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

In a nutshell, desalinating water is VERY expensive, which means the water produced is very expensive. Who wants to pay $50, for a bottle of water?

Also, the entire process can be very damaging to the environment. It requires a lot of energy, which means more pollution to produce the energy. All of the salt and minerals removed from the water have to be dumped somewhere. And there are other issues, like trying to take in sea water without damaging the life within that water, such as tiny fish eggs.

In addition, the water would be produced on the coasts, but bringing it to areas far inland (where it is often needed most) requires even more money and energy.

And so, basically, desalinating water is simply not the ideal solution to water shortages–it ends up causing more problems than it fixes, which is why it is not being used more.