Why You Don’t Have To Worry About Climate Change: Multiplication Of Uncertainties

I once did a talk on this subject at Spain’s Royal Institute of Science during the first global warming panic, but I did a lousy job.

Now, at the time of our second global warming panic (the coronadoom panic waning and needing replacement), I shall try again.

Here is how The Science happens; in particular, how vast over-certainties are generated yet still become “the debate is over”. We’ll use global warming as our example, but this works for any The Science.

Let’s start with a typical The Science pronouncement: “Because of the climate crisis, coffee production in Africa will decrease, which is why our political solutions need to be put in place.”

There are hundreds, even thousands, of statements like this, provided by an army of academics and Experts. They are characterized easily: everything bad will wax because of “climate change” and everything good will wane; good coming from “climate change” is impossible; only bad can arise.

While it is logically possible that slight changes in the average weather will cause only misery, and do no good whatsoever, it is scarcely likely. Indeed, it is absurd and proves “climate change” is part superstition, part scam, part bad science. We address the last part today.

Our archetype statement has three parts: 1) the threat of “climate change”, 2) the bad event, and 3) the promise of “solutions”. We are meant to take the thing as a whole, as if the whole were as certain as the most certain part. Rather, as more certain than the most certain part. Those who demand you follow The Science intend that the string builds in certainty as more items at to it, in a kind of successive reinforcement. Just look at all those Experts who agree!

But that certainty adds is impossible. As is not possible.

All three parts of the statement have their own uncertainties attached to them. If we consider the statement as a whole, then these uncertainties must be multiplied, more or less, resulting in a whole that is vastly more uncertain than any individual part.

Anybody with any familiarity with probability will see this instantly. But for those who aren’t as familiar, consider this scenario: “This coin will come up heads, I’ll roll greater than a 3 on this die, and draw an eight of hearts from this deck.”

Never forget! All probabilities are conditional, meaning we have to supply evidence from which to calculate them. Here, I’ve chosen common evidence sets. We have to assume these for each of the three parts of this scenario. For the coin flip, we’ll use “Here is an object which when flipped can show only heads or tails”. From that we deduce the chance of heads is 1/2.

And so on for the others. We get 1/2 for the flip, 1/2 for the die roll, and 1/52 for the card draw, all assuming standard evidence. For the entire scenario to be true, we need get all three. The probabilities multiply: 1/2 x 1/2 x 1/52 = 1/208, which is about 0.005.

But if the statement could be painted as dealing with “climate change”, and not gambling, we’d be asked to consider the probability the statement is true is at least 1/2. Or even more because of all the “corroborating evidence” from different Experts. After all, 97% of gambling scientists agree.

I picked these examples because I think they’re in the same ballpark as our coffee “climate change” scenario, though the evidence sets are trickier. Let’s step through each of the parts of the scenario to see how statements like this should be tackled.

1) The threat of “climate change”. I take this to mean Expert models predicting “large” “climate change” are accurate or the climate changes on its own, for reasons (at least in part) other than encoded by Experts in their models. Given Experts have been predicting weather doom since the 1970s, first that it would be too cold, then that it would be too hot, then that it would just be too different, and they’ve been wrong every time so far, I’m not too keen on Expert models. But I also figure that the earth’s climate has been both hotter and cooler, wetter and drier, sunnier and cloudier in the past, so it can be so again.

There is no numerical value for the probability that can be deduced from this evidence. It is too vague. But that doesn’t mean it is not useful. If pressed for a number, it is not too far, in my mind based on this evidence, from 50-50.

2) The bad event. Maybe coffee production in Africa would decrease under changed weather, or maybe it wouldn’t. Saying it will decrease is the result of another model by Experts. Who haven’t done at all well with agriculture forecasts.

Again, no numerical probability can be deduced. But I’m feeling generous, so call it 50-50 again. (Really, I believe it’s less, but I don’t want to change our example.)

3) The promise of “solutions”. Expert “solutions” here would be twofold: stopping the climate from changing, and ameliorating reductions in coffee production given the climate has changed in a direction to harm production.

This one is even trickier because some of the same evidence is used in (3) and in (1); namely, that about Experts’ climate models. This makes the multiplication trick strictly wrong.

However, it’s not too far off, either, especially because Expert “solutions” for complex situations stink, stank, stunk. That one in fifty two is being generous.

The end result is I’m not worried about “climate change”, not nearly as worried as I’d be about adopting Expert “solutions”, which in my estimation would only make things worse, or much worse.

Now it may have occurred to you that any of these tripartite statements may itself be unlikely, but given there are many hundreds (or thousands) of these, and we take all of them together, isn’t it likely that one of them might be true?

Sure, yes. But so what? It’s still true that any singular one is unlikely. We can’t go for the “solutions” to protect for all because one of them might be needed. That’s pure Safety First! thinking. Beside, that there are hundreds upon hundreds of such statements points more towards “climate change” being a superstition or scam. Those hypotheses better explain the observations.

Incidentally, the peer-reviewed paper about coffee production decreasing in Africa was from 2012. “The models show a profoundly negative influence on indigenous Arabica.” Since then, Arabica coffee has only increased, year upon year. Until 2020, when the coronadoom “solutions” hit and killed economies the world over.


Came across this banger this morning, from a professor, a thread which directly confirms everything said above:


There is some +/- to this, but only about 100 billion people have ever lived. And there’s only something under 8 billion of us now, and population looking to soon decline.

Yet – trillions!

Buy my new book and learn to argue against the regime: Everything You Believe Is Wrong.

Subscribe or donate to support this site and its wholly independent host using credit card or PayPal click here; Or go to PayPal directly. For Zelle, use my email.

Categories: Statistics

22 replies »

  1. “Multiplication Of Uncertainties” — interesting concept. When you point it out it’s obvious. But it’s not at all obvious to fanatics like the professor you quote above, that Denning fellow. He’s absolutely certain. And, glancing at his twitter page, certain also about the rest of the narrative, too; racismo, sexismo, homophlebitis, colonialoscopy, etc. Interesting how when they test positive for climate fanaticism all the other fanaticisms are sure to follow. As if they have been programmed. Or demon possessed.


  3. Hagfish,

    As simple as this is, I have the impression it is still mystifying most. Or that it’s so obvious that it’s boring by this point.


    My enemies usually insert lexigraphic and not numeric typos. They are growing stronger.

  4. Their scraping of carbon from the air to tackle climate change is what is actually causing it.

  5. 1 – obviously you are correct in this.

    2 – however it seems to me that there are two larger questions arising from the expert/media concensus that all climate change is bad: why do they believe this? and, what will it take to change this?

    On a personal note: several years ago now I had lunch with some people at what was once Canada’s leading geophysics faculty (and now hosts municipal climate adaption planners in the space their ability to earn petro-grants paid for) during which I acted on an idea that came from reading one of your earlier columns to see whether or not the troposphere is expanding. (because if the earth is warming, the “weather” envelope has to expand). I found that is it not – but no one has even tried to tell me what’s wrong with my logic. Instead, it just gets ignored. I sent to to Wattsupwiththat’s contest (which published my 2013 comment on warmism as bad science but good politics – ( ) making some of the same points you do here) but was ignored. I think it proves warming is not happening – but maybe I’m wrong. See: . If you think so.. I’d sure like to hear why.

  6. –>”the rest of the narrative, too; racismo, sexismo, homophlebitis, colonialoscopy, etc. Interesting how when they test positive for climate fanaticism all the other fanaticisms are sure to follow.”

    It’s the old “Utopian, perfectibility of mankind” fanaticism–your common errors can be refashioned into correct thinking with just a little social and economic engineering. It’s fascinating (and sad) to observe that some/many have been granted god-like powers to impose change on humanity.

  7. I’ve been saying for two years the multiplication of uncertainties makes N95 masks extremely stupid. So it’s rather easy to see the people in society that are innumerate. Doctors and bureaucrats lead that list.

  8. Not sure how explanatory this nugget from perceptual psychology is, but here goes.

    One of the factors affecting understanding of the “multiplication of uncertainty” may be that multiplication itself — yes, just simple multiplication — is not a “biologically primary” cognitive skill.

    Unlike language, or the ability to recognize faces (which we might think are hugely more complex operations), multiplication does not spontaneously appear in every human being in the course of normal human interaction. Multiplication — even the idea of it — does not arise in every culture, and it is not “culturally robust” (generally speaking, it has to be taught).

    Yes, it’s probably the case that all professors have been taught to multiply numbers. The point is that this may be like first year physics students who have memorized some equations but when confronted with a physical situation, have no idea how to handle it.

    They have no ‘feel’ for it (the meaning of the equations they’ve memorized is lost on them). Similarly, the ‘idea’ of multiplication may have never penetrated far enough into one’s thinking to grasp the “multiplication of uncertainties.” After all, the casinos would lose a lot of customers if merely having memorized the times tables would provide a grasp of it.

  9. Warmth is good, totalitarianism is bad.

    Aggregation of error is a stat/math truism. What’s missing from the equation is the evil behind the curtain. It’s not a logic problem; it’s a Satan problem. There’s only one solution.

  10. William same old story in New Zealand; ‘we all doomed, if we don’t stop using fossil fuels” my simple ?
    what products are you using today, made from fossil fuels?? I have never had a reply in almost 20 years!! from Trevor William Collins..

  11. Look back to Rene Thom’s Catastrophe Theory. Basically it demonstrates you can only accurately model simple systems. Once you get into something important it’s impossible because there are too many interacting factors to contend with.

  12. I would like to demonstrate that Briggsian starring statistics does not substitute for, or render obsolete and irrelevant, 1960’s high school science. I would also like to demonstrate to my old teachers (if there are any still alive) that, contrary to their perceptions at the time, I was not fast asleep the whole time.

    Carbon dioxide (CO2) is every bit as completely transparent to radiant light and heat as any other atmospheric gas and even more so than Oxygen that gives the sky its blue colour.

    CO2 is about 1.6 times the density of dry air so it will tend to gravitate to the lower atmosphere. It will not float up to the Stratosphere and form a “blanket” trapping heat.

    CO2 levels vary diurnally and regionally because in the dark photosynthetic plants use Oxygen and release CO2 to keep their metabolism going.

    At a concentration of 300 parts per million of CO2 (supposed pre industrial level) that is 3 molecules in every 10,000 other molecules of air. If the addition of one molecule per 10,000 (up to 400 ppm, the supposed present level) can make any difference to “climate warming” it is the most powerful stuff in the whole World.

    Increased CO2 levels vastly improve plants’ photosynthetic and water use efficiency because they can get the required CO2 with smaller stomate openings thus reducing water loss by transpiration. Commercial plant growers with controlled environments have been using CO2 enriched atmospheres to vastly improve growth rates for well over 100 years.

    Increased plant growth means that more of the sunlight and CO2 is converted to organic material (the already observed “planet greening”). There’s much more to this aspect that I don’t want to go into in this little comment.

    The upshot of the whole business is that the whole CO2 scam is malicious bullsh!t perpetrated by “clever idiots” who think that “philosophy” is any stupid ideological notion completely detached from observation and reason according to the scientific rules of logic.

  13. Multiplication of uncertainties. Yes, indeed. I think it was Martin Gardner who advised casting probability problems in terms of “and”, allowing you to multiply the individual probabilities together (assuming independence of the individual probabilities, of course).

    The classic example is a gambler who bets on rolling a pair of sixes at least once in some number of rolls. The odds of getting a pair of sixes is 1/36 with one roll. It’s tempting to assume that the odds of getting a pair of sixes in two rolls is double that, or 1/18, and assuming that the odds should exceed 50% in 20 rolls. Clearly this is flawed reasoning, though, since the chance of rolling a pair of sixes in 36 rolls is not 100% – the probabilities don’t add.

    In order to roll a pair of sixes in 20 rolls, one has to roll a pair of sixes on the first roll, OR a pair of sixes on the second roll, OR a pair of sixes on the third roll, etc. The word “OR” isn’t helping us here. But the problem can be recast: in order to NOT roll a pair of sixes in 20 rolls, one must not roll a pair of sixes on the first roll, AND must not roll a pair of sixes on the second roll, AND must not roll a pair of sixes on the third roll, etc. The odds of not rolling a pair of sixes in any one roll is 35/36. So multiply 35/36 by itself 20 times, or (35/36)^20, and one finds that the chance of not rolling a pair of sixes in 20 rolls is about 56.9%, which makes the chances of rolling a pair of sixes (100% minus 56.9%), or about 43.1%. So this is not a good bet at even odds; the odds don’t exceed 50% until the 25th roll.

    (Man, I hope I didn’t screw up the math . . .)

  14. Robin – something about that article seems really fishy. To find out how much net CO2 a plant removes from the atmosphere over some period of time, it seems like all one has to do is harvest the plant, dry it out, burn it in pure O2, and measure the CO2 emitted. How could there be any new unexpected results?

    How can plants emit any net positive amount of CO2 at all? Where does it come from? Where is their source of carbon to make this CO2 they are emitting? Do plant roots tap into underground deposits of oil or something?

    What am I missing here?

  15. Good one, Robin,
    It goes to show that W’m Briggs has some practical insight apart from his number crunching expertise… to wit ANU should be blown up while all the “experts” are in a student free staff meeting to help mitigate the nonsense they feed to their gullible students and the World at large.

    Plants only release more CO2 than Oxygen in the dark, and the amount of CO2 taken in to produce organic carbohydrates and Oxygen is limited by the CO2 available, available water, mineral nutrients, and light. These p!issw!ts apparently want to decrease normal plant activity by reducing available light with reflective semi-colloidal aerosols dumped in the atmosphere to artificially produce more “years without summer” as has occurred previously by huge volcanic eruptions dumping millions of tons of semi-colloidal aerosols into the high atmosphere. Super winters with “no summers” are a terrible infliction that might be called a chastisement somewhat less than Noah’s Flood.

    Just by-the-way, all the Carbon in the monstrous amounts of coal came out of atmospheric CO2 back before the plant material was buried in anaerobic mud.

    The more we (collectively) think that we’re “as gods knowing good and evil” the more we become perversely stupid and deservedly beget all kinds of calamities.

  16. With 100% of grant money being allocated for “climate change” research, is it really surprising that 97% of scientists agree?

  17. Did you send Prof. Denning a link to your cogent commentary? According to his university webpage, he “takes special delight in engaging hostile audiences” about climate. I don’t know if that includes non-hostile critics who provide evidence that he’s a moron. But could be worth a try. Trillions.

  18. Smith,

    I used to send posts to all authors I quoted, but I never got a response from any of them, and so gave it up.

Leave a Reply

Your email address will not be published.