Have climate models outlived their usefulness? – Net Zero Watch

Posted: June 11, 2022 by oldbrew in climate, data, modelling, opinion, predictions, Temperature
Tags:


Is more computing power just getting us the wrong results from overheated models faster?
– – –
Outside of their academic fascination, looked at in terms of their contribution to climate policy, it seems that we may have reached the useful limit of computer climate modelling, says Dr. David Whitehouse.

The first computers built in the 1950s allowed climate scientists to think about modelling the climate using this new technology.

The first usable computer climate models were developed in the mid-1970s.

Shortly afterwards the US National Academy of Sciences used their outcomes to estimate a crucial climate parameter we still calculate today – the Equilibrium Climate Sensitivity (ECS) – how much the world would warm (from ‘pre-industrial’ levels) with a doubling of CO2 — and concluded that it had a range of 1.5 – 4.5°C.

Since then computer power has increased by a factor of more than a quadrillion yet, one could argue, climate models have not much improved on that original estimate. Their range of projections has not narrowed significantly, and consequently the contribution they make to climate policy hasn’t improved concomitantly.

From the time of the IPCC’s AR1 (1990) all the way to AR4 (2007) it was 2.0 – 4.5°C. AR5 (2015) changed it only slightly to 1.9 – 4.5°C. Significantly, the most recent IPCC assessment, AR6 (2021), took a step back partially decoupling computer models and model predictions, replacing them with “expert judgement” of ECS that gave more emphasis on other sources of information.

AR6 did not consider all climate models to be equal and weighted them according to their hindcast abilities. Subsequently AR6 narrowed the ECS range to 2.5 – 4.0°C. This can hardly been regarded as real improvement.

At the time climate scientists were looking forward to new rounds of computer modelling, particularly the so-called Coupled Model Intercomparison Project (CMIP6) effort to reduce the ECS uncertainty. But it was clear very early on that the opposite was happening, uncertainty was actually increasing.

CMIP6 eventually concluded that ECS was 2.0 – 5.5°C. The fact that CMIP6 has too many climate models running too hot is telling us something important. The model democracy of the past, which we at the GWPF and others were criticised for pointing out, was indeed wrong.

In summary, not many climate models concurred with reality leading to suggestions that only those that did should be considered useful. Instead many studies encompassed all the models, including the ones that did not reproduce observations, and used the median of them all, and their spread, as a way to predict future climate change.

It was always an inconvenience that nature was not following the median of the models, and an irritation that “sceptics” pointed out that it was unscientific not to discard models that did not fit real-world data.

Full article here.

Comments
  1. […] Have climate models outlived their usefulness? – Net Zero Watch […]

  2. craigm350 says:

    Reblogged this on WeatherAction News and commented:
    As Hubert Lamb observed in 1994

    “there has been too much theory and not enough fact in predicting the future.

    Computer models are a rather expensive example of that error.

  3. Bloke down the pub says:

    ‘AR6 did not consider all climate models to be equal and weighted them according to their hindcast abilities.’
    Hasn’t anyone told the IPCC that past performance is no guarantee of future results?

  4. ivan says:

    Boys with their toys, they always want bigger and better but don’t realise they will never be able to model the future.

    It might help if they realised they can never model an analog system, such as the climate, with a digital computer but they must look good playing with their toys. Maybe if they kept the results behind closed doors of academia and didn’t try to impose the results on the people of the world they wouldn’t have so much egg on their faces when they are shown to be wrong every time.

  5. catweazle666 says:

    Climate models never had any usefulness to outlive.

    Computer games – er sorry – models based on physical processes such as radiative physics, thermodynamics and Navier-Stokes equations are not capable of predicting future climate.

    “In sum, a strategy must recognise what is possible. In climate research and modelling, we should recognise that we are dealing with a coupled non-linear chaotic system, and therefore that the long-term prediction of future climate states is not possible.”

    IPCC Working Group I: The Scientific Basis, Third Assessment Report (TAR), Chapter 14 (final para., 14.2.2.2), p774.</b?

    Anyone who claims that a purported computer game – oops – climate simulation of an effectively infinitely large open-ended non-linear feedback-driven (where we don’t know all the feedbacks, and even the ones we do know, we are unsure of the signs of some critical ones) chaotic system – hence subject to inter alia extreme sensitivity to initial conditions, strange attractors and bifurcation – is capable of making meaningful predictions over any significant time period is either a charlatan or a computer salesman.

    Ironically, the first person to point this out was Edward Lorenz – a climate scientist.

    Lorenz’s early insights marked the beginning of a new field of study that impacted not just the field of mathematics but virtually every branch of science–biological, physical and social. In meteorology, it led to the conclusion that it may be fundamentally impossible to predict weather beyond two or three weeks with a reasonable degree of accuracy.

    Some scientists have since asserted that the 20th century will be remembered for three scientific revolutions–relativity, quantum mechanics and chaos.

  6. Kip Hansen says:

    It is worse than this: “Instead many studies encompassed all the models, including the ones that did not reproduce observations, and used the median of them all, and their spread, as a way to predict future climate change. ”

    They take a median (or mean) only AFTER the model runs that have soared off into impossibly hot states or plummeted to impossibly cold states have been removed from the mix. And there are a lot of them. The failure to acknowledge this makes their results seem more sciencey.

  7. oldbrew says:

    ‘how much the world would warm (from ‘pre-industrial’ levels) with a doubling of CO2’ is a loaded question. Too many built-in assumptions.

  8. Phoenix44 says:

    They still cling to the absurd belief that ECS can be an emergent property of their models. But to assume there is an ECS is to build that in to the model and thus to prevent ECS being a true emergent property.

    For the models to work properly, they need to know ECS.

    To calculate ECS, they need models that work properly.

    THey cannot square the circle, no matter what they do

  9. stpaulchuck says:

    It is a computer truism that a stochastic output system is pretty much impossible to predict its future state.

    Then there the data diddling constantly going on that makes any prediction impossible – GIGO.

  10. oldbrew says:

    ‘The model democracy’ — giving mediocrity and failure equal status with everything else.

  11. Saighdear says:

    In a word, all, the answer is YESsssss!
    In this modern world, in general, people no longer “play” – can’t play, don’t know how to play. So if they don’t know HOW to play ( with models) they won’t REALLY UNDERSTAND how the real model works. It’s the “simple physics” of linking theory with the practical elements.
    I ‘ve been away travelling at work and recent storms form that ex tropical storm off the W Coast, SCotland, simply went to show the vagaries of “models” – THe Hills and Glens of Glencoe, Lochaber, and Wr Ross SHOW how for instance RAINFALL can vary so much within an hour and a mile along the road. Never before had I seen ( and been able to see since removal of trees from the roadside to afford a better view of our Hillsides) the WHite frothing drainage off the hillsides. In the morning, the rivers were in spate. AS the day progressed , the wind got up to stormy with some fallen full-leaf trees and SLEET at low levels some small hail, maybe, – hurt on the face. but the River levels FELL, the Loch levels fell (- probably opened sluices for power generation), and yet we had heavy rain. Mile along the road ….Wet, yes, High water? NO …. Extreme weather? at micro level maybe – as in spilling my flask of coffee over the tractor’s floor! – and then the steam on the windows condensing and trickling down onto the notepad! … and I was working with a model.

  12. Coeur de Lion says:

    On the notrickszone website there’s an archive of papers showing little tiny ECS numbers. Who is right?

  13. oldbrew says:

    Any assertions about so-called climate sensitivity are worthless without proper understanding of clouds, which is lacking and admitted to be so.
    – – –
    Transient and Equilibrium Climate Sensitivity

    https://www.gfdl.noaa.gov/transient-and-equilibrium-climate-sensitivity/

  14. catweazle666 says:

    Recent estimates of climate sensitivity:

    It is interesting to extrapolate the TCS and ECR trends out to 2025 – 2030.

  15. Ned Nikolov, Ph.D. says:

    I wonder now many more years and $Billions do we have to waste before the “establishment” realizes that the main reason climate models fail is because they have adopted a physically wrong concept, the “Greenhouse” theory! GCMs artificially decouple atmospheric IR radiative transfer from convective/advective heat transport. Since the combined heat exchange is highly non-linear with respect to temperature, this decoupling produces a solution that is mathematically & physically wrong and leads to violation of the Energy Conservation Law, which they call a non-zero climate sensitivity to CO2! This is why current GCM-based climate projections are pure junk science.

    Watch this video to learn how the “greenhouse” theory fails on the most fundamental physical level:
    https://vimeo.com/manage/videos/602819278

  16. gbaikie says:

    It’s very easy to predict global climate.
    We are in an Ice House global climate and we remain in an Ice House global climate
    for millions of years.
    We are in Ice House global climate, because the average temperature of all the ocean is cold.
    The average temperature of ocean is about 3.5 C. And 3.5 C is cold.
    Rapid warming of Earth occurs when Earth is in glaciation period when there is a vast ice sheet covering North America and we don’t have a vast ice sheet over North America, nor likely to get one any time soon. And last time we such rapid warming was more than 10,000 years, And we have cooling since that peak Holocene period. And it is called the Holocene thermal maximum or
    Holocene Climate Optimum: “(HCO) was a warm period that occurred in the interval roughly 9,000 to 5,000 years ago BP, with a thermal maximum around 8000 years BP. It has also been known by many other names, such as Altithermal, Climatic Optimum, Holocene Megathermal, Holocene Optimum, Holocene Thermal Maximum, Hypsithermal, and Mid-Holocene Warm Period. ”
    Anyhow this we when Sahara Desert was much wetter. And we had ice free polar sea ice.
    And it been cooling since that time, and continue to cool until ice sheet again form in North America.
    For Earth’s climate to warm the ocean must get warmer than 3.5 C and to get much colder the ocean temperature must get colder than 3.5 C. And it takes a long time to warm or cool the ocean.

  17. Gamecock says:

    gbaikie, it seems you are saying a warmer earth is a better earth. If so, I agree. To wit, man made global warming, if it were real, would be GOOD!

    When scientists decided the earth was warming, we should have said, “Good!”

  18. Ned Nikolov, Ph.D. says:

    Yes, warmer is typically better for all life and this is evident from past much warmer periods in Earth’s history than the present one, when life & biodiversity flourished. Of course, climates that are too hot can cause ocean hypoxia (depletion of oxygen in oceanic water) and mass extinction. However, these events are rare and require a mean annual ocean surface temperature to exceed 41C in the tropics. These conditions have occurred for short periods several times over the past 540 My… But our current climate is light years away from such conditions, since it takes a surface atmospheric pressure of well over 3 bar to cause such a “hothouse” climate…

  19. gbaikie says:

    “gbaikie, it seems you are saying a warmer earth is a better earth. If so, I agree. To wit, man made global warming, if it were real, would be GOOD! ”

    Well, a cold earth, provides a reason to keep your clothes on- there some merit to it. But if Earth warmed by 2 C, it would still be a cold Earth.
    A warmer Earth might make the Russians, happier.
    A long, long, time ago, Russia was a lot warmer.

  20. oldbrew says:

    Missed this one last year…

    New Generation of Climate Models: Increased Snowfall Will Offset Sea Level Rise From Melting Antarctic Ice Sheet

    https://scitechdaily.com/new-generation-of-climate-models-increased-snowfall-will-offset-sea-level-rise-from-melting-antarctic-ice-sheet/amp/

  21. oldbrew says:

    Net Zero Shock: Carbon Dioxide Rises AFTER Temperature Increases, Scientists Find
    10 JUNE 2022

    Dramatic new findings from two climate science professors suggest that an increase in carbon dioxide in the atmosphere follows a rise in temperature rather than coming before it and causing it, throwing into doubt the whole of the current theory of human-driven global warming.

    The scientists propose that higher temperatures increase the natural processes of soil respiration and ocean outgassing, and hence boost natural CO2 emissions. If confirmed, the information destroys the so-called ‘settled’ science basis upon which the command-and-control Net Zero political agenda depends.

    https://dailysceptic.org/2022/06/10/net-zero-shock-carbon-dioxide-rises-after-temperature-increases-scientists-find/

  22. oldbrew says:

    Published: 20 November 2018
    Global-scale multidecadal variability missing in state-of-the-art climate models
    S. Kravtsov, C. Grimm & S. Gu

    Here we show that the discrepancies between the observed and simulated climate variability on decadal and longer timescale have a coherent structure suggestive of a pronounced Global Multidecadal Oscillation.
    . . .
    While climate models exhibit various levels of decadal climate variability and some regional similarities to observations, none of the model simulations considered match the observed signal in terms of its magnitude, spatial patterns and their sequential time development. These results highlight a substantial degree of uncertainty in our interpretation of the observed climate change using current generation of climate models.
    [bold added]

    https://www.nature.com/articles/s41612-018-0044-6
    – – –
    *State-of-the-art* models eh?

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