I just ran across an interesting article in Antiquity that introduced me to an ancient environmental calamity that struck the northern hemisphere: the Dust Veil of AD 536.
Volcanic ash from the Icelandic Eyjafjallajökull volcano in 2010 makes for a pretty sunset on the northern coast of France. Photo by Angus MacRae
Long forgotten but discovered by American geoscientists in the 1980s, the dust veil of AD 536 blotted out the sun for between 12 and 18 months, and brought drought and ruin to Europe and Asia Minor, and possibly as far away as China and the Americas.
The Antiquity article focuses on Scandinavia, arguing that the people there may have been hardest hit, with perhaps as many as 75% of medieval villages abandoned by the late sixth century. Gräslund and Price believe that it may have set the stage for the Viking diaspora some 250 years later.
Gräslund B, and Price N. 2012. Twilight of the gods? The 'dust veil event' of AD 536 in critical perspective. Antiquity 332:428-443.


Comments
Mike Ballie is a Denrochronologist who’s produced some startling data on this period in time.
His book, ‘Exodus to Arthur’ is a must read.
I second that. Mike Baillie’s “Exodus to Arthur” is a book deserving of study, and perhaps more publicity. An academic, he has trodden paths not often explored by scholars.