RealClimate

The current permanent contributors to content on this site are:

William Connolley was a contributor, but has now left academia, although his posts are still online.

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9 25 SEVERAL STORIES ON WATER IN FLIPBD I SCARD TO LOOK AT; fox jrnl fail on NC coast flood

Time and Tide Gauges wait for no Voortman

18 Sep 2025 by Gavin 31 Comments

Here we go again. An obscure, methodologically poor, paper published with little to no review makes a convenient point and gets elevated into supposedly ‘blockbusting’ science by the merchants of bullshit, sorry, doubt. Actual scientists drop everything to respond, but not before the (convenient) nonsense has spread widely. Rebuttals are written and submitted, but by the time they are published everyone has moved on.

If that sounds familiar, it’s because it happens a lot. In climate science, one classic example was Soon and Baliunas (2003)which instantly made it’s way to the Senate floor (via Inhofe’s then aide Marc Morano). Other examples abound. So what is this week’s example?

As Dessler et al report laid out convincingly last week, and in multiple posts by Tamino/Grant Foster, the sea level chapter in the DOE climate science ‘critique’ was notably poor. They highlighted 5 specific US tide gauge records, showed only four of them, declared that no acceleration was visible, and concluded that no acceleration was present anywhere. Curiously the 5th record (that wasn’t shown) has a very clear acceleration. They then bungled the referencing of the projections and invented a NOAA projection that did not correspond to anything real. Notably, they did no actual analysis. Actual analyses of the tide gauge record show that acceleration is sea level rise is not only widespread, but it is increasingly clear:

*Analysis of US tide gauge records showing statistically significant acceleration in sea level rise on the East Coast all the way from the Gulf to Maine (via Tamino)

Conveniently, rather than defend the indefensible, one of the authors (Judith Curry) in response latched onto a new paper that apparently agreed with her prior vibes. The new paper is Voortman & de Vos (2025) (VdV25) which was published on Aug 27, and hit the contrary-sphere a few days later heavily boosted by Michael Shellenberger and a few others. This paper claims that acceleration in 243 global tide gauge records is only significant in 4% of them. This, to be clear, is rubbish. But as always in such papers, it takes a little work to figure out what has gone wrong.

Fortunately, a group of scientists led by Bob Kopp, have quickly put together a rebuttal and request for a retraction (that has been submitted to the journal): Kopp et al. (2025). In it, they point out that this analysis has in fact already been done properly (Wang et al, 2025, published before VdV25 was submitted), and then go on to explain the basic errors.

Apart from the basic lack of context that happens when you ignore the satellite record, the main issues are that the statistical model they use is overly complicated and not properly described, the statistical tests for significance are not applied properly, and the correction for multiple hypothesis testing (which assumes there is no correlation across tide gauge records) is just wrong and all but guarantees their erroneous result.

Curiously, almost all of these errors were also made in an earlier Voortman paper, and were raised by the commenters on that paper at the time (Le Bars et al., 2023)! Update:**They were also noted in a [blog postby Scott Simmons].

How will this all play out in the public discourse? The process of comments, replies, and retractions is relatively slow (multiple months to a year) and even with this preprint quickly available, none of the promoters of VdV25 will deal substantively with any of this (they have not done, and will not do, any analysis themselves). It may well be that VdV25 never gets raised again, having served its purpose as a momentary distraction from the critique of CWG report. Whether or not it gets retracted is not really relevant to that.

We have seen this playbook many times before. Judith Curry and Michael Shellenberger are following in the (late) Pat Michaels’ footsteps who continually championed many new ‘blockbusting’ papers that were always on the verge of undermining the climate consensus, but that (somehow!) never quite did. Once folks lose the ability to check these things for themselves, and start basing claims on vibes, their estrangement from the scientific community hardens and the seriousness with which their opinions are taken decreases.

This little episode thus tells us very little about sea level rise acceleration, but quite a lot about the seriousness of the people involved.

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Competitive Enterprise Institute to sue RealClimate blogger over moderation policy

By Joe Romm on Nov 25, 2009

Gavin Schmidt has done a wonderful job at RealClimate patiently explaining the context of the stolen emails. He’s made it perfectly clear that the claims of scientific malpractice are without foundation. He must be doing a really good job, because the Competitive Enterprise Institute intends to sue him.

That’s computer scientist Tim Lambert aka Deltoid explaining (here) the latest tactics the anti-scientific disinformers are pursuing to stifle real climate scientists from communicating with the public. The CEI, of course, runs ad campaigns aimed at destroying the climate for centuries; generally spreads disinformation (see “Santer, Jones, and Schneider respond to CEI’s phony attack on the temperature record“) and embraces the efforts of other groups to sow confusion (see “Deniers go ape for Scopes climate trial“).

But CEI’s current tactics, which they proudly announce here, have become truly extemist in nature:

[CEI seeks documents] relating to the content, importance, or propriety of workday-hour posts or entries by GISS/NASA employee Gavin A. Schmidt on the weblog or “blog” RealClimate, which is owned by the advocacy Environmental Media Services and was started as an effort to defend the debunked “Hockey Stick” that is so central to the CRU files. RealClimate.org is implicated in the leaked files and expressly offered as a tool to be used “in any way you think would be helpful” to a certain advocacy campaign, including an assertion of Schmidt’s active involvement in, e.g., delaying and/or screening out unhelpful input by “skeptics” attempting to comment on claims made on the website.

This, and the related political activism engaged in, are inappropriate behavior for a taxpayer-funded employee, particularly on taxpayer time. These documents were requested in January 2007 and NASA/GISS have refused to date to comply with their legal obligation to produce responsive documents.

Lambert notes:

Yes they’re planning to sue Schmidt for the “inappropriate behavior” of moderating comments at RealClimate. Of course, the point of this vexatious suit isn’t to win — it’s to harass and distract Schmidt because he is being effective.

It’s not for nothing that I dubbed them the Completely Evil Institute.

I would add that essentially every factual assertion in the above excerpt from the piece by CEI Fellow Chris Horner is false.

The disinformers are obsessed with the Hockey Stick analysis, even though it is just the tiniest piece of our overall understanding of climate science, which is getting increasingly dire by the day (see Climate science statement from the Met Office, NERC and the Royal Society: “even since the 2007 IPCC Assessment the evidence for dangerous, long-term and potentially irreversible climate change has strengthened”).

The ‘hockey stick’ was, in fact, essentially vindicated by the National Academy of Sciences (see NAS Report and RealClimate.org). And more important than the fact that the original analysis was defensibly correct, is that the conclusions were correct [which could be true even if the analysis had flaws in it]. Is the planet now as hot (or hotter) than it has been in a millenium? Try two millennia (see “Sorry deniers, hockey stick gets longer, stronger: Earth hotter now than in past 2,000 years“). See also “Human-caused Arctic warming overtakes 2,000 years of natural cooling, ‘seminal’ study finds.” That’s why climatologist and one-time darling of the contrarians Ken Caldeira said last month, “To talk about global cooling at the end of the hottest decade the planet has experienced in many thousands of years is ridiculous.”

RealClimate was not started as an effort to defend the Hockey Stick, but rather to “to provide a quick response to developing stories and provide the context sometimes missing in mainstream commentary” on climate science in general (see RC’s About page). As for being “owned by the advocacy Environmental Media Services,” RealClimate explains patiently in its Disclaimer:

The contributors to this site do so in a personal capacity during their spare time and their posts do not represent the views of the organizations for which they work, nor the agencies which fund them. The contributors are solely responsible for the content of the site and receive no remuneration for their contributions.

RealClimate is not affiliated with any environmental organisations. Although our domain is being hosted by Environmental Media Services, and our initial press release was organised for us by Fenton Communications, neither organization was in any way involved in the initial planning for RealClimate, and have never had any editorial or other control over content. Neither Fenton nor EMS has ever paid any contributor to RealClimate.org any money for any purpose at any time. Neither do they pay us expenses, buy our lunch or contract us to do research. This information has always been made clear to anyone who asked.

CEI received over $2 million from ExxonMobil from 1998 to 2005, but that is no doubt purely a coincidence.