Life Cycle Impact Assessment

Advancing method development has been a key research focus at ifeu for many years. We continue to develop and update major instruments such as Life Cycle Assessment (LCA) and greenhouse gas (GHG) emission calculation methodology on behalf of a wide range of clients including the German Federal Environment Agency (UBA). The ISO LCA Standards were developed with our input and guidance. With our expertise on cutting-edge approaches and state-of-the-art methodology, we are pleased to offer our competent services across a wide range of topics.

On behalf of the Federal Environment Agency, (Prüfung und Aktualisierung der Ökobilanzen für Getränkeverpackungen. UBA-Texte 19/2016), ifeu analysed relevant European and international activities to assess the merit of novel developments in Life Cycle Impact Assessment (LCIA). Examples include the ILCD Guidebook (International Reference Life Cycle Data System Guidebook (JRC 2011) developed by the Joint Research Centre (JRC) of the European Commission (EC)) and PEF (Product Environmental Footprint Guide of the EC). The proposals made in these studies and guidelines were discussed in detail with a range of consultants and LCA experts as well as the relevant Federal Environment Agency departments

Life Cycle Impact Assessment is a method to evaluate and increase the understanding of the potential environmental impacts of a product system across its entire life cycle [ISO 14040 and 14044].

The selection of the impact categories should reflect a comprehensive set of environmental concerns associated with the studied product system [ISO 14040 and ISO 14044]. However, both uncertainties in characterisation models and completeness, and quality or availability of inventory data often limit the set of impact categories available for analysis. Category indicators and characterisation models may be chosen at endpoint or midpoint level. The development of a robust linear causal chain from inventory results to tertiary impacts (endpoints) is often not possible. Therefore, the application of midpoint indicators in LCAs seem often more feasible.

The following list of proposed methodology for impact categories, impact category indicators and characterisation models reflects the current status of the minimum requirements according to the Federal Environment Agency project (UBA-Texte 19/2016).

Emission-Related Categories

Climate Change

Climate change addresses the impact of anthropogenic emissions on the radiative forcing of the atmosphere. Greenhouse gas emissions enhance radiative forcing, resulting in an increase of global temperature. The characterisation factors proposed are based on the category indicator Global warming potential (GWP) for a 100-year time horizon [IPCC 2013]. The category indicator results, i.e. GWP results, are expressed as kg CO2-e per functional unit.

Stratospheric Ozone Depletion

Stratospheric ozone depletion (ODP) addresses the anthropogenic impact on the Earth’s atmosphere, which leads to the decomposition of naturally present ozone molecules, thus disturbing the molecular equilibrium in the stratosphere. In consequence, increased levels of UV-B radiation reach the Earth’s surface, thus causing damage to certain natural resources or human health. In UBA (2016), ODP data compiled by the World Meteorological Organisation (WMO) in 2011 (WMO 2011) are proposed for category indicator calculations. The unit ODP unit is kg CFC-11-e/functional unit.

Photo-Oxidant Formation

Photo-oxidant formation, also known as summer smog or Los Angeles smog, is the photochemical creation of reactive substances (mainly ozone), which affect human health and ecosystems. This ground-level ozone is formed in the atmosphere by nitrogen oxides (NOx) and volatile organic compounds (VOCs) in the presence of sunlight.

The ‘Maximum incremental reactivity‘ (MIR) developed in the USA by William P. L. Carter is proposed as the category indicator for the impact category photo-oxidant formation. MIRs expressed as [kg O3-e / emission i] are used in several reactivity-based VOC regulations by the California Air Resources Board (CARB 1993, 2000). Current work of William P. L. Carter includes characterisation factors for individual VOCs, VOC sum parameters and NOx. The MIRs and NMIRs are calculated based on scenarios where ozone formation has maximum sensitivities either to VOC or NOx inputs. Thus, a conservative approach is adopted. The factors proposed by UBA (2016) were published by [Carter 2010]. The unit for Photo-oxidant formation potential is kg O3-e/functional unit.

Acidification

Acidification affects aquatic and terrestrial ecosystems by changing the acid-base-equilibrium through the input of acidifying substances. Effects include damage to plants (e.g. root, foliage or needle damage), animals (e.g. fish) and entire ecosystems (e.g. increased eluviation and leakage of nutrients and heavy metals from soils). The category indicator proposed by UBA (2016) is the acidification potential expressed as SO2-equivalents per functional unit according to [Heijungs et al. 1992].

Eutrophication and Oxygen Depletion

Eutrophication describes the excessive supply of nutrients (inorganic phosphorus (P) and nitrogen (N) compounds – hereafter referred to as P and N) to surface waters and soils. Increased levels of nutrients primarily stimulate the growth of biomass, which may lead to excess production and thus disrupt the food web with consequences for plant and animal species and the functioning of the entire ecosystem. Both aquatic and terrestrial ecosystems are affected by the supply of nutrients, but in different ways. An increased biomass production in terrestrial ecosystems could have a lasting effect on the sufficient availability of water and nutrients other than nitrogen and could result in potential displacement of species that are adapted to nutrient-poor conditions. Most aquatic ecosystems are primarily affected by excessive production of primary biomass (algae growth), which could lead to secondary effects like oxygen depletion. In addition to phosphorus and nitrogen compounds, organic carbon input may also disturb oxygen levels. Chemical oxygen demand (COD) is used as a measure for organic carbon input.

The terrestrial eutrophication potential and the aquatic eutrophication potential expressed as kg PO43–e/functional unit according to [Heijungs et al. 1992] are proposed as category indicators.

For simplification purposes, the potential impacts of atmospheric nitrogen deposition on oligotrophic waters are included in the impact category terrestrial eutrophication.

Particulate Matter

The particulate matter category covers effects of fine particulates with an aerodynamic diameter of less than 2.5 µm (PM 2.5) emitted directly (primary particles) or formed from precursors as NOx and SO2 (secondary particles). Epidemiological studies have shown a correlation between the exposure to particulate matter and the mortality from respiratory diseases as well as a weakening of the immune system. Following an approach of [De Leeuw 2002], the category indicator Aerosol formation potential (AFP) expressed as kg PM 2.5- e/functional unit is proposed.

Resource-Related Categories

Land Use

For the integration of land use and biodiversity into LCIA, the so-called hemeroby concept has been developed by UBA and ifeu since the 1990s and revised by [Fehrenbach et al. 2015]. This approach is operationalised by a multi-criteria assessment linking land use to different safeguard subjects: Structure and functionality of ecosystems, biological diversity and different ecosystem services contributing to human health and wellbeing. In this sense, hemeroby is understood as a mid-point indicator giving explicit information on the degree of naturalness and providing implicit information, at least partly, on biodiversity (number of species, number of rare or threatened species, diversity of structures), and soil quality (low impact).

Within the hemeroby concept, the areas of concern are classified into seven hemeroby classes: 1) natural, 2) close-to-nature, 3) partially close to nature, 4) semi-natural, 5) partially distant to nature, 6) distant-to-nature and 7) non-natural, artificial. The hemeroby approach is appropriate for any type of land-use accountable in LCA. However, production systems for biomass in particular (wood from forests, all kinds of biomass from agriculture) are assessed based on different sets of criteria.

The impact category land use is addressed by the midpoint category indicator ‘Distance-to-Nature Potential’ (DNP) (m2-e * 1a/functional unit) focussing on the occupation impact (Fehrenbach et al. 2015).

Raw Materials

The impact category resource use includes both energy and primary raw materials and combines them as input resources. The identification of a safeguard subject unequivocally linked to an environmental concern is often difficult. Although efforts to integrate intra- and intergenerational equity into sustainability assessments are laudable, LCAs then require additional socioeconomic sustainability criteria. In consequence, the method proposed by Giegrich et al. (2012) follows an approach that the legal consensus provides the rationale for interest in the safeguard subject. Due to the fact that there is no specific resource protection legislation in Germany to date, Giegrich et al. (2016) reference the state goal of safeguarding natural resources (as the natural basis of livelihood). To calculate negative impacts on the protection target ‘Conservation of primary and energy resources’, the indicator ‘Degree of material or raw material loss’ is proposed. Although a number of characterisation factors have yet to be defined, they characterise dissipative or destructive raw material use and thus the consumption of raw materials. This approach includes mining of mineral raw materials, metals, fossil fuels and biotic resources. The cumulative raw material demand (CRD) in kg serves as input data.

Literary Sources (pdf, 200 KB)

Mirjam Busch

Dipl. Ing. Ecology and Environmental Protection
Phone: +49 (0)6221 4767 75

Regine Vogt

Dipl. Ing. Technical Environment Protection
Phone: +49 (0)6221 4767 22
E-Mail: regine.vogt@ifeu.de

Horst Fehrenbach

Dipl. Biologe (graduate in biology)
Phone: +49 (0)6221 4767 16
E-Mail: horst.fehrenbach@ifeu.de