Hybrid life cycle assessment (LCA) will likely yield more accurate results than process-based LCA

Abstract

We analyse the comparative investigation into truncation vs. aggregation errors of process-based and hybrid LCA by Yang et al. 2017. We analyse the validity of their findings when the hypothetical five-sector economy is altered to account for realistic technological and sectoral interdependencies. We show that in such cases the truncation error of process-based LCA outweighs the aggregation error of hybrid LCA. To this end, we compare the dominant eigenvalue of our alternative economy with that of real economies, showing good agreement. The same validity check does not hold for the system used by Yang and colleagues. Additionally, we demonstrate that even simple process systems can have higher dominant eigenvalues, provided they are based on realistic data.