Severe deterioration of living conditions in Scandinavia in the years AD 536 – 50 was caused by two volcanic explosions following upon each other
Climatic and societal impacts of a volcanic double event at the dawn of the Middle Ages
By Matthew Toohey, Kirstin Krüger, Michael Sigl, Frode Stordal, and Henrik Svensen
In: Climatic Change (Open Source) Published on the web April 2016
In In 536 CE, observers in Europe documented a mysterious cloud which dimmed the light of the sun for at least a year and presumably longer. For a long time scientists speculated as to the cause of this dust veil. It seems the culprit has now been identified. With this follows new insight into the magnitude of the event.
Volcanic activity in and around the year 536 CE led to severe cold and famine, and has been speculatively linked to large-scale societal crises around the globe. Using a coupled aerosol-climate model, with eruption parameters constrained by recently re-dated ice core records and historical observations of the aerosol cloud, scientists recently reconstructed the radiative forcing resulting from a sequence of two major volcanic eruptions in 536 and 540 CE.
On the basis on this, they have estimated that the decadal-scale Northern Hemisphere (NH) extra-tropical radiative forcing from this volcanic “double event” was larger than that of any period in existing reconstructions of the last 1200 years.
Earth system model simulations including the volcanic forcing show peak NH mean temperature anomalies reaching more than −2 °C, and show agreement with the limited number of available maximum latewood density temperature reconstructions. However, the simulations also produced decadal-scale anomalies of the Arctic sea ice. In sum, the events in 536 – 40 may be estimated to have inflicted the climate in the Northern Hemisphere at least until summer 543. The simulated cooling has been interpreted in terms of probable impacts on agricultural production in Europe, and implies a high likelihood of multiple years of significant decreases in crop production across Scandinavia, supporting the theory of a connection between the 536 and 540 eruptions and evidence of societal crisis dated to the mid-6th century. It appears from maps published by the scientists that a broad belt across Denmark, Sweden and the Baltic was the area, which suffered the most.
The 536 mystery cloud was not only linked to crop failures and famines by ancient scholars, but has also been speculatively linked to a number of major societal crises throughout the Northern Hemisphere, including the European outbreak of the plague of Justinian in 541 CE, demographic decline and migration.
Late Antique Little Ice Age AD 536 – AD 660 – Medieval Histories