Hansen’s latest overheated global warming claims are based on poor science

James Hansen’s latest paper “Global warming in the pipeline” (Hansen et al. (2023)) has already been heavily criticized in a lengthy comment by Michael Mann, author of the original IPCC ‘hockey stick’. However Mann does not deal with Hansen’s surprisingly high (4.8°C) new estimate of equilibrium climate sensitivity (ECS)[1]. This ECS estimate is 60% above Hansen’s longstanding[2] previous estimate of 3°C. It is Hansen’s new, very high ECS estimate drives, in conjunction with various questionable subsidiary assumptions, his paper’s dire predictions of high global warming and its more extreme concluding policy recommendations, such as ‘solar radiation management’ geoengineering.

Hansen’s new 4.8°C ECS estimate is well above the best estimate of 3°C reached in the IPCC’s latest scientific assessment report (AR6), lies outside the AR6 likely (66%) range of 2.5–4°C and is almost at the top of the AR6 90% uncertainty range of 2–5°C.[3]

Both Hansen’s new ECS estimate and his earlier estimate are based primarily on information about paleoclimate changes, particularly the extensively studied transition from the last glacial maximum (LGM) some 20,000 years ago to the preindustrial Holocene. But is his new estimate (or indeed his earlier estimate) justified by the evidence?

Hansen’s primary LGM to Holocene based ECS estimation.

For his LGM-based ECS estimate, Hansen assumes a 7.0°C rise in global mean surface temperature (GMST) between the LGM and preindustrial Holocene. This value is 56% above the 4.5°C rise that Hansen used previously2. Hansen cites three studies in support of his 7.0°C LGM cooling estimate (which comes from the second of these): Tierney et al. (2020), Osman et al. (2021) and Seltzer et al. (2021).

I published in 2021 an article that was heavily critical of the Osman et al. data-assimilation (reanalysis) based temperature reconstruction. Their reconstruction uses only ocean sea surface temperature (SST) proxies and is based on a single climate model that simulates an unusually cold LGM state[4] and, strongly influenced by the model simulations, produced a 7°C estimate of LGM cooling.[5] The proxy-only based reconstruction in the submitted version[6] of Osman et al. appeared more reasonable, and as shown in my article implied LGM to preindustrial GMST change of about 4.5°C.[7]

The Tierney et al. estimate of LGM cooling (6.1°C)[8] is based on a much larger set of SST proxies, which includes all those employed by Osman et al. used, but similarly uses no land temperature proxies. Tierney et al. uses the same single-model data-assimilation temperature reconstruction method as does Osman et al.[9] Therefore, my criticisms of Osman et al.’s reanalysis-derived LGM cooling estimate very largely apply also to Tierney et al.’s estimate.

The Seltzer et al. 5.8 ± 0.6 °C LGM cooling estimate is for land only and is limited to 45°S–35°N, so does not represent GMST cooling. The authors use a groundwater-based proxy type and a complex model to convert proxy values to surface temperatures. I have concerns about some aspects of their methods.[10] Moreover, their 5.8°C land cooling estimate is based on the error-weighted average of only 15 groundwater records, which show widely varying cooling[11] and may not be adequately representative of 45°S–35°N land areas. Seltzer et al. completely ignore the uncertainty associated with these issues. Their estimate is inconsistent with most proxy-derived estimates of mean ocean cooling over 45°S–35°N, which casts further doubt on its reliability.

I regard the recent Annan et al. (2022) LGM temperature reconstruction as producing a more reliable estimate of GMST cooling than the Tierney et al. (2020) and Osman et al. (2021) studies that Hansen et al. relies upon. The Annan et al. reconstruction uses a similar data-assimilation method to those studies, but with several key differences. Unlike them it uses a simulations from large set of acceptably dissimilar climate models, rather than a single model. Importantly, unlike those two studies, Annan et al. scale the model simulated temperature changes so that the initial guess model cooling estimates used are approximately centered on the data, to minimize model-generated bias. Moreover, Annan et al. use land temperature proxies as well as a larger set of ocean SST proxies to adjust the initial guess. They use the same SST proxy dataset as Tierney et al., but extend its coverage with data from a widely used earlier SST dataset, which in particular reduces Tierney et al.’s huge gaps in coverage of the Pacific ocean.

As a result of the much better proxy coverage, the use of multiple models and the debiasing step, the 4.5°C estimate of GMST cooling at the LGM that the Annan et al. reconstruction produces should be much more realistic than the Tierney et al. (2020) and Osman et al. (2021) estimates that Hansen uses. Indeed, Annan et al. criticize Tierney et al.’s approach, using very cold simulations from a single model, pointing out that it will produce a cool reconstruction regardless of whether the data points to a milder LGM climate.

By coincidence[12], Annan et al.’s 4.5°C GMST LGM cooling estimate is the same value as I adopted for the LGM derived climate sensitivity estimation in Lewis (2023)[13]. That study reworked Sherwood et al. (2020), a very influential World Climate Research Programme linked review of climate sensitivity evidence, which had assessed the LGM to be 5°C cooler than preindustrial.  

Hansen’s ECS estimate is increased not only by adoption of an unrealistically large LGM cooling value, but also by very low estimates[14] for the various changes in forcing between the LGM and the preindustrial Holocene[15]. Hansen’s central estimate for the total Holocene to LGM forcing difference is −5.75 W/m2, much smaller than the −8.63 W/m2 assessed by Sherwood et al.(2020) and even further below the −8.93 W/m2 best estimate adopted in Lewis (2023). The LGM section of Table 1 in the Appendix gives details of all the data-variable estimates used to form the Sherwood et al. (2020), Lewis (2023) and Hansen et al. (2023) LGM–preindustrial Holocene based ECS estimates.

The combination of the large GMST change and small forcing change that Hansen adopts for the LGM results in a central ECS estimate of 4.8°C. By comparison, the Lewis (2023) LGM-based ECS estimate was 2.2°C, somewhat less than the corresponding ECS estimate from Sherwood et al. of 2.8°C.[16] Both these estimates are well below the lower bound of the 3.6 – 6.0 °C ECS 95% uncertainty range for ECS that Hansen estimates.

Hansen supports his LGM-based ECS estimate with one based on the difference in GMST between the LGM and the previous, Eemian, interglacial period. His estimate is therefore inflated by his assumption that the LGM was very cool. Moreover, compared to the LGM there is even greater uncertainty in Eemian GMST, ice-sheet forcing, and other non-CO2 forcing. IPCC AR6 mentions all these drawbacks and additionally points outs that accounting for varying orbital forcing is challenging for this period. Sherwood et al. (2020) did not attempt to estimate climate sensitivity from the Eemian to LGM or any other pre-LGM climate transition because the data available are far more limited than for the much more extensively studied LGM. I likewise did not do so in Lewis (2023), nor do I attempt such an estimate here.

Hansen’s analysis of the PETM event and its implications.

Hansen also considers the Paleocene-Eocene Thermal Maximum (PETM) warming event some 56 million years ago, adopting a best estimate for the warming involved of 5.6°C and assuming, as did Sherwood et al. (2020) and Lewis (2023), that greenhouse gases alone produced the increase in forcing that caused the warming.

Rather than estimating ECS using an estimate of the PETM forcing change, Hansen calculates what the PETM CO2 level would have had to be to cause warming of 5.6°C, based on his ECS estimate of 4.8°C, assuming a pre-PETM CO2 level of 910 ppm and that non-CO2 greenhouse gases contributed 25% as much forcing as CO2 did. Hansen thereby calculates a PETM CO2 level of 1630 ppm. In fact, the correct figure seems to be approximately1565 ppm; Hansen appears to have gone wrong somewhere in his calculations.

Although Hansen’s 910 ppm pre-PETM CO2 concentration value is closely in line with other estimates, the circa 1600 ppm value for the PETM CO2 concentration implied by his 4.8°C ECS and his other assumptions is much lower than the estimate of 2400 ppm, with a ±1 standard deviation range of 1700–3100 ppm, that Sherwood et al. (2020) reached after assessing the available evidence. It is also near the bottom of the 1400–3150 ppm uncertainty range given in AR6.

Moreover, Sherwood et al. assessed the best estimate GMST rise at the PETM to be slightly lower than did Hansen, at 5.0°C, and the non-CO2 greenhouse gas forcing to be higher, at 40% of CO2 forcing. All these differences contribute to Sherwood et al.’s PETM-based ECS estimate being, at 2.5°C, barely half Hansen’s assumed 4.8°C. Moreover, Lewis (2023), using identical data-variable assumptions as Sherwood et al. (2020) but the AR6 formula for CO2 forcing, which is more accurate at high concentrations than the simple formula Sherwood et al. used, obtains an even lower PETM-based ECS estimate of 2.2°C.

The PETM section of Table 1 in the Appendix gives details of all the data-variable estimates used to form the Sherwood et al. (2020)and Lewis (2023) PETM based ECS estimates, and the Hansen et al. (2023) estimate of CO2 concentration at the PETM. Figure 1 shows what the central estimate of the total change in forcing involved was, as a multiple of the forcing from a doubling of preindustrial CO2 concentration, for all three studies’ LGM and PETM estimates.

Although there are much greater uncertainties involved when estimating ECS from the PETM event than for the LGM – preindustrial Holocene transition, the available PETM evidence is closely consistent with the lower, 2.2°C and 2.8°C, ECS estimates derived from the LGM data-values used respectively by Lewis (2023) and Sherwood et al. (2020), but not with Hansen’s very high 4.8°C estimate of ECS.

It is also clear that Hansen’s claim that today’s human-made greenhouse gas forcing is, at 4.6 W/m2, at least comparable to the PETM forcing (which his assumptions imply was 4.67 W/m2) is strongly at variance with the evidence as assessed by Sherwood et al.[17] That evidence implies a best estimate of PETM forcing of 1.98× that for a doubling of preindustrial CO2 concentration[18] (versus 1.17× on Hansen’s assumptions), double or more the latest (2022) AR6-basis estimate, in Forster et al. (2023), of 0.88× for greenhouse gas forcing (1.00× when including that from ozone, a short lived greenhouse gas).

Figure 1.The forcing change between the LGM and preindustrial Holocene, and between before and during the PETM, implicit in each study’s assumptions. The forcing changes are expressed as a multiple of that from a doubling of preindustrial CO2 concentration. The associated ECS estimate equals in each case the corresponding assumed GMST change divided by the forcing change shown, so a higher forcing  change implies a lower estimated ECS value.


I do not consider that Hansen’s climate sensitivity estimation properly assesses and fairly reflects all the available relevant evidence. Unfortunately, unlike Sherwood et al.(2020), IPCC AR6 and Lewis (2023), Hansen et. al. (2023) estimates ECS using only paleoclimate proxy-derived evidence, which generally varies considerably according to the proxies involved and to the methods used to interpret them. This opens the door for biased (cherry picked) assessments. For instance, Hansen et. al. do not even mention any studies (e.g. Annan and Hargreaves (2013) and (2022)) that find a much lower LGM – preindustrial warming than their chosen value.

Although I respect Hansen’s ability and considerable scientific contributions, in my view papers he leads are increasingly strongly biased towards overheated projections and dire conclusions.[19] The “political recommendations” with great impact on the society in Hansen et al. (2023) cannot be justified because their foundation is very shaky, as shown here for climate sensitivity and, in relation to warming-in-the-pipeline and ocean heating, in Michael Mann’s critique.  

Nicholas Lewis                                                                                                            6 November 2023


Table 1. Paleoclimate evidence data-variable best-estimate valuesa used to estimate S and ECS

DescriptionSymbolSherwood et al 2020Lewis 2023Hansen et al 2023[20]Comment re Hansen
ERF from doubled CO2 (W/m2)F2×CO24.003.934.00 
Change in GMST (°C)ΔT−5.0  −4.5−7.0 
Changes in forcing, as ERF (W/m2)     
   CO2 −2.28−2.24 See GHG
   Methane (CH4) −0.57−0.57 See GHG
   Nitrous oxide (N2O) −0.28−0.28 See GHG
Total greenhouse gas (GHG) −3.13−3.09−2.25 
   Land ice and sea level −3.20−3.72  
   Vegetation −1.10−1.10  
   Dust (aerosol) −1.00−1.000Excluded
Forcing excluding that from GHGΔFexCO2−5.30−5.82−3.5 
Change in total forcingΔF−8.43− 8.92-5.75 
Dependence of feedback on ΔT (W/m2/°C2)α0.100.100 
Resulting estimate of ECS (°C)ECS2.792.244.87 
Change in GMST (°C)ΔT5.05.05.6 
Fractional change in CO2 concentrationΔCO21.6671.6670.72Implied
CO2 ERF relative to with log(concentration)fCO2nonLogIgnored1.1171.19See note b
CH4 forcing as a fraction of that from CO2fCH40.400.400.25 
Change in total forcingΔF7.938.705.75 
Estimate of ECS (°C)ECS2.522.264.8Assumed

a Data-values for Sherwood et al.(2020) and Lewis (2023) are medians that have been extracted from Table 3 of Lewis (2023), the notes to which are incorporated here by reference. See those papers for details of the sources used to derive their respective data-variable estimates.
b Using the Hansen et al. (2023) Table 1 formula for CO2 forcing

[1] ECS is defined as the global mean surface warming for a doubled CO2 concentration after so-called fast-feedbacks have been fully activated and the ocean has reached equilibrium (which it approaches within a thousand or so years). Earth system sensitivity (ESS), which also includes very slow feedbacks such as those from changes in ice sheets, represents global warming arising over much longer timescales. ESS is relevant when studying paleoclimate changes, but not when  projecting changes over the next few centuries.

[2] E.g., in Hansen et al (2013) Climate sensitivity, sea level and atmospheric carbon dioxide. Phil Trans Roy Soc A. https://doi.org/10.1098/rsta.2012.0294

[3] Some of the latest generation (CMIP6) global climate models do have ECS values above 5°C, but they are generally regarded by climate scientists as being too sensitive.

[4] Actually two slightly different versions, iCESM1.2 and iCESM1.3, of the same underlying CESM1 GCM.

[5] Supporting my critique of their reanalysis, I showed that its co-located estimates were uncorrelated with values from the cave speleothem proxies it used. Moreover, unlike proxy-based reconstructions (e.g., Caufman et al. (2020)), which show early Holocene GMST 5,000–9,000 years ago being circa 0.5°C  higher than late preindustrial (1750) GMST, their reanalysis showed that period as being significant cooler than late preindustrial GMST.

[6] The final, published version of Osman et al. was slightly different, with no mention of the change in the peer review files, and cooled marginally more near and at the LGM.

[7] Using a more recent model generation than the older ones Osman et al. used to derive the ratio used to convert their ex-polar sea surface temperature (SST) proxy-based estimates to GMST.

[8] No explanation is available of why, disconcertingly, this differs from the 5.9°C in their submitted manuscript.

[9] The Osman et al. cooling estimate may be greater because they use only a subset of Tierney et al.’s proxies, and have no proxy coverage at all in the central Pacific ocean.

[10] While Seltzer et al. validated their model on modern proxy data, it may not be valid for conditions at the LGM, when factors such as vegetation cover, rainfall patterns, and seasonal temperature and precipitation cycles were different. An additional concern is that Seltzer use two alternative methods to select LGM samples, which give noticeably different LGM cooling estimates (5.8°C and 4.8°C).  They prefer the method giving the higher estimate, however it will tend to pick out particularly cold temperatures from datasets, and so may overestimate LGM cooling. Interestingly, the average of the Annan et al. LGM reconstruction’s cooling estimates for grid cells co-located with the 15 proxies that Seltzer et al. use is close to the 4.8°C estimate that Seltzer et al. obtain using their second method.

[11] Thus, excluding two particularly cool, low assessed uncertainty proxy estimates would reduce the estimate by 0.4°C.

[12] Lewis (2023) was submitted earlier than was Annan et al (2022).

[13] Lewis, N., 2023. Objectively combining climate sensitivity evidence. Climate Dynamics, 60(9), pp.3139-3165.

[14] Hansen’s estimate of the greenhouse gas forcing change, relative to that from a doubling of CO2 concentration, is 27% lower than the value assessed by Sherwood et al. and also adopted in Lewis (2023). Moreover, Hansen ignores the significant dust aerosol forcing change assessed by Sherwood et al., likewise also adopted in Lewis (2023).

[15] In the formula for estimating ECS, the change in forcing (ΔF) forms the denominator: ECS = F2×CO2 ×  ΔTF, where ΔT is the GMST change in equilibrium and F2×CO2 is the forcing from a doubling of atmospheric CO2 concentration. All forcing changes given in this article are for effective radiative forcing (ERF), the principal forcing metric used in AR6.

[16] Sherwood et al. (2020) and Lewis (2023) focused on a climate sensitivity measure, S, an easier to estimate approximation to ECS that is normally derived for global climate models instead of ECS. They accordingly converted their underlying paleoclimate ECS estimates into estimates of S.

[17] Hansen’s claim here that today’s human-made GHG forcing is 4.6 W/m2 is moreover inconsistent with the statement earlier in his paper that it is 4.13 W/m2 for 2022 (1.03× his value for a doubling of CO2 concentration, close to the AR6-basis ratio), and growing by 0.5 W/m2 per decade.

[18] Based on the AR6 formula for CO2 forcing

[19] Moreover, I’m not sure that Hansen is fully up with recent developments in climate science. For instance, when discussing different measures of radiative forcing, a topic on which Hansen wrote a seminal paper in 2005, he wrongly claims that (unlike for the formulae in his equation (3)) AR6 uses the biased-low Fo measure for its long-lived (non-ozone) greenhouse gas effective radiative forcing (ERF) estimates, and on that basis adjusts the AR6 forcing values. The 2013 (AR5) IPCC assessment report did use Fo, but AR6 uses a measure that, like Hansen’s preferred Fs, excludes the effect of surface temperature change.

[20] Hansen estimates ECS from changes in greenhouse gases (GHG) between the LGM and the mid-Holocene. The GMST estimate he uses is the same for that period as for the immediately preindustrial period (circa 1750). However, changes in non-GHG forcing agents are more uncertain for the mid-Holocene than for the preindustrial period  (which most forcing change estimates relate to). In particular, aerosols and land surface albedo could have been significantly affected by deforestation starting well before the preindustrial period, a possibility mentioned in Hansen’s paper. This makes ECS estimates based on LGM to mid-Holocene changes more uncertain than those based on LGM to preindustrial changes.

129 responses to “Hansen’s latest overheated global warming claims are based on poor science

  1. Hi Nic, I very appreciate your article, showing all the pitfalls in the ECS estimations from Paleo data and all the possible “open doors” to go through to make doom*n gloom predictions to frighten the uneducated people for the future.

    • Hansen resigned from his post as climate “scientist” about a decade ago with the declared intent to focus on political advocacy. Why is anyone still expecting anything based on the scientific method from this man ?

    • Hansen et al 2002 “Climate forcings in Goddard Institute for Space Studies SI2000 simulations”:

      3.3. Model Sensitivity

      The bottom line is that, although there has been some
      narrowing of the range of climate sensitivities that emerge from realistic models [Del Genio and Wolf, 2000], models still can be made to yield a wide range of sensitivities by altering model parameterizations.


      In other words they can tweak the resulting sensitivity in either direction by a “wide range” according to criteria and motivations which are never declared.

      There you have it from the man himself.

    • Well..reposting myself from wuwt last week..
      Your (Nic) citation of different paleo-works (including yours!!) coming to different “results” only reinforces McShane and Wyner from back then:

      =>(I corrected some typos)
      Wow, amazing! Another proxy based article.. How do they keep getting those through peer review?
      The editor and reviewers must be asleep for more than 10 years..
      Is it really possible that people do not know about the rejoinder by McShane and Wyner?
      (it can be found here and ended a discussion involving Mann, Schmitt, Amman and others quite conclusively.. very well worth the read as well as their initial paper and the comments it drew.
      https://projecteuclid.org/journals/annals-of-applied-statistics/volume-5/issue-1/Rejoinder–A-statistical-analysis-of-multiple-temperature-proxies/10.1214/10-AOAS398REJ.full )
      One of several key points McShane and Wyner made quite impressively, was that any data analysis MUST include uncertainties which might arise from the proxy selection
      Consequently, the application of ad hoc methods to screen and exclude data in-
      creases model uncertainty in ways that are immeasurable and uncorrectable.
      If it was common sense before McShane and Wyner, it is now an official published answer to any proxy reconstruction article and any paper not addressing it is worthless, Hansen or not!

      My point being, that all articles above must give the SAME result for the past global temperature, it is just hidden behind sloppy science and incomplete (systematic) error analysis!

    • George J Kamburoff

      Instead of arguing, let’s just sit back and watch the climate get to unlivable.

  2. “Hansen’s ECS estimate is increased not only by adoption of an unrealistically large LGM cooling value, but also by very low estimates[14] for the various changes in forcing between the LGM and the preindustrial Holocene[15]. Hansen’s central estimate for the total Holocene to LGM forcing difference is −5.75 W/m2, much smaller than the −8.63 W/m2 assessed by Sherwood et al.(2020) and even further below the −8.93 W/m2 best estimate adopted in Lewis (2023).”

    Aren’t we talking about circular reasoning here? How would anyone know what forcing and how much forcing there was? The only thing one can do is to make some educated guesses “inspired” by common estimates on climate sensitivity. Indeed that is pretty much what they do. Then the sorcerers turn around and ta-da, they extract a climate sensitivity from their paleoclimate model. Finally they will claim the paleoclimate data would confirm(!) the climate sensitivity they initially derived from some quite transcendent “radiative flux” models.

    I am afraid, unless we have some robust information on what exactly causes ice age cycles, all attempts to learn anything on climate sensitivity from them is purely elusive. Good luck with measuring TSI a 50 mio years ago..

    • Erich wrote:
      I am afraid, unless we have some robust information on what exactly causes ice age cycles, all attempts to learn anything on climate sensitivity from them is purely elusive.

      Unless we study past data, especially ice core data, the facts will not ever be understood.

      What causes ice age cycles? Ice on land advances, covering more area and further south and causes cold ice ages.
      When oceans are cold and low, ice accumulation is not enough to sustain the ice spread on land so the ice thaws and thins and then retreats and causes the warm cycles.
      Ice accumulations are most in warmest times when the Arctic is thawed, it snows more and more ice spreads and causes colder.
      Ice accumulations are least in coldest times when the Arctic is frozen, it snows less and less ice retreats.
      Natural climate change cycles are easy to understand using ice core records.
      The sun heats the oceans and that energy is carried into polar regions to power the ice machines. The ice gets deep and heavy and spreads and causes cold times. Ice continues to spread until the ice is depleted, the ice then retreats and allows warm times.

      Ice Core Records DO provide robust information on what exactly causes ice age cycles

  3. If you can model an elephant with 4 parameters and wiggle its trunk with 5 – what do you get with the 200+ from climate models?
    Hansen is making an anime movie..

  4. “Hansen’s central estimate for the total Holocene to LGM forcing difference is −5.75 W/m2”.
    Why do you show the forcing as negative from Holocene backwards in time to the LGM. There was a positive forcing from the LGM to the Holocene. Why not say “Hansen’s central estimate for the LGM to the total Holocene forcing difference is +5.75 W/m2”.

    The table shows a vegetation feedback of 1.10 W/m2, which I assume is the albedo change from the ice sheets at the LGM to that of mostly vegetation during the Holocene. That seems much to small. The ice sheets had a very high albedo of about 85% and they covered 25% of Earth’s land area. This was replaced with grass, forests and deserts which have albedos of roughly 25%, 14% and 40% respectively. The ocean’s albedo is about 8.5%. The global land area is about 30% forests, 29% grass, 31% desert and 10% ice. AR6 figure 7.2 shows the reflected flux from the earth is 25 W/m2. WIth these values, the reflected surface land flux is 12.6 W/m2.

    In the LGM case, the ice fraction increases to 25%, and assuming forest, grass and desert areas are reduced proportionally to 25%, 24.2%, 25.8%, the reflected land surface flux is 16.0 W/m2. The change in reflected flux is 3.4 W/m2. While this is a very rough calculation, it seems that your “vegetation-albedo feedback of 1.10 W/m2 is far too low. Replacing that with 3.4 W/m2, increases the total forcing from 8.92 W/m2 to 11.22 W/m2.

    Using ECS = F2×CO2 × ΔT/ΔF = 3.93 x 4.5/11.22 = 1.58 °C.
    This is much less than your estimate of 2.24 °C.

    • The vegetation forcing (a feedback when estimating ESS, but not ECS) of 1.10 W/m2 comes from the major Kohler (2010) study, still regarded in the Sherwood (2020) review as providing the best evidence for it. I suggest that you read the Kohler paper: doi.org/10.1016/j.quascirev.2009.09.026. And see Lewis (2023) and also section 5.3.2 of its Supporting Information.

  5. I don’t see how anyone can calculate ECS from the LGM to Holocene transition. If you do that, then how on earth do you explain the fact that the warming stops.

  6. Ralph Ellis wrote a paper “Modulation of Ice Ages via Precession and Dust-Albedo Feedbacks”. He shows how ice ages come and go. See https://friendsofscience.org/pdf-render.html?page=2236

    The Earth’s precession causes the Great Year, because it gives warm and cool seasons over its approximate 23,000-year cycle. Interglacial warming happen every fourth or fifth Great Year. It isn’t caused by CO2 because when CO2 concentrations reach a minimum in the depths of the ice age, the world warms. And when CO2 concentrations reach a maximum during the warm interglacial period, the world cools. And yet this is the very opposite of what should happen if CO2 was the primary warming feedback agent.

    Every interglacial warming period is preceded by about 10,000 years of intense dust storms. Dust, mostly from the Gobi Desert, settles on polar ice-sheets. CO2 concentrations are reduced during the ice ages as the seas cooled and absorbed more atmospheric CO2. Most plants suffer severe stress at 190 ppm CO2 and die at 150 ppm. The Gobi steppe-lands turn into a true sand desert. The ensuing dust storms dump thousands of tonnes of dust onto the northern ice sheets each year. And so when the next Great Summer comes along, the dusty polar ice sheets can warm and melt and the next interglacial is born. The ice sheet’s albedo declines sharply, so the ice sheet rapidly recede. So CO2 can indeed cause global warming but its effect is much more pronounced at low concentrations, rather than high concentrations.

    • Ken Gregory:

      The paper by Ralph Ellis, which you expand upon, is totally incorrect.

      The warming that began around 10,000 years ago was caused by an abrupt cessation of volcanic activity, and with no volcanic SO2 air pollution present in the atmosphere, the Earth rapidly warmed up.

      According to Volcanoes of the World, third edition (2010), For example, between 9,950 and 6,550 there were only 52 VEI4 and larger volcanic eruptions, fewer than one per century.

      In the 20th century, alone, there 75 such eruptions.

      This is their published data. If they are off by a factor of 10, say, this would still be equivalent to the number of eruptions during the MWP (~31 in 300 years).

      • Sorry Henry, your assertion cannot be correct, no matter what paper or book you are reading.

        Firstly, the warming began 17 kyr ago, which is long before your 10 kyr claim.

        Secondly, every interglacial is associated with a northern hemisphere Great Summer (Milankovitch Maximum). Unless you can devise a rationale for volcanoes being linked to Great Summers, your counter-proposal is a bust.

        In reality, interglacial warming is 100% correlated with dust, and dust is 100% correlated with low CO2 concentrations. And unlike your nebulous volcanic theory, there is a rock-solid rationale for why CO2, dust, and warming should be intimately correlated.

        See: Modulation of Ice Ages, by Dust and Albedo.


      • Sorry Henry, your assertion cannot be correct, no matter what paper or book you are reading.

        Firstly, the warming began 17 kyr ago, which is long before your 10 kyr claim.

        Secondly, every interglacial is associated with a northern hemisphere Great Summer (Milankovitch Maximum). Unless you can devise a rationale for volcanoes being linked to Great Summers, your counter-proposal is a bust.

        In reality, interglacial warming is 100% correlated with dust, and dust is 100% correlated with low CO2 concentrations. And unlike your nebulous volcanic theory, there is a rock-solid rationale for why CO2, dust, and warming should be intimately correlated.

        See: Modulation of Ice Ages, by Dust and Albedo.
        On the Science Direct website.


      • Henry. I forgot to add…

        It is LOW CO2 that caused dust and warming, not high CO2. The opposite of current science claims.

        If you look at a temp-CO2 graph for ice ages, you will see that….
        High CO2 results in cooling.
        Low CO2 results in warming.

        Classical climate science cannot explain that connundrum, but my paper can.


      • Henry, I forgot to mention….

        It is low Co2 that caused warming, which is the opposite of classical thinking. You can see this on any paleoclimate temp-CO2 graph.

        High CO2 results in cooling.
        Low CO2 results in warming.

        Classical climate science cannot explain this, but my paper can.


      • ralph ellis,

        “High CO2 results in cooling.
        Low CO2 results in warming.

        Classical climate science cannot explain that connundrum, but my paper can.”

        I believe classical climatology explains it quite well; see, e.g., chapter 10 of Collin Summerhayes book “Paleoclimatology: from snowball Earth to the Anthropocene”. I believe your conundrum can be solved by a small change in wording:

        Declining CO2 results in cooling.
        Increasing CO2 results in warming.

  7. Surely ECS is not a constant, and the sensitivities vary substantially in different times. Earthly Systems looked much different between the LGM and preindustrial Holocene, and between before and during the PETM, and so on. The practice of accounting for temperature differences by a forcing and a constant, while convenient, is not reasonable.

    • Yes, I believe ECS(CO2) is thought to be higher at higher temperatures. That makes sense spectroscopically with both larger Doppler broadening and population spread more widely over the rotational manifold. Result being the absorption band being spread over a larger portion of the water window and less saturation.

      • The secondary CO2 absorption line becomes relatively more important as CO2 concentration rises. Mainly for that reason, CO2 forcing increases slightly faster than logarithmically with concentration. But I’m not sure if accurate line-by-line modelling (or indeed GCMs) show any significant increase in CO2 forcing with temperature, at a fixed CO2 concentration.

      • I’m not sure either if it would be significant with a, say, 5 C increase. An accurate calculation of the band shape through an atmospheric column is difficult with continuously changing temp, pressure, and radiative processes. Also likely that interacting feedbacks get stronger with temperature, more so that considering them separately. At any rate, constant ECS doesn’t make sense physically/chemically where almost processes get faster with temperature.

      • Climate sensitivity must become higher in both warmer and colder conditions. It’s the only way any of this makes sense. A “U” shaped feedback regime – with the most stable climate states in the middle, and the most unstable ones at the tips. A small change in forcing at the tips causes a large temperature change.

  8. Hansen’s famous 1988 forecast projected a warming of 1.05 deg 1988-2023. Observed warming from unadjusted weather model reanalysis (ERA, CFSR) has been roughly 0.46. That’s a hot bias of greater than 2. This is common with climate models.

    So-called “verifications” of climate models often fudge on Hansen’s Scenario (it was obviously A). Other models are usually presented with backtested data, not actual forecasts. Amazing how they all nailed the Pinatubo cooling 1990s. Its easy to “forecast” something that has already happened.

    Then there are the “adjustments”. Post WWII, in the anthropogenic era, essentially all the adjustments make the warming greater. GISS, HadCrut, RSS, etc all made step jumps that added about a quarter degree to the trend. They seem to all adjust to the highest common denominator.

    If you compare what Hansen actually forecast vs what the daily weather models have traced (CFSR, ERA) through their careful initializations, the bias is greater than two to one.

    What is the implied ECS of Hansen 1988? Whatever that value is, the actual true value is likely slightly less than half.

    In light of these verification realities, it’s amazing that Hansen and the CMIP6 have the audacity to actually increase ECS

    • From the CFSR web page: “Relatively few evaluations of CFSR have been conducted so the performance is not well-known”

      Link to CFSR data – “page not found”

      HadCRUT (6 different data sets) T rise 1988 – 2023 = 0.715 C.

      If you prefer to ascribe to conspiracy theories, rather than understand reanalysis and it’s justifications, you are free to do so.

      • HadCrut v4 1988-2020 +0.57
        HadCrut v5 1988-2020 +0.69

        The adjustment late 2020 added .12 deg to the warming for those 32 years. How could it be that wrong in such a modern period? Why do the adjustments ALWAYS increase the post WWII warming trend?

        Similar or bigger adjustment to GISS, RSS. Adjustments also applied to reanalysis data for reason that aren’t clear to me.

      • “Hansen’s famous 1988 forecast projected a warming of 1.05 deg 1988-2023.”

        I believe that is what we were discussing; real data, real sources:


        Infilled (reanalysis) global annual temperature (C) anomay data set
        1988 0.282
        2023 1.036
        RISE 0.754

        Non-infilled (no reanalysis)
        1988 0.269
        2023 1.016
        RISE 0.747
        HadCRUT 4.6 vs (both non-infilled)

        Version 4.6
        1988 0.198 0.269
        2021 0.645 0.774
        RISE 0.447 0.505

        “GISS, HadCrut, RSS, etc all made step jumps that added aboutquarter degree to the trend.”

        I’ve only looked at HadCRUT, but I don’t see anything close to “added about a quater of a degree to the trend. What there is seems to be a 0.05 – 0.12 C addition to the offset (not the trend) since 1960. If you don’t understand the reanalysis, it’s justification, you can read about it, e.g.:

        I don’t have a problem with a 25 year prediction that turns out to be a moderate overestimation. I do have a problem with cherry-picking data sets and invoking conspiracy theories to exaggerate how much the 25-year-old prediction was off.

      • I stand by my math. Hansen ’88 has a bias of >2

      • I don’t have a problem with your math. I have a problem with your input into the math. It certainly wasn’t your much lauded CFSR data. And there wasn’t any math involved in the claim of reanalysis changing the trend of various data sets by 1/4 C – it was simply an unsupported statement. I stand by my math that shows your recommended CFSR data supports Hansen’s claim of ~1.0 C for 1988 – 2023.

      • Hanson apologists need to give it a rest. He forecast 1.05 deg warming to this point. Actual warming nowhere near that no matter how many times the data is changed to show more warming.


      • It has been my experience that when someone says, “give it a rest”, it is a plea because they can no longer defend their position, and they have been called out for it. In this case, with real data (not hand waving and cherry-picking, and unsubstantiated statements), even including data from the original claimants preferred source.

      • If you are going to evaluate a forecast or projection, you need to use methodology consistent with methodology at the time of the forecast/projection. You need to stick with data sets consistent with measurement at the time, without increased coverage of the poles and modified algorithms.

      • Adjustments to reanalysis data for CFSR increased the trend post 1979 from .0132 deg/year to .0152 deg/year. For European data, ERAI, adjustments increased post 1979 trend from .0125 deg/year to .0167 deg/year. Hansen 1988 forecast warming of .038 deg/year 1988-2022. This puts the hot bias somewhere between 2.2x and 3x depending on verification data. No matter how you look at it… it’s way too hot.

    • CFSR data here. It is simply a trace of the global temperature from 4x daily runs of the GFS model. A sophisticated process is used to assure than the forecast models are in dynamic balance at initialization so that they run smoothly from t=0. In the old days, it took a while for the models to “spin up” into realistic representation obeying laws of physics.

      CFSR unadjusted temp data closely matches UAH which closely matches new USCRN pristine data since 2005 for lower 48.

      None of them match forecasts from Hansen ’88


      • Cool, the last two graphs show the current global average anomaly as just about 1.0 C above the 1979-2000 average (of which 1988 is near the middle). So, it seems Hansen’s 1988 prediction must be close to right on, not a factor of 2 too large.

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  10. ERA and CFSR are evaluated every day for accuracy, consistency and dynamic balance. That is the starting point for weather model runs. The initialization process is a complex and important process which leaves a trace of historical weather…each initialization is the best possible starting point for maximum accuracy of the forecast. Although the exact state of the atmosphere is never precisely know, I consider weather model initialization the ground truth in real time. All the other data is subject to post ex facto manipulation and a myriad of errors.

  11. Thanks, Nic.

  12. Being cynical, you can’t up the UN rhetoric from ‘global warming’ to ‘global heating’ and now ‘global boiling’ without the ‘scientists’ upping their climate model armageddon predictions significantly.

    So I see this as singing for your supper ‘answers to order’ non-science.

    ‘You want global boiling? I’ll up my Equilibrium Climate Sensitivity number in return for $5m in funding’.

    Surely not?

    • “Double, double toil and trouble; Fire burn, and cauldron bubble. For a charm of powerful trouble, Like a hell-broth boil and bubble.”

      • Jungletrunks,

        Funny, I always thought AGW and ACC denial were a religion devoted to the oil God and maintaining the status quo, regardless of climatic impacts.

      • Indèed, you present the colloquial anacronistic mindset with authority, Ganon.

        And who could ever imagine big government throwing money towards manipulating the flock anyway, what could possibly be the incentive, power? Are you kidding me?

      • ganon

        Funny, I always thought that naive, uneducated adolescents who never read the literature were the alarmists.

        It’s incomprehensible how anyone with modicum critical thinking skills after having read the totality of evidence can be an absolutist.

      • Cerescokid,

        “It’s incomprehensible how anyone with modicum critical thinking skills after having read the totality of evidence can be an absolutist.”

        How true, it works both ways. But no surprise that some things are incomprehensible.

      • Jungletrunks,

        As seen from opposite sides, there appear to be two opposing “conspiracy theories”
        (1) (the minority) Government interest in climate change is a hoax designed to gain power, control the populace and take their money. (In principle, government is evil)
        (2) (the majority) Government interest in climate change is to maintain the future habitability of the planet. (In principle, the government operates in the interest of the people)

        I know which I believe in, and it is no surprise that I support it. However, I am open-minded enough to be here and to see what supporters of the other “conspiracy theory” have to say. Thus far, I see valid (but biased), well-thought-out science skepticism, ranging down to deniers that have more insults than facts or evidence. I see screwball theories that claim that the GHE effect can’t be real and a lot of nitpicking around the edges, but nothing that convinces me that the general theory of anthropogenic climate change is not real. Whether humanity’s commitment and time are sufficient to do anything about it is a different question.

    • Rtj, who could have guessed; all this time I was thinking CAGW was an organic cultural religiosity phenomenon, and not powerful climate shepherds directing sheep for profit, and influence. You may be on to something.

  13. Robert David Clark

    Last September 28, 2022, the highs and lows switched. The high, now low, is now bringing water vapor from the equator to the Northern Hemisphere, and the low, now high is now bringing cold, low humidity, air from the Arctic.
    Nature is now adding water vapor to the upper atmosphere.
    In September of this year the HEAT radiated to the black sky EQUALED that retained from the SUN.
    Now, as the sun cools, nature is lowering the oceans to keep a relatively constant average surface temperature.
    This may last one to three thousand years.

  14. Robert David Clark

    I forgot again. It does not take long to remind me!
    DRILL baby DRILL

  15. A regression model based on a reanalysis of a reconstruction of previously concocted sea surface temperatures >20,000 years ago based on proxies, all starts with knowing the answer you intend to get before you start.

  16. I read today that the Panama Canal, whose locks require rainwater, must for the first time limit passages because of an unusual drought in Panama. Supply chains are being impacted.

    A wildfire is currently burning uncontrolled in Virginia, one mile from my daughter’s house, in November!!

    But to many who post here, since humans are not facing imminent extinction, the whole problem is liberals exaggerating a minor inconvenience to get control.

    Is Hansen right or is Mann right? I do not know. Good science is hard. But anyone who does not take the climate issue seriously is a fool.

    • Curious from Cleethropes

      Hear hear, we need the right solutions to the right solutions. The wrong solutions to the wrong problem (or something that is not even a problem), serve nobody other than those “benefitting” from “providing” the “solution”

      • aaron,

        Warm periods from interglacials of the quaternary have been used. See IPCC AR6 table 7.11 (pp. 1001 – 2). Here are the values in C (range, differing c.l.s):

        3.5 (3.1 – 5.4)
        5.7 (3.7 – 8.1)
        5.6 (3.6 – 8.1)
        4.9 (4.3 – 5.4)
        3.1 (2.6 – 3.7)
        (3.0 – 5.9)
        (6.1 – 11.0)

        The last two give no most probable value, just the range. Average of the first five: 4.56 +/- 1.20 (std. deviation, unweighted)
        More details? See the table and references

    • “ Is Hansen right or is Mann right?”

      That’s easy, they’re both wrong. Climate sensitivity is not constant and not well informed by looking at a thermal maximum or glacial maximum. It may be be helpful to look at other interglacials, however.

      • I looked at other warming and cooling cycles, climate sensitivity as defined has to be much higher than what they have now. For past climates, there papers to be no correlation between surface temperature variation and that of CO2. This makes me wonder how good are past climates data for the computer models. Probably not good at all.

    • “A wildfire is currently burning uncontrolled in Virginia, one mile from my daughter’s house, in November!!”

      Peak wildfire here is April and November.

  17. ESG, along with EVs, wind power, and solar power, is a huge fail.

    (Bloomberg) — The bad year that a lot of ESG investors are having may be about to get even worse.

    According to James Penny, the chief investment officer of TAM Asset Management and a veteran of ESG investing, the dramatic selloff that’s torn through green stocks may soon morph into a “slow burn” that could last several more years.

    The green correction — with the S&P Global Clean Energy Index down more than 30% over the past year — has “definitely shaken some investors within ESG impact sustainability,” Penny said in an interview. It’s “definitely been a tough time to be invested in thematics in sustainability.”


    • jim2,
      As a supporter of SMR nuclear I am disappointed to see this. Maybe we could make a law that requires all crypto to be mined only with power from SMRs and make them pay for it?


      “CFPP – which had secured the promise of up to $1.4bn in support from the US government – looks to have fallen victim to the soaring cost increases that have ravaged other major energy infrastructure projects, notably in offshore wind.

      NuScale in January set a new target price for power from CFPP at $89/MWh, an increase of more than 50% on previous estimates.”

      My 12 year old solar panels make electricity cheaper than these SMRs!

      • I understand how you feel, Jack. We have had 15 years of very low interest rates. That made a huge amount of money available for investments of various sorts as well as consumer spending. The government had been giving away huge sums of money to people for various reasons. Student loans repayment was placed on hold. Now all of that has come back to bite us in the form of inflation. It’s not like conservative economists didn’t tell us that would happen. They did, they were laughed at and dismissed, but now they get the last laugh.

        So what this means for future energy sources is they will have to actually bring value to the table in the form of cheap, reliable energy. SMRs are such a source. Yes, they will cost more like everything else, but they have a lot of added value. Wind and solar, do not. In fact, they incur even more cost due to their making the grid unmanageable.

      • When (not if) we discover a dirt cheap storage technology then renewable energy will crush most all other forms of electricity. Myself, I think we need to double down on geothermal.

        I think technology is going to move us all away from centralized power systems to micro grids in the long term.

      • Maybe the Chinese will let us license their ultra-deep drilling tech? There is more down there than hydrocarbons.


    • The push for SMRs is still on. In order to realize the benefits of SMRs, they have to be mass produced. We have to get over the hump.

      WILMINGTON, North Carolina—January 27, 2023—GE Hitachi Nuclear Energy (GEH), Ontario Power Generation (OPG), SNC-Lavalin and Aecon have signed a contract for the deployment of a BWRX-300 small modular reactor (SMR) at OPG’s Darlington New Nuclear Project site. This is the first commercial contract for a grid-scale SMR in North America.

      There is growing global interest in the BWRX-300. In August 2022, Tennessee Valley Authority (TVA) began planning and preliminary licensing for potential deployment of a BWRX-300 at the Clinch River Site near Oak Ridge, Tennessee. TVA has entered into a collaboration with OPG to coordinate efforts to move SMR technology forward. In addition, the NRC and CNSC are collaborating on licensing the two projects.


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  21. Nic Lewis dives deep into the nuances of Hansen’s latest paper, challenging the validity of the 4.8°C ECS estimate. Examining paleoclimate data, he questions the assumptions and methodology, highlighting discrepancies in cooling estimates. A meticulous critique urging a closer look at the science. What’s your take on the ECS debate?

    • My take is that IPCC AR6 WG1 (chapter 7.5) is probably the best estimate that we have. ECS = 3.0 (2.5 – 4.0, 66% c.l.; 2.0 – 5.1, 95% c.l.). It evaluates many papers, and many lines of evidence, not just paleoclimatic data from the LGM. It probably only includes papers up through 2019 (2020?), and could be updated. I would note that there are a number of other paleoclimate studies (table 7.11) that have an ECS > 5. Unfortunately the instrumental record analysis (ch. does not provide an ECS estimate, only lower bounds; however, composite (ECS/TCR)*TCR(inst) = ECR(inst) = 3.2 C is consistent with the average from other lines of evidence.

      The uncertainty ranges still leave lots to be desired. I hope that a transition from GSAT to ocean heat content as the primary climatic “marker” will improve this.

  22. Are they also looking at how the sensitivity changes over time? As it gets warmer, the cloud and water cycle negative feedbacks dominate over the water vapor and ice albedo positive feedbacks. The reduced insulation of lower fall sea ice offsets the reduced summer albedo.

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  24. IPCC’s definition of ECS that takes into account the role of all system’s feedbacks as a response to a change of radiative forcing is:
    ECS = –ΔF2×CO2/α , where α ist the “net feedback parameter”
    (page 993 IPCC AR6 WG1 Report, with the summary of α values on page 978).
    What happens if and when α gets near zero or even changes sign (which is not impossible in given period and location)?
    This feedback equation is fundamentally false. Isn’t it the same for all subsequent considerations for ECS?

  25. It only takes a moment’s reckoning to appreciate that the grid-scale storage electricity generated by wind or solar is a perfect nonsense.

    Those profiting from hopelessly intermittent wind and solar still claim that mega-batteries are the solution to their obvious lack of reliability. Others point to pumped hydro and even ridiculously claim that “excess” wind and solar can be converted into ‘green’ hydrogen gas; the latter is total nonsense, thanks to the laws of physics and economics.

    But then there is the gargantuan scale of the task if the object is to store sufficient wind and solar generated electricity to account for the period after sunset and sunrise when solar producers nothing and calm weather when wind power does likewise.

    David Wojick has taken a keen interest in the subject over the last few years. Here he is again, demonstrating how the grid-scale storage of wind and solar-generated electricity is just the latest in a long line of impossible dreams.


    • I think giant batteries are a helpful stopgap measure while other storage technologies are developed. Words/phrases like “perfect nonsense” and “impossible” are not helpful, indeed not even believable. To me, they only indicate a deep bias and lack of imagination.

      • Actually, the failure to see batteries won’t work may reflect deep bias and lack of imagination. Maybe someday, but not in the next several years. The installed battery watt-hours in the US is a minuscule percent of other grid watt-hours. Right now they are only useful for a very short term addition to keep frequency correct.

        Imagination is a fine thing, but it reflects something that doesn’t yet exist. We need to stop installing wind and solar plants until the batteries exist and are cheap. Probably won’t happen.

      • Perhaps you should read my first sentence again. Then read about the Bath County Pumped Storage Station – it can produce 3 GW with storage of 24 GWh. Then consider the large wind farms in Northern Oregon, situated next to the successive holding ponds for the series of large Corps of Engineers dams on the Columbia River. Then consider all the places that have topography for two successive holding ponds, separated by several hundred feet in elevation. Do we currently have storage capacity for wind and solar to provide baseload and peak power? No. Does that mean it can’t be built with proven, existing technology? No. There are many other possible forms of gravity storage that can have efficiency approaching 85%.

      • ganon – we already have efficient, cheap natural gas and coal plants. We don’t need any storage. Zero. Zip. Nada.

        The energy storage schemes will break the bank if implemented at any useful MWh.

      • jim2,

        Natural gas is not cheap, coal is not efficient, both are limited non-renewable resources, and you kinda forgot the title of this blog site. Gravity based storage will not break the bank any more than hydropower has. You think 3 GW power, (~3 full scale nuclear reactors) and 24,000 MWh at one site (Bath County Pumped Storage Station) or the Ludington Pumped Storage Plant (2 GW/15 GWh) that has been running for 50 years, are not useful scale. You might also want to look at molten salt thermal and compressed air energy storage systems that are already in commercial use (many with multi-GWh of storage):


        Lack of knowledge and imagination, denial, obfuscation, and hyperbolic statements about unspecified costs, do not change reality.
        (Notice, I didn’t even mention batteries)

      • ganon – the title of the blog is Climatge ETC. This is an Etc.

        I believe CO2 does up the temperature of the atmosphere. What I have issue with is the harm it will cause.

        The Climate Doomers believe the climate is chaotic. And it may well exhibit that to a degree. Based on that, they say the chaotic climate might slip over a discontinuity in the posited strange attractor and suddenly we have a abrupt change in climate. I suppose it could be a change to colder, but we are getting warming now, so I think base on history it would be to the warm side.

        This possibility seems to induce a good deal of fear in the Doomer’s psyche, so they believe we should spend many trillions of dollars to mitigate CO2.

        But might we be informed by the concepts underlying Bayesian inference? So what “priors” can we use?

        Well, we know about Snowball Earth or Slushball Earth hypothesis. It’s controversial, but there is some evidence for it – evidence based science, no? OK, so provisional, what else do we have? Well, we know ice ages exist. We also know that during the Little Ice Age, even if it didn’t occur at the same time around the globe, made life miserable for people.


        On the other hand, we don’t have any indication of a huge spike in temperature that killed or maimed people.

        This evidence, the “priors”, would have us modify our plans under uncertainty. We should worry about cold climate, not warm. Therefore, CO2 is a huge benefit. The last thing we should do it stop producing it!!!

        Burn natural gas and coal. Those ARE cheap because we already have the necessary infrastructure in place, whereas mitigation is already costing us TRILLIONS.

  26. ganon

    I suggest you do not see practical solutions to the hundreds of millions of people without access to electricity worldwide. CO2 emissions will continue to rise regardless of US actions.

    • You may suggest anything you like. Does not make it true.

      • Facts matter and the fact is you have no plans to try and get electricity or transportation to the 2 billion humans Who currently don’t have it. CO2 will continue to rise and all you advocate for are nonsense solutions that will accomplish little to nothing.

      • Rob,

        Don’t be silly and presumptuous. Plan = solar+wind+storage, hydro and nuclear + other non-GHG technologies where appropriate. Note that people that do not have electricity or transportation yet, have the opportunity to start from the ground up and choose what technology they will use. I don’t think you have the chops to pronounce what CO2 WILL do in the future. However, I can PREDICT that it will decrease when reserves of a limited, non-renewable resources starts to deplete, and if humanity doesn’t curtail burning fossil fuels, it will happen just that much sooner. As, for “US actions”; it is good that we, like the EU are starting to make progress and serve as an example for a world problem. We are also able to help emerging societies choose and develop cleaner options. I do not ascribe to your implied “they are bad, so doesn’t make any difference if we are bad too” attitude. Also, you do not address the climate issue – what is your plan; ignore it, pretend it isn’t real?

      • ganon

        I see no climate “issue” as you describe it, that can’t be addressed by infrastructure. Humans adapt.

      • Rob, Of course, you don’t. How anthropocentric. Irrespective of climate, what is your plan for renewing non-renewable resources?

      • “what is your plan for renewing non-renewable resources?”

        I advocate building nuclear plants in the USA in large numbers to preserve fossil fuel resources. Fusion is long term but very long.

      • What ganon advocates for won’t supply the inexpensive electricity that developing areas need. He is an unrealistic zealot.

      • What Rob advocates for won’t supply the inexpensive electricity that developing areas need. He is an unrealistic zealot.

      • Developing countries should use what they can afford or is best in the area. China as an example has used a great deaĺ of coal. Far better for population than waiting for some future cleaner tech.

      • “Far better for population than waiting for some future cleaner tech.”

        How about they (China) continue to develop and transition to EXISTING CLEANER TECH. Oh, they do – 30% of their electric comes from non-GHG technologies, not that far behind the US (Installed renewables 3.3x USA). They do use a lot of coal; however, they have 2.6 times as much wind and 3.3 times as much solar generation as the U.S.; and their in-country sales of EVs is greater than the rest of the world. Also, the world’s largest producer of solar panels. They also do a lot of development (battery and gravity) storage systems to support intermittent renewables. While they do use lots of coal and some people complain about the number of plants being built, their coal percentage of energy mix continues to fall while non-GHG technology percentages grow.

        Thanks for the good example.

      • Gabon

        The example of China demonstrates that the CO2 growth curve for humanity is unavoidable. The actions you advocate will only make a minimal change to the curve. If the world is at 550 ppm of co2 vs 560 ppm in 100 years does it matter much to the climate?

        Higher co2 levels are unavoidable and must be adapted to by Humanity.

      • Rob,

        “The example of China demonstrates that the CO2 growth curve for humanity is unavoidable.”

        Check the data: https://ourworldindata.org/energy/country/china
        Figure: “Share of energy consumption by source, China”

        Investigate before making silly claims, and try to avoid using false absolutes like “unavoidable”. Typical things that are unavoidable are, e.g., Milankovitch cycles, solar irradiance, tectonic plate movement and volcanic activity.

        “The actions you advocate will only make a minimal change to the curve.”

        From 1990 to 2020 The EU reduced it’s CO2 emissions by 31%
        The US 2000 -2020: 25%

        Those are not minimal changes, and demonstrate what is possible. My personal opinion is that we should be helping developing countries do the same, rather than blaming them for the problem and concluding we can’t do anything about it.

        “If the world is at 550 ppm of co2 vs 560 ppm in 100 years does it matter much to the climate?”

        Probably not; However, if the world is at 1000 ppmv CO2 (“business as usual”) vs 450ppmv in 100 years (mitigation to maintain approximately current levels), it will have a very large influence on what the climate becomes.

        Higher co2 levels are unavoidable and must be adapted to by Humanity.

        Again, you use that unquantified absolute “unavoidable”, without supporting evidence. To quote Iago Montoya: “You keep using that word, I do not think it means what you think it means.” Personal opinions (statements) without supporting evidence are worth about as much as the supporting evidence – zero.

        Have a good day, and try a little research.

      • gannon

        The world will not peak at CO2 @ 450 ppm unless there is a vast war to reduce the human population. The EU and the US population of roughly 600 million reduced their emissions somewhat, but that is of little consequence given the number of people needing access to electricity and transportation worldwide.

        I dispute the attachment you offered the showed China had 98% electricity coverage in 2000. I was there extensively in 2005 touring companies, and they were touting the people they were bringing in from undeveloped areas. The people in undeveloped areas had to be taught the use of bathrooms plus the use of electricity. Why has China been building 1 coal fired powerplant per week for 20 years if the already had electricity. India is little different as is much of SE Asia.

        The world WILL reach 550-600ppm of CO2. It is inevitable unless we have war. The human population will likely reach 10B and those people will want/need access to cities, transportation and power.
        Humanity will have to adapt. We have been shown to be adaptable. You are an unrealistic dreamer with nightmares. 

      • Rob,
        Sorry: declarative statements about what the future will be, claims and personal opinions without evidence, and continued personal attacks. I’m not interested – you have nothing to offer.

  27. ganon, you should examine closer the realities of what you suggest: “You might also want to look at molten salt thermal and compressed air energy storage systems”. First, pumped water storage is about as efficient as it gets. 90% up and down makes for 81% overall. Molted salt: you have heat transfer losses and process losses, and need an added multiplier like 80%, hence 65% overall. Worst – pumped air or other gas. Mechanical efficiency up/down 80%, adiabatic losses 2 x 70% (touch a compressor head to experience); total 40%. Now you have 60% waste energy from the precious renewables electricity and you heat the atmosphere with it.

    • OK, coal and nuclear ~ 33% efficiency, simple cycle natural gas 32 – 40%, combined cycle natural gas 60%. I prefer gravity based systems (to 85%). I mention the others because there are a number of sites in commercial operation and may have site advantages (molten salt – almost anywhere). And, of course, efficiency is not the only consideration, I prefer solutions that have a competitive LCOE and do not produce operational GHGs.

      • Dietrich Hoecht

        ganon, you now cite coal, natural gas and nuclear. Those a primary generation media. Previously we discussed storage, whose efficiency is added as a multiplier to the primary ones. So, if you make use of natural gas turbine power to store pumped air and reuse this energy you wind up with an output of 0.4 x 0.4 = 0.16 of input energy. A very wasteful lot of hot air to nearly nowhere.

      • Yep, those primary sources can also use storage to offset diurnal demand cycles. Like I said, I prefer source energy that doesn’t produce GHGs in generation and high efficiency storage. You are free to harp on about CAES combined with inefficient sources all you want – I mentioned it, I didn’t recommend it. I also did not include the energy and cost efficiency of nuclear and FF fuel acquisition and cleanup. Wind and sunshine are clean and free. If you have storage options that are more efficient and cleaner than gravity, I’d be glad to hear about them.

  28. Like pumped hydro, I fear compressed air energy storage is a niche technology and not a game changer. To be economical it needs to use natural caverns.

    There is a whole lot of interest right now in sodium ion batteries. There are huge supply chain and cost advantages over lithium ion batteries, and the higher weight/kwhr makes no difference for grid storage. China has a (small) demo project underway.

    • I agree about CAES. Not so much about pumped hydro, unless one considers regular hydro to also be a niche player. No doubt they have certain topographical site requirements, and work better in some places than others, e.g., mountains, Great Lakes and Norway.
      I believe demonstration projects are also underway for iron-air batteries – long life, non-toxic abundant materials, but charge lifetime perhaps only good for diurnal cycles.
      My point is really more philosophical – I find imagination, optimism, diversity and climate consideration to be a better approach than pessimism, denialism, and reliance on “dirty” non-renewable resources.

      • I agree pumped hydro may be more than a niche. But I occasionally hear it described as an overall solution to the storage problem. It is not. And yes, those who say renewables are non-starters because of their intermittent nature ignore the clear fact that long term reliance on fossil fuels is a non-starter.

      • Thanks, I wish I had missed it.

        “I don’t think you have the chops to pronounce what CO2 WILL do in the future.”

        I, nor any other real scientist, thinks they have the chops to pronounce what CO2 WILL do in the future. Science only makes predictions, preferably with best estimates of probability. Absolute pronouncements of what WILL happen are a device of the ignorant.

        “On the other hand, we don’t have any indication of a huge spike in temperature that killed or maimed people.”

        Correct, we haven’t been around long enough, but we have plenty of evidence to indicate that major climatic changes, often driven by large changes in a given forcing, including CO2, can cause major extinctions. You can ask CDC or WHO about the effect of (warming) climate change on emergent diseases and their spread.

        “Therefore, CO2 is a huge benefit. The last thing we should do it stop producing it!!!”

        Thanks, I’ll go with the scientists that understand the possibilities.

        “Burn natural gas and coal. Those ARE cheap because we already have the necessary infrastructure in place, whereas mitigation is already costing us TRILLIONS.”

        You realize that 40% of our electricity production comes from non-GHG sources and uses the same distribution infrastructure, and the LCOEs are often lower than coal or gas. Besides, gas and oil are only going to last a little while, probably less than 100 years, coal maybe a little longer – whatcha gonna do then? As for TRILLIONS, I realize, that for some people, money is more important than “doing the right thing”, and will try to justify it by claiming the right thing is the wrong thing, no matter how silly or ignorant.


      • LCOE’s include terms that are very thinly supported. You don’t seem all that “scientific” to me. You choose to ignore actual evidence from the past that was gathered by, well, …. scientists! Why would you exclude the evidence from the past and make assertions we haven’t been “around long enough” that is supported by what evidence??? None whatsoever. You need to up your game. Also, just for the record, I didn’t predict what CO2 “will do” in the future.

        What you bring to the table is a logical fallacy called “appeal to authority”.

      • Jim2,

        “You choose to ignore actual evidence from the past that was gathered by, well, …. scientists! Why would you exclude the evidence from the past and make assertions we haven’t been “around long enough” that is supported by what evidence???”
        “None whatsoever. You need to up your game.

        Try reading a good book on paleoclimatology (I can recommend a couple).

        “Also, just for the record, I didn’t predict what CO2 “will do” in the future.”

        I don’t recall that you did, I believe that was Rob. Up your game and pay atttention.

        “What you bring to the table is a logical fallacy called “appeal to authority”.”

        What authority did I appeal to, Science and scientists?

      • Jim 2,

        Appeal to authority is a logical fallacy only if the body/person appealed to does not have expertise in the subject field. A good examples would be Dr. John Clauser, or Al Gore. Appealing to CDC or WHO for their opinion on diseases and epidemiology is an appeal to authority, but not a logical fallacy. Otherwise, every time someone refers to a published paper or a SUBJECT EXPERT, you would have license to consider it a logical fallacy if you didn’t like it – and apparently that is what you are attempting to do.

      • ganon – If you have paleoclimatological evidence of a global warming runaway, please present it. Otherwise, I have to rely on the evidence we do have of global cooling (ice ages) and how hard cold periods are on humans.

        You can substitute your speculation for the evidence if you like, but it’s not a good look.

      • Jim2,

        Sure, read a good book on paleoclimatology, e.g. Collin Summerhayes’ “Paleoclimatology: from snowball Earth to the Anthropocene.”

        You can start with the Paleocene-Eocene boundary and the early Eocene (PETM, 56 – 50 Mya) where global average temperatures were up to 14 C (25 F) hotter than preindustrial. Then the Permian-Triassic extinction event 252 million years ago (also referred to as the great dying), where CO2 rose to ~2500 ppm and temperatures rose by about 8 C rather quickly (in geologic time scales). There are more – you can self-educate, if you like.

        “You can substitute your speculation for the evidence if you like, but it’s not a good look.”

        You can substitute ignorance for self-education if you like, but it’s not a good look.

        You can continue your attempted insults, if you like – I can handle it, with evidence.

      • The two events you mentioned are not well understood. There isn’t any indication that rising CO2 was the initiator in any case. Something like methane, in one case, may have overwhelmed any effect from CO2. In fact, the high CO2 levels could have been nothing more than an effect from some other cause.

        The current Doomer outlook is that rising CO2 will cause a catastrophe.

        These two events do not support that.

        They do establish that higher temperatures can cause extinctions. Well, so do lower temperatures. So really, it’s just a large change of temperature that’s problematic.

        The bottom line is I’m not convinced.

      • Jim2,

        Of course, you are not convinced. I did not expect any different. Nonetheless, you asked for paleoclimatic evidence that large temperature increases cause extinctions. I did that. Whether you understand them to your satisfaction or not, does not really matter.

      • Jim2,

        OK, so you are only comfortable with glacial-interglacial periods of the late Pleistocene. Do you realize that warming phases going into interglacials occur much faster than the cooling glaciation phases? Which do think is easier to survive with diffusional migration? If you’re not sure, you can ask the mastodons and saber tooth tigers about the first extinction pulse of the Holocene (13,000 – 9000 years ago), oh, wait …
        And do you realize that current warming (not cooling) is proceeding about 10 times faster than it did during those 4000 years. But that’s OK, you go ahead and worry about the next glacial period that might come along in about 50,000 years.


      • ganon – can you provide links to a CO2 proxy for the past billion years, give or take? Not related to anything we’ve discussed, just curious.

      • Jim2,
        Not for a billion years, but for 500 million years. Before that (most) of Earth’s crust, and corresponding geological and paleontological proxies, have since been subducted. The oldest proxies are stomata, liverworts, and paleosols. Up to about 100 million years ago, stable isotope ratio deviations, (e.g. C-13, B-11) as well as stomata and paleosols are used.


      • Jim2,

        Here is one more – a nice summary of “deep time paleoclimatic proxies”. See figure 1. for CO2 and proxies used.


      • It’s interesting as it appears the Permian/Triassic extinction revealed an advantage for plants that reproduce by seed. Do extinctions make the surviving life more robust? Not saying an extinction is a good thing, just a question about how nature works.

      • Terms like “natural selection” and “survival of the fittest” come to mind. We probably wouldn’t be here if it weren’t for the Cretaceous-Paleocene event.

  29. Spectacular cooling of the North Atlantic. It has cooled almost 1ºC in two months.

    Is this the beginning of a cold AMO phase or just the end of an episodic warming?

  30. Electricity from renewables is a good thing.
    100% electricity from renewables is a mistake.

    Electricity storage batteries is a good thing.
    100 % electricity storage is a mistake.

    Saving fossil fuels for future generations is a good thing.
    Cheap electricity is a good thing.

    Poverty is a very bad thing.
    And, CO2 does not cause Global Warming.


  31. The way I understand it, we have had old and outdated science through 2013, led by Hansen et. al. Then a revised and good science led by Mann and Solomon, which says no heat in the pipeline. In reality, Hansen et. al follow the published science. Chapter 8 of IPCC 2013, Section 8.1.1, says that forcing measures a change with respect to pre-industrial time. That is, any CO2 above 280 ppmv should continue to warm the surface. This means that there is heat in the pipeline. In short, these “prominent” climatologists should agree on their climate science first, which is not necessarily ours, before trying to convince others.

  32. Robert David Clark

    Watching WEATHER NATION again.

    They are talking about an upper level low. BLUE POINTY LINE. To the northeast on that line, you will see a coming together of the, now winter system, over North America and the now summer season over South America. This is the point at which the highs and lows are exchanging rotation.

    This junction will be moving south-west, around the next 500 to 1,000 years when the sun will begin to cool.


    DRILL baby DRILL

    Trump/Pence in 2024

    Mr. Elio build my car!!!!!!!!!!

    I thought you daughters would like to know that I have finally proved that nature designed the perfect planet for man to exist on.
    The real question is how many more are out there?????

  33. EVs are struggling.

    General Motors is building Silverado EVs. It delivered a whole 18 of them during the third quarter of this year. It planned to expand production beyond its Detroit-Hamtramck facility, also known as “Factory Zero”, by 2024 to Orion Assembly where the Bolt EV is built, albeit not for much longer. That plan has now been pushed back to late 2025, and according to GM, the decision was not made due to any supply shortages, or even the ongoing United Auto Workers strike. It could be indicative of waning consumer enthusiasm for fully electric vehicles as a whole.

    The automaker cited “evolving EV demand” and engineering improvements to the vehicle as causes for the delay. In a further statement to the Detroit Free Press, a spokesperson for the automaker expressed that “the trendline for EVs is stabilizing,” going further to explain that demand is “not rising as fast as originally forecasted.” That’s bad news for an automaker that plans to completely electrify its lineup by 2035. Of course, it’s far from the only car company with such goals.


  34. SOME EVs are struggling.

    In the US, Fully-electric vehicles (BEVs) had 7.9% market share in Q3 2023. Q3 increased by 49.8% year over year.


    Meanwhile, the year-over-year sales of ICE vehicles continues to decline.

  35. This higher interest rate environment represents an even higher barrier to BEV purchases.

    Assuming that the current laws and regulations remain unchanged, the annual percentage of newly purchased BEVs and PHEVs flattens at roughly 17-19% from 2035 through at least 2050, according to EIA projections. And while consumer interest in EVs is sensitive to the price of gasoline, the agency predicts an EV market share of less than 30% under even a scenario with oil prices as high as $190 per barrel in 2022 dollars.

    Price is the biggest barrier for consumers, Valdez-Streaty said. Despite sharp price cuts by Tesla and Ford this year, going electric still means paying a premium over the average gas-powered model. The average electric vehicle price in July was $53,469, according to Kelley Blue Book, versus an average price of $48,334 across all vehicles.

    In Cox’s consumer survey, the second biggest concern for EV considerers after price was a lack of access to charging stations.


    • The 48,469 number includes EVs. A compact ICE vehicle is substantially less in purchase price than any EV. And if it weren’t for subsidies, the differential would be much worse.

      • From your numbers, it looks like rebates more than cover the price differential. Of course, you didn’t quantify for compacts. Simple math says that 10% of sales with 10% higher price, means that including EVs with ICEs in the overall average increases it by 1%. Prices for EVs are expected to reach price parity within a couple of years.
        And then there is the difference in fueling costs over the lifespan of the vehicle. Enjoy the price at the pump and feel good about the 27 pounds of CO2 put into the atmosphere for every gallon of petrochemical burned.

  36. Hansen 1988 forecast vs observed. Bias greater than 2x no matter how you verify it. https://postimg.cc/7Ckq8KzH

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