Here it is the United Nations water report for 2015:
As California suffer through water shortage, imagine what the rest of the world looks like. Now, imagine what the rest of the world will look like in the year 2050?
By that time we should have moved to a population of 9 to 11 billion!
The first chapter is on non-sustainable uses of water. The trends, including use of water, that are not sustainable, have a way of ending on gracefully!
Case in point, California.