At https://phys.org/news/2024-06-uncovering-prolonged-cooling-events-holocene.html …. which is derived from https://doi.org/10.1038/S43247-024-01380-0 … There were eleven prolonged cooling episodes in the Holocene period – ending with the Little Ice Age that came to an end in the 17th or 18th centuries [depending on the source you consult]. In fact, we are told there were eleven prolonged cooling events in the last 8000 years – which takes us back to the 6200BC event. This involved sea level changes in various parts of the world. In other words, during the Holocene as a whole there must have been other cooling events – between 12000 and 8000 years ago.
Volcanic activity is generally blamed for these cooling periods, and this is backed up by low growth tree ring events as a result of loaded atmospheric dust veils. However, prolonged cooling events could imply something more than just volcanic eruptions – as some of these events lasted a fairly long period. A dust laden upper atmosphere = aerosols. These are thought to reflect sunlight – therefore cooling the earth. Volcanoes were no doubt involved but there is also the possibility that meteor streams interacting with the upper atmosphere were also involved. At the moment this possibility has never been explored – although astronomers Clube and Napier, and others, did make this suggestion in the 1990s.
The Little Ice Age also coincided with a solar minimum – a reduction in solar activity and therefore CMEs. Mainstream have persisted in saying the Roman Warm Period and the Medieval Warm Period were regional events, even though evidence has piled up to prove they were global in extent – as with all these cooling events. This is because cooling events affect the different climate zones differently. In the temperate north it becames cooler and wetter and in mid regions such as the Near and Middle East, it becomes drier as the monsoon belt shifts southwards. This is basic climate science as espoused by HH Lamb. Hence, the ambiguities are handy for the alarmists. Having said that this is a paper to print out or file away for future consultation whenever such subjects pop up again as Net Zero begins to bite.
The second cooling event, in AD 6th and 7th centuries seems to have missed out some cooling burps in the 9th and 10th centuries AD. This is an interesting pattern as the Little Ice Age was itself a double whammy event [separated by a hundred or so years], a pattern that reasserts itself at the end of the Late Bronze Age and the end of the EB age.
A Popular Archaeology story – see https://popular-archaeology.com/article/volcanic-eruptions-contributed-to-collapse-of-china-dynasties/ … back in 2021 also claimed volcanic eruptions were responsible for the collapse of dynasties in China and the inauguration of new dynasties. They even mention the mandate of heaven and say it was applied to volcanic dust veils. No, the mandate of heaven was quite different. It referred to unusual goings on the sky followed by drought, famine, and earthquakes etc. We may also ask why did severe cold years occur in the 1640s, 1740s, 1840s and 1940s? Is it at all possible that volcanic eruptions occurred on a centennial basis? The answer of course is that volcanoes are a known hazard but catastrophism itself is ignored – and in the latter case even solar periods play a back seat role. Volcanoes can be subsumed into the uniformitarian model quite seamlessly as they are a well known factor. Another point I spotted was that some volcanic episodes seem to have been ignored completely. Thera for example. Not all volcanoes cause dust veils, which is true, but Thera has been hyped into a super volcano, yet is discarded. Mainstream can’t even decide on the date it blew. They also describe the first millennium BC as a quiet period, even though we had the 207BC event [low growth tree ring event], the Hallstatt anomaly and the Levantine geomagnetic anomaly – among various other oddities. If you only look at volcanoes and then the answer you get is volcanic. If you don’t look seriously at other factors they will never be part of the answer dredged up.