Vahrenholt & Lüning On Shakun: “Desperate Attempt To Salvage Beloved CO2-Catastrophe Model”

 Best-selling authors Prof. Fritz Vahrenholt and geologist Dr. Sebastian Lüning comment on Shakun’s recent “Nature” paper at their site.

One of the most hotly disputed points in the climate debate is CO2 climate sensitivity. The warmists would like to have everyone believe that CO2 is the primary climate driver in the climate system.

However, climate and geological data show it aint so. More than 10 years ago a Swiss-French team published  the results of an Antarctic ice core study in Science. The scientists, among them Thomas Stocker, were able to show that atmospheric CO2 concentrations lagged behind temperature by about 800 years. This has become a painful thorn in the side of the global warmists. Clearly it showed that CO2 reacted to temperature, and not vice versa.

Rather than admitting that the CO2 global warming hypothesis is broken, the warmists have chosen instead to try to get rid of inconvenient 800-year lag.

Figure 1: CO2 lags temperature by 800 years. Timescale from 22,000 to 10,000 years before present. Source: Monnin et al. 2001.

With the IPCC 5th assessment report due to come out soon, the IPCC activists are scrambling to get their hands on a study that eliminates this 800-year lag and puts CO2 back in command.

Jeremy Shakun refabricates Earth’s history

Die kalte Sonne site writes how the IPCC is attempting to pull another Michael Mann-type history rewrite. In 2001, Man’s now bogus hockey stick was the graph celebre that re-invigorated the global warming movement. But with Michael Mann fading, the IPCC needs a new, young star, fresh with a PhD. They found him in Jeremy Shakun, lead author of a new study that claims to do away with the inconvenient 800-year lag and shows CO2 once again is the real driver.

Shakun claims that the Antarctic climate shown by the ice core reconstruction was a local artifact, and not global. Shakun and his team took temperature reconstructions from numerous locations scattered about the globe and averaged them out and suddenly, lo and behold, temperature lagged CO2. Science now settled!

Shakun an his colleagues claimed that during the last ice age CO2 concentrations surged 40%, which led to a temperature increase of about 3.5°C – precisely what the IPCC wanted to see. The media and warmist science community all breathed a sigh of relief – the climate catastrophe is coming after all. And without checking up, the mainstream media unleashed the news, e.g. Spiegel Online,, Stern.

But then came Willis Eschenbach, who quickly exposed the shortcomings of Shakun’s paper. Die kalte Sonne describes how he went about with his analysis at WUWT. Lüning and Vahrenholt write:

It is a true mystery how anyone is able to discern temperature is lagging behind CO2 from such a massive scatter of data, as the title of Shakun’s paper (Global warming preceded by increasing carbon dioxide concentrations during the last deglaciation“) claims.

Figure 2: Source: Willis Eschenbach, Anthony Watts, WUWT.

Parallels to Michael Mann

With the Shakun story, Vahrenholt and Lüning see parallels to the Michael Mann saga:

One can’t help but get the impression that all this is a renewed desperate attempt to salvage the beloved CO2-catastrophe model. Already in the case of the Hockey Stick curve statistical tricks as ad absurdum were used. When that failed, scientists very close to the IPCC tried to blame the Little Ice Age solely on volcanic activity. The Shakun paper is simply the latest sequel. It plainly shows once again that the judges (IPCC report authors) should not judge their own deeds (scientific literature). What is taken as a given in the legal system is not even questioned in the politically sensitive climate sciences. All we can do is scratch our heads in amazement.”

Vahrenholt and Lüning add:

And there are other interesting parallels to the Hockey Stick saga. Michael Mann was awarded his doctorate degree for his Hockey-Stick research, and then was put on the accelerated fast-track to professor and promoted to the IPCC top brass. Also Jeremey Shakun carried out his work, now published in Nature, as part of his doctoral thesis which he submitted in 2010 (see p. 64 in the doctoral thesist and p. 80 of the pdf). Originally the paper had been intended to be published by Science. Had it been submitted there, rejected, and then had more luck at Nature? And what is going to happen to Jeremey Shakun? Is he going to have an similarly rapid career climb like Mann did?”

The IPCC process is broken

Vahrenholt and Lüning write:

Finally, it is interesting to note that Shakun’s co-author is Peter Clark, his PhD advisor who happens to be a coordinating lead author of the new IPCC report. Also co-author Bette Otto-Bliesner is also a lead author of the new report of the IPCC.”

and add:

The stated task of the IPCC is neutral viewing and assessment of the scientific literature. How can neutrality be assured when IPCC members ultimately peer-review their own work?”

Looks like the IPCC is more broken and corrupt than ever.


9 responses to “Vahrenholt & Lüning On Shakun: “Desperate Attempt To Salvage Beloved CO2-Catastrophe Model””

  1. DirkH

    Yeah, looks like this will be a centerpiece of AR5.
    “Peter Clark, his PhD advisor who happens to be a coordinating lead author of the new IPCC report.”
    Very telling.
    Dr. Vincent Gray tears it apart in a slightly different way than Willis. Just to give some flexibility.
    The nice thing is that we’ll be shooting down the AR5 as soon as it comes out. No surprise momentum for the IPCC left. No money left for them to extort. So they’ll be irrelevant.

    But their heritage is the mental carnage they inflicted on millions of their warmist fanboys who are committed to a life of misery; believing we’re going to hell in a handcart. My heart goes out to all of you soulless idiots; despair not – you’ve just been had. There will be another day. Powered mostly by hydrocarbons.

  2. Brian G Valentine

    I haven’t seen the new study, although there appears to be no attempt to normalize local atm pressure and temperature regarding CO2 proxy composition.

    Meaning these are all over the place, just as the temperatures are.

    I dread the fact that these young people with PhD in sciences have been saturated with CO2 nonsense in the Universities. Very few of the skeptical professors actually have PhD students these days (Dr Happer from Princeton is an exception, although I don’t think he emphasises CO2 skepticism to his students)

    1. Mindert Eiting

      But these students do not live in a prison. They have access to the internet as well. Sooner or later they will start to revolt. Note also that it took a few years to debunk the hockey stick whereas it took one week to debunk this study. Internet really matters.

  3. Garry

    “Vahrenholt and Lüning write… ‘The stated task of the IPCC is neutral viewing and assessment of the scientific literature.'”

    Not so. The stated task of the IPCC is to determine how human beings influence the “cause and effect” and “disastrous” outcomes of climate change.

    It’s all stated in the December 6, 1988 IPCC charter, located here:

    Basically it’s all about creating more NGO and governmental involvement in climate matters; funding lots of U.N. studies and conferences; and “reviewing” not “assessing” literature that bolsters the predetermined U.N. agenda. I don’t see anything in the charter that implies neutrality or science. It’s politics and money all the way down.

  4. Casper

    The IPCC seems not to know the Henry’s Law 😉

  5. Lars52

    We talk about global warming but can somebody explain the European cooling that occured during 1710- 1790 (I think it was) part of the Baltic sea frooze and the King of Sweden could attac Denmark, the Dutch learned to iceskating on their canals, (Just kidding about the Dutch) anway there was a cold period in Europe for about 70-80 years, was the CO2 dropping or was it a natural variation due to something we do not yet understand.

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