Original source of "Black Death" was bacteria of fleas on marmots
“It is, perhaps, no coincidence that, in the past two decades, China has been the origin of SARS, the swine flu, and now the Covid-19 coronavirus. Nor should we be surprised that Iran and Italy have emerged, once more, as waypoints for pandemic spread”
“Some historians believe the innumerable deaths brought on by the plague cooled the climate by freeing up land and triggering reforestation. This may have led to the Little Ice Age”
Wikipedia does not identify the source of Black Death