The four stages of a life cycle assessment, what can and cannot be measured, comparing products with real numbers, and how reducing, reusing and recycling save ores and energy.
What you will learn
- Name the stages of a life cycle assessment and place an activity in one
- Compare two products from LCA data, including per use
- Calculate the energy and ore saved by recycling, with percentage composition
- Explain why an LCA can be selective or need judgement
The four stages
A life cycle assessment (LCA) adds up the environmental impact of a product from start to finish:
- Extracting and processing raw materials (mining ore, drilling for oil, growing cotton).
- Manufacturing and packaging.
- Use and operation (the fuel a car burns, the electricity a fridge uses).
- Disposal at the end of its life (landfill, burning, recycling).
Transport between stages counts too. At each stage an LCA looks at energy, water, resources used and waste or pollution made.
Energy, water and masses can be measured. How harmful a pollutant is has to be judged, so two groups can read the same data differently. A short or selective LCA can be used to back up a claim in an advert.
The rest of this lesson and its 10 practice questions are locked.
In this lesson
- The four stages
- Comparing with numbers
- Reduce, reuse, recycle
- Try it: Total each column
10 practice questions, marked as you go; about 30 minutes in all.
Key terms
Manufacturing and packaging, Use and operation, Disposal, Per use
In this unit: Using resources
Making water potable and the water practical, life cycle assessments and recycling, phytomining and bioleaching, corrosion and materials, and the Haber process with NPK fertilisers, with every calculation worked.