This is the presentation I gave to the meeting for the 50th anniversary of the Club of Rome on Oct 18th in Rome. The gist of the idea is that the fall of ancient civilizations, such as the Roman Empire, can be described with the same models developed in the 1970 to describe the future of our civilization. States, empires, and entire civilizations tend to fall under the combined effect of resource depletion and growing pollution. In the end, they are destroyed by what I call the Seneca Effect.
You can find the paper I mention in the talk, coauthored by Ilaria Perissi and Sara Falsini, at this link.