Pacific ocean [image credit: Wikipedia]
In climate propaganda land anything to do with the natural variation that is always going on is bad news, and liable to be maligned or ignored, as we see here. The PDO for example is well known to government agencies like NOAA, but that doesn’t matter to CO2-obsessed warmists trying to claim the atmospheric tail wags the oceanic dog.
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An opinion article published yesterday in Frontiers in Earth Science rebuts a recent paper by Michael E. Mann et al. who deny the existence of long known drivers of natural climate variability like the Pacific decadal oscillation (PDO) and the Atlantic multidecadal oscillation (AMO), reports The Global Warming Policy Forum (GWPF).
Applying habitual methodological shenanigans, they claim that the PDO is not distinguishable from noise and that the AMO is due to anthropogenic aerosol emissions rather than any intrinsic climate oscillation.
In her critique, Professor Müller-Plath not only highlights the methodological flaws in the Mann et al. paper but also shows that their aerosol hypothesis has long been rejected in the scientific literature, research papers Mann et al. simply ignore.
The present paper contributes a critical commentary on the recent finding by Mann, M. E., Steinman, B. A. and Miller, S. K (2020). Absence of internal multidecadal and interdecadal oscillations in climate model simulations. Nat. Commun. 11, 1–9.
Climate oscillations are recurring large-scale fluctuations in the surface temperatures of the oceans in connection with the atmosphere. This commentary focuses on the Pacific Decadal Oscillation (PDO, interdecadal timescale) and the Atlantic Multidecadal Oscillation (AMO, multidecadal timescale), which have been regarded as intrinsic climate drivers on the adjacent continents in numerous studies based on observations and paleoclimate reconstructions (Henley, 2017; O’Reilly et al., 2017). In a recent paper, Michael E. Mann and colleagues (Mann et al., 2020, hereafter M20) fail to find a PDO signal in global measured and modeled temperatures that is statistically different from noise. They further propose that the significant AMO-like signal is mainly due to anthropogenic aerosols in the 20th century, and to statistical artifacts before. Therefore they doubt the intrinsic nature of the two oscillations. The present paper shows that M20’s results are largely artifacts themselves with issues ranging from using inadequate data and referencing improper literature on anthropogenic aerosols with regards to the AMO to inappropriately interpreting the results with regards to the PDO.
After briefly sketching the rationale and method of M20, I will elaborate on these three points.
Continued here.
via Tallbloke’s Talkshop
November 28, 2020 at 06:01AM
Iowa Climate Science Education 