The greatest shortage on this planet is fresh water – though salt water covers 60% of the surface of the Earth. We also have brown non-breakable water.
If we attack a vacuum pump to a 1m high cone whose base lies below the water, we can suck the sea water up – and it boils. Even ice becomes water vapour.
So in the Arctics, is we mount 1m1 high cones below the ice surface, we can such out pure water vapour – a cheaper source of water than melting ice.
In the hot countries we get endless amounts of fresh water vapour – we pump to a high reservoir. As we release the vacuum, the water condenses and fills the reservoir.
We end global hunger and thirst – using science worked out in the 18th century.
We get the UN to fund the pumps – powered by the sun, or the wind. The amounts of energy we need are small – and the lives saved immense.