2020 can be said to be a tough year for humans due to the COVID-19 pandemic. Many lives have been lost because of this Sars-CoV-2 virus and millions of people are suffering from grief.
However, 2020 is not the only year that has been hit by bad events. There were also 1349 hit by the Black Death, or flu pandemic, in 1918. Historian Michael McCormick and archaeologist from the Harvard University Initiative for the Science of the Human Past said there was yet another year called the 'worst year' to live -- 356.
"It was the start of one of the worst periods to live in -- just in case it wasn't the worst year," McCormick told Science.
It all started with a mysterious fog that swept across Europe, the Middle East and parts of Asia. The fog cast darkness for 18 months. The sun looks like the moon, the temperature suddenly drops drastically.
The temperature in summer also drops. One of the worst was in China, where the summer was colored with snow.
From bad weather, this has an effect on failed crop yields. The famine also hit and took many innocent lives. This misfortune struck for decades, to be precise until the year 660.
So, what is the cause of the bad year 536? McCormick and glaciologist Paul Mayewski of the Climate Change Institute of The University of Maine (UM) in Orono said this was likely due to a volcanic eruption in early 536 which was followed by two major eruptions in 540 and 547.
Furthermore, from tree ring studies in the 1990s, it was shown that the summers around AD 540 were very cold. Until finally, the polar ice cores from Greenland and Antarctica provided clues to the cause of the cold era.
When a volcano erupts, it is believed it spews sulfur, bismuth, and other substances high into the atmosphere, where they form an aerosol envelope that reflects sunlight back into space, thus cooling the planet.
By matching the ice records from these chemical trails with tree-ring climate records, the team led by Michael Sigl (now of Bern University) found that nearly every unusually cold summer over the past 2,500 years was preceded by a volcanic eruption.