NEW PAPER: Why Models Run Hot: Results From An Irreducibly Simple Climate Model

NEW PAPER: Why Models Run Hot: Results From An Irreducibly Simple Climate Model

This post is one that has been restored after the hacking. All original comments were lost.

Here’s our press release. See also the Daily Mail.


A major peer-reviewed climate physics paper in the first issue of the prestigious Science Bulletin (formerly Chinese Science Bulletin), the Orient’s equivalent of Science or Nature, exposes elementary but serious errors in the billion-dollar general-circulation computer models relied on by the UN’s climate panel, the IPCC. The errors were the reason for concern about Man’s effect on the climate. Without the errors, there is no climate crisis.

The IPCC has long predicted that doubling the CO2 in the air might eventually warm the Earth by 3.3 oC. However, the new, simple model presented in the Science Bulletin predicts no more than 1 oC warming instead—and possibly much less. The model, developed over eight years, is so easy to use that a high-school math teacher or undergrad student can get credible results in minutes running it on a pocket scientific calculator.

The paper, “Why models run hot: results from an irreducibly simple climate model“, by Christopher Monckton of Brenchley, Willie Soon, David Legates and Matt Briggs, survived three rounds of tough peer review in which two of the reviewers had at first opposed the paper on the ground that it questioned the IPCC’s predictions.

When the paper’s four authors first tested the finished model’s global-warming predictions against those of the complex computer models and against observed real-world temperature change, their simple model was closer to the measured rate of global warming than all the predictions of the complex “general-circulation” models (see the picture which heads this post).

Next, the four researchers applied the model to studying why the official models concur in over-predicting global warming. In 1990, the UN’s climate panel predicted with “substantial confidence” that the world would warm at twice the rate that has been observed since.


The very greatly exaggerated predictions (orange region of the picture above) of atmospheric global warming in the IPCC’s 1990 First Assessment Report, compared with the mean anomalies (dark blue) and trend (bright blue line) of three terrestrial and two satellite monthly global mean temperature datasets since 1990.

The measured, real-world rate of global warming over the past 25 years, equivalent to less than 1.4 oC per century, is about half the IPCC’s central prediction in 1990.

The new, simple climate model helps to expose the errors in the complex models the IPCC and governments rely upon. Those errors caused the over-predictions on which concern about Man’s influence on the climate was needlessly built.

Among the errors of the complex climate models that the simple model exposes are the following:

  • The assumption that “temperature feedbacks” would double or triple direct man-made greenhouse warming is the largest error made by the complex climate models. Feedbacks may well reduce warming, not amplify it.
  • The Bode system-gain equation models mutual amplification of feedbacks in electronic circuits, but, when complex models erroneously apply it to the climate on the IPCC’s false assumption of strongly net amplifying feedbacks, it greatly over-predicts global warming. It is the wrong equation.
  • Modellers have failed to cut their central estimate of global warming in line with a new, lower feedback estimate from the IPCC. They still predict 3.3 oC of warming per CO2 doubling, when on this ground alone they should only be predicting 2.2 oC—about half from direct warming and half from amplifying feedbacks.
  • Though the complex models say there is 0.6 oC man-made warming “in the pipeline” even if we stop emitting greenhouse gases, the simple model—confirmed by almost two decades without any significant global warming—shows there is no committed but unrealized man-made warming still to come.
  • There is no scientific justification for the IPCC’s extreme RCP 8.5 global warming scenario that predicts up to 12 oC global warming as a result of our industrial emissions of greenhouse gases.

Once errors like these are corrected, the most likely global warming in response to a doubling of CO2 concentration is not 3.3 oC but 1 oC or less. Even if all available fossil fuels were burned, less than 2.2 oC warming would result.

Lord Monckton, the paper’s lead author, created the new model on the basis of earlier reviewed research by him published in Physics and Society, in the UK Quarterly Economic Bulletin, in the Annual Proceedings of the World Federation of Scientists’ Seminars on Planetary Emergencies, and in Energy & Environment.

He said: “Our irreducibly simple climate model does not replace more complex models, but it does expose major errors and exaggerations in those models, such as the over-emphasis on positive or amplifying temperature feedbacks. For instance, take away the erroneous assumption that strongly net-positive feedback triples the rate of man-made global warming and the imagined climate crisis melts away.”

Dr Willie Soon, an eminent solar physicist at the Harvard-Smithsonian Center for Astrophysics, said: “Our work suggests that Man’s influence on climate may have been much overstated. The role of the Sun has been undervalued. Our model helps to present a more balanced view.”

Dr David Legates, Professor of Geography at the University of Delaware and formerly the State Climatologist, said: “This simple model is an invaluable teaching aid. Our paper is, in effect, the manual for the model, discussing appropriate values for the input parameters and demonstrating by examples how the model works.”

Dr Matt Briggs, “Statistician to the Stars!”, said: “A high-school student with a pocket scientific calculator can now use this remarkable model and obtain credible estimates of global warming simply and quickly, as well as acquiring a better understanding of how climate sensitivity is determined. As a statistician, I know the value of keeping things simple and the dangers in thinking that more complex models are necessarily better. Once people can understand how climate sensitivity is determined, they will realize how little evidence for alarm there is.”

Contact Christopher Monckton of Brenchley,, +44 7814 556423 or +44 131 225 5551.


Well, press releases are press releases. Download the paper. Read that.


  1. Rune Valle

    I have to say that this blog-post hardly give your paper justice. I decided to read it with no small amouth of scepticism, and I found it great! I work as a physics teacher at high school level, and I find your model an inspiering aproach to extend the treatment of global warming beyond the basic mechanics of the greenhouse effect.

    Of course there is the pitfall of controversity, and as far as I can see the major pitfall in this paper is the low g argument. Using historical data it is argued that the environement operates under stable conditions. This is used as evidence that the more advanced climate models is flawed, and there are less reason for concern than IPCC indicates.

    However this argument is only working under the asumption that that particular part of history is a better predictor of the future than advanced physical theory. In general it would be easy to argue that this should be the case, but in this particular situation the argument is not so clear cut as even if you are upholding history over theory the history is ambigous. We do have clear historical indications that nature might behave “unstabely”.

    Hence taking *both* history and physical modelling into account the following and a lot more alarming conclusion seem more reasonable to me: We have enjoyed a period in which the temperature has been quite stable thanks to conditions with low g. However advanced climate modelling indicates that we are currently in a situation where this is not the case in our *current* situation. The posibility of this scenario can not be ruled out from historical records – and that mean that we might be in a particularily unstable situation: A regime process enginers are not “allowed” to go into due to risks connected with that..

    In this picture would you really feel good about suggesting that we might just as well continue to play with the system?

  2. owen

    The paper addresses theory in its outcome. As well, the foundational physics are in order. I would suggest that crafting policy around alarmism is more akin to playing with the system. Its a slippery slope to geoengineering.

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