Evaluating the environmental impacts of the water-energy-food nexus with a life-cycle approachY

This study is an attempt to fill a knowledge gap in our understanding of WEF nexus, focusing on the effects of direct and indirect resource consumption with a life-cycle approach. In Taiwan, the food subsystem is water-intensive and energy-intensive, consuming 99% of water and energy resources directly to produce food. The water subsystem directly consumes 87.18% of its energy for water production, but indirectly consumes 12.82% for operations to prepare for water production and supply. However, the energy subsystem indirectly consumes 91% of the energy and 83% of the water from operations to prepare for energy generation. Consequently, direct resource consumption in the food subsystem and indirect operations in the energy subsystem cause more environmental impacts than those caused by others. The results highlight that environmental impacts derive from not only direct resource consumption but also preparation and production for resource generation (indirect consumption). There are approximately 28% of environmental impacts derived from indirect resource consumption in WEF nexus. Without considering the indirect resource consumption, we will underestimate the total resource depletion and environmental impacts. This study can help in developing policies for saving water and energy and in enforcing resource security.