Agree that it was a catastrophe by the article's definition, but the author specifically says 'since 1500', which excludes the Mongol Wars (from what I understood from your linked page)
My first thought when I started reading TFA was that the list of catastrophes to consider would be biased because more recent events have better records. Maybe that's why the author decided on the 1500 cut off?
Author here. The Mongol invasions are in the .csv in the appendix (and represented in the scatter plot), but weren't included in the table because it restricts to events that lasted less than a decade.
If you restrict to the single "worst" decade then the Mongol invasions would have been high enough to make the list, but I didn't want to start making too many manual adjustments to the data, so I left it as-is.
My first thought when I started reading TFA was that the list of catastrophes to consider would be biased because more recent events have better records. Maybe that's why the author decided on the 1500 cut off?