"Yet, like the proverbial frog in boiling water, the average person back then may only have realised slowly just how grim conditions in their world were getting..."<p>I just have to point out that scientists have in fact tried this, and the frog in the water, as soon as it gets uncomfortably warm, jumps out. There is no evidence that it is possible to raise the temperature slowly enough that it does not do this, and it's not for lack of trying.<p><a href="https://en.wikipedia.org/wiki/Boiling_frog" rel="nofollow">https://en.wikipedia.org/wiki/Boiling_frog</a>
" ... and the Roman senator Cassiodorus noted in 538 ..."<p>If Wikipedia is correct, he wasn't a senator. His full name was Magnus Aurelius Cassiodorus Senator.
I wonder if a large body passed through the solar system around that time? Enough to disturb gravitational forces to trigger massive volcanic activity like that.
Climate change is perhaps one of the many reasons both the Roman and Byzantine empires fell or lost ability to project power. The Byzantine conquest of Italy was finishing up when these plagues hit and they never recovered their original strength again.<p>One has to wonder whether modern agriculture is no longer as affected by these kinds of changes or whether the war in Ukraine is just a sign of things to come.