life cycle assesments

Question 1

define sustainable development

Answer 1

using resources to meet the needs of people today without impacting the needs of future generations

Question 2

define finite resource

Answer 2

cannot be replenished

Question 3

define renewable resource

Answer 3

can be reproduced again once you have used it

Question 4

define carbon neutral

Answer 4

no net increase in carbon dioxide emissions

Question 5

what are the 4 main stages to a life cycle assessment

Answer 5

1. extracting and processing the raw materials (collecting the raw materials)
2. manufacturing and packing the product
3. using the product (product use)
4. disposing of it (product disposal)

Question 6

what are the problems with extracting and processing raw materials? (2 marks)

Answer 6

1. damage local environment (cutting down trees, digging of mines)
2. pollutants can be released
3. carbon dioxide production from energy use

Question 7

what are the problems with manufacturing and packing? (3 marks)

Answer 7

1. energy use
2. pollution (carbon monoxide, hydrogen chloride)
3. waste products

Question 8

compare paper and plastic bags in terms of life cycle assessment (6 marks)

Answer 8

1. plastic bags are made from crude oil
   paper bags are made from wood
2. plastic bags are made from hydrocarbons that undergo cracking to make alkenes which then undergo polymerisation to become plastic
   paper bags are made from timber which has to be pulped which has high energy costs and produces a lot of waste
3. plastic bags can typically be used multiple times whereas a paper bag is single use
4. but plastic bags are not biodegradable and take up space in landfill or get into the wild and harm animals
   and paper bags are biodegradable and non toxic

Question 9

the limitations of life cycle assessments (3 marks)

Answer 9

1. making products involves lots of different steps
   (hard to quantify how much damage each step does)
2. can easily be manipulated to support a particular company
   (hard to notice when this has been done)
3. is difficult to compare what impacts different products will have
   (lung disease vs global warming)

Question 10

what is the purpose of a life cycle assesment

Answer 10

assesses the environmental impact of a product

Question 11

what do we call LCA’s that chose to ignore certain environmental impacts of a product

Answer 11

selective LCA’s