WATER WATER EVERYWHERE

Fresh water usage on Earth is broken down like this:  85% is used in agriculture; 12% is used in industry; that leaves just 3% that is used by people.  

Here's another angle:  97% of all the water on Earth is salt water in the oceans;  that leaves just 3% which is fresh water in lakes, streams, rivers, aquifers and glaciers.  Note that glaciers, including the polar ice caps and the icebergs that break off from them, are fresh water.

Usable fresh water is a big deal in some places and may be a very big deal all over the globe some day.  It's a challenge for the world to figure out how to use that salt water where we now use fresh water.

We know how to desalinate (take the salt out) salt water and there are operations doing that right now. In fact, there are over 1800 desalination plants in operation around the world right now.  Some large ships have desalination plants built in them.

Why don't we just desalinate all the water we need?  There are a number of problems associated with desalination.

Number one is what to do with all the salt we take out and all the chemicals used to remove the salt.  Even though the ocean is made up of salt water, you can't just dump a whole bunch more salt into it.  Too much salt is bad for that ecosystem.

Number two is how much energy it takes to run a desalination plant.  Energy use makes desalination very expensive.

I have full faith that the world will overcome these problems in time.  But, if you're a young inventor/scientist, this wouldn't be a bad project to take on.

0_0