The initial cause of the sharp cold snap, crop failures, plague and famine that struck the ancient world in the 6th century were two powerful volcanic eruptions. This is the conclusion reached by German and Norwegian scientists, the authors of an article in the journal Climatic Change.
Almost nothing is known about the eruptions: the chroniclers note only the "mysterious cloud" that dimmed the sunlight in the Mediterranean in 536-537. Tree rings of the same years indicate a drop in yield. Only recently did researchers learn about the reasons for the "dim" Sun - in the ice cores of 536 and 540 years, extracted in Greenland and Antarctica, they found traces of sulfur of volcanic origin.
Climatologists tried to model the impact of the eruptions of 536 and 540 on the climate, based on the stories of chroniclers and data from cores. They calculated the approximate location of the erupting volcanoes and the spread of sulfur and other airborne particles. According to scientists, for several years, the average temperature in the northern hemisphere of the planet fell by two degrees Celsius. The decade 536-546 was the coldest in the last two thousand years, climatologists say.
However, the exact location of the culprit volcanoes is still a mystery. Scientists are discussing several candidates located in Central America, North America, and Indonesia.
In February 2016, the international collective PAGES (Past Global Changes) linked the global cooling of 536-660 with a number of significant events - from the Justinian plague to the painful transformation of the Eastern Roman Empire.