A study found that the Little Ice Age may have contributed the collapse of the Eastern Roman Empire and the start of the Arab Empire. They discovered a temperature drop that happened 1,500 years ago followed by three major volcanic eruptions that caused a unique cooling period in central Asia and Europe.
The eruptions occurred in 536, 540 and 547 A.D. and ejected large volumes of sulfate aerosols into the atmosphere that block sunlight. The unique, cooling phenomenon might have affected the food supply and caused widespread famine in the region. A pandemic soon followed.
Swiss Federal Institute for Forest, Snow and Landscape Research's Ulf Büntgen and colleagues analyzed tree ring data collected from Central Asia and Europe to analyze the unique cooling period in the region wherein some areas were about 4 degrees Celsius cooler than the others.
"Trees growing at the upper tree line are very sensitive to small changes in summer temperature. If it's a cooler summer, the rings are more narrow," said lead author Büntgen.
The unique cooling period coincided with several social disorder across Eurasia which includes the plague that swept Eastern Europe, the expansion of Slavs across Europe, the changing of Chinese dynasties and the eastern Roman Empire's shift into the Byzantine Empire.
Historians refer to this period as Late Antiquity. In the study, the researchers named the unique cooling period as the Late Antique Little Ice Age. Based on their data, Büntgen said this period was the coldest in the past 2,000 years.
"Such climatic disruption could have contributed to the movement of plague-bearing rodents into the empire," said University of Nottingham's historian Doug Lee.
On the other side, the Arabian Peninsula enjoyed increased rainfall which improved vegetation. This may have contributed to the Arab Empire's expansion in the Middle East. Improved vegetation meant more food to sustain bigger camel herds, which were used by the Arab armies. The abundant sustenance could have helped the Arabs expand to Europe and conquer the Romans.
The findings were published in the Nature Geoscience journal on Feb. 8.
Photo: Wolfgang Staudt | Flickr
