Identification of dissipative emissions for improved assessment of metal resources in life cycle assessment

Environmental dissipation is a novel approach to account for impacts from mineral resources. In contrast to all other resource-related life cycle impact assessment methods, which use data on extractions as input to calculation of indicator scores, environmental dissipation is characterized solely through emissions to the environment.

Making environmental dissipation work as a viable resource use impact category in life cycle assessment requires, however, that truly dissipative emissions are differentiated from those anthropogenic releases which do not contribute to loss of accessibility of a given resource over the time frame considered.

We present a new method that allows for this differentiation to be made for 65 metals and metalloids in a consistent way. It determines (1) whether an emission flow reported in a life cycle inventory actually contributes to loss of accessibility of a given element when environmental fate mechanisms are considered, and (2) whether the element comes from a source that would be considered as a mineral resource for any generation living between the present and the time frame of assessment.

We apply the new method to four different emission inventories, and characterize the resulting list of truly dissipative emissions using recently proposed long-term environmental dissipation potentials (EDP). This highlights the need to differentiate dissipative emissions from other anthropogenic, potentially nondissipative emission flows of elements in metal resource impact assessment.