Of course, the Carboniferous rainforest collapse happened hundreds of millions of years ago, before people were around to witness it, let alone record the event. However, a recent historical study backs up previous claims that the collapse of the Ptolemaic Empire in Ancient Egypt in 30 BC may have been the result of environmental disaster, and the ruling elite’s failure to deal with it.
Joseph G. Manning is Professor of Ancient History at Yale University and led the study “Volcanic suppression of Nile summer flooding triggers revolt and constrains interstate conflict in Ancient Egypt,” published in October 2017. Manning spoke to The Washington Post about his findings not long after the publication of the work. “For so long, [the Ptolemaic Empire] had been playing so close to the edge, fighting huge wars and growing crops that were especially vulnerable to changes in the Nile,” he said. “They refused to change their politics and it left them vulnerable once larger forces in nature and in the world came along and pushed them over the edge.”