Archaeologist, medieval historian, and Harvard University Initiative for the Science of the Human Past chairperson Michael McCormick has tagged the year 536 A.D. as the worst year ever to have been alive. Thus beating out 1349 A.D., the year the Black Plague or Black Death that killed half the population of Europe, and 1918, the year that 50 to 100 million died from the flu.
In 536 A.D, an inexplicable fog blanketed parts of the Asian continent, the Middle East, and Europe, and shrouded them in darkness for one and a half years straight.
The ambient temperatures during that year's summer decreased by 1.5 to 2.5° Celsius, which made it the coldest decade for the last 2.3 millennia. China experienced snow; crops died; many starved.
The mysterious fog puzzled historians for a long time. However, a new study using ultra-precise ice analysis of a glacier provides new insights. A volcanic eruption that occurred in Iceland released ash throughout the Northern Hemisphere in the early part of 536 A.D. In addition, two more massive volcanic eruptions also occurred in 540 A.D. and 547 A.D. These repeated eruptions, and added by plague, caused economic stagnation in Europe until the year 640.
According to the University of Oklahoma, Roman and medieval historian and provost Kyle Harper, the frozen log that records pollution and natural disasters provide precise documentation that helps understand the interconnection of events, which ultimately caused the decline of the Roman Empire and the birth of a rising medieval economy.
Studies of tree rings during the 1990s have shown the unusual coldness of summers surrounding 540 A.D. Antarctic and Greenland ice cores provided a possible reason. During a volcanic eruption, bismuth, sulfur, and other chemicals and particles get ejected into the Earth's atmosphere, forming a veil of aerosol which bounces the light of the sun back to space and causes cooling on Earth.
University of Bern's Michael Sigl and his team compared the ice record with records from tree rings. They discovered that almost all unusually cold summers in the last two and a half millennia were the results of effects caused by the eruption of a volcano.
Sigl and his team suggest that this is what happened in 536. A destructive volcanic eruption occurred in the late part of 535 or early 536, followed by another one in 540.
McCormick and his team looked for a similar occurrence and pattern in their ice core, which was drilled from Colle Gnifetti Glacier from the Swiss Alps. This core is 72 meters long, obtained from the center of Europe, and contains over two millennia of records from volcanic eruptions and dust storms from the Sahara, plus the effects of human activities. The record was analyzed with an ultra-high-resolution laser that carved 120-micron ice slivers. Each sample was analyzed for various elements.
According to Andrei Kurbatov, a volcanologist from the University of Maine, the ice core allowed for dating storms, eruptions, lead pollution, and similar events as precisely as a month or less, up to the past two millennia.
Further analysis of volcanic glass from the ice core turned out that it likely came from the Iceland eruption. The weather and winds of 536 probably brought the plume to Europe and Asia, which caused the fog.
The team also found a spike of lead in 640 A.D, which means silver smelting from lead ores and a rebounding economy, according to Christopher Loveluck, a University of Nottingham archaeologist. Then the second peak of lead occurred in 660, marking the major role that silver played in the new economy and the emergence of the merchant class.
Then, in the years 1349 to 1353, the Black Plague ravaged Europe, and lead once again disappeared from the air and ice record. The economy once again halted.