|Industrial Metabolism: Restructuring for Sustainable Development (UNU, 1994, 376 pages)|
|Part 3: Further implications|
|14. A plethora of paradigms: Outlining an information system on physical exchanges between the economy and nature|
Let's come back to the notion of "metabolism." In biology, this term is commonly used to describe the internal biochemical pathways of organic and anorganic inputs and their conversion to organic/ anorganic outputs which are necessary for an organism to grow, live, and produce its offspring. Functionally, a specific metabolism is all an organism needs to survive.
Strictly speaking, the socio-economic system is not an organism: it is not as highly integrated internally, nor can it die, because it does not "live" in a biological sense. It is a system on a different hierarchical level for which it is difficult to find a suitable biological analogy. For systems of greater complexity (such as ecosystems) the exchange processes with their environment have to be conceptualized on a more complex level than input/output-fogies will allow. To describe the metabolism of a system it is sufficient to conceptualize its "environment" as a large pool providing nutrients and sinks. For a proper description of the socio-economic system's interactions with its natural environment it is indispensable, we think, to conceive the natural environment as an array of various systems in which interventions take place. These interventions aim at colonizing the environment. This is equivalent to purposive restructuring of certain system characteristics of the environment, so it would serve specific socio-economic uses. We will elaborate on this idea below.
So the information system we propose stretches the concept of metabolism by considering not just inputs from and outputs to the natural environment, but also interventions in various natural systems.
Figure 3 gives an overview of the information system that we propose in relation to the four paradigms described above. There are three modules of indicators that differ in their theoretical reference, in their (natural sciences) background, and in their databases. Methodologically, though, they have common features: they are all expressed as physical flows over the (systemic) border between the economy and its natural environment per time period (a year); they are all formulated on a level of abstraction that (in principle) allows all economic actors to produce such flows; and they are all attributable to specific economic actors (branches of activities, including private households) on an institutional, not a functional basis.
So, what distinguishes the information modules? What is their content? And how do they relate to the concept of metabolism?
Module 1, emissions (EMIs), is the most obvious in this context. It specifies indicators for gaseous, liquid, and solid emissions (each with a number of subindicators agreed upon in a series of expert workshops) per economic branch of activity, and expressed in tons per year. For gaseous emissions we suggest two effect parameters, namely "climateaffecting emissions" (where several different substances are recalculated on a CO2 basis according to international standards), and "ozone-layer-affecting emissions" (again a recalculation of various gases in F21-equivalents). Similarly, for liquid emissions we suggest an effect parameter for "eutrophication" (in total P) and for "deoxidation" (in BOD5), and another for toxicity.
Whereas it was possible to find acceptance among experts for a fairly comprehensive list of indicators selected for importance, ubiquity, and methodological feasibility, the empirical basis for calculation is extremely weak. So we do not give any empirical example in this chapter, but we suggest further research on technological emission factors for future calculations. With regard to solid emissions, even the conceptual basis for specifying anything but sheer amounts (in tons per year) is highly unsatisfying.
With reference to the metabolism concept, EMIs represent only a rather simple feature, namely the outputs of the system into its environment, selected for possible Noxious quality.
Module 2, economic-ecological system indicators (ESIs), gives information about the physical dimensions of the economy in terms of matter, energy, and time/space. This rests upon the assumption that, ceteris paribus, the economy will have the less impact upon its environment the smaller the physical quantities handled by the system are. Several aspects can be expressed by this module. One aspect is the "size" of the economy relative to its natural environment. Another aspect is the ecological "wastefulness" of the economy: the more energy, matter, and movement (space/time) is processed for a given degree of need-satisfaction, the more ecologically wasteful the system is. Yet another aspect is the relative "closedness" of the system: how much input from the environment does it need and how much output does it produce in relation to the amounts circulated within the system?
The indicators in this module are expressed in physical amounts. (For example, how many tons of materials are handled per year, imported from and exported to the environment? How much energy in terms of joules per year is consumed resp. downgraded? How many tonne-kilometres are being transported per year?) These amounts are very meaningful in absolute terms, be it for comparisons over time or between branches of economic activity. In a second step they can also be related to the monetary side of the economy and expressed as "intensities," e.g. net energy used per unit of gross domestic product. This draws attention to the relative independence of the physical and the monetary size of the economy: an economy may very well shrink in physical terms (which should be environmentally beneficial) and at the same time grow in monetary terms (which would be environmentally rather neutral).
What these indicators have in common is that they are fairly close to standard economic statistics, in the sense that they represent their physical dimensions. They also have in common a number of (sometimes overlapping) environmental implications. (We will come back to this for the case of materials and material intensity bellow.)
ESIs have a close relationship to the concept of metabolism: on a very general level they allow, in combination with economic input-output analysis, the screening of the whole transformation process that this term implies.
Module 3, purposive interventions into life processes (PILs), is the most unconventional of the modules. It is distinguished from emissions in that it seeks to operationalize purposeful actions. Emissions may be regarded as unintended side-effects of economic production and consumption, whereas here we aim at interventions in favour of a particular social use. Roads, for example, purposefully eradicate vegetation and animal life in a particular area in order to remove barriers to human mobility. Agriculture purposively uses pesticides to prevent other species from eating the crops. Pesticides are not an "emission" (or not unless they, as a side-effect, get into rivers), but are applied for a specific economic purpose.
PILs, in common with EMIs, do not portray the metabolism within the economy but the flows over its boundaries to the environment. Other than with EMIs these flows cannot be properly identified as either "intakes" or "outputs," but have to be described (on a different functional level) as interventions in environmental systems. An example is given below.