As unprecedented drought conditions continue to ravage the planet, United Nations water experts are calling upon countries to tap the Earth’s abundant “unconventional water resources” — such as those found deep underground or in icebergs.
“Harnessing the potential of unconventional water sources could benefit billions of people,” Manzoor Qadir, deputy director of the U.N. University’s Institute for Water, Environment and Health, said in a statement.
“These sources will be essential to building a future in arid areas,” he added.
Qadir is the lead editor of a book released by his institute on Thursday called Unconventional Water Resources, produced in collaboration with the U.N.’s Food and Agriculture Organization and the U.N. University’s Institute for Integrated Management of Material Fluxes and Of Resources.
Qadir and his colleagues have determined that these potential unconventional water supplies could help many of the one in four people on Earth who suffer from shortages of water for drinking, sanitation, agriculture and economic development, according to a press release published alongside the book.
Some such unconventional water supplies include millions of cubic kilometers of water found deep in land-based and seabed aquifers, as well as in fog, icebergs and the ballast holds of thousands of ships, the authors found.
“The time has come for humanity to tap into the vastly under-used unconventional water sources,” Qadir said.
At the same time, Qadir acknowledged that implementing national action plans to tap these resources will first require assessments of the environmental trade-offs, as well as comprehensive cost analyses and innovative financing mechanisms.
Harvesting water from the air through processes called “cloud seeding” and fog collection could be particularly beneficial, as the atmosphere contains about 13,000 cubic kilometers (3,100 cubic miles) of water vapor, according to the authors.
One cubic kilometer of water is equivalent to the volume of about 400,000 Olympic swimming pools, while the annual global freshwater demand today is about 4,600 cubic kilometers — or about the size of Lake Michigan, the researchers explained.
The authors highlighted both desalination and wastewater reuse as other important options. Desalination already supports about 5 percent of the world’s population, and while the process is energy intensive today, emerging filtration technologies are already reducing energy inputs by 20-35 percent, according to the authors.
As far as wastewater reuse is concerned, about 70 percent of municipal wastewater in high-income countries is being treated today, but the same can only be said for about 8 percent in low-income countries, the researchers found.
Offshore, there are vast quantities of water — about 300,000-500,000 cubic kilometers — of water in aquifers at shallow depths in the world’s continental shelves, the authors noted. While marine electromagnetic imaging and horizontal drilling technologies exist, none of these resources have been accessed.
Brackish, salty water found deep in on-land aquifers could also provide the world with millions of cubic meters of water, the researchers said, noting that Israel and Spain are already desalinating such water to irrigate high-value crops.
The authors also identified ships as potential resources, as they discharge about 10 billion tons of ballast water every year.
Meanwhile, the more than 100,000 Arctic and Antarctic icebergs that melt into the ocean each year contain more freshwater than the world consumes, the authors noted.
“The increasing pressures on water resources requires a new era of water management,” Sasha Koo-Oshima, book co-editor and deputy director of the Food and Agriculture Organization said in a statement.
That era, according to Koo-Oshima, is “one that addresses barriers to efficient water management and ensures that water in all its forms is monitored and accounted for, including its value to food, ecosystems and health, and its role in supporting food security and basic needs of humanity and economic development.”