By Andy May & Marcel Crok
An anonymous reviewer has written a critique for the new paper “Carbon Dioxide and Climate Warming don’t matter,” published online May 29, 2024, at American Journal of Economics and Sociology.
In the introduction to the criticism, Phoma destructiva wrote: “the author and the sources cited tend to underestimate anthropogenic global warming.” We do not provide an estimate of the anthropogenic component of global warming. All it does is that if some of the observed warming is natural, the IPCC AR6 estimate of anthropogenic global warming will be too high. This is trivially true.
The first part of the main critique is actually a long critique of Javier Vinós’s book Climate Past, Present and Futurewhich has nothing to do with our paper. His criticism compares Vinós’s future projections with those made by the IPCC, our paper does not make projections. We are only discussing the current climate and the past (back to 1750), so this part of the criticism is not relevant to our paper and should be directed to Dr. Wines.
While we mention some published projections in our conclusion, we deliberately avoid making our own projections, our paper only considers past and present observations. The critics refute Vinós’s predictions about the future by claiming that the IPCC’s predictions, based on the influence of CO.2 emissions, more accurate. We currently do not know whether Vinós or the IPCC’s predictions are correct or not, because the time period discussed has not yet been completed. Our paper discusses the current and past climate conditions, future predictions are not observations and should not be confused with them.
The next section tries to dispute the existence of all multidecadal ocean oscillations based on two papers by Michael Mann and his co-author, Mann, et al. (2020) and Mann et al. (2021). Mann’s 2020 paper attempts to show that the most cited oceanic climate oscillations, the AMO and the PDO, are not statistically significant because their signals are not sufficiently above the red noise. However, he admitted that the history observations from the AMO are statistically significant, and only the climate model results are not statistically significant. Since all models are wrong (Box, 1976), this argument is quite weak.
The PDO is usually interpreted as the long-term variation in the La Niña/El Niño ratio, and (Mann, Steinman, & Miller, 2020) acknowledges that the ratio varies statistically significantly on a time scale of 40-50 years. . They simply contradict traditional PDO predictions.
We recognize that long-term ocean oscillations are poorly understood and poorly explained. However, Mann et al. (2020) do not provide valid evidence for the absence or absence of a natural component. In fact, he admits:
“Based on the available observational and modeling evidence, the most plausible explanation for the multidecadal peak seen in modern climate observations is that it reflects a response to a combination of natural and anthropogenic forcing over historical time.” (Mann, Steinman, & Miller, 2020)
We agree with this sentence, and it is consistent with our paper.
Mann et al. (2021) attempted to explain multidecadal oceanic oscillations (specifically AMO and PDO) as artifacts of volcanic activity and anthropogenic greenhouse gases and aerosols. Again, as noted in Mann (2020), Mann (2021) noted the absence of a multidecadal signal in climate model simulations but admitted that the signal can be seen in observations (Mann M. , Steinman, Brouillette, & Miller, 2021) . We would argue that these signals appear in observations and in paleoclimate proxy data, but not in climate models, this is a reason not to trust climate models, not a reason to reject the proposed natural oscillations.
We believe that anthropogenic greenhouse gases and aerosols, and volcanic activity have an effect on climate, but we believe that current warming has been “juiced” by natural ocean oscillations. These oscillations are observed in nature and have been traced back to 1567AD, before anthropogenic greenhouse gases and aerosols became a factor in climate change (Gray, Graumlich, Betancourt, & Pederson, 2004).
The evidence provided by Mann (2021) that volcanic activity causes “real” ocean oscillations is based on models, and not observations. This is problematic for many reasons, not the least of which is that the IPCC AR6 model does not reproduce the critical tropical sea surface temperature (SST) well, even though sea surface temperature is a major component of the ocean oscillation. From AR6:
“We establish with confidence that the CMIP5 and CMIP6 models continue to overestimate the observed warming in the upper tropical troposphere during the period 1979-2014 by at least 0.1 °C per decade, in part because they overestimate the pattern of tropical SST trends over this period.” AR6, p 444
“… despite decades of model development, increases in model resolution, and advances in parameterization schemes, there is no systematic convergence in ECS model estimates. In fact, the overall inter-model spread in ECS for CMIP6 is greater than CMIP5; … “AR6, WGI, page 1008.
In other words, the AR5 and AR6 climate models overestimate sea surface temperatures in the tropics, which make up almost half of the planet’s surface. In addition, ECS model estimation (Equilibrium Climate Sensitivity to a double of CO).2) is worse in AR6 than in AR5, indicating that the model is getting worse with time, not better, relative to observations (also see here). Other studies have also shown that climate models are not valid when compared to observations (McKitrick & Christy, 2020) and (McKitrick & Christy, 2018). Model evidence cannot be used to show observational evidence is incorrect.
Then an anonymous critique of our paper again to compare the predictions by Vinós, (Wyatt & Curry, 2014), and others to the IPCC forecasts. We’re not making predictions, we’re just quoting observations. The end of the time period for the various prophecies that have been criticized has not been reached, so, if they exist, the prophecies are actually unknown and will not be known for decades. Arguing which forecast is correct at this point is an exercise in futility. Prediction is an important part of science, but one should wait until the forecast period is over before criticizing.
talk
This critique is the poster child for everything wrong with modern climate science. Phoma destructiva set up a clear strawmen from the article we mentioned, which has nothing to do with our argument that observations show no danger or net harm from current climate change, and then attacked the strawmen themselves, rather than our paper. This irrelevant strawman fallacy is unfortunately all too common in climate science and is not to be trusted.
Far too often even trained climate scientists mix the results of climate models with observations as if they are important or significant, they are not. The following statement from Mann et al., 2021 is clearly incorrect:
“Our analysis reveals a strong multidecadal, narrowband (50- to 70-year) oscillatory “AMO-like” signal in simulations of the past millennium; oscillations driven by episodes of high-amplitude explosive volcanism that occurred, in the past century, to display multidecadal pacing. We do not found evidence for an internally generated 50- to 70-year multidecadal oscillation signal despite claims that proxy data showed such a signal (Mann M., Steinman, Brouillette, & Miller, 2021).
Translation, our simulations show that volcanism causes the oscillations and the proxy evidence that the oscillations are natural is wrong, because our model says. This is clearly flawed logic; But we agree that current ocean oscillations may be forced (CO2 and volcanism) and an unforced (natural) component. But as mentioned in Mann (2020), separating these two components objectively is problematic.
Climate models, like all models, are inherently wrong (Box, 1976). If done correctly, the observation is always correct, in the accuracy of the measurement. Ocean oscillations, such as AMO, PDO, and many others, are observed climate features, they are real, and cannot be disproven with the results of climate models.
Note: Neither Marcel nor Andy have a PhD, so Phoma destructiva uses the title “Dr.” incorrect.
Box, GE (1976). Science and Statistics. Journal of the American Statistical Association, 71(356), 791-799. Retrieved from http://www-sop.inria.fr/members/Ian.Jermyn/philosophy/writings/Boxonmaths.pdf
Gray, ST, Graumlich, LJ, Betancourt, JL, & Pederson, GT (2004). A tree-ring based reconstruction of the Atlantic Multidecadal Oscillation since 1567 AD Geophys. Res. Lieut., 31. doi: 10.1029/2004GL019932
IPCC. (2021). Climate Change 2021: The Physical Science Basis. In V. Masson-Delmotte, P. Zhai, A. Pirani, SL Connors, C. Péan, S. Berger,. . . B. Zhou (Ed.), WG1. Retrieved from https://www.ipcc.ch/report/ar6/wg1/
Mann, M., Steinman, B., & Miller, S. (2020). There are no internal and interdecadal multidecadal oscillations in climate model simulations. Nature Communications, 11. doi: 10.1038/s41467-019-13823-w
Mann, M., Steinman, B., Brouillette, D., & Miller, S. (2021). Multidecadal climate oscillations over the past millennium driven by volcanic forcing. Science, 3171014-1019. doi: 10.1126/science.abc5810
McKitrick, R., & Christy, J. (2018, July 6). Tests of Tropical 200- to 300-hPa Warming Rates in Climate Models, Earth and Space Sciences. Earth and Space Science, 5(9), 529-536. doi: 10.1029/2018EA000401
McKitrick, R., & Christy, J. (2020). Pervasive Warming Bias in the CMIP6 Tropospheric Layer. Earth and Space Science, 7. doi: 10.1029/2020EA001281
Wyatt, M., & Curry, J. (2014, May). A role for Eurasian Arctic sea ice in different hemispheric climate signals during the 20th century. Climate Dynamics, 42(9-10), 2763-2782. Retrieved from https://link.springer.com/article/10.1007/s00382-013-1950-2#page-1
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