The Role of the Sun – Scafetta 2023

CSS-42 The primary purpose of this post is to introduce Nicola Scaffeta’s most recent paper (“Empirical assessment of the role of the Sun in climate change using balanced multi-proxy solar records”, June 2023). The secondary purpose is a quick look at a variety of Total Solar Irradiance (TSI) reconstructions and how they compare to the Naval Research Laboratory’s NRLTSI2 version that I have been using in my evaluations.

#climatechange #delaythegreen #globalwarming #showusthedata

Here are my highlights from the paper (the bold highlights are mine).

• “However, if the proposed solar records are used as TSA proxies and the climatic sensitivity to them is allowed to differ from the climatic sensitivity to radiative forcings, a much greater solar impact on climate change is found, along with a significantly reduced radiative effect. In this case, the ECS is found to be 0.9–1.8 °C, with a mean of around 1.3 °C.”
• “Relative to the scenario discussed in Section 5.1, the ECS drops by 45% from a range equal to 1.4–2.8 °C with a mean of 2.1 °C, to a range equal to 0.8–1.8 °C with a mean of 1.2 °C using the HadCRUT4 and HadCRUT5 records. When the HadSST3 and HadSST4 records are utilized, the ECS decreases from 1.1 °C to 2.4 °C with a mean of 1.75 °C, to 0.6–1.6 °C with a mean of 1.0 °C.”

Those climate sensitivities can be compared back to the 1.8 to 5.7 °C that are used in the current CMIP6 model projections. Any wonder why the models run too hot?

• “The result also suggests that at least about 80% of the solar influence on the climate may not be induced by TSI forcing alone, but rather by other Sun-climate processes (e.g., by a solar magnetic modulation of cosmic ray and other particle fluxes, and/or others), which must be thoroughly investigated and physically understood before trustworthy GCMs can be created.”

My own preference puts the climate sensitivity in the 0.8 °C range. This value can be backed out of the University of Chicago’s MODTRAN model (used to estimate energy radiating out to space and correlated to satellite measurements) and fits with climate sensitivities that are adjusted for the Urban Heat Island Effect (UHIE). CO₂’s Climate Sensitivity is obviously not settled science (despite its importance). And until, that value is zeroed in on, the current model projections (those models that run too hot and use emission scenarios that are implausible) are useless for scientific analysis, let alone policy directives. Sadly, our political “leaders” will still follow “the science” and continue to ignore the natural forcings that will reduce global temperatures over the next few decades, leading to some real economic, physical and societal problems.

As I mentioned earlier, I have been using the NRL’s NRLTSI2 TSI reconstruction in my data reviews. There are a wide variety of TSI reconstructions based on absolute value (another small indication of the complexities in climate science). However, on a general profile basis, they all show the same solar minimums and maximums. The NRLTSI2 reconstruction falls in the middle of the pack and can be considered representative. But having looked at the other reconstructions, there are options that may tighten up the spreadsheet model temperature match I discussed in my CSS-29 – Climate Model – TSI-AMO-CO₂ post. A matter for a future post/discussion.

For more perspective and more detailed analysis, you can check out some of the following posts.

Nicolas Scafetta (June 2023) – Empirical assessment of the role of the Sun in climate change using balanced multi-proxy solar records

https://www.sciencedirect.com/science/article/pii/S1674987123001172?via%3Dihub

Open Letter Addendum

Addendum

University of Chicago – MODTRAN Model

http://climatemodels.uchicago.edu/modtran/

Climate Short Story (CSS)

CSS-29 – Climate Model – TSI-AMO-CO₂

Climate Model – TSI-AMO-CO2

CSS-30 – CMIP6 Climate Models

CMIP6 Climate Models

One Page Summary (OPS)

OPS-8 – Basic Climate Model

Basic Climate Model

OPS-55 – The State of Climate Science

The State of Climate Science

OPS-68 – Climate Change – Quick Hitshttps://climatechangeandmusic.com/climate-change-quick-hits/