Life Cycle Analysis (LCA)

Discuss the environmental life cycle approach to assessing cars. Your answer should contain:
a. A definition and brief explanation of what you mean by life cycle analysis (LCA).
b. The aim of an LCA.
c. Environmental impacts of a car throughout its life cycle? Illustrate your answer with a sketch to show how these impacts can be categorized in an LCA.
d. A conclusion which draws on the above analysis to justify your opinion of the merit of an LCA.

The life cycle analysis (LCA), a technique to pull together environmental indicators. Life cycle analysis is a system approach in that it traces environmental impacts at all stages of a product’s life cycle. It starts from the impacts arising from extracting and processing raw materials; then it identifies impacts from manufacturing and delivering a product, followed by the impacts involved in using a product, and finally examines what happens at the end of the product’s life-whether it is reused, the material from it is recycled or, if it is dumped, the environmental impacts concerned. An LCA is particularly useful if it is not immediately clear which are the major environmental impacts or at which stage of the life cycle the impacts occur.

The aim of LCA is to identify where the greatest environmental impacts occur in order to help decide the best approach to reduce them. Often a comparative LCA is undertaken on two design options: for example, the use of an electric vehicle to replace one powered by a conventional petrol engine. An electrical engine will result in no emissions at point of use, but the electricity has to be generated somehow, and so power station emissions associated with the energy used by such a vehicle need to be taken into account. An LCA can help to improve the design not only of a product (e.g. a car or train) but also of a service or a system. An example of the latter would be, if instead of traveling to a shop, you ordered shopping by the internet and it was delivered in a van servicing several households.

Student should sketch Figure 3.1 & 3.2 to show how these can be categorized in an LCA. The main materials used in the manufacture of cars are steel, non-ferrous metals (such as aluminum and copper), plastics and glass. Extracting and processing these materials involves a large amount of energy and water, the production of various emissions to air and water and the creation of a lot of solid waste. During manufacture and assembly of the car, further energy, water and other inputs are required and further emissions and solid wastes are produced.

After sale to the purchaser and during its useful life, the car will consume large amounts of petrol or diesel fuel which produces emissions, such as carbon dioxide (CO2), and air pollutants including carbon monoxide, un-burnt hydrocarbons and nitrogen oxides, which are harmful to human health and/or the environment. During its life, the car will also require the replacement and disposal of many parts and components, particularly tyres, batteries and exhaust systems. At the end of its life cycle the car will normally be broken up and many of its materials will be recycled. This may reduce energy consumption and emissions compared with sourcing virgin materials. Finally, non-recycled materials (glass, rubber and fabrics) are buried as solid waste or may be burnt, producing further emissions.

In practice, a full LCA is a complex and expensive process and the results are not always clear cut. A particular problem is deciding the relative importance of different environmental impacts. For example, a number of packaging LCAs have identified a dilemma: plastic packaging, made form oil, has one set of environmental impacts, including depletion of a non-renewable resource and emissions in manufacture, while cardboard packaging tends to involve water pollution issues. Which of the two is the more important? Simply conducting an LCA will not answer this question.

An LCA systematically creates a list (or 'inventory') of environmental impacts, but comparing these impacts or deciding what to do once this information is gathered can be tricky. Consequently, in practice, LCAs are used more often to identify the main environmental impacts and at which stage in the life cycle these occur. LCAs are particularly helpful in systematically identifying environmental 'hot spots' and clarifying the decisions that need to be made. In many cases it is obvious where the largest effects are and more detailed studies can concentrate on where the situation is unclear. The LCA also illustrates that point about trade-off between environmental issues