Purpose Political interest in the future availability of natural resources has spiked recently, with new documents from the
European Union, United Nations Environment Programme and the US National Research Council assessing the supply
situation of key raw materials. As resource efficiency is considered a key element for sustainable development, suitable
methods to address sustainability of resource use are increasingly needed. Life cycle thinking and assessment may play a
principal role here. Nonetheless, the extent to which current life cycle impact assessment methods are capable to answer to
resource sustainability challenges is widely debated. The aim of this paper is to present key elements of the ongoing discussion,
contributing to the future development of more robust and comprehensive methods for evaluating resources in the
life cycle assessment (LCA) context.
Methods We systematically review current impact assessment methods dealing with resources, identifying areas of improvement.
Three key issues for sustainability assessment of resources are examined: renewability, recyclability and criticality;
this is complemented by a cross-comparison of methodological features and completeness of resource coverage.
Results and discussion The approach of LCA to resource depletion is characterised by a lack of consensus on methodology
and on the relative ranking of resource depletion impacts as can be seen from a comparison of characterisation factors.
The examined models yield vastly different characterisations of the impacts from resource depletion and show gaps in the
number and types of resources covered. Conclusions Key areas of improvement are identified and
discussed. Firstly, biotic resources and their renewal rates have so far received relatively little regard within LCA; secondly, the
debate on critical raw materials and the opportunity of introducing criticality within LCA is controversial and requires further
effort for a conciliating vision and indicators.We identify points where current methods can be expanded to accommodate these
issues and cover a wider range of natural resources.