Earth system functioning as a separate area of protection for life cycle impact assessment

Areas of protection (AoPs) guide what is considered to be the goal of environmental protection in life cycle assessment (LCA). Currently, the general agreement is on including three AoPs of human health, ecosystem quality, and natural resources. These AoPs determine the considered impact pathways, the included impact categories, and the design of the models used to quantify the impacts. However, the current LCA framework does not directly reflect the knowledge of Earth system science and the critical role of Earth system functioning. This paper advocates for an additional Earth system AoP to extend the horizon of LCA studies with impacts on the Earth system functioning and stability. It is argued that the proposed Earth system AoP would satisfy selection criteria based on societal consensus, intrinsic value, functional value, as well as cultural value. Including the Earth system as an AoP would allow LCA to consider different impact pathways and thus different dimensions of the current environmental problems. The included impact pathways and the design of impact categories could be based on the knowledge from Earth system science and inspired by the planetary boundaries framework. This is but a first attempt at a broad conceptualization of an Earth system AoP which would require further scientific debate and methodological development to be fully operational.