Lesson 2: Life Cycle Assesments

Question 1

Why are life cycle assesments carried out?

Answer 1

• Life cycle assessments (LCAs) are carried out to assess the environmental impact of products in different stages.

Question 2

What stages of a product are involved in LCA’s?

4 different stages

Answer 2

1.) Extracting and processing raw materials.
2.) Manufacturing and packaging
3.) Use and operation during its lifetime
4.) Disposal at end of its useful life, including transport and distribution at each stage.

Question 3

What 4 things can be fairly easily quanitified (in LCA’s?)

Answer 3

1.) Use of water
2.) Use of resources
3.) Use of energy sources
4.) Production of some wastes

Question 4

Why is LCA not a purely objective process?

Answer 4

• Allocating numerical values
  to pollutant effects is less straightforward (than allocating numerical values to othe things) and requires value
  judgements, so LCA is not a purely objective process.

Question 5

What is the issue with LCA’s?

Answer 5

• Can be biased eg. to support claims of advertisers

Question 6

Carry out a simple LCA for shopping bags made from plastic and shopping bags made from paper.

Consider each stage of a LCA

Answer 6

• Plastics bags produced from crude oil (extraction of crude oil can be harmful to habitats ie. if there is an oil leak + crude oil = non- renewable.)
• Paper bags produced from wood (cutting down trees is very harmful to habitats BUT is renewable.)
• Crude oil/ wood need to be chemically processed. Requires a lot of energy/ releases waste products.
• Making paper requires huge amounts of water.
• Plastic bags = strong (can be reused.)
• Paper bags = weak (not very reusable.)
• Both plastic/ paper bags need to be transported to landfills/ recycling centre - releases CO2.
• Paper bags = heavier than plastic bags = more energy to transport
• Plastic bags = non- biodigredable (fill up land fills.)