A Commodity Supply Mix for More Regionalized Life Cycle Assessments.

Ben Ayre,Pernilla Löfgren,Toby A Gardner,Manuele Margni,Clément Suavet,Vivian Ribeiro,Laure Patouillard,Chris West,Michael J Lathuillière

doi:10.1021/acs.est.1c03060

Abstract

Supply chain information is invaluable to further regionalize product life cycle assessments (LCAs), but detailed information linking production and consumption centers is not always available. We introduce the commodity supply mix (CSM) defined as the trade-volume-weighted average representing the combined geographic areas for the production of a commodity exported to a given market with the goal of (1) enhancing the relevance of inventory and impact regionalization and (2) allocating these impacts to specific markets. We apply the CSM to the Brazilian soybean supply chain mapped by Trase to obtain the mix of ecoregions and river basins linked to domestic consumption and exports to China, EU, France, and the rest of the world, before quantifying damage to biodiversity, and water scarcity footprints. The EU had the lowest potential biodiversity damage but the largest water scarcity footprint following respective sourcing patterns in 12 ecoregions and 18 river basins. These results differed from the average impact scores obtained from Brazilian soybean production information alone. The CSM can be derived at different scales (subnationally, internationally) using existing supply chain information and constitutes an additional step toward greater regionalization in LCAs, particularly for impacts with greater spatial variability such as biodiversity and water scarcity.

Highlights

Life cycle assessment (LCA) is an approach that allows for the quantification of potential impacts of production and consumption processes throughout the life cycle of a product or service.[1]
The Global Guidance to include potential impacts to biodiversity and water use in LCA16 implies a reliable level of regionalization that can differentiate spatial variability in ecoregion land occupation and river basin water use
This spatial variability in the life cycle inventory (LCI) is relevant in the LCAs of more complex food products that rely on ingredients made from agricultural commodities such as soybean

Summary

Introduction

Life cycle assessment (LCA) is an approach that allows for the quantification of potential impacts of production and consumption processes throughout the life cycle of a product or service.[1]. LCAs originally presented average potential impacts using generic site conditions, until the 1990s when the benefits of sitespecific approaches became an important topic of discussion.[2]. Developments have highlighted the importance of representing site-specific conditions to account for differences in processes across multiple sites (e.g., electricity generation) and because emissions (to soil, air, water) in different environmental settings and locations may lead to different impacts (e.g., terrestrial acidification, eutrophication).[2,3] The inclusion of site-specific information can, in turn, affect the conclusions of LCAs that would only be based on site-generic data.[3]. Regionalization in LCA refers to the efforts to move from site-generic to more site-specific information and involves (1)

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Conclusion