Lacking access to clean water, almost two million people die each year and it is likely that in 15 years half of the world’s population will live in areas where there will not be enough water for everyone.
Our planet contains more than a billion billion liters of H2O, but little of it is drinkable.
More than 97% of the water on Earth is salty. Two-thirds of freshwater is trapped in glaciers and polar ice caps.
Of what remains, most is trapped in the ground or in underground aquifers, leaving a tiny fraction available to most living things.
In addition, humanity does not only need it to drink: almost everything we do involves water in some way.
It is difficult to imagine how high individual consumption is if one only thinks of what one drinks or spends showering or doing laundry.
But there is a “hidden” use: the water needed to grow the food we eat and make the products we use and consume.
The total global water requirement per year is more than four billion liters per year, and the natural sources of the precious liquid are no longer enough. We have long known that the scarcity of drinking water threatened to become a serious problem for the entire world. About one in ten people on the planet – almost 800 million – do not have access to safe sources.
The World Economic Forum and other institutions estimate that by 2030 there will be a 40% higher demand, which the planet will not be able to supply, which will affect agriculture and in turn cause food prices to rise.
And, as geologist Ian Steward points out, it’s not hard to imagine that if a solution isn’t found soon, the possibility of freshwater wars is high.
To clean dirty water…
Scientists have devised a range of technologies that could help deal with the water crisis.
One way to address it is by using special bottles to clean dirty water and make it drinkable. The bottles contain nano-sized filters that can remove bacteria and viruses. But some contaminants – like lead – can sneak through. However, the bottles have been used successfully in rescue operations.
Another option is known as “vapor compression distillation,” in which dirty water is heated to turn it into steam and condensed into drinking water.
So purifying dirty water is possible, but it’s expensive and inefficient.
The simplest solution might simply be to improve the way we manage what we have. In developing countries, for example, 45 million cubic meters of freshwater are lost every day through underground leaks.
And what if you could use sea water instead of fresh water? In 2009, scientists reported that they had developed salt-tolerant crops. Or maybe, there is a better alternative…
Turning sea water into fresh water, the magic solution?
Desalination seems to be the best solution to the crisis, but it is not as simple as it sounds.
In nature, a process called osmosis causes water to move across a semipermeable membrane from areas with low salt concentrations to areas of high concentration.
To desalinate, the opposite has to happen. A lot of pressure is required to force the water to pass through the membrane in the opposite direction, which implies a high energy expenditure that is also expensive.
For desalination to become a viable alternative, either a lot of cheap energy is needed or ways to make the process more efficient.
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