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Climate change makes heat waves, storms and droughts worse–Say weather attribution models

January 10, 2023

By Paul Homewood

This new report is making the rounds:



Climate change is causing the weather around the world to get more extreme, and scientists are increasingly able to pinpoint exactly how the weather is changing as the Earth heats up.

A sweeping new report by top climate scientists and meteorologists describes how climate change drove unprecedented heat waves, floods and droughts in recent years. The annual report from the American Meteorological Society (AMS) compiles the leading science about the role of climate change in extreme weather.

"It’s a reminder that the risk of extreme events is growing, and they’re affecting every corner of the world," says Sarah Kapnick, the chief scientist at the National Oceanographic and Atmospheric Administration (NOAA).

The Earth is already about 2 degrees Fahrenheit hotter than it was in the late 1800s, and scientists warn that humans must cut greenhouse gas emissions in half this decade to avoid catastrophic warming later this century.

One way to understand and predict the effects of a hotter Earth is to look for the fingerprints of climate change on extreme weather events such as floods, heat waves and droughts. The last decade has seen huge leaps forward for the field known as extreme-event attribution science, which uses statistics and climate models to detect global warming’s impact on weather disasters. The extreme drought in California and Nevada in 2021, for example, was six times more likely because of climate change.

One of the big takeaways from the new report is that heat waves that used to be virtually impossible are increasingly likely.

"Extreme heat events are more extreme than ever," says Stephanie Herring, one of the authors of the report and a scientist at NOAA. "Research is showing they’re likely to become the new normal in the not so distant future."


Note that their so-called evidence is climate attribution modelling, which by definition is not evidence at all. Ross McKittrick, Professor of Economics, produced a paper in 2021 which destroyed the credibility of attribution modelling because of fundamental statistical flaws in the modelling.

One day after the IPCC released the AR6 I published a paper in Climate Dynamics showing that their “Optimal Fingerprinting” methodology on which they have long relied for attributing climate change to greenhouse gases is seriously flawed and its results are unreliable and largely meaningless. Some of the errors would be obvious to anyone trained in regression analysis, and the fact that they went unnoticed for 20 years despite the method being so heavily used does not reflect well on climatology as an empirical discipline.

My paper is a critique of “Checking for model consistency in optimal fingerprinting” by Myles Allen and Simon Tett, which was published in Climate Dynamics in 1999 and to which I refer as AT99. Their attribution methodology was instantly embraced and promoted by the IPCC in the 2001 Third Assessment Report (coincident with their embrace and promotion of the Mann hockey stick). The IPCC promotion continues today: see AR6 Section 3.2.1. It has been used in dozens and possibly hundreds of studies over the years. Wherever you begin in the Optimal Fingerprinting literature (example), all paths lead back to AT99, often via Allen and Stott (2003). So its errors and deficiencies matter acutely.

Other scientific experts have been less reticent in their criticism. Professor Roger Pielke Jr for instance:

And Obama’s Climate Scientist, Steve Koonin, has commented:


It is significant that in this latest paper there is no attempt to use real world data to prove that the events they talk of are actually getting worse. We know, for instance, that the data on hurricanes shows that they are not, a fact which is even acknowledged by official bodies such as NOAA.

Weather attribution has been politicised since its early beginnings, and is undertaken for the express purpose of linking extreme weather to climate change. It should not be confused with real science.

  1. liardetg permalink
    January 10, 2023 5:20 pm

    How was it during the Medieval Warm Period? Must have been awful. And during the 30 year cooling 1940 -70 did we see a diminution of these terrible events? I don’t think 2 degs F in
    a hundred years could affect anything in the real world. Like going downstairs in one’s house.

    • John Hultquist permalink
      January 10, 2023 5:30 pm

      I posted the following on Pierre’s No Tricks Zone:
      On a day when the air is still, say you were at the top of the Eiffel Tower and came back to the ground. The Eiffel Tower is 330 metres (1,083 ft) tall.
      The lapse rate of nonrising air—commonly referred to as the normal, or environmental, lapse rate averages about 6.5C ° per kilometre (18.8 F ° per mile). Thus, coming down —
      In Celsius degrees you would measure about 2 degrees warmer.
      In Fahrenheit degrees that would be 3.6 degrees.
      I’ll guess I would notice this, but maybe not if with an enjoyable group.

      Now say you were teleported to the year 2050.
      At a rate of change of 0.13C° per decade, the change will be
      less than .4 C° or .7 F°.
      Whether warmer or cooler, I wouldn’t notice.

      • Cheshire Red permalink
        January 10, 2023 6:40 pm

        For goodness sake John.

        Apparently ‘our planet is on fire’, or something. What good is all this logic, rationalising of the evidence and applying context to show there’s not much happening?

        You’re supposed to glue yourself to a motorway and panic, man!

  2. ThinkingScientist permalink
    January 10, 2023 5:30 pm

    Koonin makes the point in his book Unsettled that attribution studies are basically crap and not science. I agree.

  3. GeoffB permalink
    January 10, 2023 5:37 pm

    From Grantham Institute weekly news round up…..
    “WIRED UK takes a look behind the scenes at World Weather Attribution, an initiative founded by the Grantham Institute’s Dr Fredi Otto, which ties disasters and extreme conditions to climate change—providing crucial leverage for legal and policy battles.”
    It is Bayesian statistics, it is a long time since I did the theory, so its back to school for me. I do get the impression that the climate change academics are running out of ideas to scare us. While Europe was hot hot last year, according to Met office and BBC. The UAH satellite record is not mentioned, December 2022 shows only +0.05C.

    • catweazle666 permalink
      January 10, 2023 7:52 pm

      “It is Bayesian statistics”

      AKA wild-assed guesses AKA Making Stuff Up.

    • dennisambler permalink
      January 11, 2023 11:32 am

      Dr Fredi Otto is a product of the Potsdam Institute for Climate Scares, from when Schellnhuber was in charge. She has also been Director of the Oxford Environmental Change Institute, where Professor Myles Allen has been playing around with this modelling for years. He was Lead Author on IPCC AR5, WG1, Chapter 10: “Detection and Attribution of Climate Change: from Global to Regional”.

      In a BBC interview in 2003 he said:
      “The vast numbers affected by the effects of climate change, such as flooding, drought and forest fires, mean that potentially people, organisations and even countries could be seeking compensation for the damage caused. “It’s not a question we could stand up and survive in a court of law at the moment, but it’s the sort of question we should be working towards scientifically,” Myles Allen, a physicist at Oxford University, UK, told the BBC World Service’s Discovery programme.”

      “Some of it might be down to things you’d have trouble suing – like the Sun – so you obviously need to work how particularly human influence has contributed to the overall change in risk,” the scientist, who has worked with the UN’s Intergovernmental Panel on Climate Change (IPCC), said.” “But once you’ve done that, then we as scientists can essentially hand the problem over to the lawyers, for them to assess whether the change in risk is enough for the courts to decide that a settlement could be made.”
      The World Weather Attribution (WWA) initiative, a collaboration between climate scientists at Imperial College London in the UK, KNMI in the Netherlands, IPSL/LSCE in France, Princeton University and NCAR in the US, ETH Zurich in Switzerland, IIT Delhi in India and climate impact specialists at the Red Cross / Red Crescent Climate Centre (RCCC) around the world, has been founded to…. provide robust assessments on the role of climate change in the aftermath of the event.

      The initiative is led by Drs Friederike Otto at Imperial College, and Sjoukje Philip and Sarah Kew at KNMI.

       Red Cross / Red Crescent Climate Centre: Yolanda Kakabadse is the chair of the Climate Centre’s board. Ms Kakabadse was president of the WWF International from 2010 to 2017.

    • Phoenix44 permalink
      January 11, 2023 11:34 am

      Bayesian statistics are behind a lot of worthless nonsense that ahs caused a great deal of damage. I’ve just Sir Mervyn King’s new book which is mainly about how Bayesian methodologies have taken over both economics and finance and produced nothing but harm. I have a great mistrust of Bayesian methods as they seem to conjure probabilities out of thin air. Weirdly during Covid I saw Bayesians using their magic to produce estimates of the rate of false positives when the calculation of false positive rates is simple – but you do need to know the true positive rate. But you couldn’t know that without knowing it!

      • catweazle666 permalink
        January 11, 2023 6:51 pm

        Bayesian statistics is closely allied to that other specious statistical contrick the “Linear No Threshold” model.

  4. alexei permalink
    January 10, 2023 5:44 pm

    Oh yes, NPR via the BBC World Service were blasting this through the airwaves yesterday feeding the faithful with their daily diet of climate fear. Indeed, NPR seems to manage to insert into every one of their programmes now some reference to climate as a staple requirement. However, I think their general audience must be shrinking, as their appeals for more funding (which clearly haven’t reached Gates’ ears) have quadrupled in recent months.

  5. Tim Spence permalink
    January 10, 2023 6:01 pm

    When “Report Confirms” … BS Sirens ring out in unison.

    “A report due out next week will confirm all Arctic sea ice likely to disappear by 2013” …. (Al Gore)

    • Phoenix44 permalink
      January 11, 2023 11:35 am

      It’s when they use “top scientists” that I know its nonsense. What’s a top scientist? Someone whose evidence-based conclusion are righter?

  6. lordelate permalink
    January 10, 2023 6:08 pm

    What I would like to know is what happens after the WEF et all have destroyed capitalism and modern society?

    • Aaron Halliwell permalink
      January 10, 2023 6:29 pm

      They all studied at the Pol Pot University so they must know!

      • lordelate permalink
        January 10, 2023 7:52 pm

        Ah so!

  7. MrGrimNasty permalink
    January 10, 2023 6:31 pm

    I’ve posted this before, the email hack that exposed how the Obama administration fostered this attribution rubbish.

    “It also proposed the creation of an “extreme weather SWAT team” that would immediately seize on natural disasters and other extreme weather events to advance a political and communications agenda.”

    “One cannot be handcuffed by data on a fundamental moral issue of this kind.”

    • January 11, 2023 1:52 pm

      For ‘moral’ you could easily – and more truthfully – use ‘religious’.

  8. Ben Vorlich permalink
    January 10, 2023 6:31 pm

    I have a model that predicts success in the English Premier League with the wealth of the club owners.

  9. magesox permalink
    January 10, 2023 6:31 pm

    You don’t need to be an eminent professor to work out that the attribution stuff is all utter rubbish. Apart from the bleedin’ obvious point that weather events are not climate, to make an attribution, you’d need perfect global data (including, especially, CO2 concentrations and detailed weather events) over a couple of cycles – eg 150 years. We didn’t have anything remotely approaching this until the satellite era – starting (but not complete) in 1979.
    So, the attribution studies are no more than fairy tales.

  10. Mike Dyer permalink
    January 10, 2023 6:41 pm

    Also interesting that they have reverted to using Fahrenheit, presumably because two sounds more than one and because the majority of people can’t do the conversion in their heads.

  11. Cheshire Red permalink
    January 10, 2023 6:49 pm

    Look how the headline finishes with ‘….climate report confirms’.

    In reality it did no such thing. Extreme (or just non-benign) weather events were attributed to ‘climate change’ by a computer model which was designed to get a particular desired outcome.

    The ‘report’ didn’t *confirm* anything at all. This is how media project their lies.

  12. It doesn't add up... permalink
    January 10, 2023 7:25 pm

    This looks to me like an unsubstantiated claim that is being used to justify climate policy:

    This is the key data they present, which aside from an anomalously low reading for 2019, shows no apparent trend in the size of the hole that I can detect.

    In fact it is a long running scandal that the Montreal Protocol failed to have the effect that is was proclaimed to be able to create.

  13. Broadlands permalink
    January 10, 2023 7:28 pm

    “The Earth is already about 2 degrees Fahrenheit hotter than it was in the late 1800s, and scientists warn that humans must cut greenhouse gas emissions in half this decade to avoid catastrophic warming later this century.”

    But only about one degree Celsius. “hotter”. And, cutting CO2 emissions will take no CO2 out of the atmosphere to lower the “heat”. But it will create shortages and higher prices for the energy needed for transportation, a future much more economically damaging than any model predicted warming could do.

    • Joe Public permalink
      January 10, 2023 10:10 pm

      Who in their right mind would describe water running from a tap at 15.5℃ rather than at 14.5℃, as being “hotter”?

      • Broadlands permalink
        January 11, 2023 12:41 am

        Joe..who in their right mind? That’s a job for the psychiatry industry that tries to deal with those who have what is now called climate change anxiety.

      • Phoenix44 permalink
        January 11, 2023 11:40 am

        It’s not even that. It’s a tap that used to run at between 10 and 20 degrees and now still runs at between 10 and 20 degrees but tends to run at very slightly closer to 20 and for very slightly longer than it used to.

    • January 11, 2023 1:57 pm

      And we can all easily tell when a day is 2F warmer or cooler can’t we? Hey, it’s going to be 72F today not 70F – break out the shorts and t-shirt!

  14. frankobaysio permalink
    January 10, 2023 9:59 pm

    A question that I have not seen answered is; If our “Leaders” honestly believe that they must remove all emissions of CO2 by 2050 as they have recently said, and that this actually controls the World Climate, how do they know it will not “reverse or restore” (as they often say), the weather to a previous dangerously cold climate? ie: the Winters of 1963 and 1982. They could even start a reverse “Tipping Point”….

  15. Stuart Hamish permalink
    January 10, 2023 10:01 pm

    ” Rapid attribution analysis ” reminds me of Soviet NKVD boss Laventry Berias maxim : ” Show me the man and I will find the crime “

    • Stuart Hamish permalink
      January 11, 2023 1:30 am

      Show me the weather extreme and ‘rapid attribution analysis ” will find the clime

    • It doesn't add up... permalink
      January 11, 2023 10:18 am

      It seems no accident that the name is pronounced burier. How many did he bury?

      • Stuart Hamish permalink
        January 18, 2023 3:37 am

        “Show me the Mann and he will find the clime “

  16. Gamecock permalink
    January 10, 2023 10:14 pm

    ‘The extreme drought in California and Nevada in 2021, for example, was six times more likely because of climate change.’

    Logic failure. ‘More likely’ is not a cause. ‘More likely’ is not a force.

    And, of course, ‘six times’ was pulled from someone’s heinie, anyway.

    • Phoenix44 permalink
      January 11, 2023 11:42 am

      I really don’t know what it is supposed to mean?

      It happened so it was 100% likely. Would it have happened without climate change? We can’t possibly know but it was possible, not impossible. So what is six times more likely supposed to mean?

      • Gamecock permalink
        January 11, 2023 5:49 pm

        It is an absurdity, but it is surely meant to get the reader to believe it was caused by climate change, else they wouldn’t be saying stuff like this.

        It’s their way of saying, “It was caused by climate change,” but without saying, “It was caused by climate change.”

  17. Kathy Marquard permalink
    January 10, 2023 10:23 pm

    because they want to call those who have the sense to disagree with them climate denialists, maybe they need a name too: climate cultists or climate occultists?

  18. cookers52 permalink
    January 11, 2023 10:30 am

    What is “real science”?

    • January 11, 2023 2:00 pm

      Where you don’t start with your conclusion and then work backwards to manufacture the proof.

    • MrGrimNasty permalink
      January 11, 2023 5:07 pm

      Well it’s not a theory that is confirmed by every eventuality and falsifiable by none!

  19. Phoenix44 permalink
    January 11, 2023 11:44 am

    It’s quite amazing that literally every significant weather event is made more likely by climate change. Yet the frequency of such events isn’t increasing.

    Either the models or the data are wrong.

    • Gamecock permalink
      January 15, 2023 12:02 pm

      Or the reality: climate change doesn’t exist.

      Final answer.

  20. January 11, 2023 2:36 pm

    The issue is not attribution models and the fact they have indeed been shown to be worthless to science, but clearly of value to charlatans. The issue is WHY do the products of models get media coverage but empirical data covering the same issues not? That alone should tell anyone and everyone with more than three active braincells that something is rotten in the House of Klymutt.

    It is one thing for the corrupt media to be promoting this rubbish but modeling is the stock in trade of the climate circus. Why? Well simply because unlike real data the modeller controls input which oh what a surprise controls output. Smelly brown stuff in… get the picture what comes out as product.

    I think I am correct when I say across what used to be called credible science, modelling at most contributes no more than 20% of work, empirical data based research forming the rest. The climate circus surprise surprise is diametrically opposed using at least 80% modelled output with real data only showing it’s self when it gives the right answer.

    Worst of all it is clear this attribution modeller never heard of the laws of thermodynamics which are supported by actual data which indicate they have been decreasing. Energy in the weather system is created by the difference between high and low temperature NOT maximum temperature which the average activist humanities graduate thinks is the case.

    Here is one more piece of evidence of the dangerous undermining of the Enlightenment where science lives and dies on statistically significant empirical data. Has no one told these numpties that the product of models are not empirical data but measures of statistical probability based on the input but you would never think that from reading this twaddle which makes the Beano look more and more factual every day.

  21. catweazle666 permalink
    January 11, 2023 8:41 pm

    “The data doesn’t matter. We’re not basing our recommendations on the data. We’re basing them on the climate models.”

    ~ Prof. Chris Folland ~ (Hadley Centre for Climate Prediction and Research)

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