Life cycle and ecosystem services assessments provide opposite evaluations of the food and non-food contributions of livestock farming systems

Session 24. Livestock are more than food

International audience

anglais. Life cycle assessment (LCA) and ecosystem services assessment (ESA) are often used for environmental evaluation. LCA is commonly applied to agro-ecosystems to assess the negative environmental impacts of food production (e.g. emissions of CO2-eq.), whereas ESA is applied to assess the positive contributions of agro-ecosystems, such as the supply of regulating ecosystem services (e.g. pollination or erosion prevention). Here, we applied both frameworks to a selection of twelve contrasting French meat-production systems, including two ruminant species (sheep and cattle) and two monogastric species (chickens and pigs). The LCA indicated that ruminant systems had more negative impacts than monogastric systems, which is a well-known result. For example, the production of one kg of human edible protein emitted 280 kg CO2-eq for ruminants, and 32 kg CO2-eq for monogastrics. This result is due, in particular, to the methane emitted during the rumination process. Oppositely, ruminant systems can supply more regulating ecosystems services than monogastric systems. The mean respective scores related to these services were 2.42 and 1.15, respectively. This result is due to the presence of semi-natural habitats such as grasslands in ruminant systems. Our results show the opposition between the rating of food production by LCA, and the rating of non-food contributions by ESA. Our study therefore stresses the need to reconcile these frameworks, as they can guide decision-making in opposite directions.