Although there is enough water for everyone on earth, according to the United Nations, around two billion people still suffer from water scarcity due to a lack of access or infrastructure. There are technological solutions: use of sea and groundwater, recycling of wastewater, improving distribution and consumption efficiency, and collecting water from the atmosphere. Research recently published in Nature demonstrated the ability to produce water in Death Valley, a scorching part of California’s Mojave Desert. This was achieved by collecting and purifying water from mist, mimicking the way spiders and beetles collect water. However, these advances run into a challenge that William Stanley Jevons addressed two centuries ago: as resource efficiency increases, consumption tends to increase.
The global demand for water continues to rise. According to the United Nations, water consumption has increased twice as fast as population growth over the last century. In addition, there are more and more regions affected by chronic water shortages. Jesús M. Paniagua, author of a recent book about the history, technology and future of water, said: “There is actually enough water on the planet to support its nearly eight billion people.” The problem is that it is poorly distributed , wasted, contaminated and managed in a completely unsustainable manner.”
Cristina Monge Lasierra, political scientist at the University of Zaragoza (Spain), recalls the warning of former UN Secretary Ban Ki-moon: “The battle for sustainability is being fought in the cities.” There, 75% of the population and 80 to 85% of assets be concentrated. “What happens in the cities and how they connect with the outskirts will be very important,” Monge said.
The majority of water use – about 80% according to the Organization for Economic Co-operation and Development (OECD) – goes to agriculture and livestock, in turn responding to demand for food from urban areas where most of the population lives. The remaining significant water use occurs in industrial and urban areas. “The extreme weather we are experiencing in Spain highlights the importance of integrating water as a fundamental element in the redesign of our cities,” said Luis Babiano of AEOPAS, a Spanish association of public water supply and wastewater operators.
The technology allows for efficient water distribution, although there is still progress to be made. According to Francisco Lombardo, President of the Water Economy Forum, “more than a quarter of the water distributed in Spain is wasted due to a lack of infrastructure investment.” Lombardo is committed to “rebuilding water infrastructure and implementing technologies to better control water leaks and losses.” a.
Paniagua admits that “very deficient systems lose large amounts of water” and cites the capital of Uruguay as an example. “Montevideo is facing a supply problem due to a three-year drought. Furthermore, the [water distribution] The network has losses of around 50%, which means that for every 100 liters distributed from reservoirs, unfortunately 50 are lost.”
Paniagua believes the most effective way to get more water is to tap underground reserves, practice mindful consumption, reuse wastewater and invest in desalination. The aim is for these systems to become more affordable and environmentally friendly through the increasing use of renewable energy. Desalination of seawater requires a lot of energy and produces waste such as brine. Likewise, collecting atmospheric water in regions with humidity less than 70% requires significant energy expenditure, making this solution ineffective.
Spiders show how to get water in the desert
A recent study published in Nature Water shows how researchers have improved the process of extracting water from the hot and dry atmosphere in California’s Death Valley Desert, despite temperatures as high as 135°F (57°C) and relative humidity below 7%.
“We reviewed the technology’s ability to address the increasing dilemmas posed by water scarcity, exacerbated by environmental concerns. “This technology provides a secure water resource that is not dependent on geographical or climatic conditions,” said study lead author Woochul Song.
Water treatment technology in use in Death Valley, California.Nature Water / Atli Eon
A disadvantage of using atmospheric water such as fog is the contamination it may contain. However, researchers at the Swiss Federal Institute of Technology in Zurich (ETH) have developed a technique that both extracts and purifies water from fog. They achieve this by using a metal mesh coated with a mixture of polymers and titanium dioxide, which acts as a chemical catalyst. “Our system is designed for use in areas with air pollution, such as densely populated city centers,” said Ritwick Ghosh, a scientist at the Max Planck Institute (Germany) who worked on the study published in Nature Sustainability.
Michael Tam, a professor at the University of Waterloo, Canada, has developed another water-collection technology that uses special sponges that mimic the way spiders and other insects continually absorb moisture from their environment. “A spider web is a remarkable engineering achievement that efficiently captures water. The spider doesn’t have to go to a river to drink; Instead, its net cleverly captures moisture from the air.”
Paniagua believes in technological solutions. “Throughout history, technology has always helped us overcome challenges.” His research focuses on the widespread adoption of resource-optimizing technologies in cultural fields such as: B. On-site weather stations, humidity sensors, flow and pressure monitoring systems in irrigation networks, and surveillance and tracking drones.
But Paniagua has concerns about a problem that British economist William Stanley Jevons identified two centuries ago related to technological solutions. Jevons found that improving the efficiency of steam engines did not lead to a decrease in coal consumption. Rather, there was an increase due to the increasing spread of machines. This paradox helps to explain why expanding the road network often leads to more traffic. “I’m not saying this will always happen,” Paniagua said. “But greater irrigation capacity often results in more area being irrigated. A friend of mine fears that a nuclear fusion solution to produce abundant and affordable energy could potentially be misused. “But that shouldn’t distract us from our pursuit of increasing efficiency.”
Another disadvantage of technological solutions to the water problem is the uneven increase in demand. Paniagua points to the situation in Africa, where access to resources, sanitation and energy is limited while experiencing rapid population growth. “To ensure reliable supply, it is crucial to prioritize investments and improvements. Large-scale water transfers present numerous technical to political challenges that make them infeasible. “This is a significant problem that needs to be addressed.” In March 2023, UNICEF published a report on the situation of around 190 million children in Africa without access to clean drinking water. This results in the heartbreaking deaths of 1,000 children under five every day.
The example of Cadiz
Managing a seemingly simple municipal drinking water source can be more complex than meets the eye. Luis Babiano highlights how the integration of new infrastructure to provide this important service to the residents of Cadiz (southwest Spain) has exposed a flaw in the traditional approach to the design of these facilities. “The location criteria usually only include accessibility and costs. Factors that contribute to a people-friendly city are often ignored,” he said.
The design of Cadiz’s water distribution network started from scratch, analyzing residents’ main routes during work and leisure, as well as their means of transport (foot, bicycle, public transport and private vehicles). The study even took pets’ water needs into account.
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