Conclusions

The concept of metabolism provides a very useful way of directing attention to the physical exchange processes between industrial economy (or, as we prefer to call it, the socio-economic system) and its natural environment. As we have tried to show empirically for Austria, a description of such exchange processes fits in well with standard economic statistics, and in a way mirrors some of the logical structure of the monetary SNA on a physical level.

Deciding which aspects of this metabolism should be described requires a careful selection process. This process may be guided by four basic paradigms for the relationship between the socio-economic system and its natural environment. We have described these as the poison paradigm, the entropy paradigm, the natural balances paradigm, and the conviviality paradigm.

These paradigms draw attention to very different ways in which the socio-economic system causes damage in its natural environment, thereby possibly threatening its own survival. This calls for an information system on "metabolism" that is sophisticated enough to take in a variety of aspects without becoming unwieldy.

One of the examples we demonstrated empirically was the calculation of "material balances" and "material intensities" for selected branches of the economy. The question of how much material input (in terms of weight) the economy needs either as direct extraction from the environment or from other parts of the economy, and how much material output it produces, either as goods for further use or as wastage expelled into the environment, is a crucial element of the description of its metabolism. Empirically it is interesting to note that, in the socio-economic system, water plays as central a role as it does for ecosystems.

Nevertheless? the concept of "metabolism" in its organismic analogy does not take into account a type of interaction between system and environment that is specific for, and typical of, the industrial economy. It does not just consume certain outputs of its environment (resources), and deposit used-up elements as its own output (emissions, wastes), but it purposively intervenes in the structures of the environment - it "colonizes" its environment. This implies a basic asymmetry between the socio-economic system and natural ecosystems. Natural ecosystems may interfere with the socio-economic system (and they do so all the time, sometimes quite forcefully), but they cannot intervene or colonize the socio-economic system in order to make it more useful to them. Under the circumstances of industrial economy, that is as impossible as it is for a monkey to keep a human child as a pet.

So the concept of "metabolism" has to be stretched to come to grips with this asymmetrical process, but without betraying its methodological qualities, which consist in its concentration upon flows (rather than stocks). This is what we are attempting in suggesting (and empirically exemplifying) a measure for the socio-economic intake of photosynthetically fixed energy, which is the basis of most of the life on this planet.

The stunning magnitude of the human interventions in natural systems demonstrate the gigantic size of the industrial metabolism vis-á-vis natural biospheric metabolism. Obviously, the socio-economic system is a strong competitor to all natural ecosystems. Yet one doubts that it will be able to drive them completely into extinction without at the same time bringing about its own destruction.