At https://phys.org/news/2021-07-early-humans-worst-effects-volcanic.html … an interesting exercise in musical chairs. The Toba volcano in Indonesia is said to have erupted 74,000 years ago, but has been a bit of a bugbear for the last few years as archaeologists discovered it had little effect on humans living in India and Africa. This sort of blemished the shine on the severity of the volcano, or rather, super volcano. It was hailed as the biggest volcano in the last two million years – at least. It was assumed it was devastating to life on earth, including that of humans. In fact, it had been projected it was so severe it would have caused a bottleneck in human numbers – but no evidence of this has been found by archaeologists. Quite the contrary. Human numbers remained more or less the same – at those few sites investigated. There were also no changes in material culture – which surely would have occurred if people had sought out places less affected by the volcano. This was perplexing to adherents of the super volcano theory. No evidence of any kind of setback. However, there is plenty of evidence to suggest a bottleneck in human and animal numbers did occur around 40,000 years ago. Surely the dating system cannot be in error?
Now, in a new study published by PNAS, some kind of explanation is trotted out. We are told the Toba volcano may not have affected warm and tropical regions such as India and Africa, but humans in the northern zone probably were affected. In other words, all the angst took place in northern climes. This idea was actually a product of computer simulation. Climate models were used to resolve the enigma. Some 42 of global climate model simulation in total. 'We know this eruption happened' they say – but are they sure they know when it happened. Climate modelling suggests the effects could have been severe as a result of the amount of sulphur pumped into the upper atmosphere. They add, the Toba eruption was so big that temperatures in the northern hemisphere declined by 4 degrees celsious – with regional cooling of up to 10 degrees. The models showed that cooling in the southern hemisphere was less than 4 degrees. As one of the sites of human occupation was in South Africa this is said to explain the archaeology.