The next chapter in our series on the Clintel Analysis of the IPCC AR6 Report brings us to the chapter by Nicola Scaffeta and Fritz Vahrenholt on the role of the sun in climate change. Or rather the lack of role, according to the IPCC. A long time ago the IPCC paid attention to the sun and its possible influence on climate, but as we showed in our video on the subject, that was then. Now it’s all CO2 all the time and, according to the IPCC insiders, there’s no reason to think the sun has anything to do with temperature or rainfall or anything else. But if you too are inclined to that view you may find this Clintel chapter surprising, beginning with the list of 150 or so scientific publications they cite talking about the influence of the sun on the climate.

The sun isn’t just a simple ball of fusion-powered fire hanging motionless in space. It is constantly changing, going through short and long cycles of varying output, pulsing with a vast magnetic field and hitting the Earth’s atmosphere with a full spectrum of energy. One of the recurring points in Scaffeta’s and Vahrenholt’s chapter is that for decades scientists have been noticing curious, ah, coincidences between solar cycles and weather cycles on Earth. And indeed they may be coincidences, because it is not always obvious why such changes in solar activity, very small as a percentage of its total output, should have a big climatic effect on Earth. But after a while the coincidences get too numerous to wave away.

A big one is the correlation pattern in which the sun’s output was very high during the Medieval Warm Period, then fell to an extreme low point during the Little Ice Age, then ramped up again during the 20th century where it reached, according to some analyses, its strongest level in 10,000 years. And unless you pretend there was no Medieval Warm Period (or Little Ice Age) it makes sense to look for possible reasons for the correlation.

If you try, the first obvious objection to the simple idea that the sun explains everything is the fact that the variation in output of the sun is not strong enough on its own to explain major climate changes. So there must be an amplifying mechanism of some kind.

Of course the same argument applies to CO2: the extra CO2 in the air isn’t strong enough to drive much global warming through its direct heat-trapping impact, so the climate models all have amplification mechanisms built into them to translate small forcings from CO2 into large temperature effects. But when it comes to the sun, the IPCC is completely uninterested in surveying possible solar amplification mechanisms. Granted there have been some proposed over the years that didn’t pan out, but it remains an active area of research. Just not one the IPCC sees any need to tell its readers about.

In fact, as this chapter shows, there is a lot the IPCC isn’t inclined to tell its readers about concerning the role of the sun in climate change. Which might have something to do with the way the IPCC operates. As the Clintel authors note in their conclusions:

“The public should not ignore the fact that the IPCC is a politically controlled organisation in which the IPCC bureau handpicks authors and review editors. Scientists supporting a stronger role of natural climate change in modern climate are typically excluded from the authorship of IPCC reports. But in the long run, facts and observations will prevail and the current uncertainties will be properly solved and the numerous empirical findings supporting a significant solar (or otherwise astronomical) effect on the climate will be confirmed.”

We hope their optimistic view is justified, and that we don’t have to wait for another ice age before they’re proven right.