BTW, there was no "blank spot" either ~ just very few people. And, according to contemporary accounts the skies were noticeably darker and the Sun was always red.
According to the Bretons their first forays into Brittany (as they fled Brittain to escape the invading Angles and Saxons) revealed that no one lived there.
Their own traditions were that people lived there ~ but, alas, Merlin was forced to replant all the vinyards since without people domesticated grapes had disappeared from even the Breton march state now known as the county of Beaujolais.
I'd just bet you are one of those people who continues to believe that all that happened was the fall of Rome. In reality, Rome fell nearly a century before this event. People North of Rome began having a very difficult time making a living and finding enough to eat. Virtually every burnable thing was consumed by fires as folks sought to get warm and evade death.
To the South they had the Plague of Justinian.
Now, about the handful of Arabs, they were far from being uncivilized or few in number. In fact, the early Moslems readily converted the population of Petra and drew on the largest extant population base in the Middle East (outside of the city of Byzantium).
They also paid salaries to Byzantine armies who converted to Islam en masse.
Maybe so. Wiki attributes the term to Plutarch. But he still used it as a pejorative comparison to the glory of Classical Rome. The article goes on to restate my position: that "Most modern historians dismiss the notion that the era was a "Dark Age" by pointing out that this idea was based on ignorance of the period combined with popular stereotypes: many previous authors would simply assume that the era was a dismal time of violence and stagnation and use this assumption to prove itself."
It has nothing to do with the weather or population.