Analysis of physical interactions between the economy and the environment

In this chapter methods for analysing the physical interactions between the economy and the environment will be discussed. The historic roots of such methods lie in the 19th century and go back to Karl Marx and Friedrich Engels, who used the term 'metabolism' (Stoffwechsel) to imply a relationship of mutual material exchange between man and nature, an interdependence beyond the widespread notion of man simply 'utilising nature'. Like many of his contemporary economists in the mid-19th century, John Stuart Mill linked this concept of metabolism to the idea of a 'stationary state', a form of economic development with no physical growth. This fi rst phrasing of 'sustainable development' was then forgotten for some time. It was not until the 1960 of the 20th century that the physical interactions between the economy and the environment again formed a basis for scientifi c thought, induced by the upcoming acknowledgement of the side effects of economic growth. Thus the economist Kenneth Boulding was worried that a 'cowboy economy' might not be compatible with 'Spaceship Earth', and outlined a coming change to a 'spaceman economy' that was suitably cautious in its dealings with fi nite resources. At the end of the 1960s, the physicist Robert Ayres and economist Allen Kneese laid the basis for a physical model, for the United States, of the material and energy fl ows between the economy and the environment, proposing to view environmental pollution as a mass balance problem for the entire economy

Life-cycle assessment for energy analysis and management

Life-cycle assessment (LCA) is a form of chain analysis in which structural pathways in the economic system are delineated and connected to environmental problems. As such, it can be seen as an extension of, or a complement to, energy analysis. The main developments over the past 30 years are sketched in a perspective that puts an emphasis on standardization and scientific consensus creation. We end with a logical next development: a closer cooperation and harmonization with the domain of energy analysis, and an expected growing interest from the energy-application side

Similarities, differences and synergisms between HERA and LCA - An analysis at three levels

Linkages between Human and Environmental Risk Assessment (HERA) and Life-Cycle Assessment (LCA) can be analyzed at three levels: the basic equations to describe environmental behavior and dose-response relationships of chemicals; the overall model structure of these tools; and the applications of the tools. At level 1 few differences exist: both tools use essentially the same fate and effect models, including their coefficients and data. At level 2 distinctive differences emerge: regional or life-cycle perspective, emission pulses or fluxes, scope of chemicals and types of impacts, use of characterization factors, spatial and temporal detail, aggregation of effects, and the functional unit as basis of the assessment. Although the two tools typically differ in all these aspects, only the functional unit issue renders the tools fundamentally different, expressing itself also in some main characteristics of the modeling structure. This impedes full integration, which is underpinned in mathematical terms. At level 3 the aims of the tools are complementary: quantified risk estimates of chemicals for HERA versus quantified product assessment for LCA. Here, beneficial synergism is possible between the two tools, as illustrated by some cases. These also illustrate that where full integration is suggested, in practice this is not achieved, thus in fact supporting the conclusions

Quantitative life cycle assessment of products. 2. Classification, valuation and improvement analysis

In a previous article about life cycle assessment (LCA), a methodological framework was proposed and two components of this framework were discussed in more detail: the goal definition and the inventory. In this second article, the other components of the framework are discussed in detail: the classification, the valuation and the improvement analysis. In the classification, resource extractions and emissions associated with the life cycle of a product are translated into contributions to a number of environmental problem types, such as resource depletion, global warming, ozone depletion, acidification, etc. For this, each extraction and emission is multiplied with a so-called classification factor and the multiplication results are aggregated per problem type. Classification factors are proposed for a number of environmental problem types. The valuation includes both a valuation of the different environmental problem types and an assessment of the reliability and validity of the results. For the valuation of the environmental problem types, qualitative or quantitative multicriterion analysis could be applied. Given a standard list of weighting factors the quantitative multicriterion analysis seems preferable, because of its low costs and its simplicity. The main problem, however, is to get a broadly supported standard list. In studies so far little attention is paid to the assessment of the reliability and the validity of the results. To improve this situation methods which could support this assessment are proposed. In the improvement analysis potential options to improve the product(s) studied are identified. Combined with expertise in other fields, such as costs and technological feasibility, the improvement analysis may yield a number of serious options for the redesign of a product. Two complementary techniques for the identification of the potential options are discussed. With these techniques and the active participation of process technologists and designers, LCA might become an analytic tool for eco-design supporting a continuous environmental improvement of products