Several safe boundaries of critical Earth system processes have already been crossed due to human perturbations; not accounting for their interactions may further narrow the safe operating space... Show moreSeveral safe boundaries of critical Earth system processes have already been crossed due to human perturbations; not accounting for their interactions may further narrow the safe operating space for humanity. Using expert knowledge elicitation, we explored interactions among seven variables representing Earth system processes relevant to food production, identifying many interactions little explored in Earth system literature. We found that green water and land system change affect other Earth system processes strongly, while land, freshwater and ocean components of biosphere integrity are the most impacted by other Earth system processes, most notably blue water and biogeochemical flows. We also mapped a complex network of mechanisms mediating these interactions and created a future research prioritization scheme based on interaction strengths and existing knowledge gaps. Our study improves the understanding of Earth system interactions, with sustainability implications including improved Earth system modelling and more explicit biophysical limits for future food production. Show less
McLaren, S.; Berardy, A.; Henderson, A.; Holden, N.; Huppertz, T.; Jolliet, O.; ... ; Zanten, H. van 2021
This report is the outcome of a consensus-building project to agree on best practices for environmental and nutritional Life Cycle Assessment (nLCA) methodology, and identify future research needs.... Show moreThis report is the outcome of a consensus-building project to agree on best practices for environmental and nutritional Life Cycle Assessment (nLCA) methodology, and identify future research needs. The project involved 30 nutritional and environmental LCA researchers from 18 countries. It focused on the assessment of food items (as opposed to meals or diets).Best practice recommendations were developed to address the intended purpose of an LCA study and related modeling approach, choice of an appropriate functional unit, assessment of nutritional value, and reporting nLCA results. An nLCA study should report the quantities of as many essential nutrients as possible and aim to provide information on the nutritional quality and/or health impacts in addition to nutrient quantities. Outstanding issues requiring further research attention include: defining a minimum number of nutrients to be considered in an nLCA study; treatment of nutrients to limit; use of nutrient indexes; further development of Impact Assessment methods; representation of nutritional changes that may occur during subsequent distribution and food preparation in cradle-to-gate nLCA studies; and communication of data uncertainty and variability. More data are required for different regions (particularly developing countries); for the processing, distribution, retail, and consumption life cycle stages; and for food loss and waste. Finally, there is a need to extend nLCA methodology for the assessment of meals and diets, to consider further how to account for the multi-functionality of food in a sustainability framework, and to set nLCA studies within the context of environmental limits.These results provide a robust basis for improving nLCA methodology and applying it to identify solutions that minimize the trade-offs between nourishing populations and safeguarding the environment. Show less
