Volcanic Eruptions Linked to Rise of the Black Death in Europe

The devastating impact of the Black Death on medieval Europe may have deeper roots than previously understood. A recent study suggests that volcanic eruptions occurring in the years leading up to the pandemic may have played a crucial role in creating conditions that facilitated its spread. Researchers have identified a significant volcanic event around 1345 CE, which likely led to a series of unusually cold summers. These climatic changes contributed to widespread famine across the Mediterranean region, setting the stage for the plague’s arrival.

Researchers examined a variety of historical data, including tree ring growth from eight European regions, volcanic sulfur levels preserved in Antarctic and Greenland ice cores, and documented accounts from the fourteenth century. They discovered that a major eruption or a series of smaller eruptions resulted in increased atmospheric sulfur and ash, which disrupted weather patterns. This led to crop failures and food shortages in areas such as Spain, southern France, northern and central Italy, Egypt, and the Levant.

The famine prompted Italian maritime powers to seek grain shipments from the Black Sea region around 1347 CE. While these imports helped stave off immediate starvation, the timing of the grain’s arrival coincided with the first outbreaks of the plague in port cities. This raises the possibility that fleas carrying the bacterium Yersinia pestis, which caused the Black Death, may have traveled alongside the grain shipments, accelerating the spread of the disease across Europe.

Co-author Professor Ulf Büntgen expressed his long-standing curiosity about the factors that led to the onset of the Black Death, stating, “What were the drivers of the onset and transmission of the Black Death, and how unusual were they? Why did it happen at this exact time and place in European history?” His inquiry highlights the complex interplay of environmental and societal factors that contributed to this catastrophic event.

Dr. Martin Bauch, another co-author, noted that the powerful Italian city-states had established extensive trade networks, which were initially effective in preventing starvation. However, these same networks inadvertently facilitated a far greater disaster. Interestingly, the study suggests that some major cities, including Milan and Rome, were likely spared from the Black Death, possibly because they did not require grain imports after the climatic upheaval began in 1345.

The researchers characterize the confluence of climatic, agricultural, societal, and economic factors after 1345 as a “perfect storm” that contributed to the Black Death. They argue that this event serves as an early example of the consequences of globalization. Professor Büntgen noted the increasing likelihood of zoonotic diseases emerging in a changing climate, stating, “The probability of zoonotic diseases emerging under climate change and translating into pandemics is likely to increase in a globalized world. This is especially relevant given our recent experiences with Covid-19.”

This study sheds light on the multifaceted causes behind one of history’s most infamous pandemics, illustrating the interconnectedness of environmental factors and human society. As researchers continue to explore these historical events, the findings further contribute to our understanding of how global factors can influence health crises.