Many rivers and lakes dry up, with water-rationing becoming the norm.
The United Nations projects that by 2025, some 14 per cent of the world’s population will face water shortages.
Meanwhile, much of the water on earth is saline.
Wealthy nations are investing in desalination technologies to utilise this commodity.
Researchers in Britain have come up with an efficient sieve that separates salt and water molecules.
The sieve has controlled spacing of pores which do a greater job of filtration than current desalination plants do, as these use polymer-based membranes.
Durability of the membranes while interacting with sea water, and eventual production of the equipment on an industrial scale, are yet to be worked on.
Recently, Israel has been desalinating water pumped from the Mediterranean Sea to supply to more than 1.5 million nationals.
Over half of Israel’s water is sourced directly from the sea, transforming the desert country into a fertile land.
This is not to say that there are no constraints to food security.