The 1,200 refills assumption problem- Why LCA needs to model real consumers

1,200 refills. That is what my 2019 study assumed for a reusable bottle to beat a single use one. But this week I lost my stainless steal Owala bottle. Again....

A refill every day for about three years is a generous expectation of any consumer. I now question whether it was realistic, and my own track record is not helping.

Life cycle assessment (LCA) treats technical parameters with great rigour, from supply chains to electricity grids. Human behaviour, which often determines the outcome, is usually reduced to an average or to a best and worst case scenario.

In our new Perspective in Environmental Science & Technology, Shelie Miller and I propose a framework for identifying where behaviour matters. It distinguishes six human product interactions: infrastructure heterogeneity, likelihood of adoption, heterogeneity in use, product as used versus product as designed, changes to consumption behaviour, and displacement versus additionality.

The implications are often counterintuitive. An electric car saves more emissions for the owner of an inefficient petrol car than for the owner of an efficient hybrid. A plant based burger benefits an omnivore more than a vegetarian. A new efficient fridge delivers no net gain if the old one moves to the garage. A second hand purchase does not necessarily avoid a new one. Our central argument concerns communication. Instead of “Alternative A is better than B”, the accurate claim is “Alternative A has lower impact if and only if it is used in manner X”. This also returns agency to consumers, who shape the impact of what they buy.

We call for explicit treatment of behaviour in goal and scope definition, better behavioural data, including from digital platforms, and clearer reporting when behaviour can reverse the ranking of alternatives.

Check out our paper (Open access: https://lnkd.in/dRtd4Fde) #CircularEconomy #ConsumerBehavior #Sustainability #industrialecology