Life cycle assessments consider the total environmental impact a product has over its whole life, including production, use and disposal.
The main features of a life cycle assessment are
1. Sustainability of the raw materials. Many raw materials are finite and cannot be replaced. Once all the gold on the planet has been mined for example – some estimates put this date only a few years away – that's it. We can't 'magic' more gold out of a hat.
2. Preparing for production. Mining materials damages the environment. Building a mine or producing oil disfigures the environment, and the materials must be transported, often by road or sea, which involves further use of resources, and the risk of pollution.
3. The manufacturing process. Manufacture requires a factory, people going to work every day, power, water and gas. The factory occupies land, and the people travel along roads leading to the factory. All of these subtract from the resources available to nature.
4. Using the product. Once the product has been manufactured, it must be delivered to the point of sale – a shop or warehouse. Again, this involves much use of resources not now available to nature.
5. Disposing of the product. A lot of waste is buried in large holes in the ground. This is called landfill. Landfill sites are sources of pollution, some of which is toxic eg cadmium, used in rechargeable batteries.
We are often concerned to minimise the environmental impact of a product. Life cycle assessments are an aid to this. We are especially interested in
a) Seeking alternative raw materials that are more sustainable and have less impact on the environment.
b) Reducing the incidental costs of production. These include the distances that materials must move to get to the production site.
c) Reducing the energy use during manufacture, using less labour and water, the commuting distance for workers.
d) Making products more efficient, so they use less power.
e) Making the product last longer, more easily upgradeable and recyclable. Many desktop computers are made of modular parts that can be repaired or upgraded by replacing a single component, which are made to standard specifications. This may be a model for many electronic products.