Why was 536 the worst year for humanity?

Searching for the culprit: volcanoes enter the scene

Molten lava is seen coming out of a fissure on the outskirts of the fishing village Grindavik in southwest Iceland, on April 1, 2025. The Icelandic Meteorological Office (IMO) said “an eruption has started on the Sundhnuksgigar Crater Row” north of the fishing village Grindavik that was evacuated Tuesday after lava began spewing from a volcanic eruption, the eighth to hit the region since the end of 2023. (Photo by Ael Kermarec / AFP)

For centuries, the mystery remained: where did this deadly fog come from? Thanks to advances in modern science, researchers like Michael McCormick and Paul Mayewski have finally cracked the secret. By analyzing an ice core extracted from a Swiss glacier—a veritable atmospheric time capsule—they discovered that  a volcanic eruption in Iceland  released enormous amounts of ash into the atmosphere in 536.

Imagine a volcano throwing out a gigantic black cloud capable  of darkening the daylight over all of Europe  !  In addition , two other eruptions, in 540 and 547, aggravated the situation, plunging the economy into a recession that would last  more than a century .

A slow rebirth captured in ice

However, all is not forever gloomy. Around 640 AD, scientists detected an increase in lead concentrations in ice cores, a sign that  silver mining—the driving force of trade and industry—was gradually picking up . It’s a bit like seeing the first flowers bloom after an endless winter.

Furthermore, around 660,  the widespread use of silver as currency  testifies to an economic renaissance and the rise of a merchant class. A sort of  miniature medieval “economic revolution” , rising from the ashes of a desolate era.

When history repeats itself…

But the lesson was not learned: in the 14th century, during the  Black Death , lead pollution fell sharply, a sign of a new economic collapse. Like  the breath of a forge bellows that suddenly goes out , human activity froze again.

Thanks to this fascinating research,  modern archaeology reveals that our societies remain extremely vulnerable to natural forces . And even today, by observing ice cores or tree rings,  nature continues to tell us its forgotten stories .