Climate change

Study: Volcanic Eruptions Brought the Black Death to Europe

Did volcanic climate change trigger the Black Death, or did pre-existing plague conditions determine the pandemic's spread?

Published DEC 4 2025

Study: Volcanic Eruptions Brought the Black Death to Europe

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Above: A view of the ruined ancient Roman city of Pompeii, still partially buried by the 1345 eruption of Mount Vesuvius, near Naples, Italy, on Jan. 16, 2024. Image credit: Pablo Esparza/Anadolu/Getty Images

The Facts

In research published in the journal Communications Earth & Environment on Thursday, researchers from the University of Cambridge and the Leibniz Institute for the History and Culture of Eastern Europe have proposed that volcanic eruptions around 1345 triggered a chain of events that led to the arrival of the Black Death pandemic in Europe.
Nature
Independent
National Geographic
Tree ring analysis from the Spanish Pyrenees revealed consecutive blue rings in 1345, 1346 and 1347, indicating unusually cold and wet summers across southern Europe. Ice core data from Greenland and Antarctica showed sulfur spikes aligned with these cold periods, suggesting volcanic activity that injected an estimated 14 teragrams of sulfur into the atmosphere.
Fox 28 Spokane
NBC
New Scientist
The Black Death spread through Europe between 1347 and 1353, killing an estimated 25 to 50 million people and eliminating more than half the continent's population in some areas. The volcanic cooling caused widespread crop failures and famine across the Mediterranean region, including Spain, southern France, northern and central Italy, Egypt and the Levant.
CNN
Science
The Telegraph
Italian city-states, including Venice and Genoa, had been at war with the Mongol Empire over control of Black Sea trade since 1343, cutting off access to grain supplies from that region. In 1347, facing severe food shortages, these cities negotiated a ceasefire with the Mongols to resume grain imports from the Black Sea area.
Fox 28 Spokane
Science
University of Cambridge
Grain ships returning from Black Sea ports in what is now Crimea and Ukraine in 1347 carried fleas infected with Yersinia pestis, the bacterium that causes plague. The fleas likely fed on grain dust during the voyage and jumped to local rats and humans once the cargo was distributed in Italian ports.
CNN
The Telegraph
Discover Magazine
Cities that relied on imported grain, such as Venice, experienced plague outbreaks first, while cities that grew more of their own food, including Rome, were largely unaffected during the initial wave. According to researchers, the pattern demonstrates how the climate-driven change in trade routes inadvertently facilitated the pandemic's spread.
Independent
Science
The Times (UK)

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The Spin

Climate-concerned narrative

Volcanic eruptions around 1345 directly caused the Black Death pandemic by triggering climate changes that forced Italian merchants to import plague-infected grain from the Black Sea. The eruption created a domino effect — sulfate aerosols blocked sunlight, crops failed across the Mediterranean and desperate grain imports carried Yersinia pestis-infected fleas that jumped to humans within weeks of arrival. This rare confluence of environmental and social factors demonstrates how climate disasters can inadvertently introduce devastating pandemics.

PHYS

BBC News

Popular Science

Climate-skeptic narrative

The Black Death happened when it did because plague infrastructure was already established in Europe long before any volcanic eruption. While climate changes after 1345 may have influenced grain trade routes, major Italian cities like Milan and Rome avoided the plague entirely despite the same climate conditions, proving that local disease reservoirs and existing rodent-flea vectors determined outbreak patterns. Volcanic activity was merely one short-term factor among many long-established conditions that enabled the pandemic.