This just in: Caesar murdered, Rome in turmoil, volcano at 43 BC. According to a team of scientists and historians (Yesss!) ash found in Arctic ice cores suggests that a violent “caldera-forming eruption of Alaska’s Okmok volcano in 43 BC” may help explain an upheaval in which “written sources describe a period of unusually cold climate, crop failures, famine, disease, and unrest in the Mediterranean Region – impacts that ultimately contributed to the downfall of the Roman Republic and Ptolemaic Kingdom of Egypt.” It seems climate change was not invented at the same time as the steam engine or the microchip.
It would be fatuous to explain the demise of the Roman Republic entirely in terms of a hot hollow mountain going boom. There were complex stresses and strains that resulted in the Social Wars (which incidentally were not very social), the rise of strongmen with mercenary armies and the collapse of the ramshackle constitutional order in response in significant part to the successful expansion of Roman authority. (It has been said with considerable justice that the Empire created the Emperor and not the reverse.) But this discovery points to a couple of significant facts about historical climate change starting with its existence.
Yes, folks, Michael Mann’s dratted hockey stick notwithstanding, there were significant short- and long-term temperature fluctuations throughout recorded history including the Roman Warm Period whose name, if prosaic, is quite clear. What’s more, some changes were long-term with long-term causes that at least plausibly still operate today. Others happened in response to sudden shocks and those, too, can still happen and not be our fault even if their results are our problem.
It also seems clear that cold periods are not an unalloyed good. Read again that bit about how “unusually cold climate, crop failures, famine, disease, and unrest in the Mediterranean Region… ultimately contributed to the downfall of the Roman Republic and Ptolemaic Kingdom of Egypt.” You don’t have to be a big fan of the Ptolemies, and who is except perhaps admirers of Elizabeth Taylor, to recognize that as a rule upheaval and collapse are more fun to read about than to live through (or fail to).
Third, to belabour the obvious, paleo climate change was not man-made so there must be natural sources of variation capable of causing significant climate change, and natural forces didn’t all disappear around the time Ms. Taylor gave her immortal performance as Cleopatra opposite Richard Burton’s Marc Antony. (Ironically this famously turbulent historical romance was probably a model of domestic calm next to the relationship between the two actors involved.) But if natural events can cause spikes in temperature in the ancient world, whether up or down, it is not reasonable to deny that it could happen in modern times, claim that the heat around 2016 settles the debate forever, and assert that only fools or liars would claim otherwise.
