Although I didn't listen to the 11 minute podcast, I was curious to know basically what it was about. This is what Wikipedia says about year 536:
"In 2018, medieval scholar Michael McCormick nominated 536 as 'the worst year to be alive' because of the extreme weather events probably caused by a volcanic eruption early in the year, causing average temperatures in Europe and China to decline and resulting in crop failures and famine for well over a year. Other researchers have noted additional adverse events during the year, including a mysterious fog, possibly due to the volcanic eruption."[1]