A recent study suggests that a major volcanic eruption may have played a critical role in the spread of the Black Death across Europe in the 1340s. Researchers from Germany and the United Kingdom pieced together various lines of evidence to show how climate changes induced by a volcanic event influenced trade routes, enabling the proliferation of plague pathogens during a period of heightened vulnerability.
The Black Death, which peaked in the mid-1300s, is recognized as one of the most catastrophic pandemics in history, claiming tens of millions of lives globally. The disease, caused by the bacterium Yersinia pestis, was primarily transmitted through fleas that infested rodents, leading to outbreaks that could prove fatal within days. While much is known about the impact of the plague, the origins and transmission routes remain subjects of ongoing investigation.
Historian Martin Bauch of the Leibniz Institute for the History and Culture of Eastern Europe and paleontologist Ulf Büntgen from the University of Cambridge conducted a comprehensive analysis that supports the theory that the second plague pandemic emerged from the Central Asian region, specifically Kyrgyzstan, and spread through trade networks.
Uncovering the Climate Connection
To investigate how the plague reached the Mediterranean, Bauch and Büntgen examined ice cores from Antarctica and Greenland, tree ring data from eight European regions, and historical accounts from the 14th century. The ice cores provided compelling evidence of a significant volcanic eruption around 1345 CE, indicated by a dramatic spike in sulfur levels. This spike, the 18th largest recorded in the past 2,000 years, was associated with major volcanic events.
Additionally, tree-ring data reflected unusually cold summers in 1345, 1346, and 1347, particularly around the Mediterranean region. The researchers noted that such temperature anomalies are characteristic of significant volcanic eruptions, which can disperse sulfur-rich gases into the stratosphere, creating a cooling effect that disrupts normal growing seasons and leads to crop failures.
Historical records corroborate these findings, detailing accounts of foggy skies, wet summers, and widespread famine across Europe and Asia. The unidentified volcano, likely situated in the tropics, is believed to have caused the climate crisis that preceded the pandemic.
Trade Routes and the Plague Pathogen
As the climate cooled and agricultural production faltered, the price of grain surged, triggering famines in regions such as Spain, southern France, Italy, Egypt, and the Levant. The plague made its first significant appearance in Italy in 1347, coinciding with a shift in trade dynamics. Venice lifted its trade embargo on the Golden Horde, allowing grain shipments to flow in from the Black Sea.
Research indicates that fleas carrying Yersinia pestis likely survived these maritime journeys, facilitating the initial outbreaks in ports such as Messina, Genoa, Palma, Venice, and Pisa. As grain was distributed throughout Italy, so too was the plague, which eventually spread to other regions, including Alexandria in Egypt.
The findings highlight the interconnectedness of climate events and human activity, illustrating how a volcanic eruption can have far-reaching consequences for populations across continents.
The research, published in Communications Earth & Environment, emphasizes the importance of understanding historical pandemics within the context of environmental changes and trade practices. As stated by the researchers, “A yet unidentified volcanic eruption, or a cluster of eruptions around 1345 CE, contributed to cold and wet climate conditions across much of southern Europe.”
This multidisciplinary approach not only sheds light on the timing and spread of the Black Death but also underscores the significant impact of natural phenomena on human history.
