Volcanic Eruption Half a World Away Linked to Black Death's Devastation

Scientists have found that a massive volcanic eruption may have triggered the conditions leading to the Black Death sweeping across Europe in the 1340s. By combining multiple lines of evidence, researchers reconstructed a volcanic-driven climate disturbance that altered trade and travel patterns, allowing plague pathogens to reach Europe at a critical moment.

The mid-14th century pandemic, caused by the bacterium Yersinia pestis and spread by fleas, killed millions of people across the continent. While many details of its origins remain uncertain, a key question has been whether the bacterium persisted in Europe since the Plague of Justinian in 541 CE or was reintroduced from Central Asia.

New research by historian Martin Bauch and paleontologist Ulf Bntgen supports the idea that the second plague pandemic originated in Kyrgyzstan and spread along trade routes. To trace its journey from Central Asias highlands to the Mediterranean ports, they analyzed Antarctic and Greenland ice cores, tree ring data from eight European regions, and 14th-century weather accounts.

Ice cores revealed a dramatic spike in sulfur around 1345 CE, indicating a major volcanic eruption, alongside smaller spikes in 1329, 1336, and 1341 CE. The 1345 spike ranks as the 18th largest in the last 2,000 years. Tree rings from 13451347 showed unusually cold summers across Europe, particularly around the Mediterranean, consistent with volcanic cooling that disrupted crops and led to famine. Historical records confirmed hazy skies, wet summers, and widespread harvest failures.

The eruption likely originated in the tropics. Its climate effects caused crop shortages and soaring grain prices across Spain, France, Italy, Egypt, and the Levant. In 1347, Venice lifted its trade embargo on the Golden Horde, allowing grain shipments from the Black Sea, which inadvertently transported fleas carrying Y. pestis. The plague first appeared in European ports such as Messina, Genoa, Venice, Palma, and Pisa, then spread inland as the grain was distributed. Ships also carried the pathogen to Alexandria, Egypt, before it moved north along maritime routes to England and Norway.

This research illustrates how climate, trade, and disease combined to produce one of the deadliest pandemics in human history. By linking volcanic activity to famine-driven trade shifts, the study provides a clear timeline of how the second plague pandemic erupted.

The findings are published in Communications Earth & Environment.

Author: Riley Thompson