Recently, a paper published in a Chinese journal of science by Monckton, Soon and Legates attracted a small amount of attention by claiming that climate science models "run hot" and therefore overrepresent the level of global warming caused by human greenhouse gas pollution. The way they approached the problem of climate change was odd. The Earth's climate system is incredibly complex, and climate models used by mainstream climate scientists address this complexity and therefore are also complex. Monckton et al chose to address this complexity by developing a model they characterize as "irreducibly simple." I'm not sure if their model is really irreducibly simple, but I am pretty sure that a highly complex dynamic system is not well characterized by a model so simple that the model's creators can't think of a way to remove any further complexity.

The same journal, Science Bulletin, has now published a paper, "Misdiagnosis of Earth climate sensitivity based on energy balance model results," by Richardson, Hausfather, Nuccitelli, Rice, and Abraham that evaluates the Monckton et al paper and demonstrates why it is wrong.

From the abstract of the new paper:

Monckton et al. ... use a simple energy balance model to estimate climate response. They select parameters for this model based on semantic arguments, leading to different results from those obtained in physics-based studies. [They] did not validate their model against observations, but instead created synthetic test data based on subjective assumptions. We show that [they] systematically underestimate warming ... [They] conclude that climate has a near instantaneous response to forcing, implying no net energy imbalance for the Earth. This contributes to their low estimates of future warming and is falsified by Argo float measurements that show continued ocean heating and therefore a sustained energy imbalance. [Their] estimates of climate response and future global warming are not consistent with 29 measurements and so cannot be considered credible.

The Monckton model does not match observed temperatures, and consistently underestimates them. We don’t expect a model to perfectly match measurements, but when a model is wrong so much of the time in the same direction, the model is demonstrably biased and needs to be either tossed or adjusted. However, you can’t adjust an “irreducibly simple” model, by definition. Therefore the Monckton model is useless. And, as pointed out by Richardson et al, the basic values used in the model were badly selected.

Figure 2 from Richardson et al demonstrate the problem with bias. The pink band in the upper figure and the red/pink line in the lower figure show the Monckton model tracking across time from 1850, compared to several sets of actual observations. The irreducibly simple model may not be irreducibly wrong, but it is irreducibly useless.

Monckton et al rely on the assumption that the Earth’s surface temperature varies by only 1% around a long term (810,000 year) average. This “thermostasis”, they argue, means that there are no positive feedbacks that move the Earth’s temperature higher. This ignores the fact that for that entire record one of the main determinants of global surface temperature, greenhouse gases, has also not varied from a fairly narrow range. But now human greenhouse gas pollution has pushed greenhouse gas concentrations well outside that long term range, and heating has resulted.

The Monckton model is contradicted by observation of global ocean heat content. However, recent Argo measurements of ocean heat content indicate significant warming over the last decade.

During recent years, the rate at which global mean surface temperatures have gone up has been somewhat reduced, and various factors have been suggested as explanations. Of these explanations, Monckton et al. assume only one of these to be true, specifically, that the climate models used by all the other climate scientists are wrong. They ignore other very likely factors. Monckton et al state that models used by the IPCC “run hot” without any reference to the fairly well developed literature that examines differences between observed temperatures and model ranges. They also misinterpreted IPCC estimates of various important feedbacks to the climate system.

I asked paper author John Abraham if it is ever the case that a simpler model would work better when addressing a complex system. "While simple models can give useful information, they must be executed correctly," he told me. "The model of Monckton and his colleagues is fatally flawed in that it assumes the Earth responds instantly to changes in heat. We know this isn't true. The Earth has what's called thermal inertia. Just like it takes a while for a pot of water to boil, or a Thanksgiving turkey to heat up, the Earth takes a while to absorb heat. If you ignore that, you will be way off in your results."

I also contacted author Dana Nuccitelli, who recently published the book "Climatology versus Pseudoscience," to ask him to place the Monckton et al. study in the broader context of climate science contrarianism. He told me, "In my book, I show that mainstream climate models have been very accurate at projecting changes in global surface temperatures. Monckton et al. created a problem to solve by misrepresenting those model projections and hence inaccurately claiming that they "run hot." The entire premise of their paper is based on an inaccuracy, and it just goes downhill from there."

This is not Nuccitelli's first rodeo when it comes to the Monckton camp. "It's perhaps worth noting that these same four authors (Legates, Soon, Briggs, and Monckton) wrote another error-riddled paper two years ago, purporting to critique the paper my colleagues and I published in 2013, finding a 97% consensus on human-caused global warming in the peer-reviewed climate science literature," he told me. "The journal quickly published a response from Daniel Bedford and John Cook, detailing the many errors those four authors had made. There seems to be a pattern in which Monckton, Soon, Legates, and Briggs somehow manage to publish error-riddled papers in peer-reviewed journals, and scientists are forced to spend their time correcting those errors."

Monckton et al cherry-picked the available literature, thus ignoring a plethora of standing arguments and analysis that would have contradicted their study. They get the paleoclimate data wrong, ignore over 90% of the climate system (the ocean), selected inappropriate parameters, and seem unaware of prior work comparing models and data. Monckton et al also fail to provide a useful alternative valid model.

Monckton et al failed in their attempt to demonstrate that IPCC estimates of climate sensitivity run hot. Their alternative model does not perform well, and is strongly biased in one direction. They estimate future warming based on “assumptions developed using a logically flawed justification narrative rather than physical analysis,” according to Richardson et al. “The key conclusions are directly contradicted by observations and 450 cannot be considered credible.”

Also of interest

Aside from the obvious and significant problems with the Monckton et al paper, it is also worth noting that the authors of that work are well known as "climate science deniers" or "contrarians." You can find out more about Soon here. Monckton has a long history of attacking mainstream climate science as well as the scientists themselves. To be fair, it is also worth noting that two of the new paper's authors have been engaged in this discussion as well. John Abraham has been eDebating Monckton for some time. (See also this conversation with me, John Abraham, and Kevin Zelnio.)

Author Dana Nuccitelli is the author of this recent book on climate science deniers and models.