Method of ecological scarcity

The method of ecological scarcity , also known as the environmental impact point method or method of environmental impact points , is a material flow-oriented, one-dimensional, non-monetary evaluation tool for assessing the impact in life cycle assessment studies. It is based on the comparison of the current pollution of the environment (actual amount) with the pollution that is socio-politically acceptable (tolerance amount). The ratio of the actual quantity to the tolerance quantity is referred to as ecological scarcity.

Classification of the method

Filed in the standard ISO 14040 for LCA , the method of estimation of effect serves life cycle . The inventory balance data are weighted by this method and expressed in the dimensionless unit of environmental pollution points (UBP). By adding the UBP, statements about the environmental impact of individual products and processes and comparisons are made possible. The achievement is (according to the "Distance to Target" principle German  distance to the target is determined). The underlying assumption is that there is a correlation between the importance of an environmental effect and the distance between the current level and the target level.

The results of this evaluation method can serve as a basis for decision-making for many companies or their individual business areas. The method relates to Switzerland and reflects the political goals there and current environmental pollution. The method in its current form was published for the first time by the then Federal Office for the Environment (FOEN), for 16 environmental impacts in air and water, energy consumption and waste. The method was revised in 1997, with 47 environmental impacts each receiving a weighting eco-factor, and in 2006. The method of ecological scarcity was also used in the application of life cycle assessment for companies and was further developed selectively and in various articles by the Institute for Economics and Ecology at the University of St. Gallen . The method was used for the first time in 2011 to analyze the total environmental impact of consumption and production in Switzerland.

Procedure for calculating the environmental pollution points

A calculation of ecological scarcity by calculating UBP was introduced in 1978. This article is based on the adjustment from 2006. In the meantime, there is an update from 2013, although the basic procedure has remained the same.

For the calculation, a specific location / region and a specific period are first specified. The actual quantities and tolerance quantities of certain pollutants or resources are included in the calculation. From this, the eco-factor for the respective substance or Substance group determined. Based on this eco-factor and the data from the inventory analysis, the UBP can finally be calculated. The calculation of the eco-factor is discussed below:

${\displaystyle {\text{Ökofaktor}}=K\cdot \underbrace {\frac {1}{\text{Normierungsmenge}}} _{\text{Normierung}}\cdot \underbrace {\left({\frac {\text{Istmenge}}{\text{Toleranzmenge}}}\right)^{2}} _{\text{Gewichtung}}\cdot 10^{12}}$

The tolerance quantities are quantities that are defined by national and international standards or limit values. Accordingly, they vary from region to region - sometimes considerably. The actual flow of a pollutant, a consumption amount, a resource or the amount of a characterized environmental impact in a reference area is called the actual amount. is the characterization factor of a pollutant or a resource. It is determined when the respective substance can be assigned to a specific environmental impact. The effect of a certain pollutant is related to the effect of a reference substance. Thus, methane , for example, about 23 times the greenhouse effect of CO ₂ . In order to be able to take this into account in the eco-factor for the total greenhouse gas emissions , it is 23.29 for this gas. The standardization serves to adapt the respective scarcity situation to the current emissions of a region . As a rule, the actual quantity and the normalized quantity are identical. They only differ in the case of regional or temporal differentiation in the calculation. Then the normalization quantity is the current flow of a pollutant or a resource at a specific time or at a specific location. The square of the quotient of the actual quantity and the tolerance quantity represents the weighting . As a result of this, slight excesses of the tolerance quantity are less significant than strong excesses. An additional emission is therefore weighted more heavily the higher the pollution situation. The weighting is usually based on national annual quantities. The factor 10 ¹² leads to better manageability and clarity and is the same for all eco-factors. The dimensionless unit of the eco-factor is "Environmental Impact Points (EP) per environmental impact unit". ${\displaystyle K}$ ${\displaystyle K}$

The eco-factor should be calculated for each type of emission, for energy consumption, water consumption and for waste quantities. Eco-factors relate to a reference area and a reference time (usually one year) as well as a reference unit, e.g. UBP per ton of output. They cannot be transferred from one country to another or from one region to another. The results of the inventory analysis (emissions, energy consumption, waste quantities, water consumption), which correspond to the output quantities, are multiplied by the associated eco-factors:

${\displaystyle {\text{Umweltbelastungspunkte}}_{\text{Stoff(Gruppe)}}={\text{Ökofaktor}}_{\text{Stoff(Gruppe)}}\cdot {\text{Output}}_{\text{Stoff(Gruppe)}}}$

The addition of the environmental pollution points of all inventory balance items of a product system, a process or a company results in a key figure which represents the environmental pollution in one-dimensional form, namely the environmental pollution points:

${\displaystyle {\text{Umweltbelastungspunkte}}_{\text{Unternehmen}}=\sum {\text{Ökofaktoren}}_{\text{Stoffgruppen}}}$

Regional differentiation of eco-factors

The division of the eco-factor into characterization, standardization and weighting allows a conversion from or to different regions. The weighting factor is calculated with the current and the critical flow of a certain area. The normalization is calculated with the current flow of the region for which the eco-factor is to apply. The current flow represents the environmental impact per unit of time in the region under consideration and is usually given in tons. The critical flow, on the other hand, reflects the amount of emissions per unit of time (usually one year) that is just considered ecologically acceptable. If you determine the critical flow, regional characteristics and legal requirements, such as immission limit values, must be taken into account. Laws, ordinances and guidelines have top priority. In the event that there are no legally binding regulations, existing agreements will be used, e.g. B. issued by federal and state governments as concepts or declarations of intent. If there are no agreements, statements from recognized scientific institutions or persons can be used.

Use of life cycle assessments based on this method

The results of the weighting can be used by companies (in product development, for strategy development, in purchasing, for customer advice, etc.) or in consumer advice as a basis for decision-making. For example, the application allows an entire company to assess the development of the company's eco-efficiency using environmental indicators. The method is used as part of a life cycle assessment for the exemption of biofuels from the Swiss mineral oil tax . The environmental impact of using biofuels must not be higher than that of fossil fuels. In a study of Switzerland's overall environmental pollution, it was shown that foreign trade plays an important role and that around 60% of the environmental pollution points caused by consumption occur abroad through imports of goods and services.

Advantages and disadvantages compared to other evaluation methods for impact assessment

The advantage of the method of ecological scarcity lies in the wide range of possible applications and in its high level of practicality, provided that eco-factors can be calculated according to regional specifications. As a one-dimensional procedure, it enables a direct environmental comparison of companies, products or services based on a single key figure. The method is particularly helpful where environmental aspects are to be included in the decision-making process alongside other criteria (costs, practicability, etc.).

The method is based on the political goals in a country or region. However, political goals and values ​​differ from region to region. Therefore, the method must be adapted accordingly for use in other countries and regions. Such adjustments were made e.g. B. for Germany, Japan and Jordan.

Questions about the improvement of processes and products should not be assessed with this method alone, since in these situations, as a rule, individual environmental aspects and also individual processes have to be assessed in depth. The assessment with UBP also allows an initial overview assessment of alternatives.

The critical flow contained in the calculation is problematic, as a system boundary must be selected. While in the case of greenhouse gases (e.g. carbon dioxide), on the one hand, political reduction targets can be used for individual countries, a global view should also be considered here, since global influences are involved. In contrast to this, water consumption has no global consequences and would therefore have to be detailed in terms of regional conditions far below national considerations. There are still no binding guidelines on how a specific calculation of environmental pollution points should look.

The necessary delimitation of problem areas is also problematic. Each problem area is seen as equally important in the first step. As a result, the environmental impact doubles when a problem area is divided into two areas, even if the reduction targets for both areas are the same.

In order to be able to make meaningful statements, it is also necessary - as in any life cycle assessment - to relate the calculated environmental impact points to the output volume or other services achieved (“functional unit”).

literature

• DIN EN ISO 14040 (2006), pp. 23, 24.
• DIN EN ISO 14040 (2006), pp. 14, 15.

Web links

• Method of ecological scarcity - used in Switzerland, Japan and Germany. ESU-services GmbH, accessed on November 1, 2019 (German). 

swell

1. ^ R. Frischknecht, R. Steiner, N. Jungbluth: Method of ecological scarcity - eco-factors 2006 . In: öbu - The Association for Sustainable Business (Ed.): Öbu SR . No. 28/2008 . Zurich 2008, p. 23 ff . ( eco-bau.ch [PDF; 1.4 MB ]).
2. ↑ S. Ahbe, A. Braunschweig, R. Müller-Wenk: Methodology for life cycle assessments based on ecological optimization. (= Environment series. No. 133). BUWAL, Bern 1990.
3. ↑ G. Brand, A. Scheidegger, O. Schwank, A. Braunschweig: Assessment in life cycle assessments with the method of ecological scarcity. (= Environment series. 297). BUWAL, Bern 1997.
4. ^ A. Braunschweig, R. Müller-Wenk: Life cycle assessments for companies. Haupt, Bern 1993.
5. ↑ Publications of the Chair for Sustainability Management at the University of St.Gallen. In: Alexandria Research Platform. Retrieved October 26, 2019 . 
6. ↑ N. Jungbluth, C. Nathani, M. Stucki, M. Leuenberger: Environmental Impacts of Swiss Consumption and Production. A combination of input-output analysis with life cycle assessment. (= Environmental studies. No. 1111). Federal Office for the Environment, Bern 2011.
7. ↑ R. Müller-Wenk: The ecological bookkeeping. Campus Verlag, 1978. see also: Ecological bookkeeping
8. ↑ Cf. Frischknecht, R., Büsser Knöpfel, S., Flury, K., Stucki, M .: [www.bafu.admin.ch/uw-1330-d Eco-Factors Switzerland 2013 according to the method of ecological scarcity: Methodical principles and application to Switzerland. No. Umwelt-Wissen No. 1330, treeze and ESU-services GmbH on behalf of the Federal Office for the Environment (FOEN), Bern. ]
9. ↑ Cf. R. Frischknecht, R. Steiner, N. Jungbluth: Life cycle assessments: Method of ecological scarcity - eco-factors 2006. 2008, p. 31 ff.
10. ↑ Cf. R. Frischknecht, R. Steiner, N. Jungbluth: Life cycle assessments: Method of ecological scarcity - eco-factors 2006. 2008, p. 21 ff.
11. ↑ See FOEN summary of the "Feasibility study for environmental product information based on life cycle approaches" (PDF; 54 kB)
12. ↑ Cf. E2 - Key figures on environmental management ( memento of the original from December 22, 2015 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. 
13. ↑ See Swiss Mineral Oil Tax Ordinance (MinöStV)
14. ↑ N. Jungbluth, C. Nathani, M. Stucki, M. Leuenberger: Overall environmental pollution from consumption and production in Switzerland: input-output analysis combined with life cycle assessment (short version). (= Environmental knowledge. No. 1111). Federal Office for the Environment, Bern 2011.