Explain why a life cycle assessment (LCA) is not a purely objective process.

AQA GCSE Chemistry (8462) — 4.10.2 Life cycle assessment and recycling · Explain · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Model answer (4 marks)

1. Assigning numerical values to the environmental impact of pollutants is difficult and involves many assumptions.
2. The assessment requires value judgements, for example when deciding which impacts to prioritise.
3. LCAs can be selective or abbreviated, covering only part of a product’s life cycle.
4. Such selective LCAs can be misused to support advertising claims and make a product appear greener than it really is.

Examiner tips

Use the exact wording from the mark scheme, e.g. "allocating numerical values" and "value judgements".
Show each point clearly, matching the four marks.
Keep sentences short and to the point.

Common mistakes

Writing that LCA is objective because it uses data, ignoring the value judgements.
Omitting the point about selective LCAs being misused for advertising.

Mark scheme (4 marks)

Allocating numerical values to pollutant effects is not straightforward
Value judgements are required (when assessing pollutant effects)
Selective or abbreviated LCAs can be produced / only part of the life cycle may be included
Selective LCAs can be misused, e.g. to support advertising claims / to make a product appear more environmentally friendly than it is

Key terms in this question

life cycle assessment (LCA)