Life Cycle Assessment

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CognitoLife cycle assessment

Key facts & methods

What is LCA?

LCA evaluates the total environmental impact of a product from cradle to grave.
Stage 1: Raw material extraction — mining, drilling, growing. Land use, energy, CO2.
Stage 2: Manufacturing and processing — energy use, waste produced, water use.
Stage 3: Use — energy consumed during use, maintenance, repairs.
Stage 4: Disposal/End of life — landfill, recycling, incineration, biodegradation.
Each stage has environmental costs. LCA adds them up to compare products.

Limitations of LCA

Some data is difficult to quantify precisely (e.g. damage to local ecosystems).
Different studies may use different assumptions and weightings.
Results can be subjective — which factors to prioritise?
May be used selectively by companies to present their product favourably.
Does not easily account for social or economic factors.

Using LCA to reduce impact

Compare materials: e.g. cotton vs polyester bag — LCA shows cotton bag may need 100+ uses to offset higher production impact.
Design for recyclability: choose materials and manufacturing processes that enable recycling at end of life.
Reduce packaging: less material = less extraction + less disposal.
Local sourcing reduces transport energy.
Reusable vs single-use: reusable product must be used enough times to offset higher initial impact.

Exam questions — 3 questions · 9 marks · AQA 8462 style

1 markLCA scopeAQA 8462 style

Which stage is included in a complete life cycle assessment?

A Manufacturing stage only

B Use stage only

C All stages: raw material extraction, manufacture, use and disposal

D Extraction and disposal only

4 marksCompare two productsAQA 8462 style

A student compares a glass bottle and a plastic bottle using LCA. The glass bottle uses more energy to manufacture. The plastic bottle is less likely to be recycled. Evaluate which is more environmentally friendly overall. (3 marks)

Hint: Consider: manufacturing energy (plastic wins) vs recyclability/end of life (glass wins). LCA is about the full picture — acknowledge the trade-off.

+40 XP

1 markLCA limitationAQA 8462 style

Which of the following is a limitation of life cycle assessment?

A LCA can only be applied to plastic products

B LCA results are always objective and reliable

C Some environmental impacts are difficult to quantify, making comparisons subjective

D LCA does not consider the manufacturing stage

Life Cycle Assessment

What is LCA?

Limitations of LCA

Using LCA to reduce impact

Module complete! 🎉