How does a life cycle assessment evaluate environmental impact?

A life cycle assessment evaluates environmental impact by analysing all stages of a product's life from cradle to grave.

A life cycle assessment (LCA) is a method used to evaluate the environmental impacts associated with all the stages of a product's life. This includes everything from the extraction of raw materials, manufacturing, distribution, use, repair and maintenance, to disposal or recycling. This is often referred to as a 'cradle to grave' approach.

The first step in an LCA is to define the goal and scope. This includes identifying the product to be assessed, the reasons for carrying out the assessment, and the intended audience of the results. The next step is the inventory analysis, which involves collecting data on all the inputs and outputs of the product system. This includes energy and material inputs, as well as emissions to air, water and land.

The third step is the impact assessment. This involves linking the inventory data with specific environmental impacts. For example, emissions of greenhouse gases contribute to global warming, while emissions of nitrogen oxides contribute to acid rain. The final step is the interpretation of results, which involves identifying the stages of the product's life that contribute most to the overall environmental impact.

An LCA can help to identify opportunities to reduce the environmental impact of a product. For example, it might show that a large proportion of the product's impact comes from the manufacturing stage, suggesting that changes to the manufacturing process could significantly reduce the overall impact. It can also help to compare the environmental impacts of different products or services, aiding in decision-making processes.

In summary, a life cycle assessment is a comprehensive method for evaluating the environmental impact of a product, taking into account all stages of its life. It provides valuable information that can be used to reduce environmental harm and make more sustainable choices.