[nicollo]

I disagree because Islam had not been invented yet

Think again, Mohammad was born in c. 570 and the disruption of the period created the conditions for his take-over of Arabian peninsula, filling in the gaps left from Byzantium and Sassanid (Persia) decline as a result of these climate events.

Archeological digs in Arabian peninsula show a decided change in buildings during this period from trade-oriented structures to defensive ones.

See: "On the eve of Islam: Archaeological evidence from Eastern Arabia" by Derek Kennet (sorry no link)

[gleeaikin]

With a decline in food production over decades, this could have increased the conflict between tribes of Jews, Pagans, Christians that would have stimulated Mohammad to invent his new religion. Certainly his fights with some of those groups was clearly happening.