How do volcanic winters impact global climate?

Volcanic winters are periods of global cooling triggered by highly explosive, sulfur-rich volcanic eruptions. These events release sulfur gases that form reflective aerosols in the stratosphere, blocking sunlight and lowering surface temperatures for years.

What we know

• Volcanic winters are initiated when sulfur dioxide and hydrogen sulfide injected into the stratosphere react to form sulfuric acid aerosols. [2]
• These stratospheric aerosols cool the Earth's surface by reflecting solar radiation, while simultaneously warming the stratosphere by absorbing terrestrial radiation. [2]
• The cooling trend of a volcanic winter can be prolonged for years beyond the lifespan of the aerosols themselves through atmosphere-ice-ocean feedback mechanisms. [2]
• The volcanic winter of 536, caused by multiple eruptions, dropped European summer temperatures by up to 2.7 degrees Celsius and initiated the Late Antique Little Ice Age. [3]

Still open

• The exact geographical locations and origins of the volcanic eruptions that triggered the severe volcanic winter of 536 remain unresolved.

Where to go next

• how it workedHow do sulfur aerosols reflect solar radiation?
• a case in pointWhat happened during the volcanic winter of 536?
• compared withHow does an impact winter differ from a volcanic winter?
• whenWhat was the Late Antique Little Ice Age?
• the bigger pictureHow do natural events cause historical climate change?
• an unexpected connectionCan volcanic eruptions trigger pandemics?The severe cooling and crop failures of the 536 volcanic winter closely coincided with and accompanied the devastating Plague of Justinian.

Sources

• [1]volcanic winter (Wikidata Q1162172) · CC0 1.0
• [2]Volcanic winter · CC BY-SA 4.0
• [3]Volcanic winter of 536 · CC BY-SA 4.0
• [4]Impact winter · CC BY-SA 4.0
• [5]Climate change · CC BY-SA 4.0