When does surplus = resilience ?  

Stuart at Early Warning has a look at the ability of societies to muster resources to meet existential threats - When does surplus = resilience?.

Optimists about our current civilization tend to ignore the fact that history is full of past civilizations, all of which collapsed except the ones that happened to be around when modern civilization arose and managed to get themselves incorporated into it. For example, in checking the index of Ray Kurzweil's The Singularity is Near, I find that he has a single one sentence mention (p346) of the issue. Similarly, Julian Simon's Ultimate Resource II takes almost all its data series from the industrial era and simply ignores the collapse of past civilizations. Clearly, these authors are not thinking very deeply about the data points that might tend to contradict their optimism.

On the other hand, more pessimistic thinkers often subscribe to some flavor of environmental determinism and assume that our current civilization is governed by very similar laws to past civilizations, and therefore is at risk of collapsing along similar lines. For example, Tainter in his book Collapse of Complex Societies argues that all civilizational collapses share a common dynamic: as the society becomes more complex there is a declining marginal return to more complexity, and eventually the civilization becomes overstressed and must collapse. He believes the same law applies to modern civilization and shows a variety of data series arguing that modern civilization is experiencing declining marginal returns along certain dimensions. While he's careful not to claim specific timing, he clearly thinks the same thing could happen to us that happened to past civilizations.

In this post, I want to explore the idea that there is at least one important class of threats where we might expect modern civilization to be much more resilient than past civilizations. Specifically, modern civilization operates at far higher levels of economic surplus than past civilizations, and this means that it is in a position to devote far higher levels of economic resources on solving certain kinds of problems.

It's hard to be terribly accurate about this, of course, since modern civilization and pre-industrial civilizations are very different, and past civilizations tend to be poorly documented. Still, the overall pattern is clear. For example, in a post last month, The Net Energy of Pre-Industrial Agriculture, I pointed out that the fact that 75-97% of the population of medieval European countries lived in the country must mean that the overall energetic return of their agricultural sector, taken as an entire system, must have been quite small. By contrast, in modern western countries, only 2-3% of the population is involved in agriculture.

Of course, that comparison overstates the situation; in pre-industrial societies, agriculture was the source of most primary energy, whereas in modern civilization that is fossil fuels. So I present the following graph with rough estimates showing the fraction of global GDP being expended on primary energy. Here I have used methods similar to yesterdays post, in which I am taking global fossil fuel production figures, US price indices, and PPP global GDP estimates from the IMF to estimate the fraction of global world product being expended to obtain fossil fuels. The use of US price indices introduces some inaccuracy, particularly for natural gas and coal which are less globally integrated markets than oil. Further, I have used wellhead/mine-mouth prices - delivered to the customer, you would need to add a few percentage points.

Still, the overall point is clear - we expend less than 10% of our effort as a society in securing our primary energy source, whereas our distant ancestors needed to expend well more than half of theirs. ...

In the past, much of society's surplus was appropriated for war and luxury (status-related objects and services). And the pattern isn't much different today, is it? According to Wikipedia today (Military Budget of the US):

The U.S. Department of Defense budget accounted in fiscal year 2010 for about 19% of the United States federal budgeted expenditures and 28% of estimated tax revenues. Including non-DOD expenditures, defense spending was approximately 25–29% of budgeted expenditures and 38–44% of estimated tax revenues.

Thus a big part of the problem is political, rather than just technological.