Life cycle assessment

Life cycle assessment (LCA) is a method of calculating the impact of a product, building or service on the environment. As its name suggests, LCA examines environmental impact throughout the entire life time of the item being assessed. LCA is used to measure impact on elements including the climate or ozone layer, eutrophication (excessive plant or agal growth) and acidification (a reduction in the pH of water bodies caused primarily by uptake of carbon dioxide from the atmosphere).

LCAs are based on ISO 14040-44 standards but can be done in a number of ways and to various degrees, depending on the issue.

LCA enables the establishment of environmental impact figures and the comparison of products, providing an opportunity for individuals and companies to make more informed choices about their environmental impact, or for climate risks to be assessed as part of an investment.

An LCA includes all the raw materials used to make a product, all transport, all energy use, and finally the management of waste once the product has worn out or served its purpose, such as by recycling or incineration.

The complexity of LCA varies greatly based on what you are assessing. For example, it is much more complicated to perform an LCA on a computer with many components than on a wooden floor.

LCA of a product can be compared to the nutrition list on a carton of milk. It is more of a table of contents than an eco-label and does not on its own say whether the product is good or bad from a climate perspective. In order to draw reasonable conclusions, it must be compared with another similar product. Companies can also use LCA to compare environmental impacts of a new product with those of the previous one.

An LCA is a model of reality and not a perfect representation of it. For communications surrounding findings to be credible, they must include the uncertainties that existed at the time the model was built or we risk reaching false conclusions.

For example, LCA does not differentiate where emissions occur, and because toxic substance issues may arise with varying degrees of severity in different areas, the LCA may need to be supplemented with additional analyses.

LCAs can help organisations be transparent about their environmental impact and show how they can work to improve the sustainability of their products. Vattenfall is an example of a company that frequently promotes the life cycle perspective of its services, for example, by indicating how its electricity production affects the environment and climate (“eco-declared” or “EPD-labelled electricity”).

LCA-based results can require further questioning to ensure they are credible. Some questions to consider include:

• Has anyone conducted an independent review of the findings? If not, why not?
• Is it possible to track down the original study? If not, why not?
• Are any relevant environmental aspect missing? If so, why?
• Does it give the perception of comparing apples with oranges? If so, why?

Ramboll conducts LCA at multiple levels and for a variety of purposes:

• Screening LCA: A brief study to compare the climate impact of two different materials or of energy consumption.
• LCA for buildings: These can be climate declarations meeting national requirements or for gaining points in building classification systems like DGNB, LEED, or BREEAM.
• Carbon footprint: Simplified LCA that only considers climate impact. This can include building climate declarations, civil engineering climate calculations, and greenhouse gas protocol calculations.
• Comparative LCA: Often undertaken to compare a company's product to a competitor's. It can also compare an existing product to a newly developed product to see if the new product performs better in terms of environmental performance. Depending on the complexity of the products, the scope of these studies may vary significantly.
• Calculation tool: When a customer wants to tailor an LCA or climate calculation, a calculation tool can be developed that allows the user to combine solutions in real time and receive results instantly.