4.10 Life Cycle Assessments

Question 1

LCA - Choice of materials (2)

Answer 1

• Metals have to be mined and extracted from their ores. These processes need a lot of energy and cause a lot of pollution.
• Materials for chemical manufacture often come from crude oil. Crude oil is a non-renewable resource, and supplies are decreasing. Also, obtaining crude oil from the ground and refining it into useful raw materials requires a lot of energy and generates pollution.

Question 2

LCA - Manufacture (4)

Answer 2

• Manufacturing products uses a lot of energy and other resources such as water.
• It can also cause a lot of pollution, e.g. harmful gases such as CO or HCI.
• Manufacture produces waste which has to be disposed of. Some waste can be recycled and turned into other useful chemicals, reducing the amount that ends up polluting the environment.
• Most chemical manufacture needs water which needs to be treated before it’s put back into rivers.

Question 3

LCA - Product Use (3)

Answer 3

Using the product can also damage the environment
- Paint gives off toxic fumes
- Burning fuels releases greenhouse gases and other pollutants
- Fertilisers can leach into rivers and damage ecosystems

Question 4

Disposal (4)

Answer 4

• Products are often disposed of in a landfill site at the end of their life. This takes up space and can pollute land and water.
• If the products are biodegradable, they’ll decompose quite quickly, but if they’re non-biodegradable, they’ll hang around in landfill for years.
• Products might be incinerated (burnt), which causes air pollution. But the energy released by burning can be used to generate electricity, which reduces the need for fossil fuels.
• Recycling or reusing a product reduces the impact of disposing of it. The amount of resources needed to make new products from the recycled material is also reduced.

Question 5

Why will companies have to make assumptions and estimations when making LCAs?

Answer 5

An object may be recyclable, but they don’t know how many users will actually recycle it.

Question 6

What are the limitations of lifecycle assessments? (3)

Answer 6

• Making products involves loads of different steps and it is almost impossible to quantify them. Even if you do manage to get all the data and find exactly how much energy was used and how many pollutants were produced etc. it’s still difficult to assess the harm of each step.
• Because life cycle assessments are so complex, they can easily be manipulated to deliberately support a company, which may be done to give the company positive advertising. This is hard to notice as the calculations are so complex.
• Companies may have to make assumptions and estimations when making LCAs. For example, an object may be recyclable, but they don’t know how many users will actually recycle it.

Question 7

What is the purpose of a life cycle assessment (LCA)?

Answer 7

To assess the environmental impacts of products