Joachim H. Spangenberg
This paper presents a draft system of five 'inter-linkage indicators' which connect key driving forces in the fields of environment, economy and social affairs with corresponding policy responses. These indicators are suitable for guiding policy and allowing for clear communication. The main goal is to support the development of practical long-term economic policies which minimize human impacts on the environment. In order to do this, it is necessary:
The physical dimension of sustainability refers to leaving intact, for an infinite length of time, the stability of the ecosphere's internal evolutionary processes which are dynamic and self-organizing. An economic system is environmentally sustainable only as long as it is physically in a (dynamic) steady-state. In other words, the amount of resources utilized to generate welfare is permanently restricted to a size and a quality which is called environmental space; thus. it does not overexploit the sources, or overburden the sinks provided by the ecosphere. Without this, human economies would have to continue to draw on the stock of natural resources (e.g. high grade ore, crude oil, fertile soil). From the viewpoint of energy consumption, they would continue to use up lowentropy fossil fuels which sooner or later would be exhausted. In addition, the immense (and rapidly increasing) flows of resources through the global economy would continue to lead to an increase in entropy, resulting in a variety of unpredictable and irreversible environmental impacts. These include slow, long-term changes such as global warming, as well as short- term irregularities, such as storms, stronger hurricanes and flooding rivers, resulting from the destabilization of natural systems.
While the size of stocks and their accessibility is an economic issue, there are ecological issues such as resource flows that contribute to environmental impacts2. The technical skills and innovative drive of humankind, along with the material growth of the anthroposphere, can cause an infinite number of ever-changing disruptive interactions to occur at the boundaries to the ecosphere. These disruptions are characterized by non-linear relationships between stresses and responses. Some of these effects cannot be detected within human time horizons. Moreover, if they were found and measured, they could not be attributed to distinct causes3. This precludes the observation or theoretical calculation, hence, the quantification, of the totality of the actual consequences of human (economic) activities on ecosystems4 and thus a precise and reliable calculation of carrying capacity or critical loads. There are several options, however, to describe the environmental impacts of humankind, all of which may be helpful for specific purposes. The chosen option should allow for easy translation into policy action in a sound manner.
Resource flows are of key importance to assess environmental deterioration. The throughput of resources, however, must be measured at a well-defined point to permit international harmonization. The most appropriate choice for this point of measurement is the border (functionally, not geographically defined) between the ecosphere and anthroposphere (or humansphere, as W. Rees calls it). Since there are functionally two of these borders on the input, as well as on the output side, their usefulness can now be compared.
Traditional environmental policy and research has focused on regulating the output side of the economy. Output-related regulations usually aim at qualitative product characteristics, relying on command and control mechanisms. On the other hand, input-related regulations have long been known, for example, in the form of licences for mining and logging or ground water extraction. Input-related regulations are focused on quantities to be reduced, rather than on qualities to be for- bidden. They are therefore the prime choice for the application of financial incentives and other market-based instruments.
In operational terms, the most suitable approach must be determined. First, while the number of materials entering our economic systems is limited to 50-l00 abiotic substances, including energy carriers5, output control has to handle about 100,000 substances from the chemical industry alone, each of which interacts in various ways with the ecosphere and the other substances emitted. Secondly, while the number of points of entry into the anthroposphere is limited to about 20,0006, the number of exits are beyond control. Every smokestack, every exhaust pipe, every waste dump, every drainpipe is such an exit (figures based on estimates for the German economy).
In designing appropriate policy measures, focusing on the inputs can provide higher regulatory efficiency with much less effort in control. This becomes particularly important when the introduction of market-based financial instruments is considered: regulating outputs with financial instruments will either need a new control bureaucracy or generate the risk of massive free-rider effects.
Every use of environmental space needs a realm in which it can take place and materials as the physical basis of the actors and their instruments (including energy). Thus, we propose materials and land to be the core categories of our analysis. These can, if necessary, be split up into environmentally relevant subcategories: air, water, soil, biotics and minerals for materials; fossil, renewable and nuclear for energy; or built areas, pasture and agriculture for land use.
Consequently, we have chosen to define the flows as controlled flows of materials (including energy) and land into the economic system, aiming toward sustainability. For land use, the need for a sustainable pattern is evident from the threats to biodiversity and soil fertility. In Europe, this is due particularly to erosion and the leaching of micronutrients. However, so far no broadly accepted measure for biodiversity exists, and probably none can be developed to quantitatively cover the species and genetic levels of biodiversity in the ecosystem, not least because of the lack of data. Consequently, all criteria proposed for sustainable land use strategies are more qualitative than quantitative.
Our main concern is to focus on material flows: in addition to non-renewable minerals and biomass, these include all energy carriers. This approach offers a broad basis to assess the environmental impacts of resource use, energy consumption, and (at least partially) the impacts of land management systems. Therefore, developing a measure to quantify material flows is of utmost importance for any attempt to make the concept of sustainability operational.
Each use of a natural resource, be it water for drinking or cooling, minerals for industrial production or construction, land for agriculture or air for breathing, inevitably increases the entropy of the overall system. We consider the total material flow (TMF) an appropriate measure of disturbance, and we regard the reduction of material flows a necessary (although not in all cases sufficient) means of reducing the pressures caused by humankind on the global environment in a directionally safe manner. The goal of reducing material flows is proactive, in that it does not refer to individual symptoms of environmental damage, but to the overall impact on the system. It thereby aims to prevent future damage as well as reduce the current potential for disturbance. Although a direct link of material flows to environmental stresses is evident only in a minority of cases, many of the well-known symptoms of environmental degradation, from declining fish stocks to reduced fertility due, for example, to persistent chemical accumulation, can be traced to intense material flows as the indirect cause. Consequently, we consider dematerialization to be a way to make operational key aspects of the normative concept of sustainable development.
We propose to amend the currently used Driving Force-State-Response system with a limited set of inter-linkage indicators, designed for proactive policy guidance and communication and based on the measures and targets set for use of environmental space. Given the transferable and transparent methodology, in particular for material flows, as well as clear reduction targets, interlinkage indicators can gauge performance, measuring the distance to the target and thus helping to choose the proper politicy options and to assess the progress towards sustainability.
When analysing the environmental space available, we have proposed to use the two key characteristics of the use of our physical environment as a basis for building our indicators: material extraction, including energy, and land use. The respective reduction targets are then set according to best available knowledge at a 50% global reduction compared to current levels for materials. For land use, demands are set qualitatively: no use of fragile or already degraded soils, phase out imports of related harmful products, and restore soil quality.
These targets are used to define a directionally safe normative system of environmental indicators. It needs to be linked, however, to economic and social issues to be developed into a system of interlinked sustainability indicators. This next step is a prerequisite to developing a set of indicators which can guide policy. Equally important for sustainability, along with the absolute amount of resource extraction, is the level of equity in the distribution of access to these limited resources. The distribution of access is thus our first proposed socio-environmental inter-linkage indicator, the target being equal access (on a per capita basis). This constitutes a kind of 'human right to resource use'7.
Transport intensity does not only reflect energy, material and land use by the transport system, but as well social aspects like travelling distances and the corresponding shortage of time to be spent with friends or the family. We propose to use it as an socio-environmental disturbance indicator for the direction our societies are developing (infrastructure, production-, distribution- and consumption patterns included). As a first target a reduction of 50% of transport volume is proposed (for EU countries, further research is needed for quantification).
With these settings, reduction targets are significantly modified. For Europe (as for all industrialized countries) equitable sharing means a reduction of material use by a factor of 10 and for energy by a factor of 4. These figures relate only to the average resource use of a national economy and are not to be understood to apply evenly to each economic sector, to all companies, cities, or to individual consumers.
NOTES
1 See, for example, RMNO, Towards Environmental Performance Indicators Based on the Notion of Environmental Space. RMNO 96, Rijswijk 1994. ,
2 Hinterberger, F., et al. Material Flows vs. Natural Capital: What Makes an Economy Grow? accepted for publication in Ecol. Economics, Elsevier.
3 Hinterberger, F. (1994) Biological, Cultural and Economic Evolution and the Ecology- Economy Relationship in: Van den Bergh et al. (Ed.), Towards Sustainable Development, Washington, D.C.
Spangenberg, J .H. ( 1993) Evolution und Tragheit, In: Kaiser, G. (Ed), Kultur und Technik im 21. Jahrhundert, Frankfurt.
4 Schmidt-Bleek, F. (1997) The Fossil Makers. New York (forthcoming). First published in German, Wieviel Umwelt braucht der Mensch, Berlin/Basel 1993.
5 Here, for example, limestone, crude oil or hard coal are counted as one substance each. Substances without economic value are excluded.
6 Extraction points of minerals, energy carriers and water, where they enter the anthroposphere, but excluding air. An oil field, for instance, is considered one entry point.
7 For energy and materials, as globally traded commodities, the reference is the global scale. Land use is considered a continental issue, so trade in land use products should be balanced between continents to achieve equal distribution.