Water is primarily used in forestry and fishery, agricultural production (in its entire agri-food supply chain) and is used to create and/or transfer energy in varying forms.
[6] In fact, agriculture is the largest user of freshwater, making it responsible for 70% of total global withdrawal, while more than one fourth of energy used worldwide is an input for food production, distribution, and use.
The emphasis on access in these definitions also implies that security is not so much about average (e.g., annual) availability of resources; it has to encompass variability and extreme situations such as droughts or price shocks, and the psychological resilience of the poor.
Water is used for extraction, mining, processing, refining, and residue disposal of fossil fuels, as well as for growing feedstock for biofuels and for generating electricity.
Further, return flows from power plants to rivers are warmer than the water that was taken in and/or are highly polluted and can consequently compromise other downstream usage, including ecosystems.
Adding value to the agricultural food supply chain require the interdisciplinary management of the critical factors that influence the productive capacities and sustainability of these resources.
[21] A nexus perspective increases the understanding of the inter-dependencies across the water, energy and food sectors and influences policies in other areas of concern such as climate and biodiversity.
The nexus perspective helps to move beyond silos and ivory towers that preclude interdisciplinary solutions, thus increasing opportunities for mutually beneficial responses and enhancing the potential for cooperation between and among all sectors.
Everyone in all disciplines needs to think and act from the perspective of being interlinked in order to realize the full impact of both direct and indirect synergies that can result.
A deep understanding of the nexus will provide the informed and transparent framework that is required to meet increasing global demands without compromising sustainability.
Accelerating the involvement of the private sector through establishing and promoting the business case for both sustainability and the nexus is essential to driving change and getting to scale.
A water-energy-food (WEF) nexus assessment supports natural resource management by providing an integrated framework for evaluation and decision-making.
This analysis supports the decision-making process of the nexus assessment by facilitating dialogue between stakeholders in order to achieve long term efficiencies, especially in rural landscapes where most of the services connected to WEF securities are provided.
If these concerns were not to be addressed, the nexus concept risks turning into an empty shell that merely serves powerful actors to legitimize exclusionary policies.