At http://phys.org/print374150033.html … I always find it strange when a new piece of research claims to have come up with something new when it has been written about before. Mainstream scientists catching up is not exactly new but it just goes to show that research is ignored if it comes outside the bubble. In this instance is the claim that the mid-6th century climatic downturn was responsible, in part, for the collapse of the Eastern Roman empire and the rise of the Arab empire that threatened to overwhelm the civilised world of the 7th century AD. David Keys, in his book 'Catastrophism: an investigation into the origns of the modern world' (Century:1999) said much the same, even down to blaming the low growth tree ring event on volcanic eruptions that sparked massive migrations on the Eurasian steppe that affected China in the east and Europe in the west, and ultimately was responsible for the collapse of the Persian and Eastern Roman empires and the sudden and abrupt eruption from the desert of North Arabia of fierce tribesmen fired up with a new religion and an attitude of mind that despised settled life and agricultural working of the land. The Mongols six hundred years later had a similar mind-set and laid waste the Middle East. The Arabs did much the same – but how much of the civilised world was already in ruins? How much had population dropped as a result of the Justinian Plague.
The new research, by climate scientists, trips along blissfully unaware that people outside the rich gravy oozing through climate science, reinvents it all and more or less says exactly the same as Keys did back in the 1990s. Keys was a journalist and therefore scientists ignored him – and perhaps they can continue to ignore his epic line of research as journalists, even those specialising in science, are not one of the brotherhood so to speak. The new team have even invented a term to describe their cold snap – the Late Antique Little Ice Age. It's not exactly very original – and neither are papers larded with alarmism. Basil Cracknell in his book on sea level change just called it the Late Roman cool period – but he was not in the business of making a fuss. Calling it a cool period was a description of what had occurred, an abrupt drop in temperatures consistent with debris in the atmosphere blocking the warmth of the sun. An ice age suggests a much more lengthy period – but you would need to read Clube and Napier to get a handle on that. It remains to be seen if they are taken seriously as the mid 6th century AD climate blip is generally assigned a shorter duration, although there is good reason to think in terms of a prolonged phase of climate ups and downs (together with enhanced earthquake activity, enhanced meteoric activity, and enhanced volcanic activity).
The researchers also tie in the Justinian Plague epidemic into the equation – as did Mike Baillie and Keys (years ago). The research is published in Nature Geoscience, February 2016, and their discoveries are useful as an add-on to what is already well known (in the right circles).