Models, reality and the limits to growth

Fourcultures recently pointed out the contentious relationship between computer-driven models and the reality they claim to be modelling.

More analysis of The Limits to Growth modelling  is now published in American Scientist journal.

Charles A.S. Hall and John W. Day, Jr. 2009 Revisiting the Limits to Growth After Peak Oil American Scientist Vol 97 (May-June): 230-237.

Hall and Day claim ‘We are not aware of any model made by economists that is as accurate over such a long time span’ (p.235).

You can download the full article and a good summary and discussion is at the Oil Drum.

This complements a recent report from Australian government (CSIRO) scientist Dr Graham Turner, who revisited the business as usual projections of The Limits to Growth from 1972 and found that actual observation matched the projections pretty well.

Graham M. Turner. A Comparison of The Limits to Growth with 30 years of reality. Global Environmental Change 18 (2008) 397-411. (or working paper)

This rather discredits the idea that the Limits to Growth analysis was ‘flawed’, ‘extreme’ or ‘wrong’.

Given that this kind of analysis plays right into the hands of the Egalitarian worldview (Everything’s running out! We need a radical change of heart! Let’s all share more!), and given that the Egalitarian worldview is only one of four viable perspectives, what are the alternatives?

The first thing to be said is it’s interesting that this kind of analysis is coming back out at precisely the time when the ‘growth is good’ model of Individualism is very much on the back foot. In other words there’s a connection between the arguments themselves and the contexts in which people are prepared to fund/publish read/entertain them. What in one period sounds like a lone voice in the wilderness can in short order become mainstream. As Dennis Meadows, one of the original Limits authors said when he picked up Japan’s top science award (The Japan Prize citation) in 2009,

“until recently, it seemed impossible that individual human action could damage the global economy. Now the unfolding collapse of the global credit markets and the precipitous decline in production threaten all nations,”

The second point to make is that while institutions move fairly slowly, people have a remarkable ability to defect from their previously cherished beliefs, provided a) the new belief appears to describe some aspects of ‘reality’ attractively and b) others appear to be defecting too. This means there’s always a niche for an alternative view. Grid-group cultural theory offers a typology of four mutually incompatible but mutually reinforcing views. If the Limits philosophy gains the upper hand, there are plenty of careers in opposing or otherwise profiting  it (Individualism), managing it (Hierarchy) or pointedly ignoring it (Fatalism).

A further point is that those who doubt, criticise or reject the concept of limits are entirely right to recognise it as a social construct. Limits – ‘real’ limits – are only ever met in the concrete and the particular, not in the universal and abstract. Therefore, what concrete and particular limits have to tell us about the world in general is always open to interpretation and argument. A good example of this is the collapse of the North Atlantic cod fisheries. This is a real and far-reaching event, but its meaning is still contested.

Here’s an episode (needs RealPlayer, or in MP3 format) from the marvellous radio series How to Think about Science examining the story – in an interview with environmental philosopher Dean Bavington.

See also: how to spot a model that actually works

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