Abstract :
Recent scientific discussions indicate a special need to consider temporal aspects in LCA of long-lived products. Elements thereof are already used for several impact categories such as those being related to climate changes. However, the elements are not used in a systematic and identical way for all categories. They are a basis for deriving characterisation factors and are based on the implicit assumption of a single discrete emission occurring “now”. They do not allow for calculating time-dependent loadings arising from multiple, discrete or continuous emissions over a given (future) time horizon, though these predefined time horizons are needed to model both, fate and (abiotic/biotic) effects once the emission has taken place. A systematic way to introduce temporal aspects is presented. As a consequence, the need to modify characterisation factors already considering temporal aspects such as residence times is discussed. Alternatives outside LCIA are also presented.
