Is mainstream LCA linear?

The International Journal of Life Cycle Assessment, vol. 25, pp. 1872–1882

Abstract

Abstract Purpose It is frequently mentioned in literature that LCA is linear, without a proof, or even without a clear definition of the criterion for linearity. Here we study the meaning of the term linear, and in relation to that, the question if LCA is indeed linear. Methods We explore the different meanings of the term linearity in the context of mathematical models. This leads to a distinction between linear functions, homogeneous functions, homogenous linear functions, bilinear functions, and multilinear functions. Each of them is defined in accessible terms and illustrated with examples. Results We analyze traditional, matrix-based, LCA, and conclude that LCA is not linear in any of the senses defined. Discussion and conclusions Despite the negative answer to the research question, there are many respects in which LCA can be regarded to be, at least to some extent, linear. We discuss a few of such cases. We also discuss a few practical implications for practitioners of LCA and for developers of new methods for LCI and LCIA.

Authors 1

1. Reinout Heijungs corresponding Aachen Institute of Environmental Sciences (CML)

   Leiden University · Vrije Universiteit Amsterdam

   Affiliation as printed

   Department of Supply Chain Analytics, Vrije Universiteit Amsterdam, De Boelelaan 1105, 1081 HV, Amsterdam, The Netherlands

   Institute of Environmental Sciences, Leiden University, PO Box 9518, Leiden, 2300 RA, The Netherlands