Page 286 - Materials Chemistry, Second Edition

272 R.K. Rosenbaum et al.

interpretation of the results; and finally (5) a discussion of how to manage, com-
municate and present uncertainty information together with the LCA results.

Learning Objectives
After studying this chapter, the reader should be able to:
• Explain the importance and usefulness of addressing uncertainty in LCA
• Distinguish types and sources of uncertainty and variability and explain
important misconceptions of uncertainty in the context of LCA
• List the dominating sources of uncertainty in a typical LCA
• Explain the relevant concepts and vocabulary of uncertainty
• Analyse sensitivity, uncertainty and variability and use these insights to reduce
overall uncertainty when performing an LCA
• Express and communicate uncertainty in an appropriate way, catering to the
purpose of the analysis
• Apply uncertainty information in results interpretation and decision support

11.1 Introduction

The British mathematician, science historian, author and inventor Jacob Bronowski
wrote that “Knowledge is an unending adventure at the edge of uncertainty”. This is
a perfect motto and inspiration for this chapter. Before learning how to deal with
uncertainty in the context of LCA, how to quantify it, interpret and use it, or
communicate it, which are the main objectives of this chapter, it is useful to truly
understand the concept of uncertainty in a broader sense. It is for that reason that we
have chosen to approach the subject much more holistically than just focusing on
relevant statistical methods, mathematical aspects and the like. This chapter is
neither a precise statistical method description, nor a philosophical essay about the
concepts of uncertainty, knowledge and truth, although you will find a little bit of
both.
First of all, uncertainty is always there, it is the elephant in the room no matter
what we are doing or talking about. From individuals to the entire humanity, from a
child to a stock market broker to the most accomplished Nobel laureate, many of
our daily efforts are related to knowing more, doing better, being more precise and
more accurate. Acquiring knowledge and information and reducing the uncertainty
around them is a driving force behind all human advancement, mobilising
incredible amounts of resources worldwide. It is in fact one (if not the) driving force
behind most things we do.
Uncertainty is also often the elephant in the room when people talk about or
apply LCA. It is always there but some may fear it and ignore it deliberately, some
may use it to criticise or even discredit LCA. An oversimplified understanding of