Attention environmental accounting

At the end of the year, the new "Eco-factors Switzerland 2013" were published, which are based on the ecological scarcity method [2]. This is the fourth generation of eco-factors for Switzerland, which have been made available to life cycle assessors and decision-makers since the method was first published almost 25 years ago [3], [4], [5].

Within the framework of a life cycle assessment, the "Eco-factors Switzerland 2013" make it possible to assess the environmental impact of products, services and also companies on the basis of their politically defined scarcity. The basic idea behind a life cycle assessment is to present in figures the environmental impact caused by a product or service over its entire life cycle. If we take the example of a car journey, the LCA takes into account not only the emissions caused by the use of the car, but also the provision of fuel, the manufacture, maintenance and disposal of the car, as well as the construction, maintenance and dismantling of the necessary infrastructure (road network) on a pro rata basis. All relevant pollutant emissions such as CO2, methane or NOX as well as resource extraction (e.g. crude oil, gravel, water and copper ores) are recorded and assessed over the entire life cycle.

Basic methodological concept

Bringing environmental pressures as diverse as air pollution and water consumption down to a common denominator is one of the central methodological challenges of life cycle assessments. For example, the ecological scarcity method determines how severe the environmental impact of a substance is classified in comparison to the effects of other substances. The central parameter of this method are the eco-factors, which indicate the environmental impact of a pollutant emission or resource extraction in the unit of environmental impact points (UBP) per unit of quantity. In determining the eco-factors, the method follows the distanceto-target approach, i.e. the "difference to the environmental target" is calculated. As a rule, the method uses in the weighting step (see Figure 1) on the one hand the total current fluxes of an environmental impact of a country per year (current fluxes) and on the other hand the fluxes of the same environmental impact per year (critical fluxes) that are considered to be maximum permissible within the framework of the environmental policy goals of this country. The more current emissions or resource consumption exceed the set target, the greater the eco-factor. The "Eco-factors Switzerland 2013" were determined using Switzerland's current and critical flows.

The method relies on two bases for estimating the environmental impact. The first is scientific data. They are used to determine the current quantities of emissions and resource removals. The assessment of mechanisms of action and the relative environmental impact of substances within the same category (characterization, see Figure 1) is also based on scientific methods and/or determinations by expert bodies. For example, the assessment of the climate impact of greenhouse gases is based on the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC, also known as the Intergovernmental Panel on Climate Change [6]). Second, national or international regulations and limits are used to determine tolerance levels (the critical flows). These can be legally binding intergovernmental agreements or targets set by national political bodies. In the example of greenhouse gases, the CO2 Act [7] and the Federal Council's "Sustainable Development Strategy" [8] are used to derive the Swiss eco-factor.

The eco-factors Switzerland 2013

The Swiss design reflects the environmental objectives of Switzerland and assesses the following broad range of emissions and resource extractions in the present fourth updated version (see also Figure 1):

• Water resources (freshwater, by regional scarcity)
• Energy resources (renewable and non-renewable)
• mineral primary resources (mining of metal ores, gravel, gypsum, etc.)
• Land use (loss of biodiversity, differentiated by biome)
• Greenhouse gases (e.g. CO2, methane, N2O, SF6)
• Ozone-depleting substances (e.g. CFCs, halons)
• Air pollutants and particles
• carcinogenic substances in air and water
• Heavy metals in air, water and soil
• Water pollutants (incl. hormone-active substances)
• Plant protection products
• radioactive emissions to air and water
• radioactive and non-radioactive waste
• Noise (traffic noise)

With the current edition, the data basis of the existing eco-factors has been updated, new eco-factors for traffic noise, for persistent organic pollutants and for metallic and mineral resources have been introduced, and the derivation of the eco-factors for land use and radioactive waste has been adapted to new scientific findings.

With the updating and expansion of the eco-factors, the relative importance of Switzerland's various environmental impacts has also shifted (see Figure 2). In the process, climate change has steadily increased in importance.

Ozone layer depletion, on the other hand, is hardly significant in the new version. Air and water quality impairments reached their maximum in 1997 and have been decreasing since then. The situation is similar for non-radioactive waste. An increase in importance can be observed for energy resources as well as new topics such as land use, mineral primary resources and noise.

New: Assessment of traffic noise

The newly introduced eco-factor for traffic noise is based on noise data collected by the FOEN [9]. This new data basis means that the number of people severely disturbed by traffic noise has now been recorded for the first time. The long-term goal of noise abatement is to ensure that no more people are annoyed by noise. In the medium term, i.e. by about 2035, the aim is to achieve a reduction in noise pollution of 5 dB(A) each for road, rail and air traffic. A reduction of 5 dB(A) corresponds roughly to a halving of the number of people severely affected by noise. Based on the number of people severely affected by noise, the FOEN's target for noise reduction by 2035 and the traffic performance of the individual means of transport, it was now possible for the first time to determine an eco-factor for noise. It was possible to assign an eco-factor for noise to the most important modes of transport, such as passenger cars (cars), lorries (lorries), passenger trains, freight trains and aircraft. An evaluation of different transport modes (see Figure 3) shows that the newly introduced eco-factors for noise account for between 11% and 30% of the total environmental impact for rail transport, between 6% and 12% for road transport and less than 1% for air transport.

Figure 3 shows the evaluation of different transport modes. The category climate change considers climate gases, air quality considers air pollutants such as NOX, VOC, heavy metals, carcinogenic and radioactive substances and the category land resources includes land use as well as the volume of waste to be landfilled. This also includes radioactive waste. Rail transport causes comparatively little air pollution and at the same time has a high electricity demand. The production of nuclear electricity generates radioactive waste, which is why the category of land resources is highly relevant in the assessment of rail transport.

Environmental assessment in the sense of a "true and fair view

The ecological scarcity method is suitable for assessing the environmental impacts of products (goods and services) and individual processes, as provided by life cycle inventory databases (e.g. ecoinvent and others). The method is also suitable for assessing the environmental performance of an organization in the context of environmental management, for example, for assessing environmental aspects and their development in accordance with ISO 14001. By taking into account a wide range of pollutant emissions and resource consumption and the possibility of full aggregation, the ecological scarcity method with the "Ecofactors Switzerland 2013" allows a focus on the overall picture of the environmental impacts of products, services and organizations in Switzerland. The ecological scarcity method can thus be used to provide the environmental information that is relevant for decision-making, which is why the method represents an important element for the concept of a "true and fair view" regarding environmental information that has been adopted from financial reporting [10]. The international application of the method and the interest abroad in developing their own national eco-factors show that there is a need for comprehensive valuation methods that are simple and transparent in their basic structure.