Part of a discussion on The Great Change listHere are my posted comments on the article:
In you note, the first graph of the seneca effect looks suspiciously lilke a graph which is simply exponential growth until it suddenly stops and the population goes to zero. That is in fact essentially what it is. The key statement in this article is the last:
v "Very often, we fail to understand the delayed effects of our actions. John Sterman reminds us of this point in a talk on global warming quoting Robert Louis Stevenson as saying, "Everybody, sooner or later, sits down to a banquet of consequences." The models shown here tell us that the Seneca cliff is the result of delayed consequences."
There is a very simple mathematical model which demonstrates the way overshoot is caused by delayed consequences. Start with the classic model of a system with an ultimat sustained value of 1, the growthy of which isgradually curtailed as the value approaches 1, but at first is essentially exponential. A common very simple model of this is calculated from the equation,
d/dt s(t) = s(t)(1-s(t)),
which in English says the rate of change of s is equal to s times (one minus s). As longf as s is much less than 1, the rate of growth of s is approximatelty equal to s itself, which is classic exponential growth. But as the numbers approach a sustaionable value, the growth rate slows until it becomes zero when the sustainable level is reached.
Now let's impose a delayed response. We'll use a very simple model in which we replace the s(t) inside the parentheses with zero if t is less than some time T, and with s(t) if t is later than T. In other words, we've delayed the response of the system to crowding until time T. I've made this example so simple that anyone can plot out the curve with a plain old calculator. If you do, you'll see that the bigger is T, the greater is the overshoot, because the system doesn't begin to warn itself in time that there are limits. The curve goes up exponentially until s = exp(T) (the exponential function for time t=T), and then drops precipitously, the greater the overshoot, the faster the drop. Try different values of T (including negative ones) you'll see that an eafrly-warning system results in a smooth transition to a sustainable number for s, but the more the transition is delayed, the greater is the overshoot and the more skewed is the drop.
That is precisely what is happening. We were warned about overshoot around 1970 but ignored it and tried to avoid it. More or less the same thing happened with the"dot com bust." There continue to be attempts to postpone the time of transition, which will only make things worse. The job of the people of the world is (1) to start behaving as if we need to curtail our growth immediately even if it doesn't feel that way, because the longer we wait the worse things will be, and (2) to replace the ponzi-schemers who run the world with people who recognize that T is right around the corner and behave that way.
One simple example of a time delay (of about 30 years) is the population explosion. Babies don't use as many resources as adults, so the effect of adding to the population isn't felt until the babies become adults.- an automatic "Seneca effect" even if we're not confronting exhaustion of resources.
Incidentally, there is one and there are probablhy many population systems in nature whose populations look like the Seneca Effect. One example is lady bugs, whose populations grow exponentially until their food supply is almost completely gone, and then crash almost to zero, almost instantaneously. You watch the population grow year by year until finally everything is cvered with lady bugs, and then the next year you can't find a single one. You'd think we'd know better, but we apparently don't. We have to start learning FAST, because the longer we wait, the harder will be the fall.
----- Original Message ----- From: helmut...ecoglobe.ch
Sent: Monday, August 29, 2011 5:47 PM
Subject: [TGC] Cassandra's legacy: The Seneca effect: why decline is faster than growth
[Abbreviations are explained at the bottom of the mail]
Right. Ugo Bardi explaining with graphs and figures what has been said elsewhere. Good!
The author is still very much alive. Cassandra was sold as a slave after Troja fell.
To me the method of spreading the message is crucial.
The message must be:
1. Short and poignant, credible and understandable at first sight to the majority of normal citizens, which includes a large share of the functionaries in the BPE structures.
2.1 It must be resistant against false counter-attacks by the BAU PiP.
2.2 An organised system of replying must be in place to counter any false BAU PiP reactions.
3. The message needs to be pushed bottom up, from the normal citizens to the BPE in such a way that the PiP have to follow suit and do what is necessary.
4. A credible solution must be offered that is more attractive than the BAU fake solutions of the PiP.
5. People must not get the feeling that it's all lost anyway. (This is the most difficult point. If one wants to be honest, the threats seem too huge. Nick may be right that reducing the pain on the downslope a little bit could be preferable to doing nothing at all.)
With the BPE, the media and NGOs all adhering to HOT, I find it difficult to imagine ways to organise such a drive to halt increasing overshoot and get us on the road to contraction.
Yours helmutly ... Carpe diem
<<< Steve's Mon, 29 Aug 2011 14:04:50 -0400
This is a wonderful blog. Too bad the usual reaction has been to kill the messenger.
Carpe diem ...
... quam minimum credula postero -
Pluck the day, trusting as little as possible in the future. - Horatius
Cueille le jour présent, en te fiant le moins possible au lendemain.
Plücke den Tag und vertraue der Zukunft so wenig wie möglich.
<<< some abbreviations to facilitate understanding of modernity >>>
BPE = Business, Politics and the discipline of Economics
ECONOMIC GROWTH = The difference in GDP between one year and the previous one. GDP=Money=Material. "Dematerialised growth" is nonsense sublime.
HOT = Hope Optimism Technology
LSM = Lame Stream Media
OVERSHOOT = Too many people consuming too much resources, possibly more than 400 times in excess of the planet's carrying capacity.
PiP = People In Power
PPOD = Post Peak Oil Downslope
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