Propagation of environmental variability through global food supply chains - Current knowledge and future priorities

Environmental variability is an inherent feature of human-environment interactions and challenges the stability of adequate and nutritious food supply, access, and utilization. From interannual changes in rainfall to episodes of extreme heat, this variability can be attenuated or propagated through food supply chains by various processes, either dampening or amplifying food supply variability for consumers. Identifying these processes is central to reducing risks associated with periodic food shortages. Here we present a conceptual framework of the steps and linkages within the global food supply chain that ultimately connect food production and consumption. We examine specific links for which there is already evidence of the propagation or attenuation of environmental variability, identify connections for which further research is needed, explore the interface at which environmental variability is converted to food price volatility, and highlight key responses - at the level of an individual (e.g., substituting foods), a company (e.g, switching sources), or a government (e.g., strategic reserves) - for coping with this variability. By formulating a cohesive framework of the interactions between environmental variability and actors within global food supply chains, this work can serve as a basis for highlighting steps in supply chains that are vulnerable to variability and for exploring solutions to minimize those risks.