How many persons do you think do not have access to safe water and enough sanitation? One-half-billion? Definitely not a billion? Think bigger.

According to a 2019 study by UNICEF and the World Health Organisation, 2.2 billion citizens do not have clean water handled safely, and 4.2 billion do not have sanitation controlled safely.

 Access to water and sanitation was proclaimed a human right by the United Nations General Assembly on July 2010, with its sixth Sustainable Development Target being access to safe water and sustainable sanitation for everyone by 2030.

We are halfway into the window now. But even while improvement is being made, the world's water shortage is becoming worse in certain respects. The Stephen Cole Agenda has looked at the challenges and possible answers.

Indians Tackle With Water Crisis In Chennai
(Photo : Atul Loke/Getty Images)
CHENNAI, INDIA - JUNE 28: Dry bed of Chembarambakkam lake on June 28, 2019 in the outskirts of Chennai, India. All the four major reservoirs supplying water to Chennai has dried up and the only hope for the city to tide over the water crisis is the water in Veeranam lake and the two desalination plants supplying 200 million litres of day (MLD) water to the city besides the groundwater.

Locals forced to flee homes due to water shortages

Second, in areas where water sources are still under threat, there is the question of demographic development, and the possible trigger of a migration crisis when individuals are compelled to pursue this most important aspect of human life.

Steve Killelea, the founder of the Institute for Economics and Peace, discusses how water scarcity could drive more than a billion people from their homes in the next 30 years.

Could there be remedies?

Another challenge comes from climate change. Rainfall in certain areas is getting less effective. Piers Clark, founder of Isle Utilities, discusses how "shorter, sharper bursts of rain" have rendered processing and distribution more challenging for suppliers of water resources.

It isn't just terrible news, however. Clark also reveals that "credible solutions" are being offered by breakthrough technology to deal with shortages, such as extracting water from the air itself.

Theft of clean water is a huge concern

There is another concern also while the water is in circulation - stealing. In a virtually industrial scale, a new survey estimates that up to 50 percent of the drinking water in the world is stolen.

The study was written by Adam Loch of the Centre for Global Food and Wealth of the University of Adelaide, and he shows that such theft happens not just in the developing countries of the world, mentioning cases in the U.S. and Australia.

How scientists could help

Although research has yielded advanced methods of water treatment such as membrane distillation and reverse osmosis, due to their high expense and poor efficiency, solutions are also challenging to introduce in developing countries.

Experts analyzed methods that have been formulated in the last two years to exceed this theoretical cap in the latest paper published in Solar Energy Materials and Solar Cells.

Researchers designed the 'direct touch form' method to solve this issue, in which the bulk water is protected by a double-layer framework with pores of various sizes. As a heat absorber and vapor escape path, the top layer with larger pores acts as a heat absorber and the lower layer with smaller pores is used to transfer water from the bulk to the top layer. The interaction between the heated top layer and the water is localized in this method, and heat loss is minimized to around 15 percent.

To increase the evaporation efficiency, techniques have been established to extract additional energy from the atmosphere or from the bulk water itself and recover the latent heat from high-temperature steam. 

Such techniques would retain the energy of the sun and the water to be evaporated are now being produced to reduce the energy needed for evaporation in the first place.

There are some other such techniques for architecture and several more are to come. Many related problems continue to be addressed-such as concentrated water collection, material longevity, and reliability during outdoor applications under fluctuating wind and weather conditions.

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