Originally, Life Cycle Assessment used estimates of total crustal content to calculate how many years’ worth of natural resource existed. Later, practitioners began limiting existing stocks to those identified by the United States Geological Survey in its annual Commodity Summaries. (See, for example the EU's Product Environmental Footprint resources). Because of the nature of the equations used, LCA results are highly sensitive to these differences in assumed total stock of abiotic resources. There is increasing international consensus that this aspect of Life Cycle Impact Assessment is truly broken and in need of an entire re-think.

More recently, several researchers have suggested that metal production has peaked, that resources will be depleted within decades and that declining ore grades can be used to forecast a time when mining will no longer be viable. This has underlined a lack of cross-disciplinary understanding of Mineral Economics.

In a new peer-reviewed publication, "Mineral resources in life cycle impact assessment—defining the path forward", we have come forward with probably the first globally coordinated mining industry contribution to the last twenty years of research into resource assessment in Life Cycle Thinking.

In the paper (which is freely available for download), exploration, geology, and economic experts from the global mining industry provide recommendations to ensure that future research into mineral resource assessment has a sound basis and that practitioners can utilize more appropriate tools for their work.

The paper's findings were recently debated at an International Workshop co-hosted by the Natural History Museum London (follow link for access to all presentations).

Resource accessibility for humans in the future is a complex concept and therefore needs to be adequately understood and reflected. The general equations for characterisation Life Cycle Impact Assessment models developed by the SUPRIM project represent a new state-of-art and are the most reliable of their kind thanks to the unique mix of expertise existing within the project consortium.

The proposed SUPRIM method responds to the European Commission’s call to develop a life-cycle based impact assessment method for resource use based on dissipation concepts for use in its Product Environment Footprint and Organisation Environment Footprint methodologies.

Starting from a lack of consensus on how to consistently assess abiotic resource use in life cycle assessment, a  structured approach was developed to enable a classification of perspectives on resource use, based on the socalled role of resources. Using this classification, this paper focusses on analysing links between perspectives and modelling concepts, i.e. the conceptual implementation. To analyse the modelling concepts for a selection of existing LCIA methods and other modelling approaches, the concept of the system model is introduced. It defines the relevant inventory flows to be assessed by the LCIA method, and, at the same time, to be considered in the characterization model, and how the flows and stocks of resources used to calculate the characterization factors are positioned in relation to environment (nature) and economy (technosphere). For consistency, they should be aligned with the position of inventory flows and, at the same time, reflect the perspective on resources taken by the method. Using this concept, we critically review a selection of methods and other modelling approaches for consistency with the perspectives on resource use, as well as for their internal consistency. As a result of the analysis, we highlight inconsistencies and discuss ways to improve links between perspectives and modelling concepts. To achieve this, the new framework can be used for the development or improvement of LCIA methods on resource use.

At the beginning of the SUPRIM project, there was no global consensus on the assessment of impacts from the use of abiotic resources (minerals and metals), in life cycle impact assessment (LCIA). Unlike with other impact categories such as global warming, there is not just one single, explicitly agreed-upon problem arising from the use of abiotic resources. The topic is complex and new methods are still being developed, all with different perspectives and views on resource use. For this reason, the SUPRIM project initiated a consensus process together with members from the research and mining communities, with the aim to obtain an understanding of different stakeholders’ views and concerns regarding potential issues resulting from the use of resources. This paper reports on this consensus process and its outcomes. Insights from this process are twofold: First, the outcome of the process is a clear definition of the perspectives on abiotic resources which form the starting point to further refine or develop LCIA methods on abiotic resource use. Second, the process itself has been a challenging but valuable exercise, which can inspire the evolution of other complex issues in life cycle impact assessment, where research communities face similar issues as experienced with abiotic resources (e.g. water and land use, social LCA, etc.).

This paper captures some of the emerging consensus points that came out of the workshop “Mineral Resources in Life Cycle Impact Assessment: Mapping the path forward”, held at the Natural History Museum London on 14 October 2015: that current practices rely in many instances on obsolete data, often confuse resource depletion with impacts on resource availability, which can therefore provide inconsistent decision support and lead to misguided claims about environmental performance. Participants agreed it would be helpful to clarify which models estimate depletion and which estimate availability, so that results can be correctly reported in the most appropriate framework. Most participants suggested that resource availability will be more meaningfully addressed within a comprehensive Life Cycle Sustainability Assessment framework rather than limited to an environmental Life Cycle Assessment or Footprint.

Supporting publications from The United States Geological Survey and Leiden University are also freely available in the same Special Issue of the journal "resources":
(http://www.mdpi.com/2079-9276/5/1/14, http://www.mdpi.com/2079-9276/5/1/16)