In the late 1960s, when it became culturally possible to take a critical stance with respect to economic growth and consider its environmental side-effects, the stage was set for a new twist in looking at society's metabolism. Up to this point, metabolism had mainly come up in various arguments claiming that natural forces and physical processes did, indeed, matter for the organization and development of society, and that it would be reasonable, therefore, to attribute to them some causal significance for social facts. The mainstream of social science dealing with modern industrial society - be it economics, sociology or political science - had not cared about this issue at all. In the mid-1960s this started to change and, apparently originating from the USA, a set of new approaches were developed, often triggered by natural scientists, and subsequently further developed in cooperation with social scientists. In these approaches the material and energetic flows between societies (or economies) and their natural environment finally became a major issue. The common picture of cultural evolution as eternal progress started to give way to a picture of industrial economic growth as a process which possibly implied the fatal devastation of human life. This must be considered as quite a basic change in world views, and it took hold of a wide range of intellectuals across many disciplines. It promoted something like a rebirth of the paradigm of metabolism, applied to industrial societies.
The metabolic requirements of a city can be defined as the materials and commodities needed to sustain the city's inhabitants at home, at work and at play. (. . .) The metabolic cycle is not completed until the wastes and residues of daily life have been removed and disposed of with a minimum of nuisance and hazard. (Wolman 1965, p. 179)
These lines served as the introduction to the first attempt to conceptualize and operation-alize the metabolism of industrial society; that is, the case study of a model US city of one million inhabitants. Abel Wolman was well aware of the fact that water is by far the largest input needed, but he also offered estimates for food and fossil energy inputs, as well as (selected) outputs such as refuse and air pollutants. His argument was mainly directed at problems he foresaw concerning the provision of an adequate water supply for US meg-acities. A few years later an Australian team analyzed the metabolism of Hong Kong, concentrating on its 'biometabolism' (that is, human and animal nutrient cycles) only. A comparison with Sydney (data for the years 1970 and 1971) showed a 'Western-style' diet, with the same calorific and nutrient benefit for the consumer, to be about twice as wasteful as a diet in the Chinese tradition (Newcombe 1977; Boyden et al. 1981).
In The Economics of the Coming Spaceship Earth with reference to Bertalanffy (1952), Kenneth Boulding briefly outlined an impending change from what he called a 'cowboy economy' to a 'spaceman economy' (Boulding 1966). The present world economy, according to this view, is an open system with regard to energy, matter and information ('econos-phere'). There is a 'total capital stock' (the set of all objects, people, organizations and so on that have inputs and outputs). Objects pass from the non-economic to the economic set in the process of production, and objects pass out of the economic set 'as their value becomes zero' (ibid., p. 5). 'Thus we see the econosphere as a material process.' This similarly can be described from an energetic point of view. In the 'cowboy economy', throughput is at least a plausible measure of the success of the economy.
By contrast, in the spaceman economy, throughput is by no means a desideratum, and is regarded as something to be minimized rather than maximized. The essential measure of the success of the economy not its production and consumption at all, but the nature, extent, quality and complexity of the total capital stock, including in this the state of the human bodies and minds. (Ibid., p. 9)
In 1969 Robert Ayres, a physicist, and Allen Kneese, an economist, basically presented the full outline of what - much later, in the 1990s - was to be carried out as material flow analyses of national economies (Ayres and Kneese 1969). Their article was based upon a report prepared for the US Congress by a Joint Economic Committee and published in a volume of federal programs in 1968 (see Ayres and Kneese 1968a). Their core argument was an economic one: the economy draws heavily on priceless environmental goods such as air and water - goods that are becoming increasingly scarce in highly developed countries - and this precludes Pareto-optimal allocations in markets at the expense of those free common goods. They concluded with a formal general equilibrium model to take care of these externalities. In the first part of the paper the authors gave an outline of the problem and presented a first crude material flow analysis for the USA, 1963-5. They claimed 'that the common failure of economics [...] may result from viewing the production and consumption processes in a manner that is somewhat at variance with the fundamental law of the conservation of mass' (Ayres and Kneese 1969, p. 283). Uncompensated externalities must occur, they argued, unless either (a) all inputs of the production process are fully converted into outputs, with no unwanted residuals along the way (or else they are all to be stored on the producers' premises), and all final outputs (commodities) are utterly destroyed in the process of consumption, or (b) property rights are so arranged that all relevant environmental attributes are privately owned and these rights are exchanged in competitive markets.
Neither of these conditions can be expected to hold. (. . .) Nature does not permit the destruction of matter except by annihilation with antimatter, and the means of disposal of unwanted residuals which maximizes the internal return of decentralized decision units is by discharge to the environment, principally watercourses and the atmosphere. Water and air are traditionally free goods in economics. But in reality . . . they are common property resources of great and increasing value. (. . .) Moreover (. . .) technological means for processing or purifying one or another type of waste discharge do not destroy the residuals but only alter their form. (...) Thus (. . .) recycle of materials into productive uses or discharge into an alternative medium are the only general options. (Ayres and Kneese 1969, p.283).
Almost all of standard economic theory is in reality concerned with services. Material objects are merely vehicles which carry some of these services ... Yet we (the economists) persist in referring to the 'final consumption' of goods as though material objects . . . somehow disappeared into the void ... Of course, residuals from both the production and consumption processes remain and they usually render disservices . . . rather than services. (Ibid., p.284)
Thus they proposed to 'view environmental pollution and its control as a materials balance problem for the entire economy' (ibid., p. 284, emphasis added).
In an economy which is closed (no imports or exports) and where there is no net accumulation of stocks (plant, equipment . . . or residential buildings), the amount of residuals inserted into the natural environment must be approximately equal to the weight of basic fuels, food, and raw materials entering the processing and production system, plus oxygen taken from the atmosphere. (Ibid.)
Within these few paragraphs, almost all elements of the future debate emerged. The model of socioeconomic metabolism presented (a term not used in the contribution) owes more to physics than to ecology. For an organism, it is obvious that some residues have to be discharged into the environment. In population ecology, it is the efficiency of energetic conversion that would be considered - not the recycling of materials. This clearly would be the task of the ecosystem: in the ecosystem it is the 'division of labor' of different species that would take care of materials recycling, and never the members of one species only. From the point of view of ecosystems theory, therefore, the idea of residues as a 'disservice' to the population discharging them would seem alien to the common concept of nutrient cycles.
Whereas the inputs from the environment to the economy were listed in some detail, the outputs to the environment (in the sense of residuals) were only treated in a sweeping manner. Nevertheless, all the problems that have marked the following decades of emission (and waste policies) - problems that still have not been properly resolved - were clearly set forth. It was explicitly stated that there is a primary interdependency among all waste streams that evades treatment by separate media. The authors of this article even recognized that there is one stream of waste that is non-toxic and, hence, not interesting for emission regulation: carbon dioxide. They anticipated correctly that carbon dioxide, by reason of its sheer quantity, might become a major problem in changing the climate. Finally, they were able to see that a reduction of residuals can only be achieved via a reduction of inputs. In a sense, they could be said to have 'invented' all these core insights into the materials balance approach. This contribution became the starting point of a research tradition capable of portraying the material and energetic metabolism of advanced industrial economies. It was not 'man' any more that was materially and energetically linked to nature, but a complex and well-defined social system: 'The dollar flow governs and is governed by a combined flow of materials and services (value added)' (Kneese et al. 1974, p. 54).
Judged by the standards of later empirical analyses (for example, Adriaanse et al. 1997; Matthews et al. 2000), the empirical results rendered by these pioneering studies appear to be correct within an order of magnitude: they arrive at about 20 metric tons per capita population and year as 'direct material input' into the economy. (For details see FischerKowalski 1998, pp.71ff.)
We may conclude, therefore, that the pioneer studies of economy-wide material metabolism not only set up an appropriate conceptual framework, but also arrived at reasonable empirical results. Considering this fact, it is amazing that it took another 20 years for this paradigm and methodology to become more widely recognized as a useful tool.
Was this article helpful?