BBC is reporting the results of a study of tree rings growth, calling their article, “Roman rise and fall ‘recorded in trees.’” Tree rings can show us climatic change, because trees grow more in good years, less in years of drought. The beginning of the article suggests that this sheds new light on Roman history, saying, “They found that periods of warm, wet summers coincided with prosperity, while political turmoil occurred during times of climate instability.” Okay, that doesn’t seem particularly surprising, but could be intriguing. I’d be interested to see the year-by-year in Italy during the Social Wars, or during the rivalry of Clodius and Milo– we know that grain shortages were of fundamental importance to political shifts in the late Republic, and the article seemed to suggest that we’d have further elucidation on this point.
As I continued to read the article, however, I learned that this is not the kind of thing the study looked at. By the end of the article, it is revealed that the “rise and fall” discussed in the study is actually this: “‘Increased climate variability from 250-600 AD coincided with the demise of the western Roman empire and the turmoil of the migration period,’ the team reported.” Correct me if I’m wrong, as I’m not an expert in the later Roman empire, but didn’t we know this? Didn’t we know that the southerly migrations that pushed tribes like the Vandals on to Rome were brought on by climatic change? So the way this article is written, it is suggested that we’ve unlocked a great mystery, when in fact we’ve got some good scientific corroboration to something we’ve known for a while. Of course, I am betting the study in fact could tell us quite a bit, but that the journalist had to find some kind of “hook,” and this was what he picked, perhaps not realizing that we don’t need tree rings to tell us that the late Empire migrations were caused by climate change.