eli5: If we have methods like desalination, why is the world suffering from a water shortage, when 70% of the Earth is water?

Question

Even though the water is saline, to the best of my understanding, you can convert saltwater into freshwater so why is there a water crisis?

In: Biology

Answer 1

Desalination is expensive. It’s orders of magnitude more expensive to get fresh water from desalination than it is to harvest it from natural fresh water sources. It makes it economically unfeasible for many areas of the world that couldn’t afford to build and maintain the plants.

Desalination also doesn’t scale well. Absolutely massive plants are required to generate sufficient water for even a moderately-sized community. It’s not something you can scale up to providing for large regions.

Finally, desalination doesn’t help regions located far inland. The amount of water needed by a typical community would need a monumental water delivery system to get anywhere moderately far from the coast.