California 8200 years ago

24 Jun 2017

At 8200 years ago there were massive changes in sea levels around the world, submerging huge parts of Sunda Land (leaving behind the islands of Indonesia, as well as the drowning of the North Sea basin, widening of the English Channel and the creation of the Solent, and conversely, lower sea levels in South America. The effects of all this is somewhat muted in California - but the study of speleotherms in caves has revealed a 150 year period of wet and stormy weather. The balmy climate of modern California was absent in the wake of an event dated at 6200BC (in old money). See and also, ... for details of the actual study. A Palaeoclimate study published in Scientific Reports (June 20th 2017) says the period that followed in the wake of whatever it was that caused the sea level changes in other parts of the world, was exceptionally wet and stormy in California. In Europe this corresponds to a very cool period that is thought to have persisted for around 200 years - or may be longer than that. The article acknowledges that it corresponds with the same climate anomaly as seen in Greenland ice cores that was first detected only as recently as 1997. Prior to that date the world's climate was generally regarded as stable throughout the Holocene era - so the discovery of this prolonged cooling period must have focussed some minds (and a uniformitarian solution had to be found, or a nearly uniformitarian one, not too catastrophic in nature). This is the nub. The 8.2ka event has obviously challenged a few minds and the research in California came about in order to see to what extent it affected this region of the world. Not a lot it would seem - going by the speleotherms (stalactites and stalagmites in old money). They can't of course tell you anything about the nature of the 8.2ka event - only what happened in its wake. Lots of precipitation. Speleotherms pick up dry and wet periods quite well - but not a lot else. From ice cores in Greenland we know that temperatures there fell 3.3 degrees Celsius - which is pretty dramatic. No wonder it got stormy in California. The elephant in the room here is that something extraordinary must have caused the 8.2ka event - which is beyond the remit of this report. The sudden cooling of the climate was quickly scapegoated by climate scientists,  and others of a mainstream way of thinking. The 13,000ka event (the Younger Dryas) was attributed by some climate scientists to a glacial lake in North America suddenly spilling over and pouring out of the Great Lakes region into the North Atlantic, the sudden injection of cold fresh water causing the global conveyor belt system to shut down (or the North Atlantic branch of that system). Incredibly, they decided to tie the same theory to the 8.2ka event - and although this has since been repudiated by some people it reappears in this study, fresh and bright as ever. A glacial lake emptied into the North Atlantic and shut down the ocean conveyor belt system - even as far away as California, miles apart from the North Atlantic Oscillation current. In fact, the ocean conveyor belt would have had to unwound right round the whole globe to get as far as California, which should raise an eyebrow. No doubt the ocean conveyor belt system did experience change - but it does not follow that a glacial lake was involved - when the Late Glacial Maximum came to an end 18,000 to 16,000 years ago. Do they really think a cold body of water, at extremely low temperatures, existed in some theoretical state of conservation in an unproved geographical situation, for 8000 years? Mind, if a change in the axis of rotation was involved in the 8.2ka event and then one  might envisage a lake, or lakes, emptying their contents - but where is the evidence of a flood of water sweeping across North America at this moment in time. As yet that has not been uncovered. One can see that this was an ad hoc explanation - anything to avoid a more catastrophic event of some kind. If a cosmic body was involved, or the Earth moved through a dense stream of debris left behind by the passage of a comet one might visualise an opaque sky as responsible for the cool weather - without the necessity of involving a hypothetical glacial lake collapse. The debris could also have remained in the upper atmosphere over a prolonged period - or the Earth encountered it on a regular basis until the debris had dissipated and the meteor stream had become a wider and strung out and less severe encounter, the upper atmosphere gradually cleaning itself. This is of course a theory, one based on the Taurid stream hypothesis of Clube and Napier, but it illustrates the kind of thing that might have been going on. If the Taurid streams were responsible for the Younger Dryas event there is no reason why it could not have been involved in the 8.2ka event - and various other anomalies or sudden glitches in climate on other occasions during the Holocene. Moe Mandelkehr wrote a series of articles in SIS journals over a number of years which centred around a Taurid stream encounter in the second half of the third millennium BC. All we know is that the climate suddenly changed - but what the trigger point might have been is conjecture. The study says that it became very cold in Europe, there was severe drought in parts of Africa, and weakened monsoon activity decreased dramatically across southern Asia and China.

The climate scientists are interested in the 8.2ka event because they think the switch in climate may have a climate change synchronism with modern global warming - and they assume the glacial lake theory was similar to what they think would happen if ice sheets at the poles melted later in this century (all hypothetical and driven by alarmism rather than rational common sense). That is the thinking at the core of the study. They are not concerned to find out if something more catastrophic caused the 8.2ka event - that is in the realm of fantasy, or pseudo science, in their mainstream way of thinking. It seems quite logical for them to say a catastrophic collapse of a glacial lake, or lakes, caused the ocean conveyor system to malfunction, even without having to produce any physical evidence to uphold the theory. All the speleotherms can show is that it was wet and stormy in California for around 150 years. It cannot say what caused the wet and stormy weather. The comments at the Wattsupwiththat blog do not question the glacial lake hypothesis - or most of them do not. It seems they are only sceptical of catastrophic global warming in the modern world and accept most of what mainstream has to offer on other scientific issues, which is peculiar in a way. For example, they are mostly persuaded that low sun spot activity equalises low temperatures - aka the Maunder Minimum. Unfortunately for them the Maunder Minimum occurred during the Little Ice Age which may mean that was a coincidence. . After all the Sun has been quiet as far as sun spots are concerned this last year and yet the weather is far from as cold - and certainly nowhere near 17th century temperatures. This doesn't seem to stop the Sun, via an outburst of solar wind, from pumping excess heat and energy into the earth system (as happened last week) even though sun spots had been low in the preamble up to the heat wave. Good luck with the idea that low sun spot activity equalises cool weather as the facts appear to contradict the idea. Climate scientists appear to be right about that. They might have their fingers crossed at the same time but some other factor was responsible for the Little Ice Age, and dust in the atmosphere is just the kind of thing that could reduce the ability of the Sun to warm the surface of the Earth. In fact there was a paper recently to the same effect - pointing out the amount of volcanic activity during the Little Ice Age. I shall have to root it out.