Water research for sustainability

Early warnings of impending food crises can provide valuable time to mitigate their worst impacts, but droughts have proven difficult to predict. Soil moisture autocorrelation measured by remote sensing satellites advances our ability to anticipate food security crises resulting from drought.

Potable reuse provides a reliable and sustainable option to drinking-water supply. However, its implementation is hindered by perceptions of potential health risks. Here, comparing potable reuse water with tap water, the authors show a lower level of cytotoxicity in reuse water.

The importance of ensuring access to clean drinking water is manifested in UN Sustainable Development Goals. Here, a national-level assessment of tap-water safety shows spatial variations across China. The disparity is correlated with natural and anthropogenic factors and linked to public health-risk rates.

Satellite-based measures of the area irrigated by 79 schemes find a median of only 16% of the proposed area supplied. A quarter deliver over 80% of the proposed area and a fifth are inactive.

A geospatial estimate of water scarcity in middle- to low-income countries finds that less than 37% of small-scale farms have irrigation. However, there exist considerable gaps in evidence for most commonly proposed, on-farm interventions.

Water use in river basins is an age-old resource-management question, but it is rare to quantify consumption by specific sectors. The Colorado River is being overused for beef and dairy production, endangering the entire river ecosystem.

Runoff from mountain water sources is critical to some lowland populations. In this Article, these populations are projected to increase from 0.2 billion people in the 1960s to 1.5 billion by mid-century.

Converging evidence indicates that SARS-CoVs are present in wastewater for several days with potential health risks. This Review analyses knowledge about such risks as well as the potential spread of SARS-CoVs in waterborne, waterborne–aerosolized and waterborne–foodborne pathways during a pandemic.

The challenges of meeting food, water and energy needs are interconnected, requiring integrated assessments of land use, socioeconomic policies and climate change. This study assesses the required increases in water, trade and agricultural land needed to double food production by 2050.

Millennium and sustainability goals may be well known, but the history of how those goals are formed remains hidden. This Analysis examines the political and academic factors that led to MDG 7C and how China and India have tried to achieve it.

Footprint analysis of how much water is embedded in food consumption in France, Germany and the United Kingdom finds geographical differences in water footprints and projects how different diets could affect water conservation.

A multi-objective optimization water–energy model explores the effect of dam re-operation strategies to minimize hydrological alterations in the Lower Mekong. Dam re-operation provides a feasible opportunity for the restoration of key elements of hydrological variability without hindering hydropower production.

Poor access to safe drinking water is a major global sustainability issue. Solar disinfection provides a feasible solution. Here the authors examine the potential of five most typical types of this technology, revealing their unique challenges and opportunities.

The authors show how untreated wastewater laced with microplastics and raw sewage is routinely discharged into UK river flows that are too low to disperse the microplastics downstream. This discharge creates acute microplastic contamination of river beds that threatens biodiversity and the quality of riverine habitats.

Over-canal solar photovoltaic arrays are likely to reduce water evaporation and carry financial co-benefits, but estimates are lacking. With hydrologic and techno-economic simulations of solar panels covering California’s canal network, this study shows the advantages of covering canals with solar panels.

While the food–energy–water nexus has become a focal point for inter- and cross-disciplinary studies in recent years, this analysis of rural communities contextualizes how effective the nexus is for describing and studying interactions.

By passively evaporating water from waste streams, evaporation ponds work with different waste streams but need large areas due to low evaporation rates. This study shows that a photo-thermal device converting sunlight into mid-infrared radiation could enhance evaporation and reduce land needs.

Solar-driven interfacial evaporation can be a sustainable process to obtain clean water but device efficiency and simplicity need improving. This study presents a super-wicking and super-light-absorbing aluminium surface with increased efficiency, a simple structure and strong performance.

While many regions are striving to reduce water consumption, this Article examines the side effects and downstream impacts on wastewater quality for human and ecosystem health.

Water constraints can affect plans to expand electricity capacity. This study shows that in the United States such constraints can increase the cost of electricity generation with slightly reduced electrification of end-use sectors, and can incentivize early retirement of water-intensive technologies.

Offshore mariculture could promote food security and economic development while sparing wild fisheries. This model-based study finds that the Caribbean could produce over 40 million metric tons of cobia (Rachycentron canadum), about half as much as the current global wild fish catch, and in less than 1.5% of the study area.

Substantial water savings can be achieved by coating toilet bowl surfaces to repel liquids, bacteria and viscoelastic solids such as human faeces. In this Article, the authors develop a sprayable, non-fouling coating that can reduce cleaning water consumption by ~90% compared with untreated surfaces.

Dams in the Mekong Basin are built without considering impacts on river processes. This study shows that with strategic planning in the lower Mekong, 68% of the basin’s hydropower potential could have been developed while trapping 21% of the basin’s sand load.

Despite recent technological progress, providing safe, clean and sufficient water sustainably for all remains challenging. This Review assesses the potential applications of nanomaterials in advancing the sustainability of water treatment systems, and their associated barriers.

We need consensus to accurately evaluate the performance and potential of emerging water production technologies, such as solar evaporation and atmospheric water harvesting. Here we recommend practices that would allow a fair basis to compare different studies, and help to align research input with actual demand.

While fears of ‘water wars’ have been publicized in recent years, this Article illustrates the complexities surrounding resource availability and socio-political dynamics that may induce, or prevent, conflicts over water in arid landscapes.

Poor availability and access to clean water is a fundamental sustainability challenge facing our society. Here the authors show that covalent organic framework membranes enable excellent performance in seawater desalination including high permeation flux and fouling resistance, providing a promising technological solution.

Ecosystems that provide fresh water for cities also impact sediment flows, flood mitigation and hydropower provision. This Article looks at over 300 cities globally to gauge the interactions of natural ecosystems with built infrastructure.

Two-dimensional lamellar membranes for water purification are promising but suffer from swelling that reduces their ion sieving performance in water. This study reports easy-to-fabricate, non-swelling MXene membranes prepared by the intercalation of Al³⁺ ions that could be scalable.

Photovoltaic panel conversion generates heat that reduces the energy efficiency and lifetime of the panel. A photovoltaic panel cooling strategy by a sorption-based atmospheric water harvester is shown to improve the productivity of electricity generation with important sustainability advantages.

Reverse osmosis membranes are the primary technology used for desalination and wastewater recycling, but they are prone to biofouling and subsequent performance deterioration due to poor tolerance to disinfecting agents such as chlorine. Here a chlorine-resistant polyester reverse osmosis membrane is developed to prevent biofouling and increase the sustainability of desalination and wastewater reuse.

Light-responsive smart materials hold promise for a solution to water desalination. Here the authors report an adsorbent based on a metal–organic framework that quickly adsorbs multiple ions from water in the dark, followed by release of these salts on exposure to sunlight.

The Indus river basin in South Asia is water stressed, energy insecure and intensively farmed, and research on this region often lacks a systemic approach to the issues. This study shows how the path to development in the region could be made less costly and more environmentally friendly by fostering transboundary cooperation.

The wastewater treatment industry contributes approximately 1.6% of greenhouse gas emissions. This Review analyses alternative wastewater treatment pathways for simultaneous CO₂ capture and utilization and shows the multiple benefits of microbial electrochemical and phototrophic processes.

In-stream turbines could be a viable alternative to storage-based large hydropower projects. This study finds that about two-thirds of the planned hydropower generation in the Brazilian Amazon basin could be harnessed using in-stream turbines.

Wise management is critical to sustaining fisheries. This study finds that rebuilding plans, ratification of international agreements and harvest control rules yield strong benefits and that these are cumulative.

Climate change will alter the distribution of tuna, impacting the economies of Pacific Small Island Developing States. This study finds that greater greenhouse gas emissions will worsen these impacts.

Agriculture’s ability to feed the world is limited by land and freshwater. This Perspective argues that scaling up seaweed aquaculture is needed to accommodate the 9+ billion people expected by 2050 and to meet the Sustainable Development Goals.

Hydropower is important in Brazil, but climate change and deforestation are changing river flows. This study finds that future conditions will worsen a mismatch between seasonal electricity supply and peak demand.

An international arrangement of transferable fishing rights and biomass-based allocation can incentivize establishing Marine Protected Areas while promoting the economy.

Water consumption does not put a constant stress on available supplies, but is instead a function of flexibility in demands for food, water and energy. This analysis looks at 36 years of water consumption around the globe to identify basins under the most stress, and how they can lower their intensive uses.

A large-scale economic analysis of the economics of water supplies in the greater Los Angeles area, based on the ‘full-cycle’ costs of water sources such as imported water, groundwater, and reused and storm-water capture. The study showcases an updated model and framework for urban water studies that can be applied to other cities.

Rising population and changes in water supply under climate change affect cities globally. This study finds that in 27% of cities studied, water demand is likely to exceed availability by 2050, with many other cities competing with agriculture on water needs.

The implementation of technologic solutions to complex problems can have unintended effects. This study questions the water sustainability of using shade balls in the Los Angeles reservoir to reduce evaporation during the recent drought in California, by assessing the shade balls’ water footprint.