Important new paper challenges IPCC’s claims about climate sensitivity

by Nic Lewis

Official estimates of future global warming may be overstated.

A brief summary in press release style of my new paper (written in the third person)

One of the most important conclusions of the recent 6th Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR6) was to reduce the uncertainty in estimates of climate sensitivity to doubling the amount of carbon dioxide in the atmosphere.  Since 1979, the likely range (66% chance) of climate sensitivity has been between 1.5°C and 4.5°C. This range has remained stubbornly wide, until the IPCC AR6 narrowed the likely range to be between 2.5°C and 4.0°C.

A new paper by independent scientist Nic Lewis published in the journal Climate Dynamics challenges the conclusions of the IPCC AR6 about climate sensitivity.  Lewis’ analysis reduces the magnitude of climate sensitivity by one third, relative to the range provided by the IPCC AR6. These results suggest that future global warming in response to fossil fuel emissions could be significantly less than has been assumed by policy makers.

In 2015, the World Climate Research Programme convened a Workshop aimed at reducing the uncertainty in estimates of climate sensitivity to increasing carbon dioxide.  The Workshop ultimately resulted in publication of a report (a 92 page paper) by many of the participants that thoroughly assessed all lines of evidence (Sherwood et al, 2020).  A key result of this paper was to reduce the likely range of climate sensitivity values to 2.6 oC to 3.9 oC.  While Lewis was an invited participant to the 2015 Workshop, he was not a coauthor on this paper.  The Sherwood et al. paper strongly influenced the IPCC AR6’s assessment of climate sensitivity.

Lewis’ paper critiqued the methods used in the Sherwood et al. paper, finding significant errors, inconsistencies and other shortcomings. Lewis remedied these shortcomings and also revised key input data, almost entirely to reflect more recent evidence.  The results of Lewis’ analysis determined a likely range of 1.75 to 2.7oC for climate sensitivity.  The central estimate from Lewis’ analysis is 2.16 oC, which is well below the IPCC AR6 likely range.  This large reduction relative to Sherwood et al. shows how sensitive climate sensitivity estimates are to input assumptions.  Lewis’ analysis implies that climate sensitivity is more likely to be below 2 oC than it is to be above 2.5 oC. 

The lower estimates of climate sensitivity determined by Nic Lewis have profound implications for climate models and projections of warming for the 21st century.  Climate models used in the IPCC AR6 had values of climate sensitivity ranging from 1.8oC to 5.6oC.  The IPCC AR6 judged that some of the climate models had values of climate sensitivity that were too high.  Hence the AR6 selected only the climate models with reasonable values of climate sensitivity to be used in projections of 21st century climate change.  Lewis’ analysis indicates that a majority of climate models used in the IPCC AR6 have values higher than the likely range.

Nic Lewis has authored ten peer-reviewed papers on climate sensitivity. Lewis’ latest paper is entitled ‘Objectively combining climate sensitivity evidence’. It can be freely downloaded here. A detailed explanatory article about the paper is available here.

185 responses to “Important new paper challenges IPCC’s claims about climate sensitivity

  1. Lance Arthur Wallace

    Nic reports–
    Funding: None
    Well, of course!

    • Nic is less challenging the IPCC than Hoffman & Schrag’s work on past Snowball Earth episodes.

      I somehow doubt if they were asked to review his publication.

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  3. A commendable effort by Nic to combat the exaggerated climate sensitivity estimates by IPCC and affirmers.

    The problem is that calculations of ECS and TCS start by accepting the IPCC assumption that there are no other natural contributions to climate change than those already identified, i.e., natural forcing has contributed net zero to climate change since 1850.

    As Roy Spencer showed, if natural climate change is responsible for just 40% of the observed warming, ECS drops from 2.2 to 1.0.

    https://www.drroyspencer.com/2018/02/diagnosing-climate-sensitivity-assuming-some-natural-warming/

    ECS will turn out to be much lower than what Nic calculates. And this is only if ECS is a meaningful concept, because there is no guarantee that every doubling of CO2 (or part of it) produces the same amount of warming. It could all be a modern analog of arguing about the number of angels that can dance over a pinhead.

    • Joe - the non climate scientist

      Javier’s comment – “….accepting the IPCC assumption that there are no other natural contributions to climate change than those already identified, i.e., natural forcing has contributed net zero to climate change since 1850.”

      Concurring with Javier – This is one of the illogical claims ever made by the climate scientists. Natural variability has been the rule for 100million years, but some how stopped for the last 170 years resulting in the conclusion that all the warming since 1850 is man made!

      What about :
      AMO
      PDO,
      Enso
      la nina
      el nino
      TSI
      etc

      Seriously – no skepticism by the climate scientists?

      • What do you expect when a bank holiday coincides with the funeral of the century?

        See what else it has delayed :

        https://vvattsupwiththat.blogspot.com/2022/09/international-pirate-climate.html

      • Joe

        To your list I would add the big enchilada, the LIA. Of course knowing what warming we have had since the end of the LIA is complicated due to so many uncertainties about the temperatures of 1850. There was only 12% coverage of SH land pre 1900 and millions of square miles of oceans were without in situ direct measurements pre 1900.

        Some amount of warming most certainly is from simply coming out of one of the coldest periods of the Holocene. Precisely how much is anyone’s guess.

    • thecliffclavenoffinance

      Start from the 1800s with 280ppm CO2 and end at 2022 with 415ppm. Attribute all the warming to the +48% increase of CO2.
      That’s a worst case estimate with no natural global warming,
      which makes no sense, but let’s just assume.

      If a +48% increase of CO2 caused +1 degree C. warming, with very haphazard 1880 measurements, that means the next +48% increase of CO2 will have less than a +1.0 degree C. increase, again assuming all warming is caused by CO2.

      Most of the past +1.0 degrees warming was in higher latitudes, at night (TMIN) and during the six coldest months of the year. Optimum locations and timing for most global warming. Beneficial warming — not TMAX warming in the tropics in the Summer.

      How this adds up to a high ECS, or a climate emergency, puzzles me.

    • Robert Ellison

      Energy is so much the source of human welfare that global emissions of CO2 – a lot of which happened in the past 40 years – will keep rising as regional economies keep growing. Africa, Asia and India have a long way to grow. Economic growth with fiscal prudence and conservative money management to maximise economic opportunities hopefully.

      https://ourworldindata.org/grapher/annual-co-emissions-by-region

      And I will get to the point. ‘This world places increasing faith in competitive markets, innovation and participatory societies to produce rapid technological progress and development of human capital as the path to sustainable development. Global markets are increasingly integrated. There are also strong investments in health, education, and institutions to enhance human and social capital.’ SSP5 – https://www.sciencedirect.com/science/article/pii/S0959378016300681

      https://www.sciencedirect.com/science/article/pii/S0959378016300711#fig0005

      At the SSP5 rate of economic growth if fuelled by fossils this might be some 1000 ppm of atmospheric CO2 by 2100. Enough to trigger a cloud catastrophe?

      https://www.nature.com/articles/s41561-019-0310-1

      I refer to RSS atmospheric temp anomalies as it the most conservative of the satellite series and they have better graphics. It measures changes in oxygen excitation with temperature in the troposphere – changes in the energy content of the lower atmosphere. A more consistent record than surface temperature that measures sensible heat and misses variable latent heat.

      https://images.remss.com/msu/msu_time_series.html

      Climate shifted in 1998/2001. I think it might have shifted after 2016. There are critical fluctuations between states at transitions. After which there is a new and higher plateau. If AGW was 50% of the warming of the past 40 years pushing meteorological, biological, hydrological and physical limits in sensitively dependent systems we barely comprehend?

  4. Lance Arthur Wallace

    Rather telling that Sherwood et al do not even mention the Transient (TCR) response (what we would see by 2100), which even AR6 estimates to be rather small (1.8 K). Nic further reduces TCR to about 1.5.

  5. Indeed the Sherwood et al (2020) paper calculates a surprising very high TCR median of 2.26 K/ 2*CO2 ( 17…83% range of 1.7…4.45) which points imho to methodical problems also in the ECS-calculation. Why they didn’t mention it is speculation. However with both estmations of the TCR and “onmitted warming” this gives this estimations of the warming untill 2100:
    https://i.imgur.com/YOOn3Hn.png .
    What a diffrerence, at least when it comes to the probability of very high warming rates.

  6. Dennis Laughton

    Considering that most plants are CO2 starved, I don’t see the possibility of a large atmospheric despite an increase in emissions.

    • The CO2-sinks tie down about 50% of the emissions. Therefore a reduction of the emissions of 50% would be enough to hold the concentration in the atmosphere on a constant level.

  7. Nic has an unblemished record of being wrong? But this time I suspect he might be right

    • Donald,

      Can you provide a few specifics about Nick’s record? Without some examples, you are just giving a schoolyard insult.

      • Read about 100 comments by Joshua over last year and half. In particular re: Covid in Sweden

      • Nic is batting 1000 when it comes to climate sensitivity. Re Covid, Nic provided some important insights. Was less wrong than Fauci.

      • There are dissenting opinions on unverifiable outcomes. And an inevitable need for an alternative to fossil fuels.

        But doing things that grow economies and preserves God’s world at the same time is good. Conscious capitalist mining companies if my portfolio is anything to go by. 😊

      • Everett F Sargent

        Actually closer to 0.000 as in they have increased their central estimate twice now to 2.16K.

        Given a few more tries and they will be at 3.1K for ECS!

    • I’m sure Donald Rapp has gotten plenty of things wrong. Care to give us a list of your ‘whoops’?

    • Donald,

      “Nic has an unblemished record of being wrong? …Read about 100 comments by Joshua over last year and half.”

      Good that you said that first sentence as a question. I did a quick search of Nick’s posts here about climate for the past 3 years. I see no substantive comments by Joshua. Zero.

      So your claim appears to be grossly false.

      “In particular re: Covid in Sweden.”

      I can’t imagine who cares. Nic has demonstrated expertise about climate. The wild surge of amateurs’ writing about COVID was interesting as a phenomenon, but …

      In any case, even if Nic was 100% wrong about COVID (bizarrely unlikely), that wouldn’t invalid his articles about climate.

      • Everett F Sargent

        Actually it does call into their objectivity when they have all the appearances of being an activist. Particularly when the all to obvious usage of the word “objective” appears in more than one of their paper titles. Who are they kidding with that form of wordsmithing? As if Sherwood and everyone else were to explicitly use the word “subjective” in their paper titles. Only fake experts fall for such obvious foolishness. Well maybe the editors of Climate Dynamics badly needed a journal PR boost!

    • Well, Joshua has zero credibility. He routinely misrepresents what other people say. He then repeats these misrepresentations hundreds of times. Further, he picks from a very lengthy public record a few statements that are not correct or can uncharitably be interpreted as not being correct. And he uses a simple minded pseudo-scientific view of complex systems. His insistence (repeated literally hundreds of times) that herd immunity is a cosmic constant is absurd and childlike in its ignorance.

      Nic has a reasonably good record even with covid. The covid problem is an ill-posed problem making detailed predictions virtually impossible. Ferguson and Fauci were both very wrong too about more important issues, like vaccinating children and keeping schools closed.

      Nic said that Sweden had probably reached herd immunity at a time when cases and deaths were quite low. But then winter came and cases surged. That’s because herd immunity is obviously a function of the season of the year.

    • David –

      > Nic said that Sweden had probably reached herd immunity at a time when cases and deaths were quite low. But then winter came and cases surged. That’s because herd immunity is obviously a function of the season of the year.

      Nic made predictions about the total number of additional deaths he expected, with a drop off due to having crossed a “herd immunity threshold” in IIRC May of 2020.

      His prediction was ridiculously in error. He likewise made similar erroneous predictions about a HIT being reached in London and New York and India and other places as well. Wrong.wrong, wrong, wrong.

      He agreed with Willis’ inane prediction that no country would exceed 0.085% of their populations dying from COVID. Not even remotely close.

      He thought he understood the biologic of COVID well enough to pontificate how T-cdll immunity would prevent infection and then explain why Sweden reached “herd immunity” at less than 20% population infection. Wrong in multiple ways.

      Trying his toy models to incorporate heterogeneity was a commendable thing to do. But he ignored uncertainty and allowed his political advocacy to steer him in wrong directions. And to my knowledge, he hasn’t stepped forward to demonstrate accountability.

      • From January 14, 2021

        Here is what Nic wrote:

        > I also projected, based on their declining trend, that total COVID-19 deaths would likely only be about 6,400. Subsequent developments support those conclusions. Swedish COVID-19 deaths have continued to decline, notwithstanding a return to more travel and less social distancing, and are now down to 10 to 15 a day.

        Based on HIS DEFINITION of “herd immunity,” Nic protected at total of 6,400 death. Today their reporting surpassed 10,000 dead and it will clearly go higher. I’ll guess that his projections might be off by as much as 200% by the time they get to herd immunity though used if vaccines (that you said wouldn’t matter) by the time all is said and done.

        Once again, his projections were based in HIS DEFINITION of “herd immunity.” this there is no question that his modeling if “herd immunity” was wrong as was his assertion that Sweden had crossed a “herd immunity threshold” as HE CONCEIVED THE ISSUES…

        He also said it was likely that NO COUNTRY would surpass a population fatality rate of 0.085%. There are some 30 countries that have passed that mark – some by more than double. Obviously, his erroneous thinking in that regard was to some large degree based on his misunderstanding of the mechanisms of “herd immunity.”

        There no crime in his having been wrong, but your insistence that he wasn’t wrong and that I’m incapable of pointing out his error because I’m not a scientist is just silly.

      • And Joshua is still at it …

        Because Nic’s examination of a real and interesting topic – herd immunity – produced an inaccurate but interesting thought experiment, Joshua et al declared all work by Nic to be utterly useless and politically motivated (just like all the thousands of inaccurate forecasts by climate scientists- ha, just kidding, their errors are pure!).

        https://judithcurry.com/2021/05/23/collapse-of-the-fake-consensus-on-covid-19-origins/#comment-950646

      • I don’t rember the ecacf numbers – I could go back and look it up. He predicted what, 15% more deaths, maybe 25% more – because of reaching “herd immunity.”

        They experienced what, 300% more deaths?

        But yeah, he got it right. Lol.

      • Here is some more brilliant insight from Joshua. Apparently he believes hypotheticals are supported by tons of evidence. I would like to hear him explain how that works.

        Counterfactual reasoning requires a high level of evidence because it is by definition entirely hypothetical.

        https://judithcurry.com/2020/06/21/did-lockdowns-really-save-3-million-covid-19-deaths-as-flaxman-et-al-claim/#comment-919678

      • Everett F Sargent

        But Joshua, Lewis was less wrong than Fauci. At least with regards to ECS, on all things COVID-19 obviously not so much.

        I have that from an absolutely reliable impeccable source of the highest order who also happens to be a Subject Matter Expert (SME) on all things COVID-19.

      • Everett

        > Lewis was less wrong than Fauci.

        Such a juvenile reponse from Judith.

        Nic was systematically wrong over a period of months. Always in the same direction – indicating a systemic flaw in his analysis. But he kept doubling down. He even invented biological theories to explain why his modeling arrived at herd immunity threshold at such a low population fatality. He invented viroligicsl explanations even though he had no expertise in the field.

        It’s a bad sign. Of course everyone makes errors, but accountability is important and thus far that has been lacking.

        Let’s see what happens going forward.

        But for Judith to dismiss his systematically wrong analysis by hand-waving at Fauci’s errors, as if Nic needn’t be accountable because someone else was wrong?

        Juvenile.

      • such a low population fatality

        Should be such a low population infection %…

      • “…But for Judith to dismiss his systematically wrong analysis by hand-waving at Fauci’s errors…”

        ALL the career experts were wrong. Fauci was not even the wrongest. Dr. Birx went running around telling all the governors to close businesses and schools. Luckily, DeSantis and a few other red state governors stopped taking her calls.

        https://americanmind.org/features/florida-versus-davos/

        “Over the last few years, the statistics are startling. Since COVID, more adjusted gross income has moved into the state of Florida than has ever moved into any one state over a similar time period in American history.”

        Fauci won the prize for most dishonest. “The NIH never funded gain of function research at the Wuhan lab.”

      • Joshuas says:

        Such a juvenile response from Judith.
        Her response was rational and on point, unlike the COVID topic.

        It’s a bad sign. Of course everyone makes errors, but accountability is important and thus far that has been lacking.

        So what would accountability look like to you? Would you have a single party government leader throw Nic in prison? 50 lashes? Banned for life from Climate, etc?

        I think your beef with Nic is personal with you, not related so much to his overall correctness. Even though you endlessly harp on his COVID writings, he is contributing in a positive manner to climate science. Can you admit that?

      • Joe - the non epidemiologist

        In response to Joshua’s obsession with Nic’s math error

        We all agree that Nic mathematically underestimated the % of the population that needed to be reached in order to have sufficient immunity in the general population in order to slow/stop the spread of covid.

        However, Nic did get the big picture correct
        A) covid would cease being a threat once immunity reached a certain level
        B) the only long term solution to solving the covid pandemic was to develop immunity through out the general population.

        you can argue about the minutia till you turn blue, but in the grand scheme, Nic got the big picture correct – That is immunity through out the general population was the only long term solution.

        It should also be noted that the per capital death rates by age group ( the 65+ age group being the most important metric) was remarkably similar across most countries, states and regions of the world irrespective of the level of mitigation protocols.

      • Joshua doubles down yet again on his lies. All his drivel is based on the childish lie that HIT is a cosmic constant.

        In any case, this is reality all a fallacy. Nic’s current paper on climate sensitivity is the subject of these comments. Not a word on the technical contents of that paper because Josh and his ilk are scientifically and mathematically illiterate. All they can do is attack the person based on a simpleton’s version of “science.”

      • Let’s go back in our time machine:

        jeffnsails850 | April 22, 2021 at 10:22 am |
        To recap for any lurkers: Nic attempted to figure out when herd immunity would happen, using Sweden. His forecasts for reaching herd immunity were wrong- just like every other scientists forecasts for anything COVID related. This was probably due mostly to the discovery that “immunity” is time limited (the reason people are telling you that annual booster vaccine shots will be necessary) as well as controlled by viral load (and amount of antibodies- some who caught the virus are less immune than others). Because Nic’s examination of a real and interesting topic – herd immunity – produced an inaccurate but interesting thought experiment, Joshua et al declared all work by Nic to be utterly useless and politically motivated (just like all the thousands of inaccurate forecasts by climate scientists- ha, just kidding, their errors are pure!).

        Josh posts numbers to attempt to convince you that Sweden weathered COVID far worse than nations that locked down, that today their daily death rate is unusually high, and that this must mean Sweden’s goverment failed because they didn’t pick the preferred policy.

        In reality, Sweden performed comparably or better than locked down democracies and, as a result have a daily death rate from Covid that is much, much lower than a great many western democracies that are still locked down.

      • Joe - the non epidemiologist

        Joshua’s comment – ” Second, it just then leads to a search for someone who made more mistakes than Fauci, and then for someone who made more mistakes than that person, and on and on. Whether or not Fauci was more wrong than Nic on COVID doesn’t change to one iota the amount that Nic was wrong on COVID.”

        Josh – you are displaying a huge obsession with proving Nic wrong. Yes he got the math wrong, (though less wrong than the imperial college), but he got the concept correct. Something you have yet to understand.

        Fauci on the other hand was frequently wrong on numerous items regarding covid along with HIV. His promotion of drugs for both HIV and covid were based on his financial interests (AZT and Remisver ). He was grossly wrong on the mitigation protocols.

        For the sake of your sanity along with saving everyone’s time – drop the obsession

      • Joshua once again evades and misrepresents. His main point about Nic’s posts was that Nic was wrong to claim that HIT had been reached in several places. This is “proven” by the fact that winter came and HIT went way up again. Joshua’s criticism is based on a laughably literalminded and unscientific idea that HIT is constant. Nic was actually right about HIT based on the common definition. Joshua made a grievous logical and scientific error and just goes on and on and on and won’t acknowledge the most obvious error he makes.

        How about some accountability for Joshua’s almost childish repetitious calls for accountability. First remove the beam from your own eye Joshie and stop wasting our time.

    • Donald –

      >Nic has an unblemished record of being wrong? But this time I suspect he might be right

      I wrote a comment below on the question of linking Nic’s COVID modeling to his climate science modeling. Hopefully it will come out of moderation.

      No doubt, his errors in COVID modeling shouldn’t lead anyone to conclude that his climate science modeling can’t be “right.”

    • Even if that were true, it would not matter in a scientific debate!
      I am curious why this comment which clearly is an ad hominem is not flagged as such and ignored!

      Being wrong sometimes is part of the scientific progress and it is about time that climate alarmists acknowledge thier past wrongs statements, which would also be a part of scientific progress.

      • morfuo3 –

        > Being wrong sometimes is part of the scientific progress a

        The problem wasn’t merely that Nic’s COVID modeling was “wrong,” as in way off.

        His focus on modeling a heterogenous population variable of spread of infections seemed interesting, even if not as novel as it was sometimes portrayed.

        The more relevant problem is that Nic looked at emergent phenomena, conflated signal and noise in those phenomena, and then asserted that his modeling was verified by those phenomena. Of course he was wrong about that.

        It was obvious at the time that there was the potential that he was conflating signal and noise. It was also obvious that he was wrongly claiming that his modeling was verified – because there were myriad potentially confounding variables he failed to account for.

        What’s even more problematic, he even went so far as to effectively invent a casual mechanism to explain his “motivated” confirmation for reaching a “HIT” at population infection levels even below 20%: He argued that T cell immunity (largely resulting from precious infections with other coronaviruses) would protect against infection. He didn’t allow his lack of experience in researching virology and immunology to get in the way of his theorizing – despite that people who did have such experience were clear in saying that T cell immunity against infection (as compared to against sever infection) was unlikely.

        So then the next question is whether that tendency to wrongly see confirmation of his model is a more generalizable tendency – perhaps with the influence of ideological “motivated reasoning.”

        There’s no reason to assume it would be – but neither is there a reason to dismiss that possibility.

        The unfortunate aspect of all this is the reflexive tendency among some “skeptics” to just dismiss Nic’s problematic COVID modeling and/or just dismiss the errors he made.

      • Joshua, I looked for Tweets relating Nic’s new paper and found that there is a gang, I’cant’t spell it otherwise, with the usual suspicious ( Atomsk, Pukite which got it to write:”Nic Lewis is the one that published a faulty statistical analysis of the COVID-19 pandemic leading to the death of thousands” and a few other guys) which do not discuss the science but only make abuse with matters outside the subjects area. Are you a part of this gang? One Co-Author of Sherwood et al (2020) (Gavin Schmidt) wrote on the other side: “The point of that paper was to set up folks to redo the calculation with their own or updated inputs, so not only inevitable but actually desired!”
        Are you part of the “gang” or part of science?

  8. Not once in either of these papers is the infra-red absorption capabilities of so-called greenhouse gases mentioned. They are after all, supposedly, the key factors and cause of climate change. When the absorption spectra of CO2 and H2O are determined from the HITRAN spectral data base and used to calculate the atmospheric IR absorption it is abundantly clear that CO2 has little impact for two reasons. 1 – Its absorption spectrum is already strongly saturated leaving very little room for further effect. 2- Its spectrum is strongly overlapped by H2O which possesses a much wider and stronger spectrum due to its much higher atmospheric concentration. The data for this can be obtained from the paper “The Impact of CO2 and H2O and Other Greenhouse Gases on Equilibrium Earth Temperatures” at http://www.ijaos.org/article/298/10.11648.j.ijaos.20210502.12

    And yes I am plugging my own paper, but I have yet to see a clearer explanation for the incompetence of so called climate science. If I am wrong would someone please point out how and why.

    • A planet’s IR emission spectrum doesn’t follow its mean surface temperature’s blackbody emission spectrum.
      We cannot compare two different things.

      https://www.cristos-vournas.com

      • Christos, if planets do not emit according the BB profile associated with surface temperatures is that because gasses do not emit according to BB profile, as I recently read, or is it other reasons that you are claiming? What is that mechanism?

      • Ron, the BB profile spectrum is associated with a single BB emitting temperature.
        A planet doesn’t have a uniform surface temperature.
        The planet’s mean surface temperature doesn’t have a BB profile spectrum, because planet doesn’t emit at mean surface temperature…
        Every spot on the planet’s surface at every given instant has a different emitting temperature…
        Every spot at that given instant emits with its own spectrum profile…
        A planet’s mean surface temperature’s BB profile spectrum (theoretically expected) cannot be considered as the planet’s mean BB profile spectrum.
        Planet mean surface temperature cannot be associated with any kind of BB profile spectrum.
        ————–
        Planets with the same mean surface temperature may emit dramatically different amounts of IR outgoing EM energy.

        https://www.cristos-vournas.com

      • A planet with an atmosphere emits IR from its TOA. The variation in TOA temperature corresponds (in deg kelvin) to a fourth power variation in energy emission. Obviously then, things that mute the temperature variation, like the planet’s rotation, cut off efficiently emitting peaks and thus impede emission, and thus raise global mean temperature from the TOA to the surface according to the lapse rate.

        Things that cause hot spots, like storms, that bring up vast amounts of latent heat that sneak through the lapse rate to unload sensible heat upon condensation nearer the TOA increase outgoing IR, and thus lower global temperature.

        Here is the paper I was referring to that refutes that gases emit according to BB radiation profiles. https://vixra.org/abs/1405.0103

    • Let’s introduce to the very POWERFUL the planet surface Rotational Warming Phenomenon:

      The Planet Surface Rotational Warming Phenomenon states:
      Planets’ (without atmosphere, or with a thin atmosphere) the mean surface temperatures RELATE (everything else equals) as their (N*cp) products’ SIXTEENTH ROOT.

      ( N*cp ) ^1/16

      or

      [ (N*cp)¹∕ ⁴ ] ¹∕ ⁴

      Where:
      N – rotations/day, is the planet’s axial spin .
      cp – cal/gr*oC, is the planet’s average surface specific heat.

      This discovery has explained the origin of the formerly observed the planets’ average surface temperatures comparison discrepancies.

      Earth is warmer than Moon because Earth rotates faster than Moon and because Earth’s surface is covered with water.

      What we do in our research is to compare the satellite measured planetary temperatures.

      The Planet Surface Rotational Warming Phenomenon can be expressed now also QUANTITATIVELY. And it happens so to be a very POWERFUL the planet surface warming factor.
      …………
      The Planet Surface Rotational Warming Phenomenon:
      It is well known that when a planet rotates faster its daytime maximum temperature lessens and the nighttime minimum temperature rises.

      But there is something else very interesting happens. When a planet rotates faster it is a warmer planet.

      https://www.cristos-vournas.com

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  10. Climate sensitivity is dynamic and not linear. Tipping points – aka climate shifts – are ubiquitous. I’ll update this and submit it to Judith.

    Ghil, 2013, explored the idea of abrupt climate change with an energy balance climate model that follows the evolution of global surface-air temperature with changes in the global energy balance. The plot below originates from work for Ghil’s Ph.D. thesis in 1975 and was reproduced in a 2013 World Scientific Review article to illustrate a dynamic definition of climate sensitivity in a climate system that exhibits abrupt change.

    https://watertechbyrie.files.wordpress.com/2014/06/unstable-ebm-fig-2-jpg1.jpg

    https://watertechbyrie.com/2014/06/23/the-unstable-math-of-michael-ghils-climate-sensitivity/

  11. Nic, thanks for your continued efforts to challenge government funded climate science. In the USA we National Public Radio as a shining example of how public funding often leads a thing to be controlled by special interests of the far left. Covid exposed the crazy politicization of public health policy and its underlying scientific elite, to the great detriment of the country. I think the public is becoming less apt to trust authority simply by its claim of being in the scientific mainstream. With wide censorship, coercion and funding biases, mainstream has corrupt incentives.

    “…Research has become central, it also becomes more formalized, complex, and costly. A steadily increasing share is conducted for, by, or at the direction of, the Federal government…
    The prospect of domination of the nation’s scholars by Federal employment, project allocation, and the power of money is ever present and is gravely to be regarded…Yet in holding scientific discovery in respect, as we should, we must also be alert to the equal and opposite danger that public policy could itself become the captive of a scientific-technological elite.”
    -Dwight Eisenhower

    https://en.wikipedia.org/wiki/Eisenhower%27s_farewell_address#:~:text=research%20has%20become,scientific%2Dtechnological%20elite

  12. We’ve experienced roughly 1.2 C warming above the 1850-1900 mean with a roughly current EEI (2005-1019) of 0.8 W/m^2. If ECS = 2.16 then λ = 0.58 and that means ~0.47 C additional is built into current current conditions, and the total equilibrium temperature should be ~1.7 C. Again, of λ = 0.58, then that implies we need 1.7/0.58 = 2.9 W/m^2 from some set of forcings to explain current warming. If we take round RF numbers of 2.1 W/m^2 for CO2, 0.9 W/m^2 for other GHGs and -0.8 W/m^2 from aerosols, that means we’ve experienced a total of ~2.2 W/m^2 radiative forcing. Where did the other 0.7 W/m^2 come from?

    If ECS = 3.2 C, then λ = 0.86 and we would expect 1.9 C total warming from the 2.2 W/m^2 increase in forcings. Since EEI is 0.8 W/m^2, about 0.7 C of that is in the current energy imbalance, leaving 1.2 C for the rise in temperatures. This fits empirical data pretty well.

    So it seems that we need 1) to find 0.7 W/m^2 somewhere or 2) we need to show that the above estimates are off by that amount or 3) some combination of the two.

    • Scott: I can’t follow your calculations completely, but I suggest you work through Nic and Judy’s 2018 paper. I was surprised to learn that the proper value to use for ocean heat uptake wasn’t current OHU, but the change in OHU. They analyzed roughly 1860-present and may have done 1970 or 1980 to present also.

      https://journals.ametsoc.org/view/journals/clim/31/15/jcli-d-17-0667.1.xml

      Sherwood et al (2020) repeated the same analysis with Nic’s values and slight refinements from AR6 and got a low ECS (just above 2?) – before they started playing Bayesian statistical games I couldn’t follow to combine it with estimates from pre-instrumental periods.

      With each passing decade, it makes more sense to focus on the period since 1970 or 1980, since that contains the bulk of the warming and less uncertainty. In particular, aerosols have been falling since the early 2000’s and the great uncertainty associated with the indirect effect of aerosols on cloud reflectivity becomes less important as the change in aerosol shrinks.

      IIRC, Although Nic doesn’t discuss it here, Sherwood call climate sensitivity calculate from either period S_hist and assert that it differs from true climate sensitivity because of unforced variability. Their rational is that the lack of warming and/or reduced warming in some locations in the Pacific (despite warming elsewhere) must be due to unforced variability. Good luck.

  13. “These results suggest that future global warming in response to fossil fuel emissions could be significantly less than has been assumed by policy makers.”.

    This applies to the past, too. ie, these results also suggest that much less of the global warming to date has been in response to fossil fuel emissions and therefore that more of the global warming to date has been natural.

    • AGW trends up – whereas natural variability? ‘The winds change the ocean currents which in turn affect the climate.’ Mojib Latif

      In ‘the context of the secular signals, which have timescales comparable to the length of the data record, the periodicity of such a signal cannot be verified, but the propagation of the anomalies in space in the course of the oscillation can still be established with statistical significance.35 Indeed, the reconstruction of this pair of modes for regional climate indices (Fig. 3b, c) manifests as a multidecadal signal propagating across the climate index network (with certain time delays between different indices)—a so-called stadium wave (refs. 20,35,36,37)—which we will refer to as the global stadium wave (GSW) or, when referring to the global-mean temperature, Global Multidecadal Oscillation (GMO), although, once again, the oscillatory character of this phenomenon is impossible to establish due to shortness of the data record. The phasing of indices in the GSW is consistent with earlier work (ref. 20), which analysed a limited subset of the Northern Hemisphere climate indices (Supplementary Fig. 6). The global-mean temperature trends associated with GSW are as large as 0.3 °C per 40 years, and so are capable of doubling, nullifying or even reversing the forced global warming trends on that timescale.’ https://www.nature.com/articles/s41612-018-0044-6

    • Satellites measure radiation from oxygen excitation – higher excitation with heat and more radiation – in the troposphere. Heat in the troposphere includes both sensible heat and latent heat as water vapor condenses. Surface thermometers measure sensible heat.

      It’s getting interesting. Are there now satellite series covering 2 climate shifts? 1998/2001 and 2016 – having just missed 1976/1977? AGW seems relentless – however – in a system that is sensitively dependent to changes in background conditions.

      https://images.remss.com/msu/msu_time_series.html

  14. The hysterical global authoritarians’ using the AGW hoax for socio-political purposes, needed high ‘sensitivity’ so, that’s what the corrupted Western academia gave them.

    • ‘For the last 10-20 years or more, a few of us have been saying that the IPCC has been ignoring the elephant in the room… that the real climate system is simply not as sensitive to CO2 emissions as they claim. Of course, the lower the climate sensitivity, the less of a problem global warming and climate change becomes.’ ~Dr. Roy W. Spencer

    • Does Roy give confidence limits for that?

  15. Nic … Great job, once again. Thank you.

  16. I came across this paper, which we may have seen on here posted by others. If so, sorry for the repeat. The paper isn’t unique, as we have seen several like it over the last few years. It also is in accordance with many items Judith has posted, and others, on here, such as CKid who gave us posts of old press clippings of natural disasters from yesteryear showing that such weather related events have a history far before AGW, and his dogged pursuit of the narrative of rising sea levels.

    “A critical assessment of extreme events trends in times of global warming” , in The European Physical Journal Plus 13 January 2022.

    https://link.springer.com/article/10.1140/epjp/s13360-021-02243-9

    “None of these response indicators show a clear positive trend of extreme events. In conclusion on the basis of observational data, the climate crisis that, according to many sources, we are experiencing today, is not evident yet. It would be nevertheless extremely important to define mitigation and adaptation strategies that take into account current trends.”

    We are spending a lot of money on climate change that has NOT appeared. One could say not appeared yet, but that wouldn’t justify the enormous sums being spent, the economies upended and the actual suffering that has occurred and will occur from such extreme policies. This article was bravely posted by those scientists in an era when such a paper could have gotten them cancelled, and all it states is that, essentially, we need to pump the brakes.

    Here’s an op-ed by Steve Koonin, which also calls for a greater level of circumspection about claims that have no basis on the studies posted and are used solely to create alarm.

    https://www.wsj.com/articles/dont-believe-the-hype-about-antarcticas-melting-glaciers-ice-sheet-climate-change-global-warming-sea-levels-greenland-iceberg-ocean-11663618509?st=67tlt2ys0a728mm&reflink=desktopwebshare_permalink

    • Thank you for the Alimonti 2022 paper. Amazing how people are being deceived by affirmers.

      • > Amazing how people are being deceived by affirmers.

        One of the greatest qualities a human being can possess is an open mind. One of the rarest qualities human’s possess is an open mind. Javier, you have the former, and you work very hard to increase the latter. All the best on your book.

    • Bill

      Thank you for sharing the 2 papers included in the Koonin article, especially the Graham (2013) paper about Antarctica and the oversimplification of the ice sheet dynamics. The Graham paper says in part “ In previous work, the process of sediment removal from offshore sea-bed highs was suggested to have made the Thwaites Ice Shelf more sensitive to thinning in the past by lowering sea-bed topography. Our results show that, in addition to increasing bathymetric depth, the process of flattening sea-bed highs during grounding may have also increased the likelihood of rapid retreat at Thwaites Glacier by promoting the development of ice plains at which rapid inland tidal migration of the grounding line occurred. Erosion from the tops of analogous highs on which the grounding line sits today may have broadened the modern grounding zone.”

      Further “… Assuming current retreat rates of 0.8 km per year persisted back through time, and a monotonic retreat from the bump to the present-day grounding line, the (dynamics) almost certainly pre-date the 1950s, and may be several centuries old.”

      Thwaites Glacier, aka the Doomsday Glacier, has many dynamics going on and is thought to be inherently unstable (Hughes 1981). The region also is the hotspot for geothermal activity, as shown by this heat map.

      https://agupubs.onlinelibrary.wiley.com/cms/asset/4456b766-f316-405b-b550-343c91aea98b/ggge22402-fig-0001-m.jpg

      Most likely the thawed bed found in this paper below released last week, is related to the regional geology..

      https://www.nature.com/articles/s41467-022-32632-2

      In researching any area of climate science, there is always, always, a much more complex puzzle than the IPCC and the media want to portray.

      • Since I wanted to correct the Graham paper release to 2022, I am also going to make this observation, that in many findings, the mathematics or statistical treatment or assumptions used, influence significantly the findings of that particular paper.

        This study on contribution to GMSLR of Antarctica has a wide range of outcomes in using 21 simulations.

        https://tc.copernicus.org/articles/14/3033/2020/

        Studies of GMSLR have found the same thing. Depending on the mathematical treatment of tidal gauge data shapes not only the rates but also the level of acceleration or absence thereof.

        In this post, Nic has found reasons to question the ECS because of the math and statistics.

        As a result, the public’s perception of absolutism in AGW, is at odds with what is really going on, and in the defense of most climate scientists themselves, is not what the practitioners are admitting in their own work.

      • Kid … You were the first person I thought of when I read Koonin’s piece. You’ve been unrelenting on SLR (and natural disasters), presenting evidence and argumentation from (what I think has been) an incredibly wide spectrum. Your hands must be calloused from turning over all those stones.

        And thanks for tying it all back to Nic. So true.

      • Bill

        “…turning over all those stones.”

        And there are many stones. In a lot of instances knowing more about what has occurred in the past puts us into a better position of placing the current climate into a longer term context so we can assess future threats that are confronting policy makers.

        Antarctica is a good example. Much recent work is shedding light on the dynamics surrounding the WAIS for millions, thousands and hundreds of years. Kudos to all those involved in these studies providing greater understanding of the ice sheet.

        https://www.sciencedirect.com/science/article/pii/S0031018219304845

        “ We conclude that the West Antarctic Ice Sheet has likely experienced a strong oceanic influence on its dynamics since its initial formation.”

        https://www.nature.com/articles/s43247-022-00369-x

        “… forced deglaciation of this sector from at least 10,400 years ago until 7,500 years ago – when an ice-shelf collapse may have caused rapid ice-sheet thinning further upstream – and since the 1940s.”

        https://doi.pangaea.de/10.1594/PANGAEA.875733

        “… provides the first empirical evidence for the dominant role of ocean forcing in driving past and recent WAIS deglaciation..”

        https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5510715/

    • Matthew R Marler

      Bill Fabrizio: https://link.springer.com/article/10.1140/epjp/s13360-021-02243-9

      Thank you for the link.

  17. ‘CO2 related estimates and to other input assumptions result in a major reduction in estimated climate sensitivity….’

    Other input assumptions, e.g., the Sun!

  18. We’ve experienced roughly 1.2 C warming above the 1850-1900 mean with a roughly current EEI (2005-2019) of 0.8 W/m^2. If ECS = 2.16 then λ = 0.58 and that means ~0.47 C additional is built into current current conditions, and the total equilibrium temperature should be ~1.7 C. Again, if λ = 0.58, then that implies we need 1.7/0.58 = 2.9 W/m^2 from some set of forcings to explain current warming. If we take round RF numbers of 2.1 W/m^2 for CO2, 0.9 W/m^2 for other GHGs and -0.8 W/m^2 from aerosols, that means we’ve experienced a total of ~2.2 W/m^2 radiative forcing. Where did the other 0.7 W/m^2 come from?
    If ECS = 3.2 C, then λ = 0.86 and we would expect 1.9 C total warming from the 2.2 W/m^2 increase in forcings. Since EEI is 0.8 W/m^2, about 0.7 C of that is in the current energy imbalance, leaving 1.2 C for the rise in temperatures. This fits empirical data precisely.

    So it seems that for 2.16 C to be correct, we need 1) to find 0.7 W/m^2 somewhere or 2) to show that the above estimates are off by that amount or 3) some combination of the two.

  19. “The covid problem is an ill-posed problem making detailed predictions virtually impossible.”

    I was consistently right about COVID in my Spanish blog since I first warned of what was coming our way:
    On January 30 2020:
    Scenarios and consequences of the Wuhan coronavirus pandemic
    On February 25 2020:
    Coronavirus Scenario 2: Enemy at the Gates
    And thereafter.

    It was painful to be right and watch a slow-train wreck without anybody doing what it was supposed to be done to protect people from a dangerous disease. Millions of deaths could have been prevented. We were supposed to be preparing for something like that for decades.

    The herd immunity concept does not apply to rapidly mutating viruses. Experts were supposed to know better. Coronaviruses mutate more slowly than other viruses, but the huge number of infections more than makes for that.

    • Yes, I agree that the world was unprepared for covid19 and the response was based on a flawed field of science and a host of badly flawed papers and models. You are correct that the classical theory of epidemics does not really apply to rapidly mutating pathogens or to ones where multiple infections of a single person at different times are possible.

      I haven’t read your blog but perhaps should look at it.

  20. I have reservations about statistical calculations assuming a randomness to natural phenomena. Nature does not make numerical errors. The only nontrivial solutions we have to mimic nature’s are variational in character. With respect to climate sensitivity, a variational postulate would be that nature’s solution minimizes the work necessary to maintain a flux of 240 watts from here to there. Qualitatively, nature will use any and all means available, e.g. clouds and convections, to minimize thermal gradients across the troposphere to achieve a global minimization of energy dissipation. Approximations will always lead to greater gradients and excess warming.

  21. Lewis&Curry: Do you think 2.16 C is the best estimate that we have for ECS so far, or is your lower estimate from LC18 better? (Why?)

    • I’ve read the study now, I found an explanation in the last paragraph:

      “The revised data-variable median Historical evidence estimates of S(hist) and TCR are somewhat higher than the comparable estimates in Lewis and Curry (2018), of 1.66 K and 1.33 K respectively. The excess is mainly due to a stronger aerosol ERF change, even after revising S20’s assumptions. Further revising S20’s median aerosol ERF to match the change per the AR5 time-series, extended post-2011 using AR6’s annual changes, would reduce the Table 8 median S(hist) and TCR to respectively 1.82 K and 1.40 K. Changing the base period to 1869–1882 to match Lewis and Curry (2018), avoiding the poorly observed 1861–1868 period, would further reduce those estimates, to 1.79 K and 1.37 K. The methane shortwave ERF adjustment, and greater estimated change in radiative imbalance, in AR6 can account for the small remaining differences.”

  22. Pingback: ≫ Importante nuevo documento desafía las afirmaciones del IPCC sobre la sensibilidad climática

  23. This is hilarious. I see that Joshua has once again gotten everyone to ignore the actual topic (climate) by getting their heads spinning about COVID …

    Was Nic right about COVID? Nope. But then neither were I, Fauci, Birx, the english guy who predicted over 2 million US deaths, and a whole host of other folks.

    But what does this have to do with Nic’s paper on Equilibrium Climate Sensitivity (ECS)?

    Well, not one damn thing … which is why Joshua endlessly natters on about COVID. He can’t find any errors in Nic’s climate claims, so he tries (and unfortunately often succeeds) in changing the topic to Nic’s or my or someone else’s early incorrect speculations about COVID, as if that says one damn thing about whether our climate claims are valid or not.

    Don’t bite, folks. When he starts in again about “But person X was wrong about COVID”, give that the response it deserves.

    Point at Joshua and laugh, and then ignore his response.

    w.

    • Thanks Willis, you took the words out of my mouth. All the Covid-related posts here are o/t. IMO no one who commented has read the paper in question. This is dissappointing!

    • Come to the topic!

    • I suppose it is always a legitimate questions if one’s beliefs affect reasoning and perception. It’s easy to ask that question, but quite another thing to demonstrate where in Nic’s reasoning that bias might show itself.

    • Everett F Sargent

      Willis Eschenbach is the very definition of a non sequiter.

      As to what Lewis actually said …

      “In Objective Bayesianism as well as Subjective Bayesianism, however, subjective choices will still be made by the investigator in relation to the data and model used.”

      Oh I like that one so very much!

    • jim –

      Out of respect for Frank who made the request without an accompanying attack, my last comment on this (Judith will probably Zamboni me anyway)

      > I suppose it is always a legitimate questions if one’s beliefs affect reasoning and perception. It’s easy to ask that question, but quite another thing to demonstrate where in Nic’s reasoning that bias might show itself.

      I completely agree, and feel that same logic should be applied when Judith and Nic and other “skeptics” assume a link between activism and science, when they don’t agree with the activism.

    • Please come to the topic, once again. Nobody could know that there is every re-infection with covid-19 is possible due to immune escape. We talk about the ECS, which is not involved in reinfection. Stop this red herring behaviour!

    • Yes jim2, there is a word for what Josh is doing, its called mind reading. It is unethical and proves absolutely nothing.

      The activism of many climate scientists is publicly acknowledged and does not have to be inferred. The climategate emails make clear that they slant their “science” based on that activism. In the case of Nic and Judith, the “activism” exists only in Joshie’s very small mind.

    • Yes jim2, there is a word for what Joshua is doing and its called mind reading. It’s unethical and proves nothing except the biases of the mind reader.

      The activism of many climate scientists is a matter of public record and the climategate emails prove that they skew their science to suit that activism. It the case of Nic and Judith, “activism” can only be inferred by a very biased and anonymous commenter whose knowledge of science is nil.

      What is mind boggling is why he imagines anyone cares what he thinks. Nic and Judith have very long public records that speak for themselves.

    • Back when COVID made the scene, at some point I did read that immunity to the 4 common corona viruses was not lasting. I suppose Nick could have read that. I don’t know if he did or not, but it would be fair to say that would be an element of due diligence. Of course, the fact that the response to the 4 common ones is like that wouldn’t necessarily be indicative that COVID would also be that way. Enough about COVID.

  24. I have great respect for the undoubted expertise of Nic Lewis and have no doubt that the fine tuned Sherwood estimate of ECS is all the better for it. However, like many of the other estimates, it is based on many questionable assumptions and over-heating models.

    The science has not really progressed much since that proposed by Arrhenius in 1896, despite massive research at the cost of billions of dollars spent in recent decades. As we contemplate the current temperature hiatus, propaganda driven alarmism has spread around the planet like a pandemic. Decarbonisation is the magic cure though most people who call for it have no idea what it means, what it will (or will not) achieve and what it will cost. As the madness intensifies, should scientists not bear some of the responsibility for delivering the world from this nonsense?

    The answers are around us. Not all scientists slavishly follow the teachings of the IPCC. David Coe, in an earlier comment, showed that experimental data contained within the HITRAN database shows clearly that the greenhouse gas absorbance bands are strongly saturated. There is no present or future threat of serious warming by that mechanism.

    Our contributor here, Javier, and his co-author, Andy May, have shown how the energy provided by solar insolation makes its way from the Tropics to the poles by way of the atmosphere and oceans. In so doing, it produces the earth’s weather.

    William Kininmonth, in a report published by GWPF, proposes that the transport of energy from the tropics to the poles is the dominant feature that causes warming and cooling phases that are characteristic of our climate. The oceans control our climate, not greenhouse gas. The greenhouse effect is minor and efforts to decarbonise our lifestyle is pointless.

    I believe that these scientific contributions provide compelling reasons for challenging the tired climate change claims. If you agree, please help to bring these developments to the attention of a wider audience, including decision makers. If you disagree, you are in a discussion forum, constructive debate is the scientific way.

  25. Matthew R Marler

    Nic Lewis, thank you again for this essay, and all of your work.

  26. And a few more examples of people pointing out how wrong Joshua usually is.

    atandb | April 22, 2021 at 12:44 pm | Reply
    I have for a long time contended myself with reading rather than commenting. However, your [Josh’s] use of statistics in the preceding comment is so egregious that I decided to comment. First of all you quote two numbers of an entire bicameral plot to prove your point, which is cherry picking in the extreme. A look at the entire plot without using any other information would lead to the conclusion that, at present that the death rate is a low for the graph.

    atandb | April 22, 2021 at 1:24 pm |
    As long as the graph is in the asymptotic decline, which it is, it is a decline. Does not matter what the average is, how much of the graph you want to select, etc. What you did was cherry picking. David Young’s assertion of “strongly declining” is correct, but not what I would have used. The asymptotic curve is still strongly declining according to statistics. I would not have used that description, but your objection to it is fallacious.

    Joe – the non epidemiologist | April 23, 2021 at 9:54 am |
    Context in the overall data (not the minutia) is far better to develop an understanding of the infection rate curves. As you stated, Sweden, in spite of much looser mitigation protocols, fared better than most other western countries, Josh on the other hand became so obsessed with proving nic wrong, that he lost sight of the broader picture. Classic case of cant see the forest for the trees.

  27. Don’t say you are not a scientist. Don’t say it if you value longevity in your job. The World Bank President made the unforgivable mistake of saying he wasn’t a scientist and the hyenas were in attack mode, calling for his head.

    These clowns in the media, most of whom most likely haven’t read as much of the actual science as many skeptics, probably should spend more time reading the science rather than arrogantly shooting off their mouths about the consensus and denigrating those who admit they aren’t scientists.

    https://qz.com/the-president-of-the-world-bank-isnt-sure-climate-chang-1849562293

    • So it was a surprising when David Malpass, the Bank’s president, struggled to answer a very basic question during a panel discussion hosted on Sept. 20 by the New York Times. “Do you accept,” he was asked, “the scientific consensus that the man-made burning of fossil fuels is rapidly and dangerously warming the planet?”

      After some dithering, Malpass reached for a talking point that was once a favorite of climate change-denying Republicans in the US Congress: “I’m not a scientist.”

      Is that the scientific consensus? The scientific consensus is that AGW is trending up against a deterministically chaotic backdrop. Deterministic because there must be causes in a physical system but untangling them is complex. What climate science needs is an Alexander.

      Turn him to any cause of policy,
      The Gordian Knot of it he will unloose,
      Familiar as his garter

      — Shakespeare, Henry V, Act 1 Scene 1. 45–47

      It reminds me that we will soon be overthrowing a monarch. That wouldn’t have been polite to a nice old lady. King Charles III is another matter.

  28. It appears to me that merely using AR6 best values for some of the climate system parameters had a surprising (to me) large effect.

  29. Everett F Sargent

    In how many of Lewis’s papers have they used the word objective (most often capitalized as in the current paper throughout the body of their text)?

    I kind of lost count somewhere between two and five, but it could be more than five.

    Bayesian deconstruction of climate sensitivity estimates using simple models: implicit priors and the confusion of the inverse
    James D. Annan and Julia C. Hargreaves (21 Apr 2020)
    https://esd.copernicus.org/articles/11/347/2020/

    “There is also a strand of Bayesianism which asserts more broadly that in any given experimental context there is a single preferred prior, typically one which maximises the influence of the likelihood in some well-defined manner. The Jeffreys prior is one common approach within this “objective Bayesian” framework. However, it has the disadvantage that it assigns zero probability to events that the observations are uninformative about. This “see no evil” approach does have mathematical benefits but it is hard to accept as a robust method if the results of the analysis are intended to be of practical use. In the real world, our inability to (currently) observe something cannot rationally be considered sufficient reason to rule it out. We do not consider objective Bayesian approaches further.”

    • Standard non-Bayesian (Frequentist) staistical methods also produce parameter estimates that are objective, in the sense that they only depend on observed data and model assumptions. Frequentist estimates produce confidence intervals, which are generally regarded as preferable to Bayesian ‘credible intervals’. Where only a single unknown parameter is being estimated, the use of an ‘Objective Bayesian’ method with a calculated noninformative Jefferys prior (as my paper does) has been proved mathematically to produce ‘credible intervals’ that are closer to true confidence intervals than for any other prior.

      James Annan believes in using Subjective Bayesian methods with an investigator-selected prior. His understanding of the merits and effects of noninformative priors (ones which maximise the influence of the data) is IMO incomplete.

  30. Abrupt climate change is the 1.5 degree C elephant in the scientific skeptic seminar.

  31. Everett F Sargent

    James also said …

    “All this stuff about “objective priors” is just rhetoric – the term simply does not mean what a lay-person might expect (including a climate scientist not well-versed in statistical methodology). The posterior P(S|O) is equal to to the (normalised) product of prior and likelihood – it makes no more sense to speak of a prior not influencing the posterior, as it does to talk of the width of a rectangle not influencing its area (= width x height). Attempts to get round this by then footnoting a vaguer “minimal effect, relative to the data” are just shifting the pea around under the thimble.”

    http://julesandjames.blogspot.com/2014/04/coverage.html

  32. Everett F Sargent

    Andrew said …

    “Despite what the Wikipedia entry says, there’s no objective prior or subjective prior, nor is there any reason to think the Jeffreys prior is a good idea in any particular example. A prior distribution, like a data distribution, is a model of the world. It encodes information and must be taken as such. Inferences can be sensitive to the prior distribution, just as they can be sensitive to the data model. That’s just life (and science): we’re always trying to learn what we can from our data.

    I’m no expert on climate sensitivity so I can’t really comment on the details except to say that I think all aspects of the model need to be evaluated on their own terms. And there is no reason to privilege “the likelihood,” which itself will be based on modeling assumptions.

    P.S. See here for some general discussion of objectivity and subjectivity.

    https://statmodeling.stat.columbia.edu/2015/12/07/use-of-jeffreys-prior-in-estimating-climate-sensitivity/

    • Nic and James disagree on the best priors to use. No one here except perhaps Matt Marler knows enough to comment on this disagreement with authority.

      It is more appropriate to focus on what they strongly agree on, viz., that the common use of uniform priors in climate science was common for many years and tended to inflate estimates of TCR and ECS. Nic did a real service to the field in getting the field to largely abandon uniform priors. Thanks, Nic.

      • Everett F Sargent

        Actually, the Jeffreys prior used by Lewis now is almost as bad as the uniform bounded priors used in the long ago.

        Simple put, we do know something about ECS regardless of the actual underlying statistical distributions. And what we do know suggests that a Jeffreys prior is a major no-no for all PRACTICAL purposes for determining ECS.

        Anyone can read these technical opinions elsewhere (in many many places) and easily get the gist of what all they are saying.

        So, your setup is properly frames as Lewis vs World. Heck Lewis only has less then ten (real, not fake expert) citations for the two 2018 papers, their two most recent two papers. We will ignore the Sherwood, et. al. (2020) citations for the moment (because most of those are from real experts, so no real reason to pile on there).

        Science advances one funeral at a time and thus I think the World wins here … eventually.

  33. A reminder:

    [N]o theory which incorporates non-subjective priors can truly be callled Bayesian, and no amount of wishful thinking can alter this reality.

    https://www.sciencedirect.com/science/article/abs/pii/S0378375897900690

    I am not sure Radford Neal agrees. Perhaps Nic could contact him. They seem to got along fairly well last time they chatted.

    • It is conventional to call ‘Objective Bayesian’ an approach where the parameter estimate is represented by the normalized product of a data likelihood function and a non-subjective prior (being the ‘posterior PDF’). However, although this approach is Bayesian in form, I agree that is arguably not (fully) Bayesian in reality.
      However, what really matters is not what one calls an approach to parameter inference but whether it produces estimates that accurately reflect the uncertain evidence used to derive them.

      • It is also conventional to call them uninformative, Nic, just like it is conventional to distinguish effective from equilibrium climate sensitivity. Or at least it should be.

        It should be noted that you used the word Objectively in your title, which seems to be less conventional. I suppose that scientific papers ought to get with the times and become more playful. They should also make use of the empirical results obtained by the advertising industry. Repetition matters, and every occurrence of the 23 *objective* in your paper counts, 24 if we count the title.

        Another good convention is to cite relevant lichurchur. This time you did follow it by citing AH11. It was in the same breadth as your own paper, published years later. Contrarians might still think that you are the one who DESTROYED uniform priors, but at least you did not contribute to the misunderstanding.

        Well done!

      • Willis’s iterated endorsement of Nic’s intellectually serious work is far more disconcerting than Willard’s expression of concern over Nic’s iteration of

        “objective”

        Because Willis’s narrative arc predictably ends in demanding we ignore his past predictions.

        https://vvattsupwiththat.blogspot.com/2022/09/stemwinding-climate-clock-backwards.html

      • Willard, your quote used the term “non-subjective”, which is why I used that term rather than the usual “noninformative” or “uninformative”.

        Actually, I used the word “Objectively” not as a term in itself but as part of the term “Objectively combining”. It is the method of combining the evidence from which climate sensitivity is estimated that is objective, not the choice of evidence used.

        The statistical method used is indeed objective, in the sense (as the paper states) that it only depends on observed data and model assumptions. As the paper goes on to say, In Objective Bayesianism (as used in Lewis 2022) as well as Subjective Bayesianism (as used in Sherwood et al 2020) , however, subjective choices will still be made by the investigator in relation to the data and [statistical/physical] model used.

      • Right on, Nic.

        While my own choice would be uninformative, how about uninformed? I am sure contrarian megaphones would love to advertise that uninformed methods are the best to meet their inactivist objectives.

        Speaking of which, in 2104 your uninformed methods produced a median of 1.64K in 2014-09, 1.76 K in 2018-08, and 2.1K in 2022. Could we forecast that they should reach 3.07 by 2038?

        Congrats again!

      • This is typical drivel from Willard. Nic has updated his work several times with new and hopefully more accurate data. The main new element here was the use of paleo data. I do believe however that the estimates from historical data haven’t changed that much in Nic’s work except to take account of the updated temperature data which has also grown hotter over time as algorithms are “improved.”

        It is also largely irrelevant what a method is called. In almost all cases I can think of most methods have many names in the literature. Just to give one example, stabilized finite element methods are called stabilized galerkin methods or names like SUPG, DG, etc. This class of methods is large and thus the literature is massive and you can find scores of names that have been used.

      • Oh, Dave, always classy.

        I agree with you – Nic has updated his work in the most uninformed way possible.

        You should try to ask The B Company to run their simulations with that kind of uninformed toolkit. If you can pull it off, please make sure to keep us uninformed.

        Ta.

      • It is not conventional to use *objectively* in that sense, Nic, and if you used the O word so often that plausible deniability does not work anymore.

        If you really are serious about your claim that names do not matter, use *non-informative* from now on.

      • I don’t care about what these statistical methods are called. I would defer to what the majority of specialists think. Being unable to understand the mathematics but focusing on names is an inherently political and activist way to make things seem to be something they are not. I know that textual analysis is an obscure and largely meaningless activity for idle academics. The vast vast majority don’t care and indeed shouldn’t care.

      • I am glad to hear that you don’t care about any of this, DaveY. That means you have no reason to reject my modest proposal.

      • I find it breathtaking that the discussion is here about the statisitics in the paper. BUT: The huge part of the difference in the results beween the Sherwood and the Lewis paper has it’s origins in the “rest”. As Nic wrote: “As it happens,
        neither the use of a Subjective Bayesian method nor the flawed likelihood estimation led to
        significant bias in Sherwood20’s estimate of S when all lines of evidence were combined.” The rumble of some commentors here about “uniformative” etc. is a tempest in a teapot?

      • DavidY’s spats are no tempest, FrankB.

        Perhaps you could explain how Nic succeeded in halving the sensitivity range. After all, it is a feat no one succeeded in doing for more than 40 years in the scientific community.

        Please dumb it down a bit, as most commenters have not really read the paper, and just like the objective sound of it.

  34. Back of the envelope…quite simply, climate models generally use ECS in the 3-4 range. Honest verification on out-of-sample data (hard to find) generally yields a hot bias more than 2 to 1. When I run the numbers, I consistently get a bias-adjusted ECS of ~1.5. For about ten years, I haven’t seen any reason to waver off of that. For those of you with a weather background, think of it as “Climate MOS”. Statistical post processing bias adjustment is standard practice in weather forecasting since about 1970.

  35. Radiative calculations suggest that an additional 3.7W/m^2 longwave radiation from doubling CO2 levels should warm a surface at 15°C by around a net 0.5-0.6°C. If rising CO2 forcing projects onto natural variability and increases positive Northern Annular Mode conditions, the water vapour and cloud feedbacks should be negative, as positive NAM is associated with La Nina conditions and a colder AMO (both of which also increase CO2 uptake). Increased greening from higher CO2 levels certainly is a cooling factor. Is this the real Net Zero?

  36. That is pretty much exactly what I would expect. I’m guessing the most likely value is lower than the central value of 2.16.

  37. What is only marginally discused here is the recalculation of the TCR (Tab.4 in Lewis (22)) of the Sherwood et al (20) (Sh20) paper. This value has major influence on the temperatures in 2100, and many present political desicions depend on this. The TCR value is in the Sh. paper Median 2.26 (1.7…4.5 likely) K/2*CO2. The AR6 didnt use this: 1.8 (1.4…2.2). Perhaps because the TCR was not exlicitly mentioned in Sh (20). The median value in this paper is higher than the likely range of AR6! In Lewis 22 the TCR is much more inline with the AR6-range: 1,54 (1,2…2), see Tab.. 8 in L20. IMO this is a strong argument for the L20 result also when it comes to the ECS: The very high TCR (not mentioned in S20 with any reason) points to some discrepancies in the calculation of the climate sensitivty in S20.

    • This is a good point frank. As I recall it is TCR that is more directly related to the inputs from historical data and thus is more reliable than ECS which must be derived from TCR. I’d be interested in your take on this.

      • IMO it was the first target in Sh20 to estimate the ECS. Therefore the 25 (!) authors used inputs ” by combining estimates based on different lines of evidence, such as process understanding (feedback analysis), the historical instrumental record, and paleoclimate data.” (cited from L22).
        However, a constraining of the TCR-Range to check the plausibilty of the methods is neccessary. The Sh.20 paper didn’t so, only Lewis (22) made this test and hit the target with his assumptions, with the assumptions in Sh22 it missed. A strong hint that the approach of Lewis 22 is more reliable than the one of Sh22.

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  41. Pingback: CMIP6 GCMs versus global surface temperatures: ECS discussion | Climate Etc.

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  44. The results of Lewis’ analysis determined a likely range of 1.75 to 2.7oC for climate sensitivity. The central estimate from Lewis’ analysis is 2.16 oC, which is well below the IPCC AR6 likely range. This large reduction relative to Sherwood et al. shows how sensitive climate sensitivity estimates are to input assumptions. Lewis’ analysis implies that climate sensitivity is more likely to be below 2 oC than it is to be above 2.5 oC.

    In your A detailed explanatory article about the paper is available here. You state that values between 1.5°C and 2°C are quite plausible.
    Not that they are more likely.
    I think you should amend your current article to reflect that particular correct wording instead of “more likely”.

    I noticed one commentator comment on 3 previous studies of yours with 3 slightly different results.
    Thank you [and Judith?] for your past efforts showing how low ECS is replicable even when the data input is different or longer.
    The commentator is one of a number of people who become very upset when their views of high ECS are challenged because the implication is that in pushing high ECS they have been deliberately misleading others and perhaps themselves as to the true amount of global warming possible.-
    I think your paper , and Nicola’s are causing some consternation which leads to the personal rather than scientif attacks being launched.

    • angech

      “ ….personal rather than scientific attacks being launched.”

      In the other post I just reviewed the factors that confirmed I had become a skeptic. They finished the job.

      But what started my journey were the personal attacks instead of challenges against the science.

      When I was budget director I had to really probe and question the existing and proposed funding levels. Understandably, that made the program managers a little uptight and nervous. But the ones who had the answers and had an airtight case came right back at me with solid arguments and facts.

      Those who had a flimsy case and hadn’t done their homework got into a p…..g contest with me and attacked me. That was when I knew their funding request was a sham.

      Reading all the personal attacks on skeptical scientists was my first tip that something was askew with the establishment’s narrative.

      • CKid

        “Reading all the personal attacks on skeptical scientists was my first tip that something was askew with the establishment’s narrative.”

        A very good point.
        Confirmed by that same unethical behaviour shown by some commentators here and worse, encouraged and indulged in at other sites they frequent.
        A shame since some of them have quite good skills and the ability to therefore know, themselves, that their behaviour is shameful.

        Blind to their bad behaviour.
        As you say.
        A true indication that their arguments are lacking.

    • The lower values may be more likely. 2.16 is the central value, but the most likely value may be lower. The distribution is likely strongly left skewed.

      • Aaron,
        I realise that skewing occurs.
        Most often of course in higher value ECS assessments with fat tails.
        If 2.16 is the central figure however then it is the most likely value, skewing or not.
        Nic has in his own work previously shown ECS most likely below 2.0.
        This review shows a low ECS, 2.16 most likely, not most plausible.

    • Thanks for your comment, angech. You write:
      “In your A detailed explanatory article about the paper is available here. You state that values between 1.5°C and 2°C are quite plausible.
      Not that they are more likely.”

      What I wrote here was “more likely to be below 2°C than it is to be above 2.5°C.” That statement is accurate. As I state in my paper, there is (per my estimate) a 36% probability of climate sensitivy being below 2°C, versus a 26% probability of it exceeding 2.5°C.

  45. Thanks to the Green Energy Extremists, Europe is going down the proverbial drain.

    The economic damage from the shutdown of Russian gas flows is piling up fast in Europe and risks eventually eclipsing the impact of the global financial crisis.

    With a continent-wide recession now seemingly inevitable, a harsh winter is coming for chemical producers, steel plants and car manufacturers starved of essential raw materials who’ve joined households in sounding the alarm over rocketing energy bills.

    https://www.bloomberg.com/news/articles/2022-09-27/europe-faces-an-energy-crisis-how-bad-could-things-get

  46. @jim2 | September 27, 2022 at 6:26 am | trapped in moderation

  47. Because Europe listened to the Green Energy Extremists and failed to develop LOCAL fossil fuels under their control, they now pay a dear price.

    In the clearest signal yet that Europe will have to survive this winter without any significant Russian gas flows, Nord Stream said it was impossible to predict when operations will resume. European Union leaders have repeatedly accused the Kremlin of weaponizing energy supplies.

    Germany is investigating three simultaneous gas leaks in the Baltic Sea from the damaged Nord Stream pipelines. The leaks were so big they were seen on the radars of vessels in the vicinity, the Swedish Coast Guard said. Denmark is stepping up security on its energy installations.

    https://www.bloomberg.com/news/articles/2022-09-27/nord-stream-probing-pressure-drop-at-second-russian-gas-link

  48. Europe is finding out you can’t legislate reality – reality will bite back.

    Europe’s top markets watchdog said she’s looking at ways banks can help utilities shoulder massive margin calls to keep trading power and gas, without the lenders also becoming victims of the energy crisis.

    “We believe we need to look at this very carefully to ensure we are not transferring risk from the energy markets into the financial markets,” Verena Ross, who leads the European Securities and Markets Authority, said in an interview with Bloomberg TV’s Francine Lacqua.

    https://www.bloomberg.com/news/articles/2022-09-27/europe-wants-banks-to-ease-energy-crisis-without-falling-victim

  49. @ jim2 | September 27, 2022 at 6:31 am | trapped in moderation.

  50. Joshua goes on endlessly about Nic’s COVID analysis. But what of Joshua’s record? Joshua doesn’t make many definitive statements about his beliefs concerning any topic. Instead, he continually points out the existence of counterfactuals, confounding variables, externalities, and other complications of real life, reality. There is nothing wrong with this, but the point is he seldom makes any predictions that can be evaluated now or later. He mainly dwells on complications, although one concept he as made clear is he believes global warming skeptics are skeptical because of their political beliefs. When a skeptic comes along with a reasoned argument, like Nic, Joshua reverts to sliming Nic with any past errors he can find. So has Joshua been perfect? Not at all. Here are some examples. Note that now in Europe, and especially Germany, there exists high prices for energy and a whale of a lot of high and dear costs because they failed to develop local fossil fuels at the behest of the Green Energy Extremists.

    I just read a report that Germany is now up to close to 21% from renewables, and their economy isn’t doing so bad relative to ours.

    https://judithcurry.com/2011/08/30/consumer-options-for-choosing-renewable-energy/#comment-106906

    in the post https://judithcurry.com/2011/08/30/consumer-options-for-choosing-renewable-energy/

    I often hear criticisms of Energiewende framed around the high electricity price in Germany…but I think that price is not the only relevant metric: Cost is also an important consideration.

    https://judithcurry.com/2015/12/02/german-energiewende-modern-miracle-or-major-misstep/#comment-748106

    in the post: https://judithcurry.com/2015/12/02/german-energiewende-modern-miracle-or-major-misstep/

    • >…he believes global warming skeptics are skeptical because of their political beliefs.

      That’s not accurate. Along more than one dimension.You’ve read. You think you understand. You don’t understand.

      • Once again, Joshua dances around whatever point he is trying to make. Instead of clarifying his position, note he attacks my understanding. I find this behavior disingenuous and a waste of blog real estate besides.

      • jim –

        It’s interesting that you say, with no expressed uncertainty, what it is that I believe, and then call me disingenuous when I tell you that you’re wrong in your statement about what I believe.

        Interesting, and pretty funny, actually.

        It’s probably a total waste of my time to clarify my belief here – but I suppose it can’t hurt. BTW, this will be far from the only time that I’ve explained by view on this. And it’s far from the only time I’ve explained it to people who have attributed beliefs to me that I’ve never exp;res

        Pretty much everyone is inclined towards “motivated reasoning,” or confirmation bias, or whatever you want to call it. As such, they filter information as a way so as to not conflict with how they identify. There are different components of identity. Political identity is an important one, but far from the only one. People can identify as a scientist who is dedicated to finding scientific “truth.” People can identify as a climate “skeptic.” Etc. The different components of how people identify aren’t mutually exclusive, and sometimes can even be in contradiction to one another.

        More specific to this context, people who constantly participate at a climate change-focused website are highly likely to be strongly identified as a “skeptic” or as a “realist” (those labels are imperfect, but they’re good enough to get the job done). There is a great deal of overlap in that regard within identity in the climate change realm, and political orientation. There certainly isn’t 100% congruency. There is a strong signal (particularly in the US) but it’s not absolute.

        So, you say:

        > …he believes global warming skeptics are skeptical because of their political beliefs.

        No, that’s not true. I don’t think that political beliefs (in most cases) are causal (on either side of the climate change divide). What’s *causal* is basic functioning of human psychology (wanting to maintain a consistent and positive seeming identity) and human cognition (we make meaning out of finding patterns and fitting reality to fit those patterns).

        I think that political identity often (even if not always) functions as a moderating variable, helping to explain the strength of the causal relationship between basic human psychological and cognitive attributes, and views on climate change. I think that sometimes it might even be considered a mediating variable, if the sense of political identity is strong enough.

        I think that causal mechanism is in play on both sides of the climate change divide, for the most part. There are exceptions, of course.

      • Joshua – Can it not be that some of us believe climate science really doesn’t have good handle on how the climate works. And even though there is a chance global warming is caused mostly by CO2, there is a good chance that isn’t the only cause and it might well come to pass that we enter a cooling phase. That’s the uncertainty I would like to express. Given that uncertainty, should we completely change the energy infrastructure to wind and solar and (some day) enough batteries on the grid to matter, and all that at great expense and opportunity cost, and even perhaps some people die of exposure to cold or starve because of a bad decision to kill fossil fuels? Or should we bide our time with fossil fuels and adapt if necessary to changes in the climate, while we build out nuclear power? That seems to me to be the rational course. After all, we have adapted for thousands of years. Sometimes a few have died because of it, but we as a species have survived. I opt for adaptation, and I honestly don’t see how what I identify as matters.

      • jim –

        > Can it not be that some of us believe climate science really doesn’t have good handle on how the climate works. And even though there is a chance global warming is caused mostly by CO2, there is a good chance that isn’t the only cause and it might well come to pass that we enter a cooling phase.

        Sure. I don’t know about “good chance” but it’s a complex system and it’s not unreasonable, imo, to look at it all as uncertain.

        > Given that uncertainty, should we completely change the energy infrastructure

        This is where our opinions most likely diverge

        We need a massive build out of infrastructure to meet our energy needs going forward – either way. I think we have enormous resources to being to bear, even though they are highly unevenly distributed.

        As a matter of risk management, I think we are faced with low probability high damage function risk. As such. I think it makes sense to explore meeting our future needs in a way that mitigates the high damage function risk.

        I’m terms of costs, I think that people often conflate price and cost. Increasing the price of energy doesn’t necessarily increase the cost if the increase in price is accompanied by a decrease in external costs, the risk of climate change being one potential cost but harmful air quality resulting from particular matter being a less speculative cost among the full range of externalities. If course the externalities must be evaluated in all energy pathways.

        With sufficient will, as a society, I think we can meet our pressing needs. We’ve faced analogous challenges in the past, building our current electrical grid, our railroads, our highway system, the war effort.

        It I think it will only happen if/when the need reaches a stage where there’s no ambiguity as to whether there’s anything to do but to resolve it. In the meantime, people will leverage the issue to wage petty, identity-based warfare.

        It could happen with stakeholder dialog and participatory democracy, but our species hasn’t yet embraced such practices. It would also require a flattening,to some degree, in the distribution of resources, but the “elite” who oppose such a distribution have too much power for that to take place untjl/if there is no choice. Perhaps we will reach a turning point before its too late. Perhaps it will never be necessary. I surely don’t know.

      • Joe - the non climate scientist

        Joshua – comment – “the risk of climate change being one potential cost but harmful air quality resulting from particular matter being a less speculative cost among the full range of externalities.”

        The damage, premature death etc due to harmful air quality resulting from particular matter and other pollutants is vastly over stated. As the air in Europe and north america has become much cleaner than it was in the 1950’s 1960’s, the air can only become so much cleaner. Yet the supposed incremental reduction in bad health outcomes increases faster than the incremental improvements in air quality. A reversal of the law of diminishing returns.

        Take a look at the Bell Mcdermott study of 96 US cities and the increase in premature deaths due to increases in ground level ozone. That study is considered the gold standard for the that type of studies. The Studies used for the particulate matter use the same/similar methodology.

        The flaws in the Bell Mcdermott study render the conclusions meaningless. Same with the particulate matter studies.

      • We have a old and deteriorating infrastructure in this country. So I’m in favor of a focused effort on rectifying thst situation, and dokng so by revitalizing communities and providing good employment. But we need to naively increase our infrastructure further going forward. So we have an opportunity to replace existing energy infrastructure with new infrastructure which releases particulate matter into our air. Or not. And we can vastly increase the amount of particulate matter we release with new energy infrastructure. Or not. Or we can do nothing. All up to us.

      • The nature of the damage function is unknown as far as I know. The damage may even be negative.

      • jim –

        > The nature of the damage function is unknown as far as I know. The damage may even be negative.

        Unknown, as in uncertain? OK, I’m willing to go with that. But we have to make decisions in the face of uncertainty, and try to mitigate against high damage risk (in whichever direction).

        How do you see a risk of “negative damage?”

      • Negative damage would be the case if ACO2 is a net benefit. On the topic of the damage function for any arbitrary cause, we can’t just assume the worst and try to mitigate it. That carries real costs, including opportunity costs. If we don’t know what the damage will be, then we do nothing to mitigate the cause.

      • jim –

        > Negative damage would be the case if ACO2 is a net benefit.

        Well, sure. But I was hoping you could spell that out a bit. How is ACO2 a net benefit relative to other energy pathways? Energy is clearly a net benefit, but moving away from ACO2 can still allow for providing that benefit.

        We need to make massive investment in increasing our energy and distribution of access to energy going forward. I see clear potential risk in the “costs” from fossil fuels as the source – particulate matter, risk from climate change, environmental damage, damages that disproportionately impact those who have the least resilience, and, importantly, IMO, the geopolitical costs of enriching autocratic, authoritarian governments in many of the parts of the world that produce fossil fuel energy, etc. Those cost risks are pretty hard to mitigate. The critical problem, imo, as far as engagement on this issue, is when people don’t face those costs – just dismiss them and equate price with cost as yes, the price of fossil fuels is likely to be advantageous (if we consider the issue of intermittency) going forward. But that view only holds up, in my view, if you flat out ignore the external costs.

        On the other hand, the “costs” of renewables (and nuclear) are more easily mitigated. Mostly they come in the form of price – and as a country we have the financial resources to endure that cost fairly easily, IMO. Other (external) costs are real as well, and must be dealt with and considered as with fossil fuels. But there is a general pattern where the price aspect of of non-fossil fuel energy is dropping and likely to continue to drop. But of course, it’s problematic when people ignore the “costs” of non fossil fuel energy sources as well.

      • Joe - the non climate scientist

        Joshua’s comment -.” But there is a general pattern where the price aspect of of non-fossil fuel energy is dropping and likely to continue to drop. ”

        While it is true that the direct costs of non fossil fuel energy is dropping, that stat is deceptive since those costs do not include the indirect costs of maintaining reliability in the system.

      • Joe –

        > While it is true that the direct costs of non fossil fuel energy is dropping, that stat is deceptive since those costs do not include the indirect costs of maintaining reliability in the system.

        I love that you read my comment closely enough to quote from it, yet somehow miss what u explicitly said:

        > yes, the price of fossil fuels is likely to be advantageous (if we consider the issue of intermittency)…

        What explains that? I just can’t imagine. 🤔

      • Joe - the non climate scientist

        Joshua’s comment – “I see clear potential risk in the “costs” from fossil fuels as the source – particulate matter”

        The risks/costs of particulate matter in the US/Canada/western Europe is greatly overstated.

        The Bell McDermott study I referenced above is a textbook example of a “gold Standard” “peer reviewed” study reaching erroneous conclusions. The studies used by the EPA and others on particulate matter and pre mature deaths suffer from similar shortcomings. Try reading the study. Its a great place to start to develop the skills necessary to recognize flaws in expert/peer reviewed studies, or at least develop the skills to ascertain the reasonableness of conclusions.

      • I may have more to say about this later, but since 1969 about 1.3 trillion barrels of oil. If you break down the environmental damage per kwHr, or however you want to levelize it, the damage probably doesn’t amount to much. Helping the people who are most impacted by oil production, I assume those would be the poor, can be done no matter what our energy source. But helping the poor is very problematic. There are reasons they are poor: low IQ, addiction, inadequate upbringing, and mental illness. These issues are not easily addressed. Some of the other negative effects could be mitigated if the negative impact warrants it, but I will go ahead and say it: there will be negative impacts from any widely used technology and we in many cases may just have to live with it.

        Second main point is that no major country runs on “renewable” energy. You have no idea if that’s possible, much less what negative externalities/osts it might entail.

      • Jim –

        > Helping the people who are most impacted by oil production, I assume those would be the poor, can be done no matter what our energy source.

        With this I agree. Which is why the “but think of the poors” hand-wringng about moving to non-fossil fuels seems facile to me.

        The rest – well not much agreement there.

      • Funding hostile entities is also an issue, but it must be said much of renewable energy parts come from China. I do not consider them a friend of the US.

      • jim –

        > but it must be said much of renewable energy parts come from China.

        I sae changing that as a huge opportunity, with benefits along multiple axes, not unlike ramping up a microchip industry in the US.

    • You’ve read. You think you understand. You don’t understand.

      I’ve read as much as I can.

  51. “One of the most important conclusions of the recent 6th Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR6) was to reduce the uncertainty in estimates of climate sensitivity to doubling the amount of carbon dioxide in the atmosphere”

    It helps to look at things in reverse, except driving mirrors, to understand scientific processes.

    Everyone is so focused on a rise in CO2 with a temperature rise that they have the causation around the wrong way.

    CO2 is only in the atmosphere because of the temperature and pressure on the earth surface combined with the composition of the earth surface..

    It is normally in complete balance with its substrate, whether this is the earth surface, The earth substrate, or the thin layer of water between.

    The exchange of CO2 among the 3 main layers described is pure physics. Temperature ,Pressure, How much CO2 is able to be released into the atmosphere or absorbed by the atmosphere at those pressures.

    Other factors temporarily add to the mix.
    Biological metabolic breakdown of vegetation.
    Combustible breakdown of vegetation [forest and grass fires].
    Methane [breaks down to CO2] from biological or heat induce causes.
    Volcanoes.

    This results in a known mass of CO2 in the atmosphere which is fixed in an extremely narrow band by the aforesaid 3 factors.

    More input from any of these causes does not change the CO2 being forced back into that narrow range.
    The turnover of CO2 in the atmosphere is quite large meaning CO2, just like water vapor, is being continually removed from the atmosphere and can therefore not be considered a forcing using the warmist’s own arguments.

    It does not build up and stay at higher levels by extra production because it cannot stay in the atmosphere at any level higher than dictated by the Temperature, Pressure and Substrate.

    The amount produced by humans in burning fossil fuels is trifling and insignificant and is all absorbed nearly as soon as it is produced.
    This simple fact says all that one needs to know about ECS.

    CO2 is associated with a temperature range.
    The CO2 goes up because, surprise, surprise the temperature has gone up.

    Are we hotter than at any other time in the last 100 years?
    Yes.
    Does CO2 go up with a rise in temperature?
    Yes

    The two main arguments against this are firstly that we accurately know past CO2 levels from ice cores and the level has not altered significantly in the recent and extended past.
    The only conclusion we can draw from ice cores not showing changes is that the ability to retain accurate CO2 levels in ice has been greatly exaggerated.
    Greatly exaggerated, they must leak over time and end up closer to the prevailing surface CO2.

    The second is that we know from ocean studies how the CO2 is exchanged between the ocean and the atmosphere based on the volume of CO2 in the ocean, which is low compared to the temperature rises seen.

    The fundamental mistake here is taking the CO2 in the ocean as the only water bodies containg, corralling and relaesing CO2.
    The correct way is to add in the large atmospheric water volume.
    The small rivers and lakes.
    The enormous amount of water under the surface, artesian and ground water mixed in with the surface earth and capable of releasing CO2 easily.

    Were these extra huge amounts of CO2 containing water taken into account, [and they are not]
    The amount of CO2 released from them by a simple 1 C rise in surface temperature would explain all of the current CO2 rise.

    • The fundamental mistake I see is fixating on just CO2.
      The ratio of all the atmospheric gases are changing quickly relative to historic rates of change. But rate of change is relative, no? One thousand years ago there were about one billion people on the planet and now there are 7.9 billion. Expanding ocean dead zones and declining O2 in the air may have a human connection.
      https://www.climatelevels.org/
      So long as we don’t disrupt the food web and we bend the curve on population most of the species will survive, even if we nuke ourselves.

  52. People may say what they will of Nic’s paper, but he has put it out there for all to see. Perhaps some will read it and respond to it in kind. I would be interested to read any criticisms, of the paper that is.

  53. It’s hard to do numerical simulations for things that don’t have well behaved governing equations.

    https://www.epa.gov/sites/default/files/2016-07/climate-forcing-figure2-2016.png

    Like internal climate variability. Climate evolves in patterns of spatiotemporal chaos. GCM evolve from estimates of feasible initial values in equations of state as probability distribution functions.

    https://stateoftheocean.osmc.noaa.gov/all/

  54. Nic –

    I hope that you are planning an after action review of your COVID modeling debacle.

    In particular, I hope you address why you were some 450% (and counting) off in your ideas about how many deaths we could expect in the countries examined in Flaxman et al., or why you were so off when you projected that no counties would exceed 0.085% population fatality from COVID, or whether you have an explanation for how wrong you were in your understanding of immunology that led you to conclude that T cell immunity against other coronaviruses would prevent infection from COVID, or whether you still believes the following theory you out out there (and what evidence you think verifies this claim).

    The mutations that are worrisome appear to have arisen not from an increased number of infections, but rather from well meaning (but it seems highly dangerous) health system actions that inadvertently acted rather like gain of function-like experiments carried out in non-biosafe hospitals, in the UK, Italy and quite likely South Africa.

    https://judithcurry.com/2021/01/10/covid-19-why-did-a-second-wave-occur-even-in-regions-hit-hard-by-the-first-wave/#comment-939572

    • It’s really pitiful this is all you have Joshua. I’m really curious what are, if any, criticisms of the paper the subject of this post? What specifically did Nic do wrong in his paper: ‘Objectively combining climate sensitivity evidence’. Do you have anything? At all? Just askin’.

  55. Even if the ECS is low, and the SCC is low according to Dayaratna et. al (2020) https://link.springer.com/article/10.1007/s10018-020-00263-w, there is still reason for governmental implementation of justice on climate change since countries in lower latitudes are disproportionally damaged by the warming, as shown by this paper, Tol (2019) https://www3.nd.edu/~nmark/Climate/Tol_SCC_forEveryCountry.pdf. So, countries further from the equator should pay reparations to the equatorial countries for these damages.

  56. In a New York Times article dated July 22, 2020 Gavin Schmit is quoted as saying the following in respect to Sherwood et al 2020.

    “This is a real challenge to people who think the experts are wrong to go in, change the assumptions, run the code and show us their results.”

    I guess Nic accepted the challenge and did exactly that. Bravo.