Large volcanic eruptions are one of the most important natural causes of rapid and short-term climate change. In Asia, for example, they have colder summers in the north, weaker monsoons, and thus less rainfall in the south. Cold and drought adversely affect the harvest.

Researchers led by Chaochao Gao of Zhejiang University in China and Francis Ludlow of Trinity College Dublin in Ireland have reconstructed 156 volcanic eruptions using ice cores between 1 AD and 1915. They linked this information with historical documents from 68 Chinese dynasties.

An analysis published in the journal Communications Earth and the Environment indicates that the vast majority of dynasties (62 out of 68) preceded one or more volcanic eruptions. “For the first time we have been able to show that the risk of dynasties collapsing in China after volcanic eruptions is very high.

Complex intervention

However, researchers point out that the collapse of a dynasty is complex and interrelated. For example, it underscores the fact that the Tambora eruption of 1815 and the Hyunaputina (1600) or Samala (1257) did not fall immediately. In addition to poor harvests, poor leadership and corruption in government are among the factors that destabilize a dynasty.

Researchers have shown that small climatic impacts caused by volcanoes can lead to the collapse of dynasties if political, socio-economic tensions persist. Conversely, large shocks can cause them to fall, even at previously low pressures.

Serious repercussions for vulnerable populations

Researchers suspect that moderate volcanic eruptions of the 1970s and 1990s, along with man-made sulfur emissions, may have contributed to the Sahel drought. The University of Burns estimates that 250,000 people were killed and more than 10 million were displaced by the disaster.

In connection with global warming, the authors say, major volcanic eruptions will have a profound effect on agriculture, “in some of the most populous and at the same time most marginalized areas of the world.”

https://www.nature.com/articles/s43247-021-00284-7