Climate scientist admits embarrassment over future climate uncertainty

WUWT readers may recall this chart which clearly illustrates just how uncertain climate science really is.

It seems that some climate academics are a bit embarrassed that they haven’t been able to pin down climate sensitivity. From EU Horizon Magazine

Climate sensitivity – reducing the uncertainty of uncertainty

by Jon Cartwright

A study published in January 2018 claims to halve the uncertainty around how much our planet’s temperature will change in response to rising carbon dioxide (CO2) levels, potentially giving governments more confidence to prepare for the future.

The results suggest that, when it comes to the climate, both the doom-mongers and optimists are wrong. On the other hand, they have prompted a heated debate over how certain you can be about uncertainty.

‘People are quite rightly looking at what we’ve done, because we’re claiming quite a big reduction in uncertainty, based on a pretty simple analysis,’ said lead author Professor Peter Cox of the University of Exeter in the UK.

The climate is a complex beast. To make predictions about how much temperatures will rise in the future, scientists employ hugely detailed computer simulations, which rely on swathes of experimental data as input.

But there is a big unknown in these simulations: how much warming do you get for a certain amount of CO2? This simple parameter is known as the climate’s sensitivity, and it dominates our uncertainty about future global warming.

Normally, climate sensitivity is estimated by looking at historical data on temperature and greenhouse gases – either measurements of global warming or records of past climates, such as ice cores and tree rings. Given a rise in CO2 and a concurrent rise in temperature, scientists can judge how much the former affects the latter.

Big range

For the past 25 years or so, studies based on this method have led the Intergovernmental Panel on Climate Change (IPCC) to conclude that the sensitivity of the Earth to a doubling in CO2 falls in a ‘likely’ range of 1.5°C to 4.5°C, with a central estimate of 3°C.

Prof. Cox believes this degree of uncertainty isn’t good enough. ‘I think it’s slightly embarrassing that we’ve had a range that is so large for so long,’ he said.

‘I think it’s slightly embarrassing that we’ve had a range that is so large for so long.’ – Prof. Peter Cox, University of Exeter, UK

According to Prof. Cox, it is difficult to reduce the uncertainty using conventional methods because the historical records aren’t enough to work out how much heat has been put into the system by human activities. Although scientists know how much heat has been added by increasing CO2​ levels, he says, they know rather less about the compensating cooling effects of aerosol particles – for instance sulphates, which are produced by volcanoes and the burning of fossil fuels.

To avoid this problem, Prof. Cox and colleagues ignore the historical warming trend altogether, and instead picture the climate as a spring. The length of the spring is the global temperature, and the weights on the end are the net heating due to CO2 and aerosols.

Crucially, to work out the sensitivity using this new method, Cox and his co-authors don’t actually need to know how much weight there is. All they need to do is measure the spring’s stiffness, and this is betrayed by how quickly the spring oscillates – or in real terms, how much temperatures have varied from year to year.

A ‘stiff’ climate equals a small sensitivity, while a ‘slack’ climate equals a big sensitivity. In their paper published in the journal Nature, Prof. Cox and colleagues estimate the sensitivity to be in the ‘likely’ range of 2.2°C to 3.4°C – less than half the range given by the IPCC.

Sensitive figures

To be clear, this range is not necessarily how much warming anyone should expect. It only reflects how much warming there would be for a doubling of CO2 levels since the baseline period of pre-industrialisation – although we’re about halfway to that threshold already.

Nevertheless, the researchers’ results appear to simultaneously exclude the very worst- and best-case scenarios. ‘I sort of see this as good news, in that our range says values above 4°C are unlikely, and so we’re not yet too late to avoid the 2oC limit set by the Paris Agreement,’ said Prof. Cox.

But not everyone is on board with the new statistics. Climate scientist Professor Tapio Schneider of Caltech in California, US, believes the researchers have mistakenly assumed that their springy relationship is linear, when it could be more complicated.

This view is not shared by Dr James Annan of Blue Skies Research in the UK. On his blog he describes himself as a ‘fan’ of the new approach, albeit ‘not uncritically’.

Professor Reto Knutti of ETH Zürich in Switzerland points out that Prof. Cox and colleagues are not the first to try an alternative method to cut the uncertainty surrounding climate sensitivity, and ‘it’s not obvious why theirs should be much better than others’.

‘So while I do find those emergent constraints promising, and I hope we will be able to narrow the range eventually, there is a danger of finding spurious and not robust correlations – the result being that error bars are too small,’ he added.

Prof. Cox admits that his group’s results will probably not be the last word, but he is hopeful that they can move the science of climate uncertainty forwards, beyond the IPCC range.

‘I think there’s good reason to believe climate scientists are now ready to reduce the long-standing uncertainty in ECS (equilibrium climate sensitivity). It is high-time that we did that,’ he said.

###

The study: https://www.nature.com/articles/nature25450

Emergent constraint on equilibrium climate sensitivity from global temperature variability

Abstract

Equilibrium climate sensitivity (ECS) remains one of the most important unknowns in climate change science. ECS is defined as the global mean warming that would occur if the atmospheric carbon dioxide (CO2) concentration were instantly doubled and the climate were then brought to equilibrium with that new level of CO2. Despite its rather idealized definition, ECS has continuing relevance for international climate change agreements, which are often framed in terms of stabilization of global warming relative to the pre-industrial climate. However, the ‘likely’ range of ECS as stated by the Intergovernmental Panel on Climate Change (IPCC) has remained at 1.5–4.5 degrees Celsius for more than 25 years1. The possibility of a value of ECS towards the upper end of this range reduces the feasibility of avoiding 2 degrees Celsius of global warming, as required by the Paris Agreement. Here we present a new emergent constraint on ECS that yields a central estimate of 2.8 degrees Celsius with 66 per cent confidence limits (equivalent to the IPCC ‘likely’ range) of 2.2–3.4 degrees Celsius. Our approach is to focus on the variability of temperature about long-term historical warming, rather than on the warming trend itself. We use an ensemble of climate models to define an emergent relationship2between ECS and a theoretically informed metric of global temperature variability. This metric of variability can also be calculated from observational records of global warming3, which enables tighter constraints to be placed on ECS, reducing the probability of ECS being less than 1.5 degrees Celsius to less than 3 per cent, and the probability of ECS exceeding 4.5 degrees Celsius to less than 1 per cent.

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211 thoughts on “Climate scientist admits embarrassment over future climate uncertainty

  1. By Lewandowsky’s Uncertainty Principle, the “embarrassingly” broad “likely” range necessarily makes climate cancer worse.

    So embarrassment is almost a psychopathic underreaction.

    These scientists, who were meant to protect us from our not-friend, The Uncertainty Monster, should feel shame. Dare I say remorse.

    Blood is on their hands. (It seems to be a week for bloody hands.)

  2. Thankfully, at least it’s not the painfully sincere, cool, band member, Prof Brian Cox mentioned in this item.

    Thankfully, because he manages to pop up in any publicity stunt going, including supporting AGW when his expertise is gazing at stars.

    But of course he’s a Prof, and therefore knows everything.

    • Blah blah blah blah, blah blah blah. Blah blah blah. Blah blah blah blah blah but it’s not to late to act.
      Lather, rinse, Repeat…

    • …..and even Newton foolishly, but fervently, believed in in alchemy: the transmutation of base metals into gold! Is it no wonder Hansen, Jones, Mann et al have got CAGW totally wrong!

      • PS: The notes that the alchemists took during their experiments led to the development of the science of chemistry.

      • Newton fervently believed in End Times eschatology and worked up to the day of his death on a Bible-based timeline to predict when the Last Judgment would occur. He “calculated” that Zionism would develop in the 1890s, that “the tribulation of the Jews” would end in 1944, and that the state of Israel would be re-constituted in 1948. Per Newton, the world does not end due to Climate Change™; the beginning of its End starts with the second coming of Christ, whom he predicted would be born in 1948.

      • “Is it no wonder Hansen, Jones, Mann et al have got CAGW totally wrong!”

        Professing certainty when you have no right to have it, just means you’re either dumb or dishonest. Tell us how and why they are wrong. No, don’t bother. You got nothing but bluster.

        [??? .mod]

      • Donald, apparently you have read nothing that has been published on this site over last decade or so.

    • Wish Brian Cox would come on here – it would be highly entertaining watching him get ripped apart……..mind you his like avoids any medium where his ego might be challenged – just like Attenborough, the vanity of being a presenter has taken over the science in him

      • “it would be highly entertaining watching him get ripped apart”

        The fantasist and know-it-all commentary here is truly comical to read. Do you guys have any self-awareness at all? Dripping in Dunning–Kruger.

      • MarkW, I don’t want your audience or attention. I feel embarrassed that I’m of the same specie as the people here. No kidding.

        [??? Gold specie, silver, copper, or one of the other alloys? .mod]

      • Donald making diagnosis of Dunning–Kruger. The irony, it burns.

        Here’s a tip for you, Donald. Insisting that someone is ‘Dumb of Dishonest’ for making a statement that everyone here but you knows is true only makes you look ridiculous. If you have something spacific to point out as wrong, try it. For instance.

        Hanson predicted the West Side Highway would be under water, either 10 years ago or 10 years from now, depending on how you interpret it. This was clearly wrong.

        Mann routinely uses shoddy statistics and ‘tricks’ like over emphasizing one tree in a series or using proxies that are known to be corrupted (and inverting their single to fit) to get the results he wants.

        If you want to argue these facts, please do so. But just dismissing them because they don’t fit your Climate Religion will only prove to everyone here you know nothing about the subject.

  3. Lot’s of strange things happening with the climate system. We had the big push of warm air into the Arctic and now a complete drop in the Arctic temperature to near or below average levels (depending on baseline).

    The WUWT ENSO page is also showing a big surge of cold water into what was looking like a large surge of warm water just below the surface. Did this just cut off a blooming El Nino?

    How can anyone claim any degree of climate change certainty?

    • Richard, along with those lower Arctic temperatures, Arctic ice extent has grown strongly, well after the usual average maximum. After stalling first week of March, Arctic ice is coming on strong now. The image above shows the last week, setting new maximums for 2018 for NH overall, as well in Barents Sea. The graph below shows that as of yesterday, Barents is well above the 11 year average, and even ahead of 2014 the highest year in the decade.

      https://rclutz.wordpress.com/2018/03/16/arctic-freezing-week/

      • And, as it has for the last 6 months (mid-August to mid-April), less Arctic sea ice = more cooling of the exposed Arctic oceanfor increased heat loss. Your point being? It is only those four fleeting months of mid-April to mid-August that the arctic sun actually increased the heat gain to the arctic ocean. Yet the arctic sea ice anomaly is near-constant all year long.

        Oh. By the way, 2018’s Antarctic sea is now larger than 2017’s Antarctic sea ice for this same date in mid-March. 1/3 of Greenland area’s more sea ice in just 12 months. Does this not trouble you?

      • C, so what?
        That average that has you so fascinated is merely the “average” since the start of the satellite era, just over 30 years ago. At a time when it was unusually cold.
        Beyond that, the number is especially meaningless because of how it is calculated. Small changes in wind patterns can have huge changes in ice extent, merely by compacting all the ice about against land somewhere, or by pushing the ice out of the arctic into warmer waters.

      • Arctic sea ice is some 7% reduced from its 1979-1981 high point. Been generally steady at -1.2 Mkm^2 since 2006-2007. (11 years of no significant decline.) No increase either.
        Mid-September low points – when there are only 50- 100 watts PER DAY difference between sea ice and open ocean heat absorption rates – are the same general anomaly: -1.5 to -1.0 Mkm^2 from the earlier 1980-2010 average. But within 1 std deviation of the more recent 2000-2010 average, and indistinguishable from the most recent 8 years of sea ice minimums.

        Always remember: Less sea ice over an entire year = More loss of heat from the exposed arctic ocean over the entire year..

      • ” number is especially meaningless because of how it is calculated.”

        Data is data, and the trend it shows speaks for itself. It’s also very funny of you to disparage satellite data for ice, but embrace it for showing the pause with respect to oxygen brightness. PS, the “average” spans a 30 year interval, and unless you have data that is better than pictures from space, you have no argument.

      • The longer term records of sea ice going back over a century show a quasi-60 year self-oscillating arctic water/ice/atmospheric system: low in the 40’s, high in the 70’s, low in the 00’s.

      • ” Yet the arctic sea ice anomaly is near-constant all year long. ” Correct……..at 3 standard deviations below the 30 year average. The problem is that this has been happening consistantly for the past decade, being below the average. One would think that there would be at least one year in the past ten where the extent would at least be equal to the average. Additionally your argument about less ice equaling more cooling, although technically correct, does not account for the source of the heat that is melting the ice.

      • No, not true. Exactly the opposite in fact.

        That only one month in one year EVER exceeded the +2 std deviation from the self-called “average sea ice” (1980-2010 period) shows that the self-called “Arctic sea ice daily average” extents is incorrect. That EVERY daily arctic sea ice extent is lower than the 1980-1990, 1990-2000, and 2000-2010 – that each 10 year average is below the previous 10 years shows that “The original 1980-2010 daily sea ice average extents” is NOT reflective of the behavior of the arctic sea ice.
        Does it show a cyclical behavior – that we are looking at the first half of a 60-80 cycle of sea ice? Perhaps. We do not know enough to claim that. Yet.
        But is absolutely confirms that the myth of a steady “single sea ice average daily extents” (beginning in 1979) is wrong.
        Do increasing hourly temperatures from 7:00 to 8:00 to 9:00 to 10:00 forebode agony in 48 hours? No.

        From today’s arctic sea ice extents, there is no “death spiral” – only increasingly negative feedbacks (increasing heat losses 8 months of the year) as sea ice declines.

      • 2 to 2-1/2 std deviations lower perhaps. And that from an artificially high average beginning in 1979-1980.
        Less than 1 std deviation from the most recent daily average extents.

        Oh, by the way, 2016 and 2017 marked the first time EVER that the Sea of Okhotsk and Bering Sea did NOT melt out completely in the summer. December 2017 Hudson Bay sea ice was higher as well. The Gulf of St Lawrence melted out many weeks later than ever before.

        Does this high reflectivity at 60 degree north not trouble you? Ice Ages kill.

      • No, it does not. Global totals are pretty low:

        And, by that, you are discrediting yourself completely: Do you not understand that “global sea ice totals” are meaningless? That the local sunlight levels falling on each square kilometer of sea ice (or exposed ocean that used to be sea ice 30 years ago) differs by latitude and day-of-year? Exposed ocean at 80 north CANNOT be compared to 70 north, 60 north nor 58 north. Even worse is to compare the “polar opposite hemispheres” at any month of year ( except March.) Each latitude band (Arctic central 70-90 north), Arctic regional seas at 60 degree north, and the Antarctic band of 58-70 degrees south) must be separately compared.
        They behave differently each day-of-year, each month.

        When the Antarctic was surrounded by excess sea ice greater than the entire area of Greenland in June 2014, did it not trouble you that “too much” sunshine was being reflected by the ever-larger Antarctic sea ice? This year, an area 1/3 the size of Greenland has “re-appeared” … And you ignore “inconvenient” increases in sea ice of tremendous area, yet “celebrate” and publicize the “harm” of “greater glacier ice loss” when one iceberg the size of Manhattan breaks off, and promptly jams in the seaway?

      • Clutz: “The longer term records of sea ice going back over a century……”

        You cannot splice old data with satellite data. Kinda like Marcott splicing instrumental data to their proxy data.

      • Fortunately, no splicing is required since ice charting is still done by the Russians, Norwegians, Danes, Canadians and Americans (MASIE being the US product), of course incorporating satellite in the analysis. You should also know that microwave sensor results are skewed in the transitional periods: trouble discerning difference between open water and ice ponds. You linked to a microwave sensor product

      • No splicing? ” ice charting is still done by the Russians, Norwegians, Danes, Canadians and Americans”
        ..
        But there is not the same “coverage” as pictures from space. The charting doesn’t cover the entire pole, nor does the charting take samples every 90 minute orbit. Two different data sources, you cannot splice them together.

        What happens when bad weather prevents the charting from happening? Bad weather doesn’t affect a satellite. Do they infill missing data points in the chart?

      • RACook says: ” Do you not understand that “global sea ice totals” are meaningless? ”

        Nope.

        They are just another data point showing global warming. Ice is melting and sea levels are rising. You can argue all you want about month to month variations, but the fact remains that over the observed 30 year climatic interval, total global ice has shrunk. The symptom is shrinking ice, the disease is rising temps.

      • I did NOT say that. I said, very specifically, that there was ONLY one time that Arctic sea ice was greater than +2 std deviations above the official 1980-2010 average.

      • C. Paul Pierett

        ..
        “one” time does not beat 10 years in a row.
        ..
        You don’t have much competence in statistics.

        Hmmmmn. IF a sequence of data is really randomly distributed around a mean, then the distribution of high points and low points will be equally distributed about that same mean. That, in 38 years of data collection, only one month of data is “above” +2 std deviations above the assumed (constant) “mean” is present, and that dozens of YEARS of data is below that same “mean”, yields only one thing: The assumed constant mean is NOT CONSTANT. The “Average Arctic Sea Ice” varies year-to-year.
        Now, as to individual qualifications: Yes, my Masters is in Statistical Quality Assurance. What is your academic qualification to challenge it?

      • ROTFLMFAO @ Mr. ” Masters is in Statistical Quality Assurance”

        “38 years of data collection, ”

        2018-38 = 1980

        ” Look at the 1979 display”

        You fail arithmetic.

      • Mr Masters is in Statistical Quality Assurance, here is the error in your analysis: “IF a sequence of data is really randomly distributed around a mean”
        .
        When there is some kind of external forcing that causes a significant downward trend in the data, it’s no longer “random”
        .
        The problem you have is that it is not distributed in that fashion, and statistical tests of normality will tell you that.

      • Ron Clutz March 16, 2018 at 3:30 pm
        No need to be sarcastic Paul. It is all about the pause in ice decline, since the regime change starting after 2007.,/blockquote>

        It is always worth looking at Ron’s blog, he has many insightful articles.

        As the MAISIE data shows, there has been no trend in the data. See:

        It would appear that since 2007, whilst there has been much annual variation, the declining trend has at any rate stabilised. Whether Arctic Ice extent will continue to stabilise, or will in fact once more decrease, or will perhaps increase over the coming decade, no one knows.

        The only thing we can be reasonably certain of is that the many forecasts of an ice free Arctic are wildly premature. These extrapolations fail to take account the geometry of the planet and the very short period when the Arctic receives significant solar iradiance. Unless there is a significant change in oceanic currents, we will not be seeing an ice free arctic anytime soon.

      • C, there you go again, putting your ignorance on display for all to see.
        Yes, data is data, but how you interpret that data varies depending on how the data was gathered.

      • @ C. Paul Pierett March 16, 2018 at 6:15 pm; “…the disease is rising temps.” That’s like saying “…the disease is pregnancy.” Not only are both entirely natural, they both produce something beneficial!

      • It’s like a massive amount of water (a thousand miles wide) got pushed up hundreds of meters in one week. I suppose it could be equipment malfunction. I wonder how many sensors were involved in reporting that change.

      • How many sensors were involved in reporting that change?
        Being positive – 1.
        Being negative – 0.
        It’s just the effect of smoothing sensors from 1,000s of miles away.

  4. “…he is hopeful that they can move the science of climate uncertainty forwards, beyond the IPCC range.”
    This is unrealistic given that they wrongly set the stage with: “Given a rise in CO2 and a concurrent rise in temperature…”

    No matter, it is the Adjustocene

    • Their estimate of climate sensitivity is based on simulations and politics, rather than actual investigation and data.

      That is why it does not change, the politics have not changed, so they are not allowed to change the ECS.

    • Nice graph, Willis. But maybe Nir Shaviv has one thing wrong: does “the most important question in climate” have anything to do with CO2?

      • Mike Jonas March 16, 2018 at 4:16 pm

        … does “the most important question in climate” have anything to do with CO2?

        To be more clear he could have said “what establishment climate scientists say is the most important question in climate” …

        w.

    • This comment could have gone anyplace, really, but it wound up here… The Equilibrium Climate Sensitivity with respect to CO2 cannot be determined anymore precisely than it has been in the past because THERE AIN’T ONE! No line of evidence can actually show that the Earth’s temperature responds at all to doubling (or halving, even) of CO2, while multiple lines of evidence show that the atmospheric CO2 level responds to temperature. The whole fr@ud of Anthropogenic, oops forgot the Catastrophic Anthropogenic Global Warming, ummm… Climate Change, uh, Global Weirding, oh nevermind…, has been a house of cards constructed on shifting sand in a hurricane. Which proves only that this never was about climate, this was only the mask worn by the camel’s nose to (ultimately) bring about government control of global energy consumption. As many in the UN have stated gleefully many times over. Wake up, People!

  5. “although we’re about halfway to that threshold already.”….then the next half would be less than 1 degree

    • Following their assumption that the response is linear across the range… Yes.

      But that is a big assumption. Weather is chaotic. Why would the integral of weather over time (climate) not be chaotic?

      A slight difference in starting state can lead to completely different outcomes after each iteration, in a chaotic system.
      If climate is chaotic then your well-reasoned calm and this prediction of a “climate scientist” are both unjustified.

      • The assumption is that it’s not linear…..the next half will have even less effect…wash rinse repeat

      • Sorry. My language was poor. Beer-Lambert’s Law should apply. The decline would be logarithmic if the response was consistent. If.

        A log response is still a smooth response to a second order differential. It’s still not changing the rules entirely as you go “up”.
        Chaos means more than the effect is not 1 to x.

        Chaos means you are playing ‘Snakes and Ladders’, throw a 6 and land on the Mousetrap board. No longer do you fear a snake. Suddenly the trap might stop you entirely or the diver might miss and nothing happens.
        A whole new boardgame.

      • These are excellent questions, and they get at the heart of the matter for a lot of people, I think. I wondered for a long time how they treat random incidents like volcanoes. I worked it out, I think (?) while camping in the Wyoming for the eclipse (amazing!!!) after talking to a guy there who controlled weather satellites.

        Weather is chaotic. It is forecast at high resolution with great models but will never get past a couple weeks because of the chaos. It results in model instability.

        Climate is instead treated as stochastic (this is my guess). Stochastic processes can be mathematically accounted for. This allows a degree of random internal variability that is constrained by a normal distribution. That’s how you can produce the effects of storms (for instance) and find out their frequency even without being able to say when one will happen.

        It’s really fascinating to me that they can do this: build a model with thousands of variables that will run through even a few iterations and have it do something.. But it works. They start running the bare bones hundreds of years ago to “spin it up” then add things along about the Industrial Revolution, make sure they can get present day right, and on into the future…. And it’s stable! And they all generally agree qualitatively about the important things. That’s the thing: there is quantitative uncertainty but qualitatively the agreement is remarkable. It’s possible the IPCC left a wide range of possibility open not because it’s no more likely that we will have a 3 degree rise than a 4.5 one, but to get the point across that this is flexible. It’s dependent on how humans respond. Look how narrow a range most of the means are in on the chart at the top…..Ah, and look at the mean for all the IPCC5 models, how different it is. What’s been left off the chart??? Those two at the top wouldn’t account for that.

      • It’s possible the IPCC left a wide range of possibility open not because it’s no more likely that we will have a 3 degree rise than a 4.5 one, but to get the point across that this is flexible. It’s dependent on how humans respond.

        No it isn’t. Human response has nothing to do with this. Only natural processes (aside from the sources of CO2 and maybe aerosols) are supposed to be captured in the models.

      • “It’s possible the IPCC left a wide range of possibility open not because it’s no more likely that we will have a 3 degree rise than a 4.5 one, but to get the point across that this is flexible.”

        Ok Kristi, if there is an wide range of flexible possibility, added in with a chaotic probability, then why isn’t there an equal chance that things could just as well as be colder temperatures in the computer model?
        Like several years ago, they never predicted colder winters because of global warming, but made inference that we won’t know what snow is, that winter’s will always be milder as things warm up, and not have to try and explain now why we are having colder winters and more snow. Isn’t it possible they introduced human bias into the model, by thinking the sensitivity to CO2 is higher than it actually is? What if it turns out the sensitivity to CO2 is as stated theoretically (1.2 C per doubling) since without the mystery feedback loops that give us the 1.5 C to 4.5 C rise by 2100, there really is not a lot of significant man made global warming to follow? The Pause seems to be telling us that…

      • Kristi Silber, a stochastic approach to one off events isn’t science. At best it’s opinion.

        How do you model the effects of an Industrial Revolution? How many have we averaged?
        How have we distinguished the effect of man from nature?

        And even if we could then the uncertainty should reduce. We have seen that the world is not following the energy mix of RCP8.5. Yet it doesn’t reduce.

        Because if it did the models and science would be proven to be wrong.

      • Tsk Tsk,
        Was that quote from the paper in question? I am curious because it is so blatantly wrong that I would hope that not even a warmist scientist would make the assertion.

      • tsk tsk
        “No it isn’t. Human response has nothing to do with this. Only natural processes (aside from the sources of CO2 and maybe aerosols) are supposed to be captured in the models.”

        Normally if one were looking at a calculated range there would be a mean and different intervals corresponding to probabilities, and the numbers wouldn’t be nice and round. Instead there is a broad range with a “certainty” of “likely.” If the data are approximately normally distributed, that means that it is more likely that sensitivities lie in a smaller range. This is my reasoning behind a complete speculation, which very well may be wrong.

        Only natural processes are supposed to be in the models? I thought land use change was also in some of the models; aerosols definitely are..
        …………………………..
        Earthling2
        “Ok Kristi, if there is an wide range of flexible possibility, added in with a chaotic probability, then why isn’t there an equal chance that things could just as well as be colder temperatures in the computer model?”

        If climate were truly chaotic there would be no long-term cycles or patterns, and you are right, it would be unpredictable. But there are patterns, interactions and feedbacks that keep it within an approximate dynamic equilibrium, and it is this dynamic equilibrium that models need to be able to reproduce. I imagine it’s trickier to model future climate than that in the past because it is out of equilibrium: the energy balance of the planet is off. One has to figure out where the extra energy is going, what it’s affecting. To me it seems that modelers have done a good job considering the difficulty of the task. The fact that all the models point to increased temp in the long term suggests they are doing something right, since such agreement would be highly improbable if random.

        “Like several years ago, they never predicted colder winters because of global warming, but made inference that we won’t know what snow is, that winter’s will always be milder as things warm up, and not have to try and explain now why we are having colder winters and more snow. Isn’t it possible they introduced human bias into the model, by thinking the sensitivity to CO2 is higher than it actually is? What if it turns out the sensitivity to CO2 is as stated theoretically (1.2 C per doubling) since without the mystery feedback loops that give us the 1.5 C to 4.5 C rise by 2100, there really is not a lot of significant man made global warming to follow? The Pause seems to be telling us that…”

        Actually I remember in the fall reading that that “they” (not sure who) predicted a colder, snowier winter for the upper midwest and northeast.

        Climate scientists never predicted uniform warming, either chronologically or regionally. The pause was and remains an opportunity to learn.. It may have been embarrassing to alarmists, I don’t know and don’t care. Scientists might have cursed it simply because it provided ammo to deniers. It in no way weakens the theory of AGW, which never denied natural variation would still be expressed.. The harsh winter may be an instance of natural variation interacting with human effects.

        ……………………………………….
        M Courtney

        “Kristi Silber, a stochastic approach to one off events isn’t science. At best it’s opinion.
        >>>No, the stochastic approach isn’t to one-off events, it’s to events collectively that are repeated at intervals, with a variety of intensities. It would be an algorithm that encapsulates these events. One can look back through time and get an approximate idea of how often and how intense volcanic eruptions are, and what their likely climate fallout, then add this to the model in order to account for the effects without having to be able to predict them from other model parameters, which would be impossible.

        “How do you model the effects of an Industrial Revolution? How many have we averaged?
        How have we distinguished the effect of man from nature?”

        (I have to make it clear that I’m just learning about modeling, and what I say is a combination of speculation and reading.) I on’t know what you mean, how many have we averaged. From my reading I understand that the different modeling groups have different interests and focus on different aspects of a model, which is one reason the mean of the whole is a better overall predictor than any single one. Anyway, these groups also build their models differently, including whether as part of the process they try to match the 20th It’s the source of debate within the community (says The Art and Science of Climate Tuning, a fascinating paper). This doesn’t answer any of your questions, though. There are a few ways of distinguishing the effects of humans. There are statistical ways like PCA and multiple regression, calculations based on measured parameters, and comparisons of models run with and without human influences. I’m sure there are others.

        “And even if we could then the uncertainty should reduce. We have seen that the world is not following the energy mix of RCP8.5. Yet it doesn’t reduce.”

        “Because if it did the models and science would be proven to be wrong.”

        No, why proven wrong? RCP8.5 is just one modeling scenario. There is no proof that we will not once again follow that path. I don’t quite understand you here.

        To prove the models wrong based on their predictions you would have to say that their long-term predictions in general are wrong or that there is some fundamental element of the models that makes them too weak to be reliable, or you would have to demonstrate that models come up with predictions that are totally implausible. You can’t say with good reason, “Hurricanes aren’t getting more common, showing modeling is false!” or “Look at the winter, the models are wrong!’

        Again – this is my understanding. Don’t quote me.

      • You say “don’t quote me” but I’m going to anyway, just to add clarity. I recognise that you are not expecting a nit-picking evaluation of every word. That would be unfair.

        “And even if we could then the uncertainty should reduce. We have seen that the world is not following the energy mix of RCP8.5. Yet it doesn’t reduce.”

        “Because if it did the models and science would be proven to be wrong.”

        No, why proven wrong? RCP8.5 is just one modeling scenario. There is no proof that we will not once again follow that path. I don’t quite understand you here.

        RCP8.5 is a modelling scenario that assumes that coal is the dominant energy source for the last thirty years, now and beyond and that energy efficiency changes do not happen – but they have and it isn’t. RCP8.5 is redundant and should be discarded.

        However, if it was discarded then all the model outcomes that derive from that scenario would have to be discarded. That happens to include all the models that can lead to dangerous rates of warming after the slow rate of warming we have had since Rio in the early 90s.
        If the total range of sensitivity is reduced (by throwing out the unrealistic scenarios) then the envelope of climate models doesn’t reach the newsworthy region. The world is not ending.

        On the other hand if the climate sensitivity range is reduced while keeping in the scary outcomes of RCP8.5 then the envelope of model outputs no longer includes the currently observed reality. The models are then wrong.

        If climatology were a real science then the observations would determine the acceptable choice of models. But as climatology is a pseudoscience that assumes the truth and then looks for evidence to back it up… the models are allowed to stand and no progress can be made.

      • I shouldn’t have quoted you. Because the /blockquote was missed.
        All the inner quote are my new words.

    • We have had 68 years of massive fossil fuel burning with only 0.5C increase in temp. And with no acceleration in temp. Extreme weather events have not increased in that time. Noone has died from heat exhaust from global warming . Noone has drowned from sea level rise which is not accelerating. The Arctic has not melted. Greenland has not melted. Antarctica has not melted. Even if all the glaciers in the whole world were to melt sea level rise would only be 40mm. There has not been 1 bad thing to have resulted from any warming. Only good things have happened because of more CO2 in the air like 18 % more greenery globally in last 30 years. So why are we spending hundreds of billions of $ worldwide fighting a bogeyman like global warming?

      • Prior to that, we had around 70 years with very little fossil fuel burning, and a 0.3C rise in temperature.

      • Why not start with the assumption that CO2 sensitivity is ZERO? That, it seems to me, is the proper null hypothesis. CO2 “sensitivity” is assumed by warmest experts to be something other than zero, I suppose, perhaps, just because the Keeling data series shows CO2 doubling in what might be viewed as an alarming rate. However, there is no reason to assume that the tiny fraction of the atmosphere which is CO2 will have any measurable effect (other than greening) on climate.
        Ronald Havelock, Ph.D. (psychology.) In my program at Boston University rigor was important. We had to take a lot of statistics, not to mention scientific method, and we had to learn what good study design was. That was science. Unfortunately, most scientists don’t really know what science is. Proof of that is AAAS endorsement of CAGW theory. Theory without supporting data is not science. Models are theory. So is theology.

  6. The global warming fear industry got traction not from Al Gore but from mathematical projects that were incomplete and now proven to be grossly inaccurate in one direction . In essence they collectively are a failed forecast yet governments have not recognized the forecasting farce and adjusted course .
    This fact demonstrates the pressure modellers are under to produce a product the government wants . That being alarmist nonsense to try and justify three main objectives , more taxes , reward “clean energy ” corporate welfare , and to further liberal globalist objectives .
    Normally when forecasts are wrong over and over all in one direction anyone interested in the truth
    adjusts to the circumstances by recognizing the repetitive forecasting errors and shortcomings , then
    making decisions on reality .
    This has not happened with respect to the earth has a fever industry because in would undermine the
    three main objectives of the industry which hopes to continue with a $trillion fraud .
    The climate models are a work in progress that don’t even pretend to calculate the main drivers of climate , those of natural variables .
    Current climate models are equivalent to sticking a mirror on a car and then estimate the cars speed
    without knowing the cars other main mechanical parts .
    The real question is how did the farce get this far while tax payers have been ripped off and killed by
    incredibly stupid policies ?

    • the core of this is even more foul. It is the vehicle of eugenics. The transhumanists and technocrats work hand in hand with the neo-marxists. These people want to huddle everyone into complete surveillance high urban density smart cities, elminate combustion engines and thus also severely limit personal transportation with electric vehicles, slowly kill off the population using energy restrictions through smart devices, and as AI gets better and better, they need significantly less people around…to the tune of 500 million.

      For the life of me I don’t understand why so many people can see the minutia but refuse to look at the history, words, actions, and outcomes of these interrelated fields of domination.

      LONG TERM SOFT KILL. period. and the next generation is eating it up in this disgusting prussian “education” system.

      • and as crazy as that sounds…go have an in depth discussion with most alarmists.
        THey have totally bought into the malthusian, misanthropic, hatred of humanity. They are typically pro-abortion, anti-death penalty (what a hell of a backwards worldview- sure let’s eliminate those who haven’t had a chance to live but keep the one’s who have given up the right…typical leftist horseradish), anti-gun, anti-Christian (not that I’m a fan but I’m not anti), pro-unlimited genders based on feelings, collectivist, pro-government statists. I talk about this daily with everyone I can get a conversation with. The overlap of moral relativism is undeniable in these people. Useful idiots, contributing towards the final destruction of the individual.

        They seriously cannot be helped. Gary Pond is one of those very individuals.

  7. I do love the way that they move the pea under the walnut shells … you have to watch very carefully. The headline says that this is a study developing an “Emergent constraint on equilibrium climate sensitivity from global temperature variability”. Sounds good, something that is actually observation based.

    However, as my beloved Dad used to say,

    “The big print giveth, and the small print taketh away … blessed be the name of the print.”

    And bearing that out, in the abstract it says “We use an ensemble of climate models to define an emergent relationship2between ECS and a theoretically informed metric of global temperature variability.”

    So the headline really should be:

    Emergent constraint on equilibrium climate sensitivity from a bunch of climate models

    w.

  8. They should be embarrassed to call themselves scientists, yet they choose the “uncertainty in ECS” to be slightly embarrassed about. It’s like bank robbers being “slightly embarrassed” about the way they dress when they rob banks.

  9. Fake uncertainty. Certainly it is certain the certainty is not as uncertain as they ascertain.

  10. It only reflects how much warming there would be for a doubling of CO2 levels since the baseline period of pre-industrialisation

    Pre-indsutrial commonly being cited as 1750 AD, apparently the earth was at some ideal temperature at that time? The truth is we’re WAY better off TODAY on almost every metric there is, food production first and foremost. So why do they insist on setting a 2 degree limit based on 1750? Should they not be setting limits from where we are NOW?

    Of course they will not. First, they’d be admitting that the warming since 1750 has been beneficial. Second, the cause for alarm would evaporate. In 1750 it would have taken 280 ppm of CO2 to double. Today it would take 400. CO2 is logarithmic, the discussion should just stop there. The 120 ppm we added in the last 267 years was an increase of 43%. The next 120 ppm is an increase of just 30%. As soon as we start calculating from where we are TODAY, all the numbers shrink accordingly.

    • And until they figure out what caused the Little Ice Age, this is probably a futile endeavor. As there are other things going on, many unquantified if even recognized, this single-minded concentration on GHG levels will probably never yield an accurate climate model.

    • Of course “they cannot” (name set points that are relative to today’s climatic optimum). Because it’d end up being laughable.

      It is much more “worrying to ordinary blokes and lasses” to have greatly magnified numbers relative to the previous mini-Ice Age. 1750 AD is a perfect starting point. Colder than a witch’s tît, it was. Today is at least +2°C hotter. Already. If instead, we were to harken back to oh, say, 1977 when McCall’s (was it?) dictionary printed up a whole oh-my-gawd looming Ice Age edition of their yearly encyclopedic science summary, people were genuinely worked up that another REAL (not mini Maunder-Minimum type) Ice age Approacheth. It was a bit warm, but due to become cold … don’t you know.

      But it would be almost laughable to say, “if temperatures go up more than 0.3° over the 1977 optimum, we’re going to fry, our children will die, oh my, oh my” with a serious face. People would look at the proclaimant and chuckle… ⅓ of a degree? I can’t even get my house HVAC to within 3 degrees of “comfortable”, and all it takes is one of my idiot-kids leaving the back stoop door open on a hot day to ruin the whole kitchen “retreat zone”.

      Just saying.
      Activism requires spectacular projections.
      They in turn need unreasonable basis conditions.
      And cherry-picking the least accurate, most egregiously improbably models’ results.

      This is climate tech.
      Today.
      A farce.

      GoatGuy

      • The existence of something we call an electron is settled, but it would be wrong to say the mass of an election is settled. The existence of increasing CO2 in the atmosphere is settled, but it would be wrong to say the impact of increasing CO2 is settled, which is exactly what is implied everytime the settled science argument is whipped out.

        It is a lie with no defense.

        Not sure what point you were trying to make.

      • “Relative Uncertainty: 1.2 x 10-8”

        Let me know when ECS uncertainty gets within 5 orders of magnitude of that…

      • There is no such thing as a settled science. Science rejects the null, it never validates it. Huge difference. People are found not guilty, not innocent. That is why OK didn’t go to jail for killing two people.

  11. How is it that they always “miss” the pauses (70 years out the last 150 years)
    CO2 was rising during those pauses, including the current pause.
    Or “miss” the several cooling periods.

  12. ECS cannot be calculated from first principles, else someone would have done it long ago. The assumption that all warming since 1750 was caused by CO2 is completely unscientific. After all, this was in the middle of the coldest period in this interglacial, the Little Ice Age. What made it so cold then? Why was it warmer in Roman times and the Medieval Warm Period, as well as 4000 years ago?

    Radiation’s effect on CO2 is well-understood, but the way the atmosphere radiates to space, through the CO2 at TOA, is immensely complex. Hence, no one knows how much extra energy will be retained in the atmosphere by an increase in CO2.

    No One Knows, that is all there is to it.

  13. Although the lack of certainty would seem bad , it is also ‘useful ‘ for when one claim fails you can quickly move onto another with a dust of may’s could , possibles behind you. Its actual a ‘strength’ of climate science to ‘facts’ which are like nailing jelly to a wall.

  14. Science is a near-frame (space and time, forward and backward) philosophy with cause. What is unknown and unwieldy necessarily constrains our skill and perception.

  15. “Although scientists know how much heat has been added by increasing CO2​ levels”

    No they don’t.

    “Crucially, to work out the sensitivity using this new method, Cox and his co-authors don’t actually need to know how much weight there is. All they need to do is measure the spring’s stiffness, and this is betrayed by how quickly the spring oscillates – or in real terms, how much temperatures have varied from year to year

    A ‘stiff’ climate equals a small sensitivity, while a ‘slack’ climate equals a big sensitivity. In their paper published in the journal Nature, Prof. Cox and colleagues estimate the sensitivity to be in the ‘likely’ range of 2.2°C to 3.4°C – less than half the range given by the IPCC.”

    This is absolutely ridiculous and childish method, and really no different than all the other oversimplified methods. They seem to presume that all year to year temperature variation is caused by changes in CO2, and that the response time is immediate. Both of these assumptions are obviously flawed.

    The entire field of climate science is an absolute joke. Calling it science is an insult to real scientists.

  16. Climate science needs to reduce their stated uncertainty. It’s a political necessity.

    No science can fail to make any progress over 30 years with the investment climatology has been lavished with.
    No science can fail to make any progress with lots of new instrumentation such as the satellites and ARGO buoys that climatology has been lavished with.
    No science can fail to make any progress with the increase in computational power to support their models buoys that climatology has been lavished with.

    QED, climatology is not a science.
    We know this anyway. Science does not try to reverse the null hypothesis, corrupt peer review or seek to silence dissent rather than debate.

    Climatology has been a faith-based belief system since the UNFCCC demanded it sought evidence for CO2 dominance of the climate instead of letting scientists seek evidence to attack all assumptions. That’s how real science works.

    Scientists seek evidence to attack all assumptions and those that survive can be trusted. Climatology trusts too soon.

    • Ive been searching for the holy grail heat radiative transfer equations that all the alarmists talk about. I cant find them

    • But M Courtney,

      we’re the ones preventing any progress in climate science by not believing in it. The caravan cannot move on until consensus is achieved. Isn’t it a little chutzpaceous, even by our audacious standards, to hold its stasis against it, when that stasis is deniogenic in aetiology?

      • Brad Keyes, of course you are right.
        But doesn’t that condemn them for lack of faith?
        We are few and have quiet voices. Yet we can steer their whole consensigarchy.

      • Brad,

        It appears you keep keeping the Zipf law valid for the order of low-frequency words. That’s good, we need to shame the people who keep machine-translating ‘battery low’ as ‘accumulator below’. It gives me creeps when the manual of a medical device is fed to a garbagerator.

      • We are few and have quiet voices.

        Hmmmm.

        This assertion flies in the face of the general Law of Disproportionate Vocality, better known in its special form, the Law of the 4 Magical Jews. If the former (your bold opinion) is right and the latter (Merchants of Doubt Theory) is ipso facto wrong, then Religious Studies scholars will have to go back to the drawing board if they want to explain how The Cause lost its juggernautical inertia circa 2010 and became… well, inert. For the world’s poseurs and poseuses this problem will go from a poser to a paradox overnight.

  17. Does this mean…….. that the world isn’t ending? What will I tell my friends at school?

  18. Ever since “Climategate” their problem has been how to stealthily segue from “We’re doomed!” to “Never mind”.

    • As i understand it thiis article it is basted on a doubling of co2. But there is no mention of the logerithmic effects of co2.

      A doubling of co2 would have very little effect on the worlds temperature.

      Anyway we already know that the ” magic molucle ” does not retain heat, but only re-radiates it.

      Mje

      • The log doesn’t make a big diff (compared to a linear approx) between 410 ppm and 550 ppm. And it is not exactly log either..

      • MarkW: “Heat that is re-radiated, is retained.”

        That implies: light reflected in a room full of mirrors is retained

        Now let’s consider duration, how long is it retained? How long does a room full of mirrors stay lit after turning out the lights? That’s the order of magnitude for the duration of your ‘retention’?

        And, what of the heat that is ‘re-radiated’ out to space, where is that heat retained?

        Looks like you’ve got some clarification work on your proclamation.

  19. It seems that some climate academics are a bit embarrassed that they haven’t been able to pin down climate sensitivity.

    It would be even more embarrassing if it didn’t exist.

  20. why are people surprised by any of this? the CO2 IR lines in the atmosphere are saturated, and they were at about 10% of pre-industrial levels. this isn’t even in contention, otherwise folks would be talking about a linear sensitivity (degrees per %CO2) rather than a logarithmic one (degrees per doubling).

    the whole mess started when folks ASSUMED that the 90s temp rising was due to CO2, and assumed an ad hoc multiplier in the models to make it so. extrapolations of disaster resulted. ever since then, the planet has not cooperated, as CO2 continued to rise while temps didn’t. the ad hoc multiplier kept shrinking and has now practically disappeared as they have been forced to include the last 20 years in the model.

    unfortunately, our government agencies are not scientists — a scientist would re-evaluate the hypothesis when the data fails to fit it. instead, they want to change the data to fit their model. the historical databases have now been corrupted unbelievably, as they keep cooling down the temps from the early 1900s. modifying the data to fit the model and then claiming the data supports the model is ridiculous — and one must conclude that those responsible are either incredibly corrupt or incredibly stupd – there is no third choice.

    when will somebody out this loudly enough for the media to notice?

    • jeff March 16, 2018 at 3:53 pm

      why are people surprised by any of this? the CO2 IR lines in the atmosphere are saturated, and they were at about 10% of pre-industrial levels. this isn’t even in contention

      Thanks, Jeff. I fear that you’re in a common misunderstanding about CO2, that it’s like a coat of paint. People say things like this:

      If you paint a pane of glass with paint thinned way down so it’s partly transparent, that’s like when CO2 is not saturated. But if you put a full coat of paint on the pane of glass, that’s when it is saturated … and putting more coats of paint on it does nothing at all.

      In fact, this is a misconception. If you put a solid coat of paint on glass, NO light gets through. Every photon absorbed by the paint. Full saturation.

      But the same is not true with CO2. Even though every photon is absorbed if the CO2 band is saturate, the same number of photons are then emitted, with ~ half going up and ~ half going back to earth.

      So the difference is, a saturated coat of paint cuts the light to zero, but a saturated CO2 band merely cuts the radiation leaving the earth in half.

      And as a result, when you add more CO2 to a saturated situation, it reduces the number further. If on average each photon is absorbed by CO2 not once but twice on its way to space, even less of the energy makes it out to space … and even less than that if on average each photon is absorbed three times … so despite the CO2 lines being saturated, more CO2 absolutely makes a difference.

      Best regards,

      w.

      • Willis, it is in fact thermalised at a ratio of thousands to one. Should it warm, instantly the radius of movement leaos and so does the CO2 molecule(s). Uplifting energy to space…… So much for holding. Gases have no surfaces, no fixed constraints. They can go with the power, leaving the LT the cooler for it.

      • Thanks, Willis. I understand the physics of saturation. If you notice, I did not say that the climate sensitivity was zero, but that it was logarithmic, as all agree. That is the typical effect of saturation. Your paint analogy is better stated as a paint that blocks 99%…… another coat blocks 99% of the 1% that is left, and so on.
        I also agree that the physics is scattering, not absorption. That nevertheless has the same effect — adding more CO2 to a saturated system just compresses the thickness of the layers for scattering closer to the ground. The most profound thing that you will do by adding more CO2 to an overly saturated earth is lower the elevation where the “knee on the curve” of scattering occurs.

    • not saturated.
      pressure broadening.
      i guess you never read any of the air force work in the 50s that forms the basis of this.
      smh

    • Ignore the lower troposphere where long wave photons travel only a short distance before being absorbed by GH molecules and thence mostly thermalized. Any GH magic occurs in the upper troposphere in the characteristic emissions layer where a substantial portion of long wave emissions escape to space. This is governed by the atmospheric pressure at that altitude. The magic pressure appears to be about 1/10 bar and is labeled the tropopause. The tropopause at about 1/10 bar can be observed in the atmospheres of other planets in our solar system.

  21. I sense a glimmer of hope here. They are admitting failure in estimating the ECS after years and $$$ of research. These particular scientists are essentially pleading for someone to scientifically increase the confidence in the ECS estimate. If no-one can then these particular scientists have no choice but to embrace skepticism – all their scientific credibility will evaporate if ECS remains quite uncertain and yet they still stick to the script of unstoppable catastrophic warming. They may be on our side soon. Maybe.

    • Only when they retire because if any active climate scientist questions global warming they are either fired , lose their right to publish, lose their grant money, or are shunted aside with no promotions.

    • failure?
      huh.
      you never worked on wicked estimation problems. i bet you are an engineer.

  22. The environmental lapse rate should correlate with the insulation effects of the atmosphere. The higher the lapse rate the more insulating is the atmosphere. If CO2 really affected climate then the increase in CO2 over the past 30 years should have caused at least a measureable increase in the dry lapse rate in the troposphere but that has not happened. In terms of the measured effect of CO2 on the lapse rate over the past 30 years, the climate sensivity of CO2 is zero. The climate sensivity of CO2 being a small number is a good reason why no one has been able to actually measure it. Theoretically, a doubling of CO2 should slightly lower the dry lapse rate which is a cooling effect. Based on how CO2 should effect the dry lapse rate. the climate sensicity of CO2 should be slightly negative.

    For those that believe in a radiative greenhouse effect, the initial radiametric calculations performed decades ago came up with a value for the climate sensivity of CO2 neglecting feedbacks of 1.2 degrees C. One researcher has pointed out that these initial calculations failed to take into consideration that a doubling of CO2 in the tropshere will cause a slight decrease in the dry lapse rate in the troposphere. That decrease in the lapse rate will cause a reduction of the climate sensivity of CO2 by more than a factor of 20. So now we have a value for the climate sensivity of CO2 excluding feedbacks of less than .06 degrees C.

    An important part of the AGW conjecture is that H2O provides a positive feedback to any CO2 based warming. The idea is that CO2 based warming caused more H2O to enter the atmosphere which causes even more warming because H2O is also a so called greenhouse gas with LWIR absorption bands. The IPCC really is not sure how strong this positive feedback effect is but they like to use numbers like 3. H2O is actually a stronger absorber of IR than is CO2 and according to greenhouse gas theory is by far the primary greenhouse gas so much so that the addition of CO2 is trivial. However; the AGW conjecture ignore’s the fact that besices being the primary greenhouse gas, H2O is a primary coolant in the Earth’s atmosphere transfering heat energy from the Earth’s surface, which for the most part involves some sort of H2O, to where clouds form via the heat of vaporization. According to some energy balance models, more heat energy is moved by H2O via the heat of vaporization then by both oonvection and LWIR absorption band radiation combined. The net cooling effect of H2O is evidenced by the fact that the wet lapse rate is significantly less than the dry lapse rate. Hence rather than amplify the climate sensivity of CO2 by a factor of 3 a more realistic effect would be to reduce the climate senisvity of CO2 by a factor of three yielding a climate sensivity of CO2 of less than .02 degrees C which is a trivial amount.

    The AGW conjecture depends upon the existance of a greenhouse effect caused by trace gases in the Earth’s atmosphere with LWIR absorption bands. A real greenhouse does not stay warm because of LWIR absorbing heat trapping gases. A real greenhouse stays warm becaue the glass reduces cooling by convection. It is a convective greenhouse effect that keeps a real greenhouse warm and not a radiative greenhouse effect. So too on Earth. Gravity and the heat capacity of the atmosphere act to provide a convective greenhouse effect that keeps the Earth’s surface on average 33 degrees C warmer than it would be otherwise. 33 degrees C is the amount derived from first principals and 33 degrees C is the amount that has been observed. No additional warming has been observed that could be attributed to a radiant greenhouse effect. The radiant greenouse effect has not been observed in a real greenhouse, on Earth, or on any planet in the solar system with a thick atmosphere. The radiant greenhouse effect is science fiction so hence the AGW conjecture is science fiction. Without a radiant greenhouse effect the climate sensivity of CO2 cannot be greater than zero.

    It is tempting at first to believe that CO2 causes waming because it has LWIR absorption bands but the reality is that all good absorpers are also good radiators and heat transfer by convection and couduction dominates in the troposphere. CO2 does not trap heat any more than any other gas in the Earth’s atmosphere. If CO2 were a great insulator then there would most probably be some engineering applacations there CO2 was uses as an insulator but no such applications exist.

    There is evidence in the paleoclimate record that warmer temperature cause more CO2 to enter the atmopshere which is because warmer water cannot hold as much CO2 as cooler water, but there is no real evidence that the additional CO2 adds to any warming. Climate models, really computer simulations of climate, that have hard coded in that more CO2 causes warming. beg the question and hence are useless in terms of acertaining whether CO2 affects climate. These climate models have failed to adequately predict today’s global temperatures and hence have been wrong. If anything these simulations show that icreasing CO2 is not the cause of the climate change we are experiencing today.

    Considering all what I have presented above, a good value for the climate sensivity of CO2 would be zero.

    • will…I’m pretty sure you just explained why there’s no such thing as run away global warming

    • willhaas
      March 16, 2018 at 4:15 pm: Thanks Willhaas, very succinct, accurate, and informative. Brett

      • More CO2 actually lowers the dry lapse rate. It is a mater of how CO2 affects the heat capacity of the atmosphere. Increaseing the lapse rate decreases heat flow from the surface whereas decreasing the lapse rate increases the flow of heat up from the Earth’s surface.

    • The dry adiabatic lapse rate (DALR) is just that: adiabatic. It has nothing to do with adding energy to the system as CO2 absorbing long-wave radiation would do. It is to do with the pressure change as air is moved up and down. It is determined by the change in pressure, hence the air density which is unaffected by tiny changes in CO2. Hence the lapse rate in the lower stratosphere is approximately zero, as the air does not move up and down significantly.

      • Just to clarify, my last sentence should have read “Hence the environmental lapse rate in the lower stratosphere is approximately zero”, because the air does not move up and down significantly so there is no adiabatic warming or cooling.

    • **Considering all what I have presented above, a good value for the climate sensivity of CO2 would be zero.**
      Now we are getting “warm”.

  23. lets see.
    2.7 c has been my guess for 10 years.

    its also the ecs for nasa climate model
    modelE.

      • Everyone guesses. It’s the best way to make a testable hypothesis.
        Without a guess you’ve nothing to test against – no challenge – no science.
        But, in my opinion, 2.7°C is far too high. Truthfully, it’s immeasurably nearer zero.

      • you know…it would pretty much have to be zero..or damn close to it
        Otherwise, once it started warming….there would be run away global warming from CO2, methane, etc

      • The effect has to be zero or close to it……otherwise every increase would release more CO2/methane…and continue, wash rinse repeat, that until it’s depleted….runaway CO2/methane

        There’s something stopping it…..

    • I sincerely hope for humanity’s sake it does get to 2.7C and a further doubling of CO2 – that way I reckon crop production will continue to outstrip population increase and power requirements in winter will be less. It also seems that deserts will continue shrinking as well (or at least green up further). At some point an equilibrium between the atmospheric and ocean temperature will be reached or perhaps a maximum and sea levels will stabilise and stop this silly conjecture that the antarctic and greenland icecaps will start to thaw

  24. The science shows it is maybe 1 degree, most likely less and could even be negative. That is not catastrophic and will not fund any new studies. Thus, the only answers that are fiscally possible to put forward have to have larger, much larger numbers.

  25. I was not aware the following has ever happened.

    Given a rise in CO2 and a concurrent rise in temperature, scientists can judge how much the former affects the latter.

  26. When you are continually adjusting the temperature records, and often just making up temperatures by homogenising huge areas of the Earth, the result will be impossibly large ranges of uncertainty, as anything is now possible.

      • Steven,
        Stop telling half-truths if you want to be taken seriously.

        The problem isn’t that CO2 is a GHG, or that absent feedbacks, CO2 forcing would otherwise drive the troposphere temperatures up. Modeling the physics without feedback makes that clear, which is why the models produce a tropospheric hotspot in the tropical latitudes.
        The huge problem for climate science is the model-predicted (CO2-only theory predicted) tropospheric hotspot has not been detected in observation by satellites or balloons.

        The modellers simply make the feedback positive with parameter tunings to double to triple the the CO2 only sensitivity. Their need for confirmation bias is abetted by poorly constrained observational limits on many of the model parameters that deal with water and the consequences of its phase changes.

        But the inconvenient reality for them is the sign (+ or -) of the feedback is not known. If it is negative, a CO2 sensitivity of 1.0-2.5 deg C so be easily cancelled out to well less than 1.0 deg C by higher precipitation rates or cloud albedo in the future.

  27. One simple question. If you had “66 per cent confidence limits” that the bridge would hold your weight would you carry a bag of rocks across for me? Are You 66% confident in the 66% confidence level? Okay, that is two simple questions but It seems to me any degree of confidence is really no confidence at all. That is about the point I have reached in respect to scientists (the climate brand), governments, and bureaucracy.

      • Decreasing emissions of plant food is wholly and completely unnecessary, what is needed is to repair the Carbon Sinks AKA forests of fast growing large leaf trees and rain forests.

      • No, you need to take into account of the price in lives, money of the decrease compared to not decreasing emissions. OTOH there are some marginal emissions that can be cut without a high price. But, theyre marginal so probably cutting them won’t make other than marginal changes. Going full nuclear takes a century and new reactor types. Wind and solar will just get us annoyed. So we’re stuck.

      • According to Steven, we should never do anything until after science has proven that it is 100% safe. At a minimum.

        When you can show me why 500ppm is a danger, when 5000ppm wasn’t, I’ll listen to your predictions of doom.

      • MarkW, there was no agriculture or humans for that matter when CO2 levels were that high. Luckily we won’t witness that kind of a scientific experiment. Currently I find it improbable the humanity would ever reach 2xCO2, let alone this or the next generation.

      • Steven,
        When the cost of insurance exceeds the cost of damages, you don’t insure. The effects of varying ECS is even more murky and subject to hysteria than the value of ECS.

    • Is it a coincidence that Earth’s atmospheric temperatures center around the apex of this curve?

      • I don’t think anything is by accident. Philosophically. But I know it is rather difficult to define how you could recognize an accident. We could theoretically live in a simulation that has no accidents whatsoever. Or it could be everything is indeterministic.

        To the topic. I guess the apex helps stabilize the climate, but I don’t immediately see why a planet should be 15C warm. So it is an accident, but still anthropic-argument forced.

      • Thanks Hugs – “… I guess the apex helps stabilize the climate …”

        That’s what I think we should explore, it sure looks like a self-correcting force. If there is a force driving from either end towards the apex, would this force then determine the temperature?

      • Thomas Homer March 17, 2018 at 6:20 am

        Is it a coincidence that Earth’s atmospheric temperatures center around the apex of this curve?

        I don’t understand this. The average earth surface temperature is on the order of 15°C … hardly the “apex of this curve” …

        w.

  28. One should never be embarrassed when they fail to do the impossible. One should be embarrassed that they even thought they could! (Especially when they continue to ignore the huge amount of evidence that falls under the category of natural climate variability.)

  29. C. Paul Pierett
    March 16, 2018 at 5:33 pm: It gets tiresome seeing folk use the warm end of a cycle as if it proves anything about the whole. The AMOC is switching so learn from the next 20-30 years please.

    • Which MODEL are you using for the AMOC?

      I could care less what your MODEL predicts for the next 20-30 years, all I’m telling you is that it doesn’t explain the past 150 years or anything else for that matter.

      Do you run your AMOC modell on super computers?

    • c.paul pieret. given your ramblings i have to think you may not be here long. however ,as is my custom when i read any arctic alarmism my first response is the offer of a bet regarding what year arctic sea will disappear in summer. the word “disappear” is like many words used by alarmists, its standard meaning does not apply.

      as you will know “disappear” in arctic alarmism terms actually means 1 million square kilometres of sea ice. would you like to have a bet on when this threshold will be reached and if so how much. i have a few charities close to my heart and they always welcome donations from people that lose bets with me :).

  30. The good professor is ‘slightly’ embarrassed after Billion$ and Billion$ spent over 30 years yield no change to ECS uncertainty range in the proclaimed settled science? He should be more than embarrassed! He should be re-assessing his dogged determination to an increasingly unsupportable hypothesis. He should be profoundly concerned about his participation in this profligate waste, fr@ud, and abuse of taxpayer dollars.

  31. From the article: “But there is a big unknown in these simulations: how much warming do you get for a certain amount of CO2?”

    There is the heart of the matter. A VERY BIG unknown.

    How much warming do you get from CO2? This fella doesn’t know and noone else does either. Yet the Alarmists continually make all sorts of wild, unsupported claims about the future, based on the assumption that they *do* know how much warming we get from a certain amount of CO2. All of them are guessing. Their studies are guesses without foundation because they are based on a VERY BIG unknown.

    This is Climate Science today: Speculation, speculation, speculation. No evidence.

  32. The physics and data are unambiguously clear that the climate sensitivity is somewhere between the sensitivity of an ideal BB at 255K and one at 288K, or between about 0,2C per W/m^2 and 0.3C per Wm^2 and no where near tthe 0.4C-1.2C per W/m^2 initially claimed in AR1 where its only requirement was that it be large enough to justify the formation of the IPCC and UNFCCC.

  33. Prof. Cox
    Your paper is wrong on two counts:

    1) A spring follows Hooke’s law:
    F = k x
    Where: F is force applied, k is string constant (or stiffness), x is displacement or change in length
    It’s a linear relationship. You double the force, the displacement also doubles.
    Temperature sensitivity to CO2 is not linear but logarithmic

    2) Following your spring analogy, the weight on top of the spring is not only CO2 forcing but also other forces and there is a hand holding the weight and you don’t know if the hand is pushing down or pulling up the weight. You only know the net weight after the “hand effect.” The hand is the feedback: push down is positive and pull up is negative

    • More importantly, the temperature sensitivity to forcing is not linear or even approximately linear across the range of temperatures found on the planet. The temperature sensitivity to forcing is a function of 1/T^3. The IPCC’s self serving consensus’s assumption that this is approximately linear is one of the biggest mistakes ever made in climate science (the relevance of Bode’s LINEAR feedback amplifier analysis being another that was layered on top of it).

      Far too many are misled by the many levels of misdirection, misrepresentation and obfuscation related to how the sensitivity is quantified. Worst of all is moving the uncertainty from that of the sensitivity itself to that related to uncertainty about how much CO2 we emit relative to the various bogus RCP scenarios.

  34. I’m noticing quite a few more alarmists on this site. I expect to see more as the lipstick on the CAGW pig washes off. Is the current saturation a cyclical uptick or is this trend abnormal?

    • when a group of people with faith in a position have that faith shaken to the core the first stage of grief appears to be “denial”, then comes anger. it would appear alarmists are fluctuating between the two and lashing out wherever they can. expect more of this in years to come.

      a similar thing can be witnessed in the brexit debate in the uk and with trump in the usa.

      • It’s a wild circus right now, in’it?
        I assume most people don’t pay attention to my comments since it’s more politically (globalism, individual rather than collective type comments) based rather than scientific, but I’ll repeat that I am voluntaryist in my worldview. I have no skin in the politics arena. That being said, I’ve never noticed the Left so incensed and childish. Maybe because in my 20’s I leaned to that emotional low hanging fruit but goodness, these anti Trump, pro nanny statists are a circus until themselves.
        It’s quite disturbing

  35. Total waste of ink.There is nothing new. Aerosols effects have been over weighted prec8sely to maintain a higher than reasonable ECS. This is exactly what they should be embarrassed about! They make it sound like there has been genuine efforts to constrain ECS by alarmists.

    The Pause caused there to be narrower and lower estimates made by sceptics and this was resisted when it was clear that if the ECS was in the lower range indicated, then there was no need to worry about the modest future warming. This would not do!

    It is also disingenuous to assume that aerosols are the only negative feedback. Clouds/albedo, phase change of water in which incident energy is absorbed without manifesting itself in temperature rise, and the greening of the planet which ties up atmospheric sourced CO2, is exothermic (cooling) and exponential. Recent estimates are an over 15% increase in forest cover in 35 years. This makes a 2.2-3.4 ECS too high and more reasonable recently published levels support the idea that business as usual emissions still wouldn’t cause a rise of more than 1.5C limits hoped for by IPCC.

  36. to a point .with such uncertainty what exactly is a climate sceptic? The funny thing is i firmly believe that most climate scientists think actual uncertainty is larger…

  37. “All they need to do is measure the spring’s stiffness, and this is betrayed by how quickly the spring oscillates – or in real terms, how much temperatures have varied from year to year.”

    Except that the fact that the climate is a complex, coupled, multi-variate system means this is not an apt comparison. Springs have a purely negative feedback which is, per Hooke’s Law, roughly linear and dependent only on the extension. Climate is almost exactly not like that.

  38. What type of scientist continues to promote a major hypothesis that has failed the first, fundamental, most critical part? How can you have a global warming hypothesis based on CO2 when you cannot display a causal relation between CO2 and warming?
    These turkeys wonder why experienced scientists laugh at them. Geoff.

  39. The real embarrassment should be that the two most (2017) papers have very tight error limits — which don’t overlap at all, with more than a degree C difference between their ranges.

  40. “ECS is defined as the global mean warming that would occur if the atmospheric carbon dioxide (CO2) concentration were instantly doubled and the climate were then brought to equilibrium with that new level” This is a double impossibility. As such, it entitles the pseudo scientific ex falso, quodlibet, to ‘prove’ anything you want to ‘prove’.

  41. “scientists employ hugely detailed computer simulations.”

    Well at least they admit they are “simulations” and not physical models.

  42. There is no scientific proof that any
    warming has been caused by CO2.

    The warming between 1975 and 2000,
    claimed to be caused by CO2,
    is similar to the warming from 1910 to 1940,
    claimed to be natural.

    There is no logical reason to ASSUME
    the 1975 to 2000 warming was NOT
    natural warming.

    And there is no explanation
    for why 4.5 billion years of natural
    climate change would suddenly stop
    in 1975, and man made CO2
    would suddenly start “controlling”
    the average temperature.

    The climate sensitivity to CO2 doubling,
    net of feedbacks,
    could be too small to measure.

    But if you attribute ALL the warming
    in the weather satellite era,
    (they are only GLOBAL measurements,
    that are not mainly wild guess infilling),
    then the WORST CASE climate sensitivity
    is about +1 degree C. per doubling of CO2.

    Whether near zero, or +1 degree C,
    THERE IS NO CO2 CRISIS.

    In fact, adding CO2 to the air has been
    the BEST thing humans have even done
    to improve the planet, inadvertently
    boosting CO2 levels that were too low
    for optimum plant growth.

    Slightly warmer nights
    in cool, dry northern latitudes
    have also been good news,
    whether caused by CO2, or not.

    My climate blog for people with common sense.
    Leftists please stay away !
    Over 15,000 page views so far:
    http://www.elOnionBloggle.Blogspot.com

  43. “…climate sensitivity is estimated by looking at historical data on temperature and greenhouse gases…” I would assume that during the last glacial period during which a sheet of ice a mile thick covered much of Canada, atmospheric humidity would have been very low. With a significant decrease in atmospheric water vapor content, that major greenhouse gas reduction would definitely have lowered world temperatures – lowered CO2, not so much.

  44. And to summarize . A series of wild ass guesses with a range all over the map .
    So this is what “scientific consensus ” looks like ?
    Just imagine if they could actually accurately do math models that demonstrated the
    cause and effect of natural variables that are still running the show .

  45. Yes, Mark, I agree with you that given what was known in his time Newton’s interest in alchemy was not unscientific. Elements cannot be transformed into each other by chemical means but substances in nature do not come to us labeled “element”, “compound” or “mixture”. Thus water was long thought to be an element but turned out to be a compound and air was long thought to be an element but turned out to be a mixture.

    There is a tendency to describe discarded or disproven past scientific theories as “pseudoscience”. Thus the phlogiston theory is often described as “pseudoscientific” although it was supported in it’s time by the eminent chemist Joseph Priestly. Lord Kelvin believed in the ether theory and Maxwell expended great efforts on attempting to develop a mechanical theory of electromagnetism. These theories were eventually discarded but that does not mean that Kelvin or Maxwell were “pseudoscientists”. Just that they were wrong about some things.

  46. The problem, as I am tiring of restating, is that there is no such thing as an “equilibrium climate sensitivity,” because there is no such thing as an equilibrium climate state. Just for starters, the solar energy input to the earth varies by +/- 47 W/m^2 every 182.5 days. That’s an order of magnitude above the supposed retention of energy by CO2. the short term fluctuations due to cloud albedo can change the balance by +/- 4% on an hourly basis, with no ability to predict. Cloud cover isn’t predictable by any current physical model And it isn’t averagable. The whole premise of an equilibrium climate sensitivity is false. There can be no such thing. So it isn’t any wonder that no progress is made on analyses based around it.

  47. R. Clark has one of the best descriptions on Ghg effect…. Including line broadening….search for this
    .THE GREENHOUSE EFFECT
    Roy Clark PhD
    Ventura Photonics
    Thousand Oaks, CA
    Ventura Photonics Monograph VPM 003.1
    January 2018

  48. The error bars in pseudo-temperature are typically bigger than the pseudo-effect. When they are not, they are contradicting each other heavily. This is not science, it’s religion.

    • It is a religion and the bishops of Climate are still collecting funds from the poor while the monks in their abbeys continue the struggle to determine how many angels can stand on the point of a pin.

  49. Based on my family history over several generations, my expected life span is between 42 and 103 years.
    With that level of uncertainty, I’ll never die

  50. “However, the ‘likely’ range of ECS as stated by the Intergovernmental Panel on Climate Change (IPCC) has remained at 1.5–4.5 degrees Celsius for more than 25 years1. The possibility of a value of ECS towards the upper end of this range reduces the feasibility of avoiding 2 degrees Celsius of global warming, as required by the Paris Agreement. ” Extract from the Abstract

    My comment
    It also equally follows that the possibility of a value of ECS towards the LOWER end of this range (1.5 to say 2 c ) increases the feasibility of even beating or at least meeting the Paris Agreement global temperature target of 2 c increase without taking any action.

    I suggest this is just as valid a position to adopt as the one adopted above by Professor Cox as the rationale for making his “spring analogy” ECS analysis ( which one contributor says anyway is not consistent with Hooke’s equation to measure the responsiveness of a spring)

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