A critical look at “The uncertainty has settled” documentary by Marijn Poels


(Zie de Nederlandse versie door Jos Hagelaars op ons Klimaatverandering blog)

The documentary “The uncertainty has settled” from Dutch filmmaker Marijn Poels follows him on his journey in rural Austria and Germany to witness how energy policies impact traditional agriculture. That is the stepping stone to also look into different ideas about how and why the climate is changing. Unfortunately Poels has no clue how to distinguish fact from fiction, and by his own admission he has no interest in making that distinction. As a result the documentary offers a mix of basic scientific insights, plain falsehoods, and misleading statements regarding climate science. As an unwitting viewer you are left utterly confused –cued by Poels’ facial expression at those times- how to reconcile these seemingly opposing viewpoints. Creating confusion was apparently his objective (as he acknowledges on his website), but it makes for a surreal experience if you know you’re being fooled. I think spreading falsehoods is doing a disservice to the public, as I’ve said to Marijn Poels during a radio-debate (in Dutch).

Let’s look more closely at some of the things being said about climate change in the documentary.

Marijn Poels meets another Dutchman in rural Germany, who laments how climate policies have led to the disappearance of local nature. He says it’s insane to think that a CO2 concentration as low as 0.035% (currently 0.04%) could have any impact on climate. That’s clearly fallacious reasoning (argument from incredulity): there are plenty of examples of compounds that have serious impacts at the same or lower concentrations (e.g. a CO detector will sound the alarm at such a concentration and you had better leave the premises). Without any CO2 in the air the globe would quickly become a frozen ball of ice, since the main air constituents (nitrogen 78%, oxygen 21%, argon 1%) don’t impede the infrared heat loss to space.

Later in the documentary he meets with climate scientist Hans von Storch, astrophysicist Piers Corbyn and physicist Freeman Dyson. Those in the loop will immediately recognize that this is not at all a fair representation of the scientific debate, but rather provides a very skewed vision thereof by emphasizing outlier views that are demonstrably false.

Hans von Storch accurately describes our current knowledge about climate change: We know that the earth has warmed and we can’t explain this warming without considering the human-induced increase in greenhouse gases in the atmosphere. He also distinguishes how scientific knowledge may be very uncertain in specific details, while the core tenets are robustly known: “The fact that CO2 has a significant influence on climate is indisputable.”

It’s astonishing how many falsehoods and conspiracy theories Piers Corbyn mentions over the course of few minutes.  Some of the things he said:

FALSE: The increasing CO2 concentration in the atmosphere is coming from the oceans

If Corbyn were right, the concentration in the ocean should have decreased in order to explain the increased atmospheric concentration (a simple consequence of conservation of mass). However, CO2 concentrations have been observed to increase both in the atmosphere and in the ocean. In reality, the excess CO2 in both atmosphere and ocean originates from fossil fuel burning, as is evident from the isotopic signature and the concomitant decrease in atmospheric O2 concentration.

FALSE: CO2 only follows temperature

During the ice age cycles CO2 acted as an amplifying feedback on the warming which was initiated by changes to the earth’s orbit. During those times of relatively slow warming the temperature indeed started to increase before the CO2 concentrations did, after which the CO2 caused even more warming. Hence it’s a bit of a chicken-egg issue with CO2 and temperature, but Corbyn’s statement is misleading. The current CO2 increase is unequivocally anthropogenic and ~100 times faster than it was in glacial to interglacial transitions. Moreover, we have known since the mid-nineteenth century that CO2 absorbs infrared radiation and thus acts as a greenhouse gas which impedes planetary heat loss and thus warms up the surface.

FALSE: Termites produce more CO2 than human activity does

Termites produce less CO2 than human activity does. Moreover, while anthropogenic emissions have led to the increased CO2 concentration, there’s no sign of tremendous changes in termite populations or emissions. In general, CO2 uptake and release by the biosphere (through assimilation and respiration/decomposition, respectively) approximately balance over multi-annual timescales. Termites also emit methane, another greenhouse gas, though around 40 times less than is released through human activity.  [Text about termite emissions has been updated 17-07]

FALSE: A new mini-ice age cometh

Corbyn has been predicting this for a while now (at least since 2010), but reality so far has been going in the opposite direction compared to his predictions. Scientists have investigated the potential consequences of a quieter sun in the near future, but generally find that increased greenhouse gas concentrations will dwarf any realistic decrease in solar activity, and hence the globe will continue to warm for the foreseeable future.

CONSPIRACY THEORY: The increased temperatures are a result of fraud with the observations

Globally averaged temperatures are computed independently by a number of different research group and they all agree within a close margin of each other. The raw data are available, so everyone who’s interested and who has the requisite skill can try to reproduce (or falsify) these calculations. A number of ‘skeptical’ people have indeed done so, and lo and behold, they found the same result: the globe really is warming.

Corbyn continues with his conspiracy theories and doesn’t even seem bothered that they’re mutually inconsistent with each other: on the one hand he claims that the ‘climate ideology’ has been made up by international big business interests, on the other hand he also claims that the ‘myth of climate change’ is a scheme to de-industrialize the West. How can you possibly take someone like this seriously?

Next up is renowned physicist Freeman Dyson, who is very skeptical of the ability of climate models to make accurate projections of future warming. In the documentary he paints a false dichotomy between observations on the one hand and models on the other hand, whereas in modern science they really go hand in hand and models form an integral part of science. Model simulations agree very well with observations, despite Dyson’s claims to the contrary. For good measure he also throws in a conspiracy theory by claiming that climate modelers only want to scare people, because they wouldn’t get money for their research otherwise. This goes to show that otherwise brilliant people can still make silly claims about a field of science that they don’t know much about.

So why did Marijn Poels chose to interview people who are demonstratively wrong (and who are not actually climate scientists)? His whole idea with the documentary was as a personal quest in which he listened to various viewpoints without judgment or evaluation. In a radio-debate I did with him on Dutch Radio NPO1 he proclaimed that he doesn’t feel any responsibility to figure out who’s talking sense and who’s talking nonsense. On twitter he has since confirmed that he doesn’t care what true and what’s not. I find that a very strange attitude for a documentary-maker, as I tried saying at the end of the radio-debate:

Scientists are seeking a better understanding of the world around us. What I hear Marijn Poels say is that it doesn’t matter to him what’s true and what’s not. That goes against everything I value as a scientist.

He also tweeted that “if there are multiple scientific perspectives, then it’s worthy of debate”. So the problem is not only that he doesn’t care about whether something is true or not; he doesn’t see that some of what he calls “scientific perspectives” are plain untruths. Claiming that the CO2 might just have come out of the ocean is no more a ‘scientific perspective’ than claiming that vaccines cause autism or that smoking is not linked to cancer. Science has conclusively shown these statements to be false.

In a public debate about smoking regulation there’s no point in discussing whether smoking is really bad for you: we know that by now, based on scientific evidence.

Likewise, in a public debate about climate policies  there’s no point in discussing whether CO2 really contributes substantially to climate change: we know that by now, based on scientific evidence.


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21 Responses to “A critical look at “The uncertainty has settled” documentary by Marijn Poels”

  1. jchilds Says:

    A key issue with the debate is seen in this statement: “The fact that CO2 has a significant influence on climate is indisputable.”

    Can you spot the problem with the sentence? The sentence mixes fact and opinion and paints both as fact. Here’s a sentence that is factual:
    “The fact that CO2 has an influence on climate is indisputable.”

    Boom. Nothing wrong with that statement. But once “significant” is inserted it’s a matter of subjective belief. My wife thinks that a 5 pound weight gain is “significant.” And no doubt, this is “indisputable” if I know what’s good for myself.

    If a simple statement of opinion like “significant” was not put out there as an “indisputable” “fact” – or even if the word “significant” was kept out of it altogether (the only think it adds to the statement is a chance to deny the whole statement) I am convinced that deniers would look worse.

    Instead of the science community looking bad because, well, most people actually DO understand the implications of the word “significant.”

  2. Raymond Horstman Says:

    Climate change is real and facts has to be accepted.

  3. Bob Brand Says:


    The word “significant” here is meant to communicate that a major portion (probably 100% or even more) of recent climate change is caused by the anthropogenic increase in greenhouse gases.

    If that word would not be there, the statement: “The fact that CO2 has an influence on climate is indisputable”, could be interpreted by deniers as:

    — well, yes, ‘an influence’ but that might be just +0.01 °C or so?

    — this ‘influence’ may well be vastly surpassed by internal variability or natural causes, in either a warming or cooling direction?

    The word “significant” here is a statement about what ‘IS’, in Humean terms. It may indeed have implications about what we ‘OUGHT’ to do, but that would also involve moral and ethical judgment which is not necessarily implied in the statement you quoted.

  4. jchilds Says:

    This makes sense. I am not a scientist, and I am reading this statement from a scientist, and I am saying what the lay public is saying: “what the heck does he mean ‘significant’ is a fact?”

    Here’s a factual statement: “CO2 affects climate.” There. It’s a fact without anything added. I’m a lay public member: “Damn. That is a fact. From a scientist. Okay.” And then it’s up to me to provide the significance.

    I’m pointing out why it is that communication of climate science is proving so difficult: because the climate community is shooting itself in the foot by: (1) saying what they want to say instead what the public should hear; and (2) saying what the believers already believe.

    The climate community is NOT talking to the masses, in terms the masses understand, and in ways that the masses will accept it. I’ve brought this up for over a decade now, and the standard response is, “If they choose to be ignorant that’s their problem.”

    I disagree. It’s my problem..

  5. Bob Brand Says:


    First of all, please note that the sentence: “The fact that CO2 has a significant influence on climate is indisputable”, is a direct quote from prof. Hans von Storch in the above mentioned documentary. Bart is only quoting literally what von Storch says in the film.

    At the bottom of hs piece, Bart summarizes his own conclusions as follows:

    Likewise, in a public debate about climate policies there’s no point in discussing whether CO2 really contributes substantially to climate change: we know that by now, based on scientific evidence.

    I would agree that the word “substantially” is better chosen and less prone to a different interpretation.

    The reason Von Storch used the word “significant” is indeed because he is a scientist. He is very much used to thinking in statistical terms (he is a true expert in that field), where ‘significant’ means that alternative hypotheses can be rejected with a high degree of probability.

    I am certain that Von Storch does NOT mean that this has (necessarily) “significance” for politics or for what we ‘OUGHT’ to do. Why? Because Von Storch is well known for his somewhat cynical stance that emissions reduction doesn’t have much of a chance to be feasible (for social and economic reasons). To put it a bit simplistically: Von Storch is mostly an ‘abstainer’ from policy and politics.

    The word ‘significant’ here is meant in a statistical sense. In that context it SHOULD be there to prevent the deniers’ response which i already mentioned.

    But I do agree ‘substantial’ is a better choice of words. 😀

  6. Tom Fuller Says:

    Hmm. Piers is as crazy as his brother Jeremy.

    Hans von Storch is a reputable scientist who came up with the same percentage for the consensus on climate change as you did. 66% And he did it much earlier.

    Freeman Dyson may be the second smartest person on the planet. That doesn’t mean he’s automatically right. It does mean that you should pay attention to him and not dismiss him because he disagrees with you, Bart.

    There’s also the slight detail that Dyson worked for 15 years in climate science, which doesn’t mean he’s automatically right. It does mean that you should pay attention to him and not dismiss him because he disagrees with you, Bart.

    It is entirely legitimate to come to different conclusions than Dyson with regards to climate change. He says that himself, so no surprise there.

    But if the two of you have different evaluations of the efficacy of climate models and you ask me to pick whose opinion I would favor, it would be Dyson every time.

  7. Bart Verheggen Says:


    I don’t dismiss Dyson because he disagrees with me. I disagree with him because I find his arguments wanting, as explained in the blogpost.

    The question is not whether you believe Dyson or me. The question should be who has the better arguments in a particular instance. Just believing someone because of their title or how intelligent you perceive them to be isn’t always a smart move I think, esp if someone talks outside of their area of expertise. (I dont think Dyson has worked for 15 years in climate science, but perhaps you can show me wrong?) If it’s too tricky to evaluate the arguments on their merits it would still be wiser to place your bets with the relevant scientific community than with some individual, no matter how intelligent. Plus, there are of course other hints you can use to check the credibility of an argument (e.g. https://ourchangingclimate.wordpress.com/2009/02/08/who-to-believe/).

  8. Tom Fuller Says:

    Hiya Bart,

    I went around on this with Tobis a couple of years ago–he said pretty much exactly what you said.

    “Around 1979, Dyson worked with the Institute for Energy Analysis on climate studies. This group, under the direction of Alvin Weinberg, pioneered multidisciplinary climate studies, including a strong biology group. Also during the 1970s, he worked on climate studies conducted by the JASON defense advisory group.[22]
    Dyson retired from the Institute for Advanced Study in 1994.” (Wikipedia).

    I disagree with you about the efficacy of models. I think they have done a fantastic job at what they were originally designed to do–to track the broad sweep of climatic changes and identify and quantify the major forces that impact those changes. There should be a Nobel in there for some people–maybe after Dyson finally gets his…

    What they were not designed to do, what the modelers said they were not designed to do, what the IPCC says they do not in fact do, is predict future climates. They do not resolve to a regional level. They do not adequately distinguish at a decadal level between natural variability and anthropogenic forcings.

    Dyson notes all of this and I don’t see you disagreeing. And yet they would have to solve all of those problems to be the ‘third leg of the stool’ regarding consensus claims for future climate.

    Dyson talked with Manabe about the very first climate models. What Manabe has said is that they should not be used for climate predictions, but that nobody would listen to him and they would use them for exactly that. Dyson agrees.

  9. Marco Says:

    Tom, the citation you provide from Wikipedia does not show in any way that he worked on climate for 15 years. The Institute for Advanced Studies does not equal the Institute for Energy Analysis.

    It also appears that these “climate studies” of Dyson generated one paper: https://doi.org/10.1016/0360-5442(77)90033-0
    That’s it. One. One trees sucking up CO2.

    At JASON his only encounter of climate studies would likely have been assessment of some proposals.

    That Manabe supposedly warned of the first models to be used for predictions is somewhat questionable, considering he wrote a paper in 1975 in which he did exactly that:

  10. Tom Fuller Says:

    Marco, you do read things outside of Wikipedia, don’t you?

    “Dyson: I think the difference between me and most of the experts is that I think I have a much wider view of the whole subject. I was involved in climate studies seriously about 30 years ago. That’s how I got interested. There was an outfit called the Institute for Energy Analysis at Oak Ridge. I visited Oak Ridge many times, and worked with those people, and I thought they were excellent. And the beauty of it was that it was multi-disciplinary. There were experts not just on hydrodynamics of the atmosphere, which of course is important, but also experts on vegetation, on soil, on trees, and so it was sort of half biological and half physics. And I felt that was a very good balance.

    And there you got a very strong feeling for how uncertain the whole business is, that the five reservoirs of carbon all are in close contact — the atmosphere, the upper level of the ocean, the land vegetation, the topsoil, and the fossil fuels. They are all about equal in size. They all interact with each other strongly. So you can’t understand any of them unless you understand all of them. Essentially that was the conclusion. It’s a problem of very complicated ecology, and to isolate the atmosphere and the ocean just as a hydrodynamics problem makes no sense.

    Thirty years ago, there was a sort of a political split between the Oak Ridge community, which included biology, and people who were doing these fluid dynamics models, which don’t include biology. They got the lion’s share of money and attention. And since then, this group of pure modeling experts has become dominant.

    I got out of the field then. I didn’t like the way it was going. It left me with a bad taste.”

    As for Manabe, “Syukuro Manabe, right here in Princeton, was the first person who did climate models with enhanced carbon dioxide and they were excellent models. And he used to say very firmly that these models are very good tools for understanding climate, but they are not good tools for predicting climate.”

  11. Marco Says:

    Yes, Tom, I do. You apparently didn’t, because your 15 years-claim comes from a simple 1994-1979 calculation, two dates mentioned on Wikipedia, which mixes up two institutes.
    And again, Dyson’s supposed “climate studies” amounted, from what I could find, to one single paper. That strongly contradicts he did climate studies for 15 years.

    And why do you keep so strongly to what Dyson *claims* Manabe said, while ignoring a paper *Manabe* wrote, in which he predicted future climate?

  12. Tom Fuller Says:

    I guess you would feel comfortable in calling the following a prediction from Manabe:

    “An attempt is made to estimate the temperature changes resulting from doubling the present CO2 concentration by the use of a simplified three-dimensional general circulation model. This model contains the following simplications: a limited computational domain, an idealized topography, no beat transport by ocean currents, and fixed cloudiness. Despite these limitations, the results from this computation yield some indication of how the increase of CO2 concentration may affect the distribution of temperature in the atmosphere. It is shown that the CO2 increase raises the temperature of the model troposphere, whereas it lowers that of the model stratosphere. The tropospheric warming is somewhat larger than that expected from a radiative-convective equilibrium model. In particular, the increase of surface temperature in higher latitudes is magnified due to the recession of the snow boundary and the thermal stability of the lower troposphere which limits convective beating to the lowest layer. It is also shown that the doubling of carbon dioxide significantly increases the intensity of the hydrologic cycle of the model.”

    I would not.

  13. Tom Fuller Says:

    You, like many of the consensus, seem to confuse or at least conflate ‘science’ with ‘academic publication.’ I make many mistakes, but not that one.

    Your method of evaluating scientists would have Michael Mann a greater scientist than Albert Einstein. I make many mistakes, but not that one.

    The goal of science is not published papers. It is greater understanding. Freeman Dyson has contributed more to that, in my honest opinion, than almost all scientists.

    Your somewhat desperate attempt to disqualify him from consideration on climate issues says more about you and your consensus than anything else.

    Is your consensus so weak that you have to exclude one of the greatest minds of the century for lack of a required number publications?

    How frightened you appear of the weakness of your consensus that you must do such a weak and puerile thing.

  14. Marco Says:

    Yes, Tom, I would call that Manabe using a climate model to make a prediction about the future. And yes, he uses the appropriate careful language that you can also find in the IPCC reports (that, however, talk about projections, for good reasons).

    And no, Tom, I do not make the mistake of just counting publications. However, that one single publication of Dyson shows that him dabbling in climate science was likely not a very long-term process, and certainly not the 15 year that you made it. None of the ‘evidence’ you provided for that 15 years came close to that form of evidence. Why can you not simply admit that you have *no* evidence for your claim that Dyson worked for 15 years on climate science? The interview that Wikipedia uses as reference to Dyson working on climate science makes it clear that he quickly left the topic again.

    And yes, I exclude one of the greatest minds of the century when he, in various interviews, says stuff that is either just plain contrarianism, or just plain wrong.

    Your good friend Michael Tobis already had Dyson pegged ten years ago:

    It is quite telling of the weakness of your luckwarmerism that you decide to put your faith on one scientist.

  15. Hugh Abercrombie Says:

    You obviously know nothing about Henry’s Law to spout such nonsense about how CO2 in the oceans should be going down as CO2 in the atmosphere goes up. Marijn Poels is to be commended for questioning groupthink without preaching. As he himself says, it is the duty of every citizen in a democracy to question dogma and consensus, to try and understand rather than believe. Bravo Marijn for taking the red pill and exposing the hubris and contempt of the climate justice warriors for even questioning their version of the truth.

  16. Marco Says:

    “You obviously know nothing about Henry’s Law to spout such nonsense about how CO2 in the oceans should be going down as CO2 in the atmosphere goes up. ”

    Care to tell us how you are getting Henry’s Law to work with the atmospheric CO2 concentration increasing due to ocean outgassing (Piers Corbyn’s claim), and at the same have ocean CO2 concentration increasing, too?


    I saw this documentary only this week and looked for reviews, finding yours. As so often not a bad idea to judge by the counter arguments. Have to say, yours are seriously wanting.

  18. Mark Says:

    The Khalil paper you linked to says that termites emit around 2e15g/yr of CO2 – which is much greater than human activity. So why do you conclude that Corbyn’s assertion is wrong?

  19. Marco Says:

    Mark, annual anthropogenic emissions of CO2 are around 40 gigatons per year. A gigaton is 1e15 g, so anthropogenic emissions are actually a factor 20 larger than the number you mention.

  20. Mark Says:

    Thanks Marco, you are right. I managed to get the full text and the authors do mention that termite emission is about 25-50% of man made emission, I suppose part of the discrepancy is that man made production was lower in 1990. Were termites included in the IPCC models?
    There is a 1982 paper by Zimmerman that puts the termite emission at up to 5e16g/yr but I presume that is no longer trusted? Factors of 10 like that are worrying.
    Do you happen to know what the total contribution is from all animals and if similarly significant how they are included in the PICC models?

  21. Marco Says:

    Mark, part of the discrepancy will indeed be that anthropogenic emissions were (substantially) lower in 1990. The Zimmerman et al paper was an old estimate solely based on some lab measurements on certain termites and subsequent extrapolations to the estimated worldwide termite population, so there should be no surprise that there are newer estimates that substantially differ (see e.g. https://agupubs.onlinelibrary.wiley.com/doi/10.1029/96GB01893 – with substantially lower values, lower even than Khalil et al). Knowledge progresses.

    Regarding the “IPCC models”: these do not exist. There are models discussed by the IPCC, but the IPCC does not have any models of its own.

    And yes, the models do include “termites”, in the sense that they are part of the natural carbon cycle. Not sure how well the potential positive feedback is included (warming increases their range, and we’re killing off many of their predators quite efficiently…).

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