We may be on the cusp of a drought that could last a millennium, but instead developing alternative sources of water, like desalination, we are dithering with accusations and promoting false hope that we can prevent it.
You want desalination on a VAST scale? Set up a whole string of thorium-fueled molten salt reactors along a coastal sea front, along with water distillation towers, and a pumping and pipeline system to move the water recovered from the distillation towers. A quantity of sea water is then subjected to the heat generated by the nuclear reactor, and as the brine is ever more concentrated, either evaporate it to dryness, or discharge the now extremely salty brine to the depths of the sea, where the greater density of the concentrated brine sinks to the bottom of the ocean, and is essentially removed from the locality. As the concentrated brine is discharged, replace it with a new quantity of sea water, to be distilled in its own turn. This way, desalinated water is continually produced in large quantity, and when pumped to the dry interior, may be used to make deserts bloom and sustain the flow of fresh-water rivers.
Now, returning to the brine or the quantities of dried sea salt, there are many more things than sodium chloride dissolved in the sea water. Metallic elements of EVERY element are present in some quantity, and may be extracted from the brine or the dried salt bed, by electrolysis or by the very simple method of fractional crystallization. As brine dries, the first least soluble minerals form a distinctive strata, while the more soluble remain in solution, until those also reach their point of crystallization, again forming a distinctive strata. On and on, until the entire bed is dry. These dried solids may then be rendered into their respective elements, as this is now a very concentrated ore for metallic elements, and a rich source of chlorides, sulfates, phosphates, carbonates, iodine, and even some nitrates.