-4- Question 3 (a) Polyethene is used to make plastic bags. Table 3.1 shows data from a life cycle assessment (LCA) for a plastic bag and a paper bag. Plastic bag Paper bag Crude oil / natural gas Wood Raw materials Energy used in MJ 1.5 1.6 Mass of solid waste in gram 14 52 0.2 0.3 CO2 produced during manuf. in kg Fresh water volume used in liters 250 4500 Table 3.1 A company stated: 'A life cycle assessment shows that using plastic bags has less environmental impact than using paper bags'. Evaluate this statement. To do so, please use your knowledge and the information from Table 3.1. [5 marks] (b) A life cycle assessment (LCA) determines the environmental impact of a laptop. Describe the five stages that are assessed in a life cycle assessment for this product and give two examples for each stage. [10 marks] (c) Explain how life cycle thinking and life cycle assessment should generally lead to selection and design of more sustainable processes and products. Illustrate your discussion with an example for sustainable processes or products. [5 marks]