The question about climate change and empire is sadly ever more relevant as climate change drastically transforms the world. So more research like this is valuable:
A new paper, just published Monday in the journal Nature Geoscience, proposes a link between a marked cooling event in the fifth and sixth centuries AD and a period of dramatic social change across Europe and Asia, including a pandemic plague outbreak, food shortages, political turmoil in China, migrations and even the rise of the Islamic empire. It’s impossible to say for sure whether the climatic shift was actually responsible for all the upheaval that went on during that time, the researchers say — but since the two periods coincided, the scientists are proposing that a connection is likely.
“There are a lot of things that occurred at the same time, and now it’s certainly very difficult to disentangle to what degree was it caused by climatic fluctuations,” said the study’s lead author, Ulf Büntgen, who heads a research group specializing in tree-ring science at the Swiss Federal Institute for Forest, Snow and Landscape Research. “But we just cannot exclude it anymore.”
In Europe, the colder climate is believed to have contributed to a decrease in agricultural output, which resulted in widespread food shortages. Around the same time, there was an outbreak of plague in the Byzantine Empire, which started around 541 AD and eventually achieved pandemic status as it spread throughout Europe, killing millions and contributing to the weakening of the Empire.
The researchers have hypothesized that the agricultural declines may have helped the plague bacteria spread from Asia into Europe via wildlife moving into the increasingly abandoned agricultural fields, although they acknowledge in the paper that much remains unknown about the plague’s origin and its link to climate during this time.
Additionally, historians believe there was a great deal of political turmoil in central Asia during this time period, with particular conflict within the regimes governing northern China. Meanwhile, it appears that Slavic populations were spreading across Europe. These events may have also been triggered by social instability caused by famine, crop shortages and disease outbreaks.
The authors have even suggested that there may be a link between climate and the eventual rise of the Islamic Empire. Changes in precipitation patterns, caused by the cooling, may have helped enable the growth of scrub vegetation on the Arabian peninsula, they note in the paper, adding that“larger camel herds may have facilitated transportation of the Arab armies and their supplies during the substantial conquests in the seventh century, during which the reconstructed fraction of human land use seems relatively high in the Arabian Peninsula.”