A life-cycle analysis (LCA) is a systematic evaluation of the environmental impacts associated with a product or service throughout its entire life. Its five stages are raw material extraction, manufacture, distribution and transport, use and maintenance, and disposal and recycling.
How Life-Cycle Analysis Works
LCA follows a cradle-to-grave approach. The “cradle” represents the extraction and processing of raw materials, while the “grave” represents recycling or final disposal.
At each stage, designers examine material and energy inputs, waste, emissions, and other environmental effects. These may include global warming potential, air, water and soil pollution, ecotoxicity, and resource depletion.
| Stage | What designers assess |
|---|---|
| 1. Raw material extraction | Mining, harvesting or producing resources; processing materials; energy use; habitat damage; and resource depletion. |
| 2. Manufacture | Energy and water used in processing and assembly, manufacturing waste, and pollutants released. |
| 3. Distribution and transport | Packaging, transport distances, transport methods, fuel use, and associated emissions. |
| 4. Use and maintenance | Operational energy, consumables, cleaning, repairs, replacement parts, and the product’s useful lifetime. |
| 5. Disposal and recycling | Reuse, repair, remanufacture, recycling, incineration or landfill, including the energy and waste involved. |
For example, an aluminium bottle may require substantial energy during mining and manufacture. However, its environmental impact per use can decrease if it is reused many times and recycled at the end of its life. LCA therefore reveals trade-offs rather than automatically identifying one material as sustainable.
A common misconception is that LCA examines only end-of-life disposal. It assesses the product’s complete life cycle, and one stage should not be considered in isolation.
IB Exam Technique
C3.2 is an HL-only topic. For an “explain” question, name the five stages in the correct order and connect each stage to specific material inputs, energy use or environmental impacts. For “discuss,” consider competing impacts and trade-offs before reaching a supported conclusion.