Mineral resources in life cycle impact assessment: part II – recommendations on application-dependent use of existing methods and on future method development needs
Creators: name: Berger, Markus
name: Sonderegger, Thomas
name: Alvarenga, Rodrigo
name: Bach, Vanessa
name: Cimprich, Alexander
name: Dewulf, Jo
name: Frischknecht, Rolf
name: Guinée, Jeroen
name: Helbig, Christoph
name: Huppertz, Tom
name: Jolliet, Olivier
name: Motoshita, Masaharu
name: Northey, Stephen
name: Peña, Claudia A.
name: Rugani, Benedetto
name: Sahnoune, Abdelhadi
name: Schrijvers, Dieuwertje
name: Schulze, Rita
name: Sonnemann, Guido
name: Valero, Alicia
name: Weidema, Bo P.
name: Young, Steven B.
Publisher: name: Technische Universität Berlin
Year: 2020
Subjects: subject: 577 Ökologie
subject: life cycle assessment
subject: life cycle impact assessment
subject: Life Cycle Initiative
subject: mineral resources
subject: raw materials
subject: resource depletion
subject: resource dissipation
subject: task force mineral resources

description: Purpose: Assessing impacts of abiotic resource use has been a topic of persistent debate among life cycle impact assessment (LCIA) method developers and a source of confusion for life cycle assessment (LCA) practitioners considering the different interpretations of the safeguard subject for mineral resources and the resulting variety of LCIA methods to choose from. Based on the review and assessment of 27 existing LCIA methods, accomplished in the first part of this paper series (Sonderegger et al. 2020 ), this paper provides recommendations regarding the application-dependent use of existing methods and areas for future method development. Method: Within the “global guidance for LCIA indicators and methods” project of the Life Cycle Initiative hosted by UN Environment, 62 members of the “task force mineral resources” representing different stakeholders discussed the strengths and limitations of existing LCIA methods and developed initial conclusions. These were used by a subgroup of eight members at the Pellston Workshop® held in Valencia, Spain, to derive recommendations on the application-dependent use and future development of impact assessment methods. Results and discussion: First, the safeguard subject for mineral resources within the area of protection (AoP) natural resources was defined. Subsequently, seven key questions regarding the consequences of mineral resource use were formulated, grouped into “inside-out” related questions (i.e., current resource use leading to changes in opportunities for future users to use resources) and “outside-in” related questions (i.e., potential restrictions of resource availability for current resource users). Existing LCIA methods were assigned to these questions, and seven methods (ADP ultimate reserves , SOP URR , LIME2 endpoint , CEENE, ADP economic reserves , ESSENZ, and GeoPolRisk) are recommended for use in current LCA studies at different levels of recommendation. All 27 identified LCIA methods were tested on an LCA case study of an electric vehicle, and yielded divergent results due to their modeling of impact mechanisms that address different questions related to mineral resource use. Besides method-specific recommendations, we recommend that all methods increase the number of minerals covered, regularly update their characterization factors, and consider the inclusion of secondary resources and anthropogenic stocks. Furthermore, the concept of dissipative resource use should be defined and integrated in future method developments. Conclusion: In an international consensus-finding process, the current challenges of assessing impacts of resource use in LCA have been addressed by defining the safeguard subject for mineral resources, formulating key questions related to this safeguard subject, recommending existing LCIA methods in relation to these questions, and highlighting areas for future method development.