The study authors believe an eruption occurred around 1345, about two years before the start of the pandemic, from either a single volcano or a cluster of volcanoes of unknown location, likely in the tropics. The resulting haze from volcanic ash would have partially blocked sunlight across the Mediterranean region over multiple years, causing temperatures to drop and crops to fail.
Wow, that’s exactly what happened just before the Plague of Justinian (i.e., the volcanic winter of 536). I’m surprised they don’t mention that in the article.
I think the framing of questions like this assumes that there are certain “physical” things that follow one intrinsic set of laws, and certain other things that follow a fundamentally different, incommensurate set of laws.
But we don’t actually have direct knowledge of any intrinsic laws, physical or otherwise—the best we have are a set of purely provisional laws we’ve made up and regularly revise on the basis of cumulative evidence. And our method for revising these provisional laws requires that any new evidence that contradicts them, invalidates them—they have to apply to everything without exception. If we give ourselves the out that contradictory evidence might just have “non-physical” causes, we can never invalidate anything nor revise our understanding. So dualistic models are inherently unscientific—not because they’re wrong, but because starting with such assumptions is incompatible with the scientific method.