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Consistency check for life cycle assessments

Abstract

Purpose

This paper seeks to provide a detailed procedural description for performing a consistency check for LCA as required by the ISO 14044 standard.

Methods

Consistency is defined as freedom from logical contradictions. The requirements of ISO 14044 are reviewed, and detailed guidance is provided for these and other related consistency issues.

Results and discussion

The procedural guidance reflects the iterative nature of the phases of LCA. Some inconsistencies can be of a more fundamental nature that does not allow a single consistent solution. Instead, more than one separately consistent solution can then be found and applied as separate “scenarios” presented to the decision maker with appropriate explanation of the fundamental differences of the scenarios, and their respective strengths and weaknesses for the decision context.

Conclusions

Revisiting and correcting inconsistencies can avoid most consistency problems. However, lack of resources may prohibit such adjustments, and the inconsistencies and their implications for the conclusions may then simply be stated and the conclusions modified accordingly.

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Notes

  1. 1.

    This confusion is due to an unfortunate rewording during the 2006 revision (which was explicitly not intended to change the original requirements of the standards), in which the list in Clause 4.3.4.3.1 was given the status of a hierarchy, a status it did not have in the original ISO 14041 text.

  2. 2.

    An LCSA is a combination of an LCA and an Environmental LCC as defined by Hunkeler et al. (2008). If fully monetarised, Hunkeler et al. (2008) calls such an LCSA a “societal LCC”.

  3. 3.

    In combined production, the amount of one co-product can be changed independently of the amount of the other co-products. In joint production, the amount of co-products cannot be changed independently, i.e. their amounts are always produced in the same fixed proportion.

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Acknowledgements

The development of this text was prompted by a request from the SETAC/UNEP Life Cycle Initiative Task Force on Interpretation, and was originally intended to be part of the article reporting from this Task Force (Laurent et al. 2018), but due to its degree of detail it was decided to provide it as a stand-alone article. I wish to express my gratitude for constructive comments from two anonymous reviewers.

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Correspondence to Bo P. Weidema.

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Responsible editor: Serenella Sala

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Weidema, B.P. Consistency check for life cycle assessments. Int J Life Cycle Assess 24, 926–934 (2019). https://doi.org/10.1007/s11367-018-1542-9

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Keywords

  • Attributional
  • Consequential
  • Goal and scope
  • Interpretation phase
  • ISO 14044
  • Procedural description