Volcanic eruption may have triggered Europe’s Black Death plague

A volcanic eruption around 1345 may have triggered a chain reaction that triggered Europe’s deadliest pandemic, the Black Death, scientists say.

Evidence preserved in tree rings suggests that the eruption triggered a climatic shock and led to a series of events that brought disease to medieval Europe.

In this scenario, ash and gases from a volcanic eruption caused extreme temperature drops and led to crop failures.

To avoid famine, the highly populated Italian city-states were forced to import grain from regions around the Black Sea, bringing plague-carrying fleas that also carried the disease to Europe.

Experts say this “perfect storm” of climate shock, famine and trade is a reminder of how diseases can emerge and spread in a warmer, globalized world.

“Although the coincidence of factors contributing to the Black Death appears rare, the likelihood of zoonotic diseases emerging under climate change and translating into pandemics is likely to increase in a globalized world,” said Dr Ulf Büntgen of the University of Cambridge.

He added: “This is particularly relevant given our recent experiences with Covid-19. »

The Black Death swept through Europe in 1348-1349, killing up to half the population.

The disease was caused by a bacteria known as Yersinia pestis Spread by wild rodents, such as rats and fleas.

The outbreak is believed to have started in Central Asia and spread around the world through trade.

But the precise sequence of events that brought the disease to Europe – killing millions – has been studied extensively by researchers.

Researchers from the University of Cambridge and the Leibniz Institute for Eastern European History and Culture (GWZO) in Leipzig have now filled a missing part of the puzzle.

They used clues from tree rings and ice cores to examine climatic conditions at the time of the Black Death.

Their evidence suggests that volcanic activity around 1345 caused a sharp drop in temperatures over consecutive years due to the release of volcanic ash and gases that blocked some sunlight.

This led to poor harvests throughout the Mediterranean region. To avoid famine, Italian city-states traded with grain producers around the Black Sea, allowing the deadly bacteria to unwittingly take hold in Europe.

Dr Martin Bauch, GWZO historian of medieval climate and epidemiology, said climate events met a “complex food security system” in what amounted to a “perfect storm”.

“For more than a century, these powerful Italian city-states established long-distance trade routes across the Mediterranean and the Black Sea, allowing them to activate a very effective system to prevent famine,” he said. “But ultimately it would inadvertently lead to a much bigger catastrophe.”

The results are reported in the journal Communications Earth & Environment.