Simplified tools for global warming potential evaluation: when ‘good enough’ is best

In spite of a number of lingering issues, life cycle assessment (LCA) is widely recognised as one of the most powerful tools to investigate the environmental performance of a product or service. Carbon footprint (CF) analysis can also be considered a subset of LCA, limited to a single impact category (i.e. global warming potential (GWP)). However, the inherent complexity of a full LCA or CF analysis often stands in the way of their widespread application in the industry and policy-making sectors. For these latter ambits, this paper advocates the adoption of tailor-made streamlined approaches, with reduced inventory requirements and impact assessment scope. Two such examples are provided, respectively addressing the evaluation of GWP in the development of new product standards and the GWP savings attainable through the use of recycled materials.

Both the application examples presented here are firmly rooted in life cycle thinking, and follow the guidelines provided by the current ISO standards on LCA. At the same time, the employed models are structured in such a way as not to require the deployment of specific LCA software but rely on simple algorithms instead, complemented by tables of data for the associated background processes sourced from standard life cycle inventory databases.

In the first example, the simplified algorithm was found to produce reliable and satisfactorily accurate results in terms of GWP, i.e. within 10% of those produced by a fully fledged LCA performed in parallel for validation purposes. In the second example, the adopted simplification only applied to the goal of the study (i.e. assessment of the absolute GWP savings, with no quantitative indication of their relative extent with respect to the total). Within these limits, the proposed simplified tool provided accurate indications, which enabled a clear ranking of the analysed products, in terms of desirability of recycling.

To the extent possible within the given set of constraints, simplified tools such as those presented here do not lose their scientific rigour and take into account all phases of the product life cycle. Their reduced goal and scope does of course limit the breadth of the information that they can produce, but this can be mitigated through a case-specific selection of the adopted inventory simplifications and impact category/ies.

The two application examples presented here have provided solid evidence that streamlined approaches such as these can go a long way in facilitating the introduction of life cycle thinking and LCA in the day-to-day practice of industries and policy makers, while still producing scientifically sound and robust results.

Simplified LCA tools lend themselves to a wealth of possible applications in the industry and policy-making sectors. More case studies are in order, and it will be advisable not to limit the goal and scope of all streamlined approaches to carbon footprint evaluation but to pick the most relevant impact categories to be included in the model on a case-by-case basis.