A company produces two versions of a carrier bag: one made from plastic and one made from cotton. Explain why a selective life cycle assessment (LCA) of the cotton bag could be misused to make the cotton bag appear more environmentally friendly than the plastic bag.

A selective LCA only considers a limited number of life‑cycle stages, so the study can omit stages that are detrimental to the cotton bag. By including only the stages that favour cotton (e.g. lower energy use in production) and excluding the unfavourable stages (e.g. high water use or soil erosion during cotton farming), the assessment will present a biased, overly positive picture. Furthermore, assigning numerical values to pollutant effects involves value judgments; the analyst can choose impact categories or weighting factors that minimise the cotton bag’s score. Finally, the company could present this selective LCA in advertising, claiming the cotton bag is more environmentally friendly, even though the full life‑cycle comparison would show otherwise.