Happer Contradicts Himself on Climate Sensitivity

W. A. van Wijngaarden and William Happer (WH) have periodically attempted to circumvent publishing manuscripts in peer-reviewed journals and have instead taken to uploading manuscripts on the arXiv. As I understand it, the intended use for the arXiv is to allow pre-published manuscripts to be read and evaluated by scientists before the peer-review process is completed. This gives scientists faster access to the newest research, but with the caveat that these manuscripts may need to be revised significantly before being published, once going through the peer review process. Some may not even be published at all, so scientists often look at these manuscripts with interest but also with a grain of salt until the final version passes peer review. WH are apparently using the arXiv to store manuscripts for which they have no intention of submitting to any peer-reviewed journal. The manuscripts are formatted to look like scientific papers, but they will never see the light of day in an academic journal. Their purpose is to be used by political organizations like the CO2 Coalition, the Heartland Institute, etc. to make use of these "findings" in an attempt to affect policy. 

In March 2023,[1] WH put a manuscript on the arXiv that claims ECS is about 1 C for 2xCO2. While they admit that adding more CO2 will cause more warming, they say, 

It is difficult to calculate exactly how much, but our best estimate is that it is about 1 C for every doubling of CO2 concentration, when all feedbacks are correctly accounted for. Alarming predictions of dangerous warming require large positive feedbacks. The most commonly invoked feedback is an increase in the concentration of water vapor in the upper troposphere. But most climate models have predicted much more warming than has been observed, so there is no observational support for strong positive feedbacks.

It's relatively non-controversial that sensitivity to 2xCO2 with no feedbacks is in the neighborhood of 1 C (about 1.15 C is a pretty standard estimate). So they are essentially arguing that there are no positive feedbacks that amplify the warming signal from CO2, and they specifically rule out the most notable (and most demonstrably valid) positive feedback, water vapor. And this is odd because they essentially admit to the positive water vaper feedback in the manuscript. They write, "It should be noted that by far the most abundant greenhouse gas in the atmosphere is water vapor. There is little that one can do about water vapor on our watery planet Earth, with 70% of its surface covered by oceans." And since we know that water vapor increases with temperature, an atmosphere warmed by increasing CO2 on a planet whose surface is 70% covered by water will contain still more of the most abundant greenhouse gas and amplify the warming signal caused by CO2.

This is a concept that WH at least used to understand. In another manuscript they placed on the arXiv in 2020, they claimed,

Doubling CO2 concentrations with water vapor feedback increases the surface temperature warming to ∆θo = 2.3 K from ∆θo = 1.4 K, or by a factor of 1.6.

This estimate for a clear-sky ECS of 2.3 K is not that far below the minimum estimate by the IPCC, who place the likely range between 2.5 and 4 K. If cloud feedbacks are net positive (which they likely are), that might even push WH's estimate into the likely range. In other words, WH used to understand the water vapor feedback well enough in 2020 to admit that a positive water vapor feedback would amplify ECS by 1.6x. So why did they change their minds? It's not because of evidence. In their 2023 paper, they write,

But most climate models have predicted much more warming than has been observed, so there is no observational support for strong positive feedbacks. Indeed, most feedbacks in nature are negative as expressed by Le Chatelier’s Principle: When any system at equilibrium  for a long period of time is subjected to a change in concentration, temperature, volume or pressure, the system changes to a new equilibrium, and this change partly counteracts the applied change.

So they have two reasons: 1) models predict too much warming and 2) Le Chatelier's Principle. Both of these reasons are demonstrably false. Models have in general done a pretty good job at predicting the increase in GMST throughout the 20th century and into the present. This has been summarized in a paper by Zeke Hausfather.[3]

These comparisons show that there has been general agreement among most models since the 1970s. And more recent models have continued to make accurate predictions of surface temperatures. For instance, here's how well CMIP5 has done.

Obviously more recent models have less time to be compared with observations, but they do reproduce past warming and make accurate predictions of how warming has progressed since the publication of the models. More puzzling is WH's claim that positive feedbacks somehow violate Le Chatelier’s Principle. In my view, this is completely wacky. The principle simply states that if a system at equilibrium is disturbed, the system generally changes until it reaches a new equilibrium state. This is precisely what climate scientists estimating ECS to be ~ 3 C observe. A radiative forcing of 2xCO2 (about 3.7 W/m^2) will disturb GMST, but a new equilibrium will be achieved at about 3 C warmer. Le Chatelier’s Principle is observed. The only difference is that new equilibrium occurs at ~3 C warmer (an amount confirmed by observational evidence) and not ~1 C warmer (a claim that is unsupported by observational evidence). In another post I describe how this works. It turns out that the sum total of all of positive feedbacks are still smaller than the Planck response, which is essentially a large negative feedback that ensures that a perturbation of the Earth's energy balance by changes in greenhouse gas concentrations will ultimately reach a new equilibrium temperature. We will not achieve a runaway greenhouse effect like Venus by anything resulting from human activities.

So why would Happer invent these two fake reasons to object to climate science? And why would they contradict their own previous position on ECS from just 3 years ago? Why do they now deny the well-established physics concerning water vapor and positive feedbacks that they acknowledged before? It's hard to say with absolute confidence because some of the answer requires knowledge of their motives. But we can say that Happer and Lindzen in 2022 have written political tracts for the CO2 Coalition making the more outlandish claims found in this 2023 manuscript. And those tracts were riddled with typos, blatant mistakes, and egregious errors that I documented in another post. But it seems reasonable that they would want a science-looking manuscript to point to in support of the outlandish claims in these political tracts, and their 2020 effort simply isn't outlandish enough.  We've also seen that Happer at least has agreed to promote these kinds of fringe views in support of the fossil fuel industry's positions on climate in exchange for money. To be clear, I've not seen evidence that Happer was personally or directly paid to write these articles. Instead, he asked that the funding be given to CO2 Coalition through the Donors Trust, a secretive funding channel set up to avoid public disclosure of funding sources. This is not illegal, but it does show that Happer is willing to produce content with predetermined conclusions in exchange for funding to a political think tank.

He also admitted that his "research" would not pass any rigorous peer-review process. He wrote in an email to a fake organization in the sting operation, 

I could submit the article to a peer-reviewed journal, but that might greatly delay publication and might require such major changes in response to referees and to the journal editor that the article would no longer make the case that CO2 is a benefit, not a pollutant, as strongly as I would like, and presumably as strongly as your client would also like.

To me this seems to be a blatant admission that he is willing to exchange "research" products agreeable to fossil fuel interests in exchange for funding for his favorite political think tank. And it also explains why WH are willing to simply place manuscripts on the arXiv without any attempt to get the paper to pass peer review. Admittedly this sting operation happened in 2015, long before WH placed their 2020 estimate for ECS that acknowledged known physics related to the water vapor feedback on the arXiv. I suppose it is pure speculation that new funding prompted WH to contradict their previous manuscript and lower ECS into the range of radical fringe positions. But at the very least, we can say that Happer's positions are strongly correlated to his political allegiances and funding sources within the fossil fuel industry. And apparently he can't make up his own mind on the physics of the water vapor feedback and the effects of doubling of CO2; he's perfectly willing to blatantly distort Le Chatelier’s Principle to justify denying known positive feedbacks. I don't believe there's any reason to think that Happer can be trusted on the science of climate change.

References:

[1] W. A. van Wijngaarden and W Happer. Atmosphere and Greenhouse Gas Primer. Unpublished manuscript. 2023.
https://arxiv.org/pdf/2303.00808v1.pdf

[2] W. A. van Wijngaarden and W. Happer. Dependence of Earth’s Thermal Radiation on Five Most Abundant Greenhouse Gases. Unpublished manuscript. 2020.
https://arxiv.org/pdf/2006.03098.pdf

[3] Hausfather, Z., Drake, H. F., Abbott, T., & Schmidt, G. A. (2020). Evaluating the performance of past climate model projections. Geophysical Research Letters, 47, e2019GL085378. https://doi.org/10.1029/2019GL085378