I wonder what connection, if any, there is between the 6th century cold period and the 7th century rise of Islam.
As the Roman Empire failed due to weather and political corruption it was no longer a force of power in the Eastern Mediterranean and Islam ran wild after the collapse. But the Roman Empire was already in decline before Islam existed.
Islam is entirely a political cult, sprung from either a single person, or from some small group which led to a later group of ad hoc theologists who invented a single founder.
This reminds me a bit of Lycurgus, the supposed lawgiver of ancient Sparta — he was said to set up his legal code, then said to obey it without changes until he got back from Delphi, then went off and starved himself to death.
There’s not much Spartan literature (they don’t seem to have been readers, authors, or artists), but the oldest surviving work contains zero about him. He was probably invented as a supporting myth for their pretty hideous political system.