This isn't a new idea. David Keys wrote a book "Catastrophe" 15 years ago dealing with the same subject, although in his case he picked a different volcano as the probable cause.
He also looked at the effects on a world-wide basis, not just in Europe.
To quote from the book's marketing literature: "In AD 536, a volcanic eruption meant our planet was enveloped by a cloak of lethal dust which changed the climate for decades. The sun's rays grew dim and total darkness reigned for days. It was a catastrophe of unparalleled proportions."
He also looked at the effects on a world-wide basis, not just in Europe.
To quote from the book's marketing literature: "In AD 536, a volcanic eruption meant our planet was enveloped by a cloak of lethal dust which changed the climate for decades. The sun's rays grew dim and total darkness reigned for days. It was a catastrophe of unparalleled proportions."
http://www.amazon.co.uk/Catastrophe-Investigation-Origins-Mo...