The Earth’s population is expected to exceed 9 billion by 2050, posing significant challenges in meeting human needs while minimally affecting the environment. To support this population, we will need secure and safe sources of food, energy, and water. The nexus of food, energy, and water is one of the most complex, yet critical, issues that face society. There is no more land to exploit, and the supply of fresh water in some areas of the world limits the use of land for food. All solutions must also deal with the overlay of global climate change. Meeting current and future populations needs will require security in food, energy, and water supplies. A nexus approach is needed to improve food, energy, and water security integrating the management of the limited resources while transitioning to a more “green” economy, which provides adequate food, energy, and water for the expanding human population.

Emerging interdisciplinary science efforts are providing new understanding of the interdependence of food, energy, and water (FEW) systems. These science advances, in turn, provide critical information for coordinated management to improve the affordability, reliability, and environmental sustainability of FEW systems. Here we describe the current state of the FEW nexus and approaches to managing resource conflicts through reducing demand and increasing supplies, storage, and transport. Despite significant advances within the past decade, there are still many challenges for the scientific community. Key challenges are the need for interdisciplinary science related to the FEW nexus; ground‐based monitoring and modeling at local‐to‐regional scales; incorporating human and institutional behavior in models; partnerships among universities, industry, and government to develop policy relevant data; and systems modeling to evaluate trade‐offs associated with FEW decisions.

Allocation and management of agricultural land is of emergent concern due to land scarcity, diminishing supply of energy and water, and the increasing demand of food globally. To achieve social, economic and environmental goals in a specific agricultural land area, people and society must make decisions subject to the demand and supply of food, energy and water (FEW). Interdependence among these three elements, the Food-Energy-Water Nexus (FEW-N), requires that they be addressed concertedly. Despite global efforts on data, models and techniques, studies navigating the multi-faceted FEW-N space, identifying opportunities for synergistic benefits, and exploring interactions and trade-offs in agricultural land use system are still limited. Taking an experimental station in China as a model system, we present the foundations of a systematic engineering framework and quantitative decision-making tools for the trade-off analysis and optimization of stressed interconnected FEW-N networks. The framework combines data analytics and mixed-integer nonlinear modeling and optimization methods establishing the interdependencies and potentially competing interests among the FEW elements in the system, along with policy, sustainability, and feedback from various stakeholders. A multi-objective optimization strategy is followed for the trade-off analysis empowered by the introduction of composite FEW-N metrics as means to facilitate decision-making and compare alternative process and technological options. We found the framework works effectively to balance multiple objectives and benchmark the competitions for systematic decisions. The optimal solutions tend to promote the food production with reduced consumption of water and energy, and have a robust performance with alternative pathways under different climate scenarios.

Sustainability scholars increasingly recognise that environmental and security challenges that societies face today cannot be understood in isolation from one another. The rising popularity of a nexus approach to water–energy–food–environmental security analysis reflects this trend. Yet, little is known about exactly how previously disconnected scholarship on water security, energy security, food security and environmental security have converged in this way—and how this convergence can become more holistic and analytically meaningful. This paper outlines major conceptual turns within the literature on these four concepts and reflects on the use of nexus analysis in sustainability science as well as ways forward from where we currently stand. A salient finding is that while a nexus approach suggests more integrated analyses, there is still a tendency for siloed approaches focussed on how, for example, water security connects to energy and food security rather than truly integrated approaches.

Z. Habib, 'Resource conservation and civil society: water and food security in Pakistan', 2014

The formation of societies is based on the dynamics of spatial clustering, which optimizes economies of scale in the management of the water–energy–food (WEF) nexus. Energy and food are determinant measures of prosperity. Using the WEF nexus as an indicator, we evaluate the social impacts of the current (2022) conflict and in particular the economic sanctions on Russia. As Russia and Ukraine are major global suppliers of energy sources, food, and fertilizers, new threats arise by their limitations and the rally of prices. By analyzing related data, we show the dramatic effects on society, and we note that cities, which depend on a wider area for energy and food supplies, are extremely vulnerable. This problem was substantially worsened due to the large-scale urbanization in recent decades, which increased the distance from food sources. We conjecture that the Western elites’ decision to sanction Russia dramatically transformed the global WEF equilibrium, which could probably lead to the collapse of social cohesion.

As economies develop and societies change, emerging sets of challenges are placed on water resources and its governance. Population growth and economic development tend to drive the demand for more water, and push river basins into situations of scarcity. Agriculture, globally the largest user of water, is a major driver of water scarcity, and also the sector that has to bear the consequences of scarcity. Yet governance arrangements the world over have difficulty coming to grips with the management of agricultural water within the larger water resource context. The four major agricultural water governance challenges are: to manage transitions from abundance to scarcity; to deal with the large informal sectors of the agricultural water economy; to adapt to the changing objectives of society; and within each of these challenges, to craft contextspecific solutions. This paper presents examples of these challenges and uses them to derive a conceptual framework to help us understand present agricultural water-use contexts, and to develop context specific solutions. The framework is based on two important and shifting contextual dimensions: the degree of scarcity within a basin, and the degree of formality in water use. Looking at agricultural water governance within this framework shows that some standard prescriptions for water problems may not always be appropriate and that â??second bestâ?? solutions can in fact be the best way forward. The challenge for governance is to facilitate the development of these solutions | David Molden et al., 'Governing to Grow Enough Food without Enough Water?Second Best Solutions Show the Way', International Journal of Water Resources Development, vol. 26(2), pp.249-263, Informa UK Limited, 2010

The challenges of the 21st century require resilient societies and a robust international regulatory framework [1]. The current disruptions to the global framework (most notably by the Covid-19 pandemic and the war on Ukraine) as well as the historic experiences especially of the Great Depression and the Lehman crisis (Annex II) elucidate the importance of the UN Sustainable Development Goals (SDGs) as a global regulatory framework. The SDGs provide new targets for resilient development. In this paper we set specific focus especially on SDG 17 “Partnerships for the Goals” and its aim of a free multilateral trading system (Annex I, SDG 17.10-17.12) for sustainable development [2]. Against this background the German Resilience Index was developed as a new measure for defining the resilience of the German society based on the SDGs including the explicit consideration of trade dynamics. The German Resilience Index (GRI) enables an analysis of the extent to which Germany has succeeded in building socio-economic-ecological resilience to defy the storms of globalization. The index is based on the German Sustainable Development Goals and the defined targets, considering also ethical values derived from the Universal Declaration of Human Responsibilities of the InterAction Council and trade relations as corner stones of resilient development. The analysis thus provides a first approach for systematically considering the impact of Germany’s intensive participation in globalization and the ethical values of the German Sustainability Strategy and its SDGs. The results are important for the political decision-making process and the political as well as social discourse about the future course of sustainable, and thus resilient, development in Germany.

Given the large amounts of water, land, and food embodied in the trade of goods and services, a key step in decoupling extensive resource consumption from the economic system is to understand the full impact of socioeconomic development on the water-land-food nexus. This study integrates input–output analysis, ecological network analysis, and Dempster–Shafer evidence theory into a supernetwork model to detect the water-land-food nexus among economic sectors with an aim to explore effective strategic paths for resource management and to facilitate the construction of a resource-saving society. Results show that most sectors of China are resource inefficient and that all resource systems are unsustainable as reflected in the low performance of their Finn's cycling index and system robustness. Meanwhile, results of flow networks analysis show an extremely uneven land resource allocation where more than 94% of the land used in China is classified as direct agricultural land. The water-land-food nexus can gain resource saving bonus via enhancing the robustness of economy. However, the co-benefits from the nexus are negligibly small for the resource utilization efficiency. The results also indicate that the relevant resource-saving policies on food and water are highly likely to gain resource co-benefits due to their similarities in sectoral importance. Correspondingly, a set of strategic measures, including adopting a tiered resource price, deepening industrial convergence of agriculture, enhancing agriculture-food nexus, and managing water or land use from the food consumer side, are designed to build a resource-saving society. The findings of this study can provide additional insights into the impacts of the economy on the water-land-food nexus, which is beneficial for achieving an efficient and coordinated management of resources.

The nexus represents a multi-dimensional means of scientific enquiry which seeks to describe the complex and non-linear interactions between water, energy, food, with the climate, and further understand wider implications for society. These resources are fundamental for human life but are negatively affected by shocks such as climate change and characterize some of the main challenges for global sustainable development. Given the multidimensional and complex nature of the nexus, a transdisciplinary approach to knowledge development through co-production is needed to timely and effectively inform the decision making processes to build societal resilience to these shocks going beyond the sectorality of current research practice. The paper presents findings from five themed workshops (shocks and hazards, infrastructure, local economy, governance and governments, finance and insurance) with 80 stakeholders from academia, government and industry in the UK to explore the impact of climate and weather shocks across the energy-food-water nexus and barriers to related responses. The research identified key stakeholders’ concerns, opportunities and barriers to better inform decision making centred on four themes: communication and collaboration, decision making processes, social and cultural dimensions, and the nature of responses to nexus shocks. We discuss implications of these barriers and how addressing these can better facilitate constructive dialogue and more efficient decision-making in response to nexus shocks.