A multidisciplinary study finds evidence that an unrecorded tropical volcanic eruption around 1345 produced a sulphur spike and a short period of cooling that strained European harvests. Ice‑core chemistry, tree rings and contemporary chronicles all point to cold summers from 1345–1347 and failing crops. The resulting food shortages likely prompted renewed trade with the Golden Horde through Caffa, reopening routes that brought fleas carrying Yersinia pestis into Europe and helping trigger the Black Death (1347–1353). The authors warn that similar climate‑driven disease risks could increase under modern globalisation and climate change.
Study Suggests Undocumented 1345 Tropical Volcano Helped Spark the Black Death
A Volcano May Have Started the Black PlagueProPIC - Getty Images
A new multidisciplinary study argues that an unrecorded tropical volcanic eruption around 1345 cooled global temperatures, worsened harvests and helped set the stage for the Black Death. By combining polar ice‑core chemistry, tree‑ring data and contemporary chronicles, researchers link a sulphur spike in 1345 to unusually cold summers through 1347 and to economic pressures that reopened risky trade routes between Europe and Central Asia.
Evidence From Ice, Trees and Texts
The team, from the University of Cambridge and the Leibniz Institute for the History and Culture of Eastern Europe (GWZO), compared sulphur anomalies in Greenland and Antarctic ice cores with dendrochronological records from eight European sites and with written accounts from the mid‑14th century. Ice cores show a clear sulphur spike dated to 1345, and tree rings indicate suppressed growth consistent with cold summers from 1345–1347. Contemporary chronicles report hazy skies, failed harvests and food shortages in the years immediately before the pandemic accelerated after 1347.
How A Volcano Could Have Changed History
The authors propose a plausible chain of events: volcanic aerosols caused short‑term global cooling and crop stress, which increased famine risk and food insecurity across Europe. Facing starvation and depleted local supplies, Italian merchants reportedly renewed trade with the Golden Horde despite prior tensions and a de facto embargo at the Crimean port of Caffa. That reopening of trade, the study argues, likely allowed infected fleas and rodents carrying Yersinia pestis—already traced to wild rodents in what is today Kyrgyzstan—to enter broader Black Sea trading networks and reach Europe between 1347 and 1353.
"Answering why the Black Death began when and where it did requires many different lines of evidence," says co‑author Ulf Büntgen. The study couples paleoclimate proxies, tree rings and historical records to provide a coherent climatic and documentary picture for 1345–1347.
Volcanic Precedents
The paper places its findings in the wider context of volcanic impacts on human societies. Explosive eruptions can inject ash and sulfur into the stratosphere, triggering temporary global cooling and crop failures. Famous examples include the Santorini eruption (circa 1600 B.C.E.) and the 1815 Tambora eruption, which produced the “Year Without a Summer” in 1816. The 1345 event was likely less visually dramatic than Tambora but sufficient to depress seasonal temperatures and stress food systems.
Why This Matters Today
Between 1347 and 1353 the bacterium Yersinia pestis, transmitted by fleas living on rodents, killed millions across Europe, with local mortality rates reaching as high as 60 percent in some regions. The authors stress that while the specific coincidence of factors that produced the Black Death may have been rare, similar climate‑driven pressures combined with globalized trade could increase the risk that zoonotic diseases emerge and spread rapidly today. The study underscores the importance of multidisciplinary approaches—linking paleoclimate science, dendrochronology and historical scholarship—to understand complex past events and to inform present‑day risk assessments.
Source: Communications Earth & Environment; research teams at the University of Cambridge and GWZO Leipzig. (Includes analysis of ice cores from Greenland and Antarctica, tree‑ring chronologies across Europe, and contemporary documentary evidence.)
