Food–energy–water metrics across scales: project to system level

Although much theoretical work has been put into stressing the importance of understanding the food–energy–water nexus, if this burgeoning focus of inquiry is to have any impact on development pathways, we must advance metrics to guide policy planning and action. In this paper, we outline a framework for establishing such a suite of indicators based on system science and life cycle assessment. We identify a number of considerations that should be addressed including the following: (a) scope, ranging from project level (for example, a thermoelectric power plant) through higher system network levels (industry to national to global-level analysis), and (b) the category of the metric, which is defined by two dimensions, (i) intrinsic vs. extrinsic and (ii) absolute vs. relative units, whether the metric indicates an absolute value (for example m3 of freshwater consumption or kWh of electricity used by a power plant) or a value relative to an industry/policy performance benchmark or some environmental indicator (e.g., available water within the basin in which our power plant is located). By understanding the scope and category of metrics derived from economic, life cycle, or other modeling and accounting methods, we understand how various stakeholders are motivated to focus on certain metrics over others. This understanding in turn creates the means to translate between metrics and models for food–energy–water planning and stakeholder collaboration. It should be noted that the primary objective of this paper is to spur discussion, rather than to flesh out a fully formed theoretical framework. We hope, however, that our efforts may prove to be of some use in the crucial discussion of food–energy–water nexus issues.