I defined as the "Seneca Cliff" the tendency of some systems to collapse after having peaked. Here I start from some considerations about whether the collapse could be smooth or an uneven process that we could define as "punctuated." I am taking the Roman Empire as an example and showing that it did decline much faster than it grew. But the decline was surely far from smooth.
The idea of an impending collapse of our civilization is already bad enough in itself, but it has this little extra-twist that collapse may be given more speed by what I called the "Seneca Cliff," from the words of the Roman Philosopher who had noted first that, "Fortune is slow, but ruin is rapid". The concept of the Seneca Cliff seems to have gained some traction over the Web and many people have been discussing it. Recently, I found an interesting comment on this point by Jason Heppenstall on his blog "22 billion energy slaves". He summarizes the debate as:"In the fast-collapse camp are the likes of Dmitry Orlov (who bases his assessment on his experience of seeing the USSR implode) and Ugo Bardi, who expects a ‘Seneca’s Cliff’ dropoff. James Kunstler, Michael Ruppert and any number of others can probably also be added to the fast-collapse camp.
By comparison, the likes of John Michael Greer reckon we are in for a drawn-out era of terminal decline punctuated by serious crises which, at the time, will seem rather severe to all involved but which will give way to plateaux of relative stability, albeit at a lower level of energy throughput."
Actually, the two camps may not be in such a radical disagreement with each other as they are described. The idea of the fast (or Seneca-like) collapse does not necessarily mean that collapse will be continuous or smooth. The model that describes the Seneca effect does give that kind of output, but models are - as usual - just approximations. The real world may follow the curve in a series of "bumps" that will give an impression of recovery to the people who will experience the painful descent period.
So, collapse may very well be "punctuated: a series of periods of temporary stability, separated by severe crashes. But it may still be much faster than the previous growth had been. I discussed this point already in my first post on the Seneca Effect, but let me return on this subject and let me consider one of the best known cases of societal collapse: that of the Roman Empire.
First of all: some qualitative considerations. Rome's foundation goes back to 753 BC; the end of the Western Empire is usually taken as 476 AD, with the dethroning of the last Western Emperor, Romulus Augustus. Now, in between these two dates, a time span of more than 1200 years, the Empire peaked. When was that?
The answer depends on which parameter we are considering but it seems clear that, whatever choice we make, the peak was not midway - it was much later. The Empire was still strong and powerful during the 2nd century AD and we might take the age of Emperor Trajan as the peak (he died in 117 AD) as "peak empire." We may also note that up to the time of Emperor Marcus Aurelius (who died in 180 AD), the empire didn't show evident signs of weakness, so we could take the peak as occurring in mid or late 2nd century AD. In the end, the exact date doesn't matter: the Empire took around 900 years to go from the foundation of Rome to the 2nd century peak. Then, it took just 400 years - probably less than that - for the Empire to wither and disappear. An asymmetric, Seneca-like collapse, indeed.
We also have some quantitative data on the Empire's cycle. For instance, look at this image from Wikipedia.
It shows the size of the Roman military over the Empire's span of existence. WIth all the uncertainties involved, also this image shows a typical "Seneca" shape for both the Western and the Eastern parts of the Empire. Decline is faster than growth, indeed.
There are other indicators that we can consider about the collapse of the Roman Empire. In many cases, we don't have sufficient data to say much, but in some, we can say that collapse was, indeed, abrupt. For instance, you can give a look to a well known image taken from Joseph Tainter's book "The Collapse of Complex Societies"
The figure shows the content of silver in the Roman "denarius" which by the 3rd century AD, had become pure copper. Note how the decline starts slow, but then goes on faster and faster. Seneca himself would have understood this phenomenon very well.
So, the Roman Empire seems to have been hit by a "Seneca collapse" and that tells us that the occurrence of this kind of rapid decline may be commonplace for the entities we call "civilizations" or "empires".
It is also true, however, that the Roman collapse was far from being smooth. It went through periods of apparent stability, interrupted by periods of extremely fast descent. The chroniclers of the time described these periods of crisis, but none of them seem to have connected the dots: they never saw that each crisis was linked to the preceding one and leading to the next one. Punctuated collapse seemed to be invisible to the ancient Romans, just as it is for us, today.