The Ecoindicator Method
The Ecoindicator method is defined as a weighting and assessment method of environmental effects (damaging ecosystems or human health) on a European scale, proposing itself as a tool for the evaluation, in the design phase, of the various options that may arise during the analysis of a product/process. It is the authors' opinion that the lack of definition of the relative importance of effects (acidification, greenhouse effect, etc.) does not allow a unique evaluation of the total environmental impact, which therefore remains undetermined. The project "Eco-indicator 95" (later updated to "Eco-indicator 99") proposes the inclusion in LCA methodology of normalization and weighting procedures in order to synthesize, in a single value called Eco indicator, all environmental indicators.
"The higher the value of the Eco indicator, the greater the potential environmental impact."
Regarding the environmental effects considered, the method takes into account those that are believed to damage the ecosystem or human health on a global or regional scale: greenhouse effect, ozone layer depletion, acidification, eutrophication, photochemical smog, and emission of toxic substances (heavy metals, carcinogenic substances, or pesticides).
Not included are:
- Toxic substances which pose a problem only in the workplace: toxicity is in fact linked to exceeding certain concentration values, an event limited to the workplace and therefore a local effect;
- Consumption of raw materials: the indicator does not express the scarcity of a particular raw material and therefore the impact of its consumption as such, but only the emissions resulting from the extractive process;
- Waste: the emissions produced by waste management are considered, but not the quantity of waste itself and the resulting resource space consumption.
Eco-indicator defines a reference value as the average annual contribution of a certain environmental impact attributable to a European inhabitant; thus, the impacts are comparable in terms of equivalent inhabitant, making it possible to assess the magnitude of the potential impact relative to each environmental effect. However, this initial result does not tell us what the relative importance of the different environmental effects should be: the problem still lies in defining a correct level of comparison since different environmental effects cause different types of damage. Thinking about photochemical smog, for example, it is observed that it is harmful to both human health and forests, giving rise to the phenomenon of acid rain. The relative importance of the different effects should then be established through appropriate weighting factors that allow a comparison of the severity of the different potential impacts standardized on the same reference scale (Ecoindicators points); in practice, a comparison correlation is established that allows to determine equivalent damage levels for the different environmental effects. This ultimately leads to a total and unique result of the environmental impact of the process under consideration, defining the Eco-indicator as the sum of the Eco-indicator points calculated for the individual impacts.
The weakness of the entire method lies, as logically expected, in the definition of the factors used for impact weighting. For this reason, the Eco-indicator uses the criterion of "Distance to Target", whereby the basic assumption is that there is a correlation between the severity of a specific effect and the distance between the current level and a preset target level. For example: if the goal is to reduce the greenhouse effect by a factor of 10 in the next 10 years and by 5 times that of acidification, the greenhouse effect is considered more serious than the latter by a factor of 2. To agree on the target level, however, it is necessary to define equivalent levels within different types of damage. The following damage levels have been assumed by the authors as equivalent:
- number of deaths caused by environmental effects (accepted value of 1 death per million);
- number of people getting sick as a result of environmental effects (for smog, the fixed level corresponds to the occurrence of smog periods with a certain rarity);
- ecosystem degradation (5% maximum degradation for the subsequent period).
The Eco-indicator method therefore aims to achieve a definition of objectives (and corresponding damage levels) independently of political and economic feasibility assessments, solely based on scientific information. However, the definition of these damage equivalence levels remains entirely subjective and therefore there is the possibility of making different assumptions and thus arriving at different weighting factor values.
The indicator does not have a universal and absolute meaning.
Source [The Eco indicator 95 - Manual for designers, Mark Goedkoop et al., 1996]
