A farmer driving a tractor early in the morning.

This article was first published by American University in Cairo’s Cairo Review of Global Affairs. It was published as part of UCF’s partnership with AUC, thanks to the generous support of Jonathan and Nancy Wolf.


The WEF Nexus as a Framework

To assess interactions among the three resources controlling the structure and function of human communities and natural ecosystems—water, energy and food—it is helpful to think of them as a nexus. System sustainability depends on maximizing resilience in the interactions among the resources comprising the three-legged stool of the water-energy-food (WEF) nexus, but it is challenged by the reality of declining resources and increased demand associated with changing human demographics, land use, and climate change. Public health is a reflection of WEF stability and economics similarly is a reflection of the extent to which nexus sustainability and resilience is controlled.

A WEF nexus model is useful for both assessing national sustainability under existing conditions and gauging societal and ecosystem response resilience to resource availability and consumption under a variety of other scenarios. Tracking annual demand for each WEF component of the nexus as a percent of resource availability can help predict the the tipping point of resource depletion beyond which a resource is no longer sustainable; the three-legged stool becomes wobbly or tips over if changes in the other WEF components are not made to counteract the negative impacts.

Nexus models must recognize that multiple biomes—geographical areas of comparable physical environment and climate with distinct plants and animals adapted to that set of conditions—exist within a given nation, and each provides specific services to the WEF nexus reflecting regional climate, elevation, geology, and hydrology. Individual biomes are easily recognized (desert, montane, rainforest, etc.) and widely distributed globally.

Urban areas are dependent on water, energy, and food supplied from the surrounding biome; there is thus an increasing urban-rural disconnect that can have profound effects on nexus resilience to meet long-term trends and catastrophic events. To increase cities’ resilience, the concept of the “urban biome” was coined to recognize that cities have common structures and functions that transcend the natural biome where they are located. Studies have stressed the importance of developing a specifically urban WEF nexus that can buffer the oft-seen urban-rural disconnect observed during long-term change and catastrophic events. More resilient urban biomes would have increased self-reliance in the production and recycling of water, energy, and food.

Nexus Response to Long-Term Change

Some long-term factors, like climate change and increasing demand for declining resources, disproportionately affect the Middle East and North Africa (MENA) and arid regions of South America. Increasing aridity from climate change in MENA has resulted in the expansion of the Sahara desert and frequent droughts, while loss of Andean glaciers is having profound impacts in Bolivia and Peru. In both regions, rapidly increasing populations and urbanization and expanding agriculture are escalating demands on the WEF nexus.

In MENA, there is great disparity in the status of the different components of the WEF nexus; some see total collapse, while an over-dependence on energy has burgeoned in an attempt to stabilize them. Somalia, Yemen and Syria are recent examples of the WEF nexus exceeding its tipping point, leading to collapse and chaos. For all three nations, depletion of water resources from excessive irrigation and climate change has resulted in the collapse of agriculture and emigration of rural populations to urban centers, leading to social unrest and national economic and political collapse.

While other nations in the region may not have reached the tipping point, they face serious problems; Jordan has limited water and energy resources and faces rapidly increasing demands from refugee influx and failing agriculture. Saudi Arabia has averted WEF collapse from over-exploitation of water resources by prohibiting water-intensive agriculture and switching to energy-intensive desalinization to meet all domestic needs. Fortunately, the economy is robust enough to support near-total food importation and energy-intensive water procurement, but reliance on one leg of the WEF stool to support a nation is not sustainable. Moreover, it is dependent on economic conditions—the ultimate driver of the nexus.

Climate change has been the major disrupter of the WEF nexus in Latin America. Droughts have reduced the water supply for Sao Paulo, Brazil, and water dynamics in both Peru and Bolivia have driven the countries to the tipping point for the collapse of the nexus. Both Lima and La Paz are dependent on Andean glaciers for their water supply, which are receding rapidly in response to climate change and will likely disappear in the near future. La Paz has reached a water crisis, and there is a major urban-rural disconnect; as glacial supplies decline, urban basic requirements accelerate and rural populations demand more water for expanding agricultural production in crops like quinoa. The social unrest that has resulted in La Paz appears to have been a major factor in the recent replacement of the Bolivian national government.

The WEF nexus is also facing instability in the small island developing states (SIDS) within the Caribbean basin. Initial results suggest that many SIDS are approaching the tipping point for one or more of the WEF spokes due to lack of agricultural capacity, imported energy, and overly depleted water resources. In addition to facing climate change, the economies of many nations are shifting to tourism as the panacea for sustainability. This is the first tangible example of how a concerted effort to alter the economy, can either push island WEF resources over the tipping point or provide support to develop best management practices that maintain or enhance resources.

Response to Catastrophic Weather Events

Understanding of the responses of the WEF nexus to both catastrophic weather events and the current COVID-19 pandemic is in its infancy. Hurricane Maria, which struck Puerto Rico and several SIDS in the eastern Caribbean in September of 2017, is an optimal case study in the recovery times of societies after catastrophic weather events.

Although incomplete, most information on the impact of Maria on the WEF nexus comes from Puerto Rico. Food production was devastated, water supplies were threatened from watershed deforestation during the storm and associated sedimentation of reservoirs, and power production capacity was reduced. The storm expanded the urban-rural disconnect to a breaking point as infrastructure, including roads and the power grid, was destroyed throughout the island. The response to the disaster focused on urban areas as it was impossible to access most rural areas. It took over one and a half years to restore electric power to the island. Puerto Rico imported over 80 percent of its food supply before the storm, and it has been striving to increase local production since.

Water resources too have been slow to recover. In 2015 and 2016, prior to Maria, the island experienced a major drought that seriously reduced total mountain reservoir capacity. The storm disrupted both the potable and sewage networks, resulting in cross contamination and forcing segments of the population to use untested, sub-standard water supplies. Recovery has been hampered by another major drought in 2019 and 2020 and inadequate funding to repair aging infrastructure.

The impact on public health from the crumpled WEF nexus is still being evaluated. One clear message from Hurricane Maria in Puerto Rico is that it is  critical to decentralize the infrastructure of the nexus components, incorporate nature-based solutions to fill gaps, and maximize the resiliency of traditionally-engineered infrastructure.

Response to the COVID-19 Pandemic

The current exponential spread of COVID-19, the novel coronavirus that has caused over 133,000 reported deaths globally since January, provides a unique opportunity to examine the response of the nexus to a major disruption in health, which has direct ties to  water, energy, and food.

While the impact of WEF stability on public health has been documented for years, there is little data concerning the impact of public health on critical resources. Current efforts to combat the coronavirus have widened urban-rural disconnects globally by focusing almost totally on urban impacts, while down playing potential rural impacts because of low population density.

Water, energy, and food resources appear to be intact currently, but nexus stability is threatened by the link between COVID-19 mitigation responses and potential negative economic impacts. Some are advocating a shift from societal protection if the economy begins to show major disruption leading to recession. To our knowledge, this is the first time health and economy have been directly linked without consideration of the WEF nexus. Current disruptions to the WEF nexus are related to supply-chain economics and lack of sufficient infrastructure; but, as COVID-19 expands throughout rural areas, agricultural production will suffer from a virus-related reduction in the workforce.


Tom Crisman is State Department Jefferson Fellow on global water and a fellow for UCF Global Perspectives & International Initiatives.

Zachary S. Winters is a graduate student in the School of Geosciences at University of South Florida.

Posted March 21, 2022