Life Cycle Analysis & Recycling (AQA GCSE Combined Science: Trilogy: Chemistry): Flashcards

A life cycle assessment (LCA) is an analysis of the total environmental impact of a product across all four stages of its life: extraction of raw materials, manufacture, use, and disposal.

The four stages assessed in a life cycle assessment (LCA) are:

1. Extraction of raw materials

2. Manufacture

3. Use and distribution

4. Disposal.

Each stage is assessed for environmental impact including energy use, waste produced, and habitat damage.

False.

Some aspects of an LCA can be quantified (e.g. water used in manufacture), but others require value judgements that are subjective.

Different assessors may weight factors differently, and LCAs used in advertising are often incomplete or biased.

Advertising LCAs often only present the stages where a product performs well environmentally, while omitting or downplaying stages with a high environmental impact. This gives an incomplete and potentially biased assessment.

Plastic bags are made from crude oil (a finite resource) but are reusable and durable, reducing impact per use.

Paper bags are biodegradable and recyclable, but manufacture uses more energy and produces sulfur dioxide.

Conclusion depends on usage: a reused plastic bag typically has lower impact than a single-use paper bag.

Recycling is the process of collecting, sorting, and processing used materials so they can be reformed into new products. It reduces consumption of finite raw materials, lowers energy use compared with extraction, and decreases waste sent to landfill.

Environmental advantages of recycling metals include:

• Less mining is required, reducing habitat destruction

• Recycling uses less energy than extracting metals from ores, producing fewer CO₂ and greenhouse gas emissions

• Less waste is sent to landfill, reducing the space needed at landfill sites.

False.

Cost savings are an economic advantage, not an environmental one. Environmental advantages include less mining, reduced energy use, fewer greenhouse gas emissions, and less waste going to landfill.

Examiners ignore references to cost when awarding environmental advantage marks.

Recycling metals reduces the need for mining, decreases energy use compared to extraction, and reduces waste going to landfill sites.

Disadvantages of recycling as a way of reducing resource use include:

• Collection and transport of recyclable materials requires energy and fuel

• Materials must be sorted before processing, requiring labour and energy

• Products made from recycled materials may not always be of the same quality as those from raw materials