A team from the University of Cambridge (UK) and the Leibniz Institute for the History and Culture of Eastern Europe (Germany) says a volcanic eruption around 1345 may have triggered a chain reaction that led to the pandemic known as the Black Death. This catastrophe claimed the lives of about half of Europe’s population and fundamentally transformed medieval society.
Thanks to clues preserved in tree rings, researchers suggest that the eruption caused a climatic shock, leading to a series of events that brought disease to medieval Europe. According to this scenario, ash and gases from the volcanic eruption caused a sharp drop in temperatures and widespread crop failures, as reported by BBC.
To prevent famine, densely populated Italian city-states were forced to import grain from regions around the Black Sea. Along with the grain, fleas carrying the plague bacterium made their way to Europe. This perfect storm of climatic shock, famine, and trade vividly illustrates how diseases can emerge and spread in a warming, globalized world.
“While the combination of factors that contributed to the emergence of the Black Death seems rare, the likelihood of zoonotic diseases arising in the context of climate change and evolving into pandemics in a globalized world is likely increasing,” noted Dr. Ulf Büntgen, a co-author of the study.
He added, “This is particularly relevant given our recent experience fighting COVID-19.”
What new insights have scientists gained about the medieval plague epidemic?
Between 1348 and 1349, Europe was swept by the Black Death epidemic. The disease was caused by the bacterium Yersinia pestis, which is transmitted by wild rodents (such as rats) and fleas. Scientists hypothesize that the outbreak began in Central Asia and spread worldwide through trade. However, the exact sequence of events that led to the disease’s arrival in Europe and the deaths of millions remained unclear to researchers.
The new study fills these gaps in knowledge. Researchers analyzed tree rings and ice cores to determine the climatic conditions during the time of the Black Death. The data revealed that volcanic activity around 1345 led to a sharp drop in temperatures for several consecutive years due to the emission of volcanic ash and gases that blocked some sunlight.
Tree rings from the Spanish Pyrenees indicate an extremely cold summer in 1345, 1346, and 1347.
This, in turn, led to crop failures across the Mediterranean. To avoid famine, Italian city-states traded with grain producers around the Black Sea, inadvertently facilitating the entry of the deadly bacterium into Europe.
Martin Bauch, a co-author of the study and a historian of medieval climate and epidemiology, said, “Climatic events collided with a complex food security system, creating something akin to a perfect storm.”
“For over a century, these powerful Italian city-states established trade routes across the Mediterranean and the Black Sea, creating a highly efficient system to prevent famine. But ultimately, this inadvertently led to a much larger catastrophe,” Dr. Bauch said.
The findings of the study were published in the journal Communications Earth & Environment.
Photo: pixabay.com
