At https://physicsworld.com/a/did-cosmic-rays-cause-ice-ages/ … we have a new idea, resting on the shoulders of an older idea, that change in the flux of cosmic rays hitting the Earth could have caused the Ice Ages. The research paper is currently at the pre print server – go to https://arxiv.org/pdf/physics/0407005.pdf … and challenges the established insolation theory of glacial cycles. An interesting idea. Beryllium 10 is produced when cosmic rays interact with particles in earth’s atmosphere – which then fall to the surface. They are found in undisturbed ocean sediments. The authors also appear to have developed the theory from the 1997 study by Henri Svensmark and Eigil Friss-Christensen of the Danish Space Research Institute. They proposed that change in the strength of the solar wind could lead to changes in the cosmic ray flux. Measurements of Beryllium 10 in stalagmites in Oman and the Alps seem to support the hypothesis.
At https://tallbloke.wordpress.com/2023/12/18/the-sahara-desert-used-to-be-a-green-savannah-research-explains-why-its-a-climate-cycle/ … people playing around on computers very often find evidence of cycles. It seems some researchers have found a Sahara cycle – between greening by wetter and drying by drought [the desert]. We all know that in the early Holocene period the Sahara and Arabian deserts did not exist. The climate in that zone was wetter – with streams and bubbling brooks, and lakes with fish, and so on. It gradually became desertified – with some humans adapting and others migrating. The problem is what caused it to green and what caused that greening to disappear. Apparently, the claim is that green Sahara’s come and go on many occasions. They have identified 27 different times in the past when the Sahara was green. The same must apply to Arabia. Each of these occasions are separated by periods of 21,000 years – over 8 million years. Uniformitarians can weald big cycles of time quite easily – they have all the time in the world, They are mostly referring to the very dry region of mid and southern Libya, Niger, Mali, and Chad. To bring rain to these areas requires a switch in the monsoon track. Or that was the consensus not so long ago. The tropical zone can also move – and therefore its rain track. This can be seen to affect regions in central and southern America – leading to heavy drought and abandonment of cities left to the jungle. However, cycles of 21,000 years are a magnitude larger. One may wonder if it would have been productive if they had investigated the top of Africa – or conversely, the Sudan belt south of the Sahara. Did they become dry as the Sahara greened? Or did they enjoy a temperate climate when the Sahara greened. They are looking at solar insolation as a reason for the wetter and drier episodes, reminiscent of Milankovitch. It seems movement of the monsoon track are not in vogue at the moment.