{"id":26379,"date":"2026-02-07T13:37:17","date_gmt":"2026-02-07T18:37:17","guid":{"rendered":"https:\/\/www.realclimate.org\/?p=26379"},"modified":"2026-02-08T12:43:56","modified_gmt":"2026-02-08T17:43:56","slug":"koonins-continuing-calumnies","status":"publish","type":"post","link":"https:\/\/www.realclimate.org\/index.php\/archives\/2026\/02\/koonins-continuing-calumnies\/","title":{"rendered":"Koonin&#8217;s Continuing Calumnies"},"content":{"rendered":"<div class=\"kcite-section\" kcite-section-id=\"26379\">\n\n<p><strong>At a public event debating the DOE CWG report, Steve Koonin embarrasses himself further.<\/strong><\/p>\n\n\n\n<!--more-->\n\n\n\n<p>This week there was a bit of a peculiar event at the <a href=\"https:\/\/www.civitasinstitute.org\/events\/powering-the-future-climate-innovation-and-the-ai-energy-surge\" title=\"Civitas Institute at UT Austin\">Civitas Institute at UT Austin<\/a>,  with three of the CWG authors (John Christy, Steve Koonin and Ross McKitrick) being rebutted by Andy Dessler (working solo).<\/p>\n\n\n\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe title=\"Powering the Future: A Look at Key Findings in the DoE Climate Report\" width=\"500\" height=\"281\" data-src=\"https:\/\/www.youtube.com\/embed\/yTYLswTEVS8?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" class=\"lazyload\" data-load-mode=\"1\"><\/iframe>\n<\/div><\/figure>\n\n\n\n<p>The event itself was a rehash of the CWG&#8217;s reports &#8216;findings&#8217; (or rather, a repeat of their cherry picks, uncontextualized statements, and ignoring of the literature), and Dessler somewhat successfully pointing this out. The event seemed a bit rushed (too much content being crammed into too short a time) and is a great example of the applicability of the <a href=\"https:\/\/en.wikipedia.org\/wiki\/Brandolini%27s_law\" title=\"Brandolini's Law\">Brandolini&#8217;s Law<\/a>. <\/p>\n\n\n\n<p>There would be a lot to criticise in the presentations if one wanted (most of this was gone over in the <a href=\"https:\/\/www.realclimate.org\/index.php\/archives\/2025\/09\/climate-scientists-response-to-doe-report\/\" title=\"Climate Scientists response to DOE report\">Scientists response to the DOE report<\/a> that Andy helped organise), but the presentation by Koonin went even further into nonsense territory than the CWG report itself. Apparently, &#8220;internal variability&#8221; (something noticeably ignored in many claims by the CWG) is the &#8220;last refuge of fools and scoundrels&#8221; (at least according to Koonin)!<\/p>\n\n\n\n<p>What this stems from is Koonin&#8217;s reliance on Nicola Scafetta&#8217;s work on evaluating climate models &#8211; readers here will know that is a very bad idea, and we went through a lot of this <a href=\"https:\/\/www.realclimate.org\/index.php\/archives\/2022\/03\/issues-and-errors-in-a-new-scafetta-paper\/\" title=\"Issues and Errors in a new Scafetta paper\">in respect to a GRL paper that Scafetta published in 2022<\/a>. That led to a whole <a href=\"https:\/\/www.realclimate.org\/index.php\/archives\/2023\/09\/the-scafetta-saga\/\" title=\"The Scafetta Saga\">saga<\/a>, which took so long that while we were trying to get the 2022 paper retracted on the grounds of being totally wrong, Scafetta basically published the same analysis <a href=\"https:\/\/www.realclimate.org\/index.php\/archives\/2022\/10\/scafetta-comes-back-for-more\/\" title=\"Scafetta comes back for more\">again<\/a> (with almost all the same errors and some new ones) in another journal. Our enthusiasm to go another round pointing out his mistakes was limited, and so the second paper still stands nominally unrebutted in the literature despite having been pre-rebbutted by our comment on the first paper <span id=\"cite_ITEM-26379-0\" name=\"citation\"><a href=\"#ITEM-26379-0\">(Schmidt et al., 2023)<\/a><\/span>. This came up in the &#8216;internal review&#8217; of the CWG report, where one of the reviewers said that the CWG should deal with our criticism of Scafetta&#8217;s work (pointing to the published comment), and were blown off by the CWG who claimed that because they cited the second paper (not the first), our comment was moot. Classic dissembling.<\/p>\n\n\n\n<p>Anyway, Koonin&#8217;s presentation at the Civitas event (starts around 20:20 in the video) repeats the errors, but goes even further. First, he notes that some CMIP6 models have climate sensitivities that are too high. That&#8217;s fine &#8211; I have made the same point <a href=\"https:\/\/www.realclimate.org\/images\/cmip6_ecs_update.png\">here<\/a>, and in <em>Nature<\/em> <span id=\"cite_ITEM-26379-1\" name=\"citation\"><a href=\"#ITEM-26379-1\">Hausfather et al., 2022<\/a><\/span>. But then he elides from &#8216;some models&#8217; to &#8216;the models&#8217; without even taking a breath (<a href=\"https:\/\/www.realclimate.org\/index.php\/archives\/2021\/08\/notallmodels\/\" title=\"#NotAllModels\">Hmm&#8230;<\/a>). He doubles down on <a href=\"https:\/\/www.realclimate.org\/index.php\/archives\/2024\/01\/spencers-shenanigans\/\" title=\"Spencer\u2019s Shenanigans\">Spencer&#8217;s cherrypicking<\/a> (itself not peer-reviewed of course), and claims that people pointing out that something has been cherry-picked are trying to &#8220;change the topic&#8221;. Yes, that metric that no-one had ever mentioned before Spencer did this analysis is *the* topic that the assessment was designed to address \/sarc.    <\/p>\n\n\n\n<p>Koonin additionally claims that the mainstream scientists are blaming model-observation discrepancies on internal variability for the last twenty years, while ignoring it for the previous twenty years. Of course, he provides no citation nor evidence that anyone has ever done such a thing. Worse, in response to a suggestion that they utilise the uncertainty in the modeling (esp. the internal variability), he makes an incredible statement (starting at 30:47):<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>Well, if you do that, it effectively broadens the uncertainty so much as to be almost essentially useless.<\/p>\n<\/blockquote>\n\n\n\n<p>Let&#8217;s parse this out. He isn&#8217;t claiming that the internal variability isn&#8217;t real (it is of course). He is claiming that his model-observation comparison doesn&#8217;t show any discrepancy if you include the uncertainties and that <em>therefore it&#8217;s useless<\/em>! To repeat, Koonin is stating that he isn&#8217;t including the uncertainties because it would undermine the conclusion he is trying to draw. <\/p>\n\n\n\n<p>This is as clear an admission of scientific misconduct as I&#8217;ve heard. <\/p>\n\n\n\n<p>He then illustrates this with reference to <span id=\"cite_ITEM-26379-2\" name=\"citation\"><a href=\"#ITEM-26379-2\">Tokarska et al. (2020)<\/a><\/span> (Fig 3, Panel A) which is not really trying to do the same thing, but fine. [I think there must be a second half to that slide showing individual runs &#8211; but I&#8217;m not sure where that would have been from]. However, we addressed this exact issue with the comment on the first Scafetta paper:<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large is-resized\"><img decoding=\"async\" width=\"2100\" height=\"2100\" data-src=\"https:\/\/www.realclimate.org\/images\/\/scafetta5.png\" alt=\"\" class=\"wp-image-24322 lazyload\" style=\"--smush-placeholder-width: 2100px; --smush-placeholder-aspect-ratio: 2100\/2100;width:536px;height:auto\" data-srcset=\"https:\/\/www.realclimate.org\/images\/scafetta5.png 2100w, https:\/\/www.realclimate.org\/images\/scafetta5-300x300.png 300w, https:\/\/www.realclimate.org\/images\/scafetta5-600x600.png 600w, https:\/\/www.realclimate.org\/images\/scafetta5-150x150.png 150w, https:\/\/www.realclimate.org\/images\/scafetta5-1536x1536.png 1536w, https:\/\/www.realclimate.org\/images\/scafetta5-2048x2048.png 2048w\" data-sizes=\"(max-width: 2100px) 100vw, 2100px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" \/><figcaption class=\"wp-element-caption\"><em>Multi-decade temperature differences in ERA5 and CMIP6, showing individual simulations and ensemble means, plotted against Climate Sensitivity. <\/em><\/figcaption><\/figure>\n<\/div>\n\n\n<p>The question being asked is whether there is a discrepancy between any specific model and the observations. An initial condition (IC) ensemble starts the model with a different weather pattern, but each run has the same forcing. The standard deviation of the IC ensemble is a reasonable measure of the internal variability (i.e. the spread that could occur only as a function of the (unpredictable) weather. The real world can be considered a single realization of the real world climate, so the standard way to assess whether the a model is consistent with the real world is to estimate the probability that the real world result could be part of the model distribution. In practice, one can calculate the 95% confidence interval for the model (based on it&#8217;s ensemble) and ask whether the real world data falls within that range. Wherever it is, you can calculate the probability of getting that result, assuming that model distribution. The further away the observation from the model spread, the less likely that it could have generated by that distribution.<\/p>\n\n\n\n<p>So if the real world falls inside the 95% CI, it is clearly consistent with the distribution, even if the ensemble mean is different from the observations. As the signal grows, the spread due to the internal variability will shrink, and discrepancies might emerge more clearly. But no-one is arguing that internal variability should be ignored for one period, and used in another. Rather, it should be used consistently at all times. If that prevents Steve Koonin from trashing the models, so be it. <\/p>\n\n\n\n<p>To go back to the claim though, there are multiple models with sensitivities up to about 5\u00baC that have surface temperature trends that are compatible with the observations. A few models don&#8217;t have sufficient simulations to say, and a few are clearly incompatible. This is what Koonin says: <\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p>They say that the fact I can find one starting point that agrees with the data is enough to validated that model. In fact that doesn&#8217;t sound right at all. I don&#8217;t think that would pass peer review &#8211; at least among my peers. <\/p>\n<\/blockquote>\n\n\n\n<p>This is not quite an accurate reflection of the mainstream position, nor do his feelings on the issue make sense. The mainstream position is first more nuanced (as explained above); it is not that seeing that observations fall within the spread validates the model, rather if this happens you should not reject that model (a much less onerous claim). But why does this sound strange to Koonin? Is he in the habit of rejecting models that are consistent with observations? And of course, this position has passed peer-review many times, though I will accept that his peers might not agree (which is a statement about his peers, not the claims). <\/p>\n\n\n\n<p>To wrap this up, I updated the figure above to look at a slightly longer period (the change to 2015-2025) using the latest observations from ERA5. <\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large is-resized\"><img decoding=\"async\" width=\"2100\" height=\"2100\" data-src=\"https:\/\/www.realclimate.org\/images\/\/scafetta_2025.png\" alt=\"\" class=\"wp-image-26382 lazyload\" style=\"--smush-placeholder-width: 2100px; --smush-placeholder-aspect-ratio: 2100\/2100;width:534px;height:auto\" data-srcset=\"https:\/\/www.realclimate.org\/images\/scafetta_2025.png 2100w, https:\/\/www.realclimate.org\/images\/scafetta_2025-300x300.png 300w, https:\/\/www.realclimate.org\/images\/scafetta_2025-600x600.png 600w, https:\/\/www.realclimate.org\/images\/scafetta_2025-150x150.png 150w, https:\/\/www.realclimate.org\/images\/scafetta_2025-1536x1536.png 1536w, https:\/\/www.realclimate.org\/images\/scafetta_2025-2048x2048.png 2048w\" data-sizes=\"(max-width: 2100px) 100vw, 2100px\" src=\"data:image\/svg+xml;base64,PHN2ZyB3aWR0aD0iMSIgaGVpZ2h0PSIxIiB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciPjwvc3ZnPg==\" \/><figcaption class=\"wp-element-caption\"><em>As above, but for a period extending to 2025.<\/em><\/figcaption><\/figure>\n<\/div>\n\n\n<p>It is still clear that some models are not consistent with ERA5 (notably the five models with the highest sensitivity), but it is also clear that many of them are &#8211; and that Koonin&#8217;s claims (like Scafetta&#8217;s before him) are hogwash. His implicit claim that you should ignore uncertainty if that gets in the way of your preferred conclusion is simply embarrassing for someone who likes to think of himself as an &#8220;eminent&#8221; scientist. <\/p>\n<h2>References<\/h2>\n    <ol>\n    <li><a name='ITEM-26379-0'><\/a>\nG.A. Schmidt, G.S. Jones, and J.J. Kennedy, \"Comment on \u201cAdvanced Testing of Low, Medium, and High ECS CMIP6 GCM Simulations Versus ERA5\u2010T2m\u201d by N. Scafetta (2022)\", <i>Geophysical Research Letters<\/i>, vol. 50, 2023. <a href=\"http:\/\/dx.doi.org\/10.1029\/2022GL102530\">http:\/\/dx.doi.org\/10.1029\/2022GL102530<\/a>\n\n\n<\/li>\n<li><a name='ITEM-26379-1'><\/a>\nZ. Hausfather, K. Marvel, G.A. Schmidt, J.W. Nielsen-Gammon, and M. Zelinka, \"Climate simulations: recognize the \u2018hot model\u2019 problem\", <i>Nature<\/i>, vol. 605, pp. 26-29, 2022. <a href=\"http:\/\/dx.doi.org\/10.1038\/d41586-022-01192-2\">http:\/\/dx.doi.org\/10.1038\/d41586-022-01192-2<\/a>\n\n\n<\/li>\n<li><a name='ITEM-26379-2'><\/a>\nK.B. Tokarska, M.B. Stolpe, S. Sippel, E.M. Fischer, C.J. Smith, F. Lehner, and R. Knutti, \"Past warming trend constrains future warming in CMIP6 models\", <i>Science Advances<\/i>, vol. 6, 2020. <a href=\"http:\/\/dx.doi.org\/10.1126\/sciadv.aaz9549\">http:\/\/dx.doi.org\/10.1126\/sciadv.aaz9549<\/a>\n\n\n<\/li>\n<\/ol>\n\n<\/div> <!-- kcite-section 26379 -->","protected":false},"excerpt":{"rendered":"<p>At a public event debating the DOE CWG report, Steve Koonin embarrasses himself further.<\/p>\n","protected":false},"author":2,"featured_media":26382,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":""},"categories":[5,1,75,9,161,34],"tags":[90,182,180,89,172],"class_list":{"0":"post-26379","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-climate-modelling","8":"category-climate-science","9":"category-featured-story","10":"category-instrumental-record","11":"category-model-comp","12":"category-skeptics","13":"tag-cmip6","14":"tag-cwg","15":"tag-doe","16":"tag-scafetta","17":"tag-steve-koonin","18":"entry"},"aioseo_notices":[],"post_mailing_queue_ids":[],"_links":{"self":[{"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/posts\/26379","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/comments?post=26379"}],"version-history":[{"count":6,"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/posts\/26379\/revisions"}],"predecessor-version":[{"id":26388,"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/posts\/26379\/revisions\/26388"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/media\/26382"}],"wp:attachment":[{"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/media?parent=26379"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/categories?post=26379"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.realclimate.org\/index.php\/wp-json\/wp\/v2\/tags?post=26379"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}