Does resilient mean eco-inefficient?

Resilience is a property of systems that is deemed essential for their sustainability. The term “resilience” has become a vague buzzword in the last few years but the literature agrees that resilience depends on the structure and architecture of a system. It increases with system complexity, because the redundant connections between elements of a system make it less efficient but also more flexible and adaptable and allow to perform a function even if some connections are interrupted or missing. Balancing between resilience and efficiency seems to be the key for sustainability intended as long-term perfomance. Resilience is not explicitly taken into account within life cycle assessment (LCA). LCA determines the eco-efficiency of product systems, i.e. the ratio between the function provided by the product and its impact on the environment. The question is whether a product system which structure is improved or designed to be more resilient will not only be more inefficient, but also eco-inefficient, when studied by means of LCA. In this work a two steps approach is proposed to study resilience of product systems: 1) assessment of disturbance conditions and their inclusion within the scope of the LCA study; 2), system expansion, i.e. changing the structure of the system by including additional disturbance-preventing processes and disturbance-dependent ones. This theorethical LCA modelling approach was tested on two fictional case studies using data from literature: A) the example of two different waste management systems of a remote island distrubed by stormy weather; B) the example of two different biofuel systems, single- and multiple-feedstock, disturbed by climate changes. Results shows that if proper LCA modelling is applied, resilient product systems are not necessarily less eco-efficient than their vulnerable counterparts and instead can allow for eco-efficiency gains. This goes against the intuitive idea that optimizing a system for efficiency only will necessarily allow achieving eco-efficiency as well, and suggests that design for resilience may be a valuable idea towards sustainability. However, further experimental work on the subject is needed to draw more robust and generalizable conclusions.