help”
        It helps. CO₂ is held in solution (as carb or bicarb) because it is sharing an electron pair. It is displaced and evolved when a stronger acid comes and takes that pair. But if that acid is CO₂, no progress can be made. It could only replace one CO₂ with another.

  7. Fundamental fact: If the earth temperature rises, it will radiate more which will lead to cooling. That is the very definition of a thermostat. If it cools, it will radiate less. This is the most basic concept, yet no one even talks about it. Unbelievable. Of COURSE there is a natural thermostat – but it seems no one actually understands it.

    • “This is the most basic concept, yet no one even talks about it”
      Of course they do. Here’s Wiki

      As the temperature of a black body increases, the emission of infrared radiation back into space increases with the fourth power of its absolute temperature according to Stefan–Boltzmann law.[66] This increases the amount of outgoing radiation as the Earth warms. The impact of this negative feedback effect is included in global climate models summarized by the IPCC. This is also called the Planck feedback.

      • NS,
        BINGO! The weathering effect described here in may be a tertiary or lesser effect but you finally stated that the real controlling thermostat is S-B. That means that CO2 Is NOT, yes NOT, a significant factor in the Earths temp. It’s about time!

      • Except that Earth isn’t a perfect black body. And that short wave radiation bouncing around in the atmosphere cannot re-warm the Earth’s surface, so there is no “feedback” loop to speak of. And that the IPCC models aren’t accurate compared to observations.
        But except for those three tiny little things…

      • Nothing can be a ” true black body “.
        There’s NO such thing, it’s all fictional mathematics (very useful).
        We can even make somewhat close approximations over limited frequency ranges.
        You can even buy your very own ” Copper Freeze ” laboratory near black body.

      • Well wiki is up a creek. Having a black body radiator increase its output as Temperature increases IS NOT FEEDBACK; it’s Theoretical Physics, and if the Temperature keeps increasing, the rate of radiation will keep on increasing; forever if need be.
        “FEEDBACK” is when a portion of the OUTPUT is used to MODIFY the INPUT.
        If you keep on increasing the Temperature of a black body radiator, it will never stop increasing its rate of radiative energy output, and start cooling.

      • Barry,
        “you finally stated that the real controlling thermostat is S-B”
        That’s like saying that what controls our health is gravity. It keeps us from drifting out into space. But that doesn’t mean we don’t need doctors. Control knobs are things you can vary.

  8. The NASA, US, and ISO Standard Atmospheres are simple and empirically verified(!) models of the earth’s atmosphere that establish the controlling factor for the atmospheric temperature as the adiabatic lapse rate: dT/dh = – g/Cp where T = temperature, h = height, g = gravitational acceleration, and Cp = the heat capacity of air at fixed pressure. The the main consideration that affects the value of Cp is absolute humidity, and CO2 concentrations are nearly irrelevant. Dry air cools at about 10 C/km.
    The effect of moisture on Cp is effectively that of a negative feedback. Removal of CO2 by chemical weathering will have a negligible effect on Cp, as the value of Cp for CO2 is nearly the same as that for N2 and O2, which together comprise 98+% of the atmosphere.
    Water has a Cp value much larger than that of dry air, so that moist air usually cools at less than 6 C/km. The convection of wet air is nearly twice as efficient at transporting energy from the troposphere to the stratosphere. When the wet air rises high enough (so the ambient temperature drops below the dew point) the moisture condenses, forming clouds which increase the albedo of the air, reflecting more solar energy back into space and cooling the atmosphere further.
    Thus the additional heat absorbed by water at the surface, causing the water to evaporate and humidify the air, leads eventually to a cooling cloud cover – and a strong negative feedback.

    • Yes, and no mention of any fictitious “Greenhouse” mechanism because none is required and none exists. Thank you for your clear concise contribution.

    • …and all convection and conduction below thunderstorms and hurricanes.
      The additional energy is exponentially used up, accelerating the hydrological cycle.

  9. These two scientist are arguing that a “trace gas”, which represents only 0.04% (.0004) of the Earth’s atmosphere is controlling the Earth’s temperatures? CO2 must be one magical green house gas.

    • Well Dick, the computational device on which you presumably typed your erroneous conclusion, relies on the fact that some parts of the pieces of silicon inside it, contain “trace” impurities (atoms) that may be present at concentrations less than even one part in a million.
      Single crystal Silicon contains about 5 x 10^22 Si atoms per cc.
      Some of the doped layers that make it operate as a semiconductor device, may be doped at 10^16 impurity atoms per cc; or less, so that’s a mere one part in five million.
      So it is nonsense to claim 400 ppm of CO2 in the atmosphere is negligible; it isn’t.
      Nor is it all powerful; but it does have an effect on outgoing long wave radiation, which is not the same as warming the atmosphere.

  10. Um… Did I miss the proof? All I saw was some loose correlation put together into a bunch of speculation. I really do not doubt that rock weathering slows down when its really cold, but I do sort of doubt that is the only or even most important “thermostat” working to control temperature.
    I don’t know, but I have a sneaky suspicion the life on the planter contributes to temperature control as well.

    • Glad i wasn’t the only one thinking that was pretty flimsy. They are implying that not only does this process absorb the co2 that is there, but that it also stops new co2 from appearing as well? Eh?
      The more obvious conclusion is that co2 is the syptom of something else. The warmer it is, the more co2 is released (oceans). Previous studies have shown that co2 comes after warming and not prior.
      They also don’t account for the role of orbital shifts, continental drift and ocean currents.
      All they have shown is that this process absorbs some co2 when it is there and less when it is less abundant. They haven’t attempted to explain how this is anywhere close to being a thermostat.
      Much like trees absorb co2 and release oxygen. Imagine if i then said trees were the thermostat without offering anything to explain how the co2 increased to begin with.
      Its circular thinking.

    • Shuuuusssshhh!! The warmunists don’t like to talk about Earth’s history of abrupt climate changes prior to human civilization. To them, it’s never happened before. They actually think that the current climate on Earth is the “norm” when all the empirical evidence demonstrates that if placed into Earth’s timeline in the proper perspective, it’s really very unusual.

    • Damn humans were breaking up rocks to make tools and building fires for warmth! Some geniuses of the time said to not do it but they did anyway!

  11. So … according to these guys ….. CO2 is primarily removed from the atmosphere by dissolving in water droplets and falling as rain. So increased precipitation results in more removal of CO2 from the atmosphere. But it would also seem to follow that the concentration of carbonic acid in rain would also increase …… so, the question is, has there been an increase in carbonic acid rain over the last 20 years? I remember the acid rain scare of the 80s, but that was nitric and sulfuric acid. I dont remember anyone mentioning an increase in carbonic acid rain. But then, I could have missed it. Anybody know?

    • Dr. Deanster,
      I believe the answer to your question is that the amount of CO2 that can be absorbed by a droplet is a function of the partial pressure of CO2 and the time it takes the droplet to fall to the ground. Thus, pH is going to be fairly constant, about 5.5. However, you are right that if it rains more there are more droplets to remove CO2. However, as CO2 is removed, the partial pressure of the CO2 drops and less is absorbed into the droplets. The whole system seems to be a series of interconnected negative feedback loops.
      It would seem that water droplets are a more effective way to remove CO2 from the atmosphere because of the high surface area to volume compared to direct absorption at the surface of the oceans.

      • “negative feedback loops”. A modern term for Le Chatelier’s Principle, which we obviously need to re-learn.

      • Rain drops may be more efficient as you say, but do we have an accurate understanding of how much CO2 reacts with minerals after the drops hit the ground? It seems to me that the cycle of CO2 between air and ocean should be fairly constant. Massive vulcanism might provide a temporary surge in CO2 ( Deccan Traps or Siberian Traps formation) but a balance would eventually be restored by. weathering. I am not aware of any proven increase in planetary temperatures associated with those events.

      • CRISP,
        Le Chatelier’s Principle is just one specific feedback loop. I referred to many within the whole system.

      • John,
        Geologists, physical geographers, and geochemists have studied weathering extensively. In general, chemical weathering proceeds at a faster rate with elevated temperatures (as in the tropics) and with abundant rainfall. Presumably, increased CO2 might increase the acidity of raindrops, although I suspect that they are close to being saturated already. Mechanical weathering tends to be greatest with lower temperatures such that frost wedging can be effective and/or glaciers can remove surficial materials by brute force. There seems to be evidence that the elevation of mountains have a control over mechanical weathering, probably related to the additional potential energy of water courses.
        I don’t subscribe to the idea that CO2 has as much effect on temperature as alarmists claim.

      • It is not at all clear that leChatalier’s principle is a feedback, but one thing it isn’t is “one thing”.
        It is a general property of real systems that the effect of their operation is to set in motion an action opposing the original action. Notice that in modern parlance, that alone would designate that a priori, le Chatalier’s principle is ALWAYS a NEGATIVE “feedback”. Le Chatalier never said anything about something once started, goosing itself to even greater heights as in a positive feedback.
        But take the motor-generator system for example.
        The reason that a Tesla model S beats almost anything (even a Saturn 5 Rocket) off the mark to 60 MPH, is because an electric motor puts out its greatest torque when the rotor is completely stalled, and not rotating at all.
        Once the rotor starts turning, the whole thing stats behaving like a generator, and the direction of the generated voltage, and armature current, is ALWAYS opposite to the applied EMF, so even with the same applied voltage and the increasing rotation rate, the armature current drops, until it reaches the maximum rotation rate that it can sustain with that current, and the resulting torque.
        It’s not really a feedback, it’s a natural consequence of the operation.
        An exactly analogous situation is the evaporation of water molecules from a quantity of water in a sealed container.
        At whatever Temperature, the more energetic H2O molecules in the liquid at the high end of the M-B distribution, escape to the vapor phase, thereby reducing the mean KE of the remaining liquid molecules (effectively lowering the temperature. At the same time, the number of H2O molecules in the air above the liquid increases, so more of them end up colliding with the water surface, and returning to the liquid phase thereby lowering the evaporation rate, and that process continues until the number leaving is equal to the number returning during the same time.
        It’s not really a feedback, it is a natural settling to the new stable condition in response to a change in some variable of the system.
        But I do think LC is much closer to the truth than the Bode nonsense.

  12. If it’s like the office thermostat someone is always adjusting it (aren’t they Pinatubo and Sol!) and the rest of us suffer. So just leave it alone and it will settle to the correct temperature.
    But what is the correct temperature ?

  13. Pfft, the entire study assumes Earth’s global temperature is ultimately regulated through atmospheric CO2 concentration. Clouds/convection currents don’t enter into it at all?

      • micro6500 – “I like the chart, but how do you get negative grams of water in dry air?”
        Good question. I do not have an answer, and admit it looks odd.
        I look at that curve in general and see that Earth’s temperature range mirrors the apex of the curve. If either extreme of the curve has a tendency to ‘drive’ back towards the apex then we have a thermostat for the Earth.

        • I look at that curve in general and see that Earth’s temperature range mirrors the apex of the curve. If either extreme of the curve has a tendency to ‘drive’ back towards the apex then we have a thermostat for the Earth.

          I have been kind of vocal about this since last year.

          See the change in slope in the cooling curve?
          The first part, the high cooling rate, that corresponds to the high negative cooling net radiation, is the rate defined by ghg’s other than water. In dry air, it’s 5 or 6 F/hour.
          But as the air cools at night, it crashes into that line, and as it does, it releases latent heat, IR. But half that IR points down. And that reduces net radiation.
          And that changes the cooling rate, to the slow rate. As you can see in net radiation.
          Now here’s the magic.
          If Co2 increases increases yesterdays Tmax by 2F. That isn’t changing the dew point, inland there just isn’t a lot of water, and if there is it’s rate is already pretty well defined.
          So, the temp air has to be before the cooling rate slows is the same, no matter what max T is. If’s warmer, it cools at the high rate until that excess is radiated. In this it looks to be near 5F/hour, but let’s use 4F/hr.
          2F warmer needs 30 minutes longer to cool at the high rate to catch the unwarmed situation, so it loses 30 minutes of slow cooling. Which looks to be less than 1F/hour.
          So it ends up 0.5F warmer, with 2F of warming.
          But this chart, 30 Minutes isn’t even 0.5F, and as the days get longer it hits the line, until it starts laying down frost.

          But this process explains the effect of different amounts of water vapor, then the surface gust follows dew points.

        • Now here’s the magic.
          If Co2 increases increases yesterdays Tmax by 2F. That isn’t changing the dew point, inland there just isn’t a lot of water, and if there is it’s rate is already pretty well defined.
          So, the temp air has to be before the cooling rate slows is the same, no matter what max T is. If’s warmer, it cools at the high rate until that excess is radiated. In this it looks to be near 5F/hour, but let’s use 4F/hr.
          2F warmer needs 30 minutes longer to cool at the high rate to catch the unwarmed situation, so it loses 30 minutes of slow cooling. Which looks to be less than 1F/hour.

          let me try that again.
          “Now here’s the magic.
          If Co2 increases yesterdays Tmax by 2F. That isn’t going to change the dew point, inland there just isn’t a lot of water to evaporate, and if there is (lakes and rivers) it’s rate is already pretty well defined based on boundary conditions.
          As temps air fall at night, the air temp that has to be reached before the cooling rate slows is the same, no matter what max T was the prior day. If’s warmer, it cools at the high rate until that excess is radiated. In this example it looks to be near 5F/hour, but let’s use 4F/hr.
          2F warmer needs 30 minutes longer to cool at the high rate to catch the unwarmed situation, so it loses 30 minutes of slow cooling. Which looks to be less than 1F/hour.”

      • Is it possible this chart shows vapour pressure rather than moisture capacity? Atmospheric pressure as 0?

      • Well you not only do not get negative grams of water in dry air, but you don’t even get dry air. There is still a non-zero partial pressure of water vapor over ice at -30 deg. C

    • Homer et al: “like the chart, but how do you get negative grams of water in dry air?”
      Maybe the water gets ‘frozen out below -10C?
      And about rock weathering….never mind the incredibly weak carbonic acid how about Nitric acid… Lightning discharges at 40-100 per second world wide depending on whose satelite is being ‘Gored’ (sorry!).. lots of NOx and some Ozone generated which disolves readily in water ( tends to be plentiful in thunderstorms) … Nitric/Nitrous acid releasing CO2 from Carbonate rocks to allay fears of over sequestering Carbon, while enriching the soil with nitrates for the plants that can’t help themselves directly from the atmospheric Nitrogen.

    • This is the first time I’ve looked over your info completely, Micro. It certainly reduces the inferred delay for heat dissipation due to CO2 to something insignificant. I have been fairly certain since I started looking into this that water and water vapour are the real controlling elements in our weather. CO2 can’t be anything but a tiny footnote when we look at the fantastic amount of heat that is shed on a daily basis, let alone what the Earth sheds seasonally.
      It has done this efficiently for 4 billion years and through CO2 levels at several multiples of today’s.

      • The additional energy is exponentially used up, accelerating the hydrological cycle, which accelerates the motion of heat energy to space, while reducing the input of SWR into the oceans.
        ( do not underestimate the last, as ocean residence time of SWR is very very very long, and contains hundreds of times the energy of the atmosphere)

      • ” Heat ” (noun) does NOT escape to space, there is nothing in space to convey it, and the KE of any molecules in the air is less than escape velocity.
        Don’t tell me you’re one of those people who believes electro-magnetic radiation is “heat.”
        What is the Temperature of that “heat” once it has escaped to space ??

  14. The number one cause of dramatic climate changes is the opening and closing of oceans and redirection of ocean currents that changes with continental drift. The amount of subsea volcanism changes over time, affecting ocean temperature. You can pontificate about how many watts per square meter are warming the ocean, or you can consider how a spreading center releasing 1250 C lava field warms the ocean. It makes a big difference if a rift center is in an ocean, or runs down a continent like east Africa. You cannot have the same climate over geologic ages with oceans opening and closing on those time scales. Second, it is not idiot weathering, it is weathering of what kind of rocks, where, and how much of them is exposed at the surface. This is not fixed on geologic time scales either. Measuring granite, lava, and schist weathering is pointless on scales less that 50 million years. What they are inferring is erosion of limestone and dolomite rocks.

    • Interesting that the spastic NH glaciation cycles develop at about the same time that the panama isthmus was geologically closing a few million years ago. Restricting, then stopping, a major ocean current from the Pacific to the Atlantic oceans near the equator.

  15. Twisted reasoning from the kings of twisted reasoning.
    Silicate weathering is probably the biggest threat to life on earth. It causes a gradual secular trend of CO2 depletion frim the atmosphere which will lead inevitably to biosphere extinction due to CO2 starvation, regardless of climate.
    But again here, reason and truth have been turned on their heads.
    A fictional role of the CO2 trace gas in controlling temperature changes silicate weathering from being the destroyer of life, to being its saviour.
    Photosynthesis is real science. CAGW is dystopian fiction and reality-bending falsehood. It will lead nowhere good.

  16. What a bunch of crap….
    Again with the silly and now disconfirmed drivel that CO2 is the global thermostat control knob…. Not so much…
    CO2 has VERY little to do with warming or cooling, but EVERYTHING to do with floral and fauna survival.. Below CO2 levels of 150ppm, all life on earth goes extinct. 12,000 years ago at the end of the last glaciation period, CO2 levels hit the very dangerous level of 170ppm–just 20ppm away from an global extinction event…
    After reading this article’s headline, i was expecting to read about how cloud cover fluctuations were the actual control knob of earth’s climate, but, alas…. more CO2 drivel…
    The cooler the climate, the less ocean water evaporation, leading to less cloud cover, which allows more solar radiation to enter the oceans and work as a natural warming mechanism. Conversely, the warmer it gets, ocean evaporation increases, which increases cloud cover and reduces the amount of solar radiation entering the oceans…
    Willis has done some excellent work on the cloud-cover/global warming/cooling mechanism.
    Once Milankovitch cycles, PDO/AMO cycles, El Nino/La Nina events, volcanism, and solar cycles are factored into historic climatic events, it becomes painfully obvious that CO2 is a VERY minor player in global climate. CO2 level fluctuations are a RESULT of natural global warming/cooling, not the cause of them:
    Sure, manmade CO2 emissions have increased CO2 levels, but these emissions have beneficially increased CO2 fertilization and perhaps contributed 0.3C of the 0.83C of total global warming recovery we’ve enjoyed since the end of the Little Ice Age in 1850, which equates to a CO2 induced warming trend of just 0.017C/decade over the past 167 years…. Oh, the humanity….

    • It appears that rcp 8.5 and 4.5 scenarios are not representative of the future evolvement of temperatures.
      It would be interesting to see this plot done on the basis of the rcp 2.5 scenario.
      It is long past the time that the IPCC should abandon high Climate Sensitivity, and should get rid of the rcp 8.5 scenario.
      It would appear that the IPCC in AR6 should set their projections based upon the rcp 2.5 with their highest confidence level, and recp 4.5 scenario with a far lower confidence level.

      • I would like to see boundary lines for past limits of natural variability. A handy reference when one is looking for reasons to panic. Or not.

  17. Sorry. The assumption here is that CO2 is the important climate driver. It isn’t. So, even if this mechanism actually works it is irrelevant.

  18. Question: can anyone supply me with a web link that shows real time satellite photos of Antartica? Thanks in advance.

  19. Climate scientists get all giddy when they see the word “weathering”. They suspend all rational thought when it is used an explanation for anything.
    Weathering is only 0.02% of the annual carbon cycle and thus plays absolutely no role whatsoever in the CO2 levels in the atmosphere.
    But let’s think of the cloud feedback mechanism in the theory.
    You put more water vapor in the atmosphere and you get less clouds.
    You put less water vapor in the atmosphere and you get more clouds.
    It’s a no-brainer that this is just wrong.

  20. Can someone explain to me HOW rock weathering can remove CO2 from the atmosphere?
    In other words, rock weathering is a cause or an effect?

    • Correct me if I’m wrong, but basically CO2 from air reacts with water and Ca in rocks, creating calcium carbonate. Acid rain weathers rocks. Weathering is an effect of CO2, and sequestering is an effect of weathering.
      The process is slow, because CO2 makes rainwater only mildly acidic, but eventually much of the free CO2 is bound to limestone. Tectonic movements may break the CaCO3 and free the carbon dioxide in some hundreds of millions of years, so there is a slow recycling going on all the time.
      In my opinion, the theory is beautiful, but the problem is there’s a false dichotomy that CO2 is a primary climate driver. The Sun and oceans are much more important than CO2, be it at 300 or 400 ppm. And I’m still pretty sure we can’t get it to 600 ppm. Even if we tried particularly, but certainly not by accident. The oceans eat up too much CO2.

      • Correct me if I’m wrong, but basically CO2 from air reacts with water and Ca in rocks, creating calcium carbonate. Acid rain weathers rocks. Weathering is an effect of CO2, and sequestering is an effect of weathering.

        So let me see if I well understand. Water in the surface of rock react with CO2 just above it and CA of the rock and create calcium carbonate. Say a thin layer over the rock that will be removed by the acid rain?
        Is it correct? If so, my question is: “How much CO2 is involved in such a process around the Earth?

  21. So we need to paint the rocks? Or bust up rock depending which T we want? Ha!
    I read about a guy who had a near death experience. He went to heaven for a while. They told him that mankind was going to learn how to control the weather. Ergo, I conclude this paper may be a gift from heaven.

  22. If and only if CO2 is the primary driver of warming, which I don’t believe is valid Too bad they couldn’t “calculate” the concentration of carbon dioxide.

    • Hey that’s an interesting take. Take past temperature (say 10000 years), and based to variation in temperature, calculate the amount of CO2. Should be easy, if it is the primary driver.
      Well, obviously not.

  23. You must bear in mind that back in your school days, the science community was very primitive, They could only do things like split the atom, invent radar, go to the moon and other silly little things like that.
    These days the scientific community can do wondrous things like develop climate models to the nth degree despite false assumptions and they can arbitrarily homogenise data like the world has never seen before.

  24. The moderator did not noticed that the idea about CO2 controlling the climate is the old claim by IPCC- minded scientists. The referred study claims that CO2 is also guilty for glaciations and this would mean that CO2 is responsible for all extreme climate periods on the Earth. No way.

  25. There is a natural thermostat, however it has nothing to do with CO2. It’s the water cycle.
    Water evaporates and cools the surface, it then moves up into the atmosphere where it condenses and releases that heat to space.
    As the temperature warms, the water cycle speeds up and removes more heat. As it cools, the water cycle slows down.

  26. Whether the weathering weather would show,
    When fierce dry or humid winds do blow.
    Carbon dioxide in rain, ice, and snow,
    Corrodes rocks, with mildly acidic flow.

  27. A couple of troubles with this idea:
    a) evidence of a much smaller temperature sensitivity to CO2 increases than had been proposed a decade ago are seeming more likely (warming from models 3x observations, and more if cooling resumes)
    b) natural variation (the Pause for example and a series of major warm and cool periods throughout the Holocene with relatively little change in CO2 ) is gaining weight as the main cause of warming and cooling on all scales. A decade ago, natural variation was opined by the consensus to be insignificant, but since, the major ocean oscillations (pointed to by sceptics) have been ‘discovered’ by the consensus when the Pause and clear correlations with global temperature forced their consideration.
    c) except for the tropics, the effect of weathering is truly skin deep and that ‘skin’ attenuates further weathering. For the tropics weathering is deep but temperature there doesn’t change much over major global warming and cooling cycles. A look at rocks scraped and polished across the Canadian Shield by the last ice max still retains a high polish and fine scratches are preserved. Weathering over the Holocene is not very significant. Can’t find a decent glacially polished Precambrian granite picture.

  28. This study is absolutely no proof at all. Sure, reacton rates increase with temperature. That has been known for hundreds of years. Nothing new at all here. Still absolutely no proof that CO2 had anything to do with controlling temperature though.

  29. My daughter bought a water carbonation bottle (old term ‘siphon’?) which uses a small CO2 capsule. The pressurized gas is introduced above the water level in the flask. I was amazed that dissolution of CO2 was almost instantaneous, orders of magnitude more soluble than salt or sugar. This assures me that where water vapour is present in some ordinary amount in the atmosphere, the 400ppmv CO2 must virtually all be dissolved in water. Where it rains, it most certainly is.
    Does carbonic acid have a similar spectral absorption to CO2? I suspect not (I looked for data). If I’m correct, then water in the atmosphere has more effect than just its absorption of LWIR and the enthalpy differences of its phases. Does combination with H2O reduce CO2 LWIR?
    I suspect I will hear from someone on WUWT on this.

  30. All discussion of chemistry and volcanism aside, I’m totally puzzled as to what correlation between weathering and temperature they’re talking about. They describe a process that takes at least ‘hundreds of thousands of years,’ yet it’s clear from various proxy records that significant temperature changes have been much more rapid on multiple occasions.

  31. Statistical analysis of the time series for atmospheric CO2, (Mauna Loa, Macquarie Island, Mount Waliguan) and satellite lower troposphere temperature, UAH, show that the temperature drives the rate of change of CO2 concentration. As the Tropics has the highest average temperature it must produce CO2 at the greatest rate across the globe. That CO2 must disperse North and South away from the Equator into the Polar regions. As the solubility of CO2 increases with decreasing temperature it must be precipitated at the Poles within the ice and snow or as dry ice when the temperature is below the sublimation point of -78 degrees Celsius. That is, there is a continuous circulation of carbon from the Equatorial Zone through the atmosphere as CO2 to the Poles where it is locked into the Polar ice sheets until those sheets move sufficiently far from the Pole to melt and the CO2 becomes a component of sea water.
    The Tropics is a source for the atmospheric CO2 and the Polar regions are the sink.
    Rainwater containing dissolved CO2, which causes weathering of rocks to form calcrete, is yet another sink.

  32. This seems to accept the premise that carbon dioxide is a significant driver of “global temperature”, whatever that is.
    If we substitute “heat in the climate system” for “global temperature”, I’m still skeptical that carbon dioxide content has particularly much influence.

  33. “global chemical weathering rate declined by a factor of four”
    Whenever i see statements like this, it’s like nails on a chalkboard to me. Assuming the weathering rate cannot be negative (and I don’t even know what that would mean), it cannot possibly decrease by a factor of more than one. If you decrease anything by a factor of one, then it is, by definition, zero.
    Let me show it mathematically, if R0 is the original rate of weathering, and R1 is the new rate, and F is the factor by which the rate decreases, then:
    R1 = R0 – FxR0
    if F = 1, then R1 = R0 – 1xR0 = R0 – R0 = 0.
    If F is 4, then R1 = R0 – 4xR0 = -3R0. So not only did weathering completely cease, but some process of “REVERSE-weathering” took over, and was three times as strong as the previous weathering was. or in other words during the Hirnantian glaciation, material was ADDED TO the rocks, at 3 times the rate that it is eroded from the rocks during warmer periods. This is, of course, impossible (or at least impossible for it to have been caused by rainfall or lack thereof).
    What the authors, I believe, are trying to say is that the weathering rate during the Hirnantian glaciation was ONE-FOURTH of what it was during warmer periods. The decrease, therefore, is only by a factor of three-fourths.
    It’s similar to the sign on water-conserving urinals you sometimes see in men’s restrooms. They proudly proclaim to “use 8 times less water per flush than standard urinals”. What they really mean is these urinals use 1/8 the water of a standard urinal, but that’s not what the actual words mean. If a standard urinal uses 1 gallon per flush, then “8 times less” means 8 gallons less than the 1 gallon per flush of a standard urinal. 8 gallons less than 1 gallon is -7 gallons. So not only do these magic urinals not use any water at all, flushing them actually increases the water supply, by 7 gallons per flush. If this were true, we could resolve any drought anywhere by installing a few of these urinals and just hiring people to flush them constantly until the water levels are restored.

  34. “The main mechanism for removing CO2 from the atmosphere” is NOT rock weathering, it’s photosynthesis. This is compensated by respiration and carbon dioxide exsolution from warming oceans, of course. Permanent removal of CO2 is effected by shell rain along with carbon pumping to the ocean depths, too, but the point is moot. CO2 is NOT a greenhouse gas, and it doesn’t cause global warming (it absorbs and re-emits by line spectra in the bandwidth 13 to 17 microns, which corresponds to temperatures of -51 to -103 degrees C, well below normal Earth surface temperatures, and therefore can’t possibly contribute to global warming.)
    I find it highly irritating that such willful and especially peer-reviewed disregard of important principles of Earth science can so profoundly hamstring scientific research, thereby hindering the further understanding of the actual workings of the Earth system. Unfortunately, this revered arcane belief in the CO2/warming link pervades geological, oceanographic, and climatic investigations to a depressing degree and is found almost everywhere one looks. Nonetheless, one single hard-data confirmation of the principle in fact still remains to be found in the scientific literature. As I understand things, to be considered valid, all good scientific theories MUST be supported by multiple sources of hard evidence, but greenhouse warming theory has been somehow unaccountably excepted from this vital constraint. Isn’t it about time that something was done about that?

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