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D r a f t. Life Cycle Assessment A product-oriented method for sustainability analysis UNEP LCA Training Kit Module i – The mathematics of LCIA. D r a f t. Characterisation models Characterisation factors The characterisation step. Contents. Characterisation models. impact.
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D r a f t Life Cycle AssessmentA product-oriented methodfor sustainability analysisUNEP LCA Training KitModule i – The mathematics of LCIA
D r a f t • Characterisation models • Characterisation factors • The characterisation step Contents
Characterisation models impact mass (or concentration)
Characterisation factors (1) impact mass (or concentration)
Characterisation factors (2) • Infinitesimal small change: • Substance and category dependence: • Multiple substance dependence
Characterisation models (1) • Characterization models express the relationship between the category indictor and the outputs • Characterization factors are derived from models that predict the impact
Characterisation models (2) • Often developed outside LCA • IPCC, WMO, … • derivative • linearised model • only valid for small change • partial derivative • constant background
The characterisation step (1) • Conversion and aggregation • conversion • aggregation • together
The characterisation step (2) • Or in matrix form • or even more condensed • here no problems with inversion or non-square matrices