Life-cycle Assessment - Critiques

Critiques

Life cycle assessment is a powerful tool for analyzing commensurable aspects of quantifiable systems. Not every factor, however, can be reduced to a number and inserted into a model. Rigid system boundaries make accounting for changes in the system difficult. This is sometimes referred to as the boundary critique to systems thinking. The accuracy and availability of data can also contribute to inaccuracy. For instance, data from generic processes may be based on averages, unrepresentative sampling, or outdated results. Additionally, social implications of products are generally lacking in LCAs. Comparative life-cycle analysis is often used to determine a better process or product to use. However, because of aspects like differing system boundaries, different statistical information, different product uses, etc., these studies can easily be swayed in favor of one product or process over another in one study and the opposite in another study based on varying parameters and different available data. There are guidelines to help reduce such conflicts in results but the method still provides a lot of room for the researcher to decide what is important, how the product is typically manufactured, and how it is typically used.

An in-depth review of 13 LCA studies of wood and paper products found a lack of consistency in the methods and assumptions used to track carbon during the product life cycle. A wide variety of methods and assumptions were used, leading to different and potentially contrary conclusions – particularly with regard to carbon sequestration and methane generation in landfills and with carbon accounting during forest growth and product use.

The Agroecology tool "agroecosystem analysis" offers a framework to incorporate incommensurable aspects of the life cycle of a product (such as social impacts, and soil and water implications). This tool is specifically useful in the analysis of a product made from agricultural materials such as corn ethanol or soybean biodiesel because it can account for an ecology of contexts interacting and changing through time. This analysis tool should not be used instead of life-cycle analysis, but rather, in conjunction with life-cycle analysis to produce a well-rounded assessment.

Read more about this topic:  Life-cycle Assessment