Water is leaving us behind

I was watching National Geographic channel yesterday.  I don't know why - ultimately every show on that channel seems to end up talking about man-made global warming.  There was a show on talking about the droughts of 2012-2013 being worse than the dust bowl of the 1930's.  Imagine that. It must have been all over the news as a national existential crisis right?  Did I miss that?

I'm no climate scientist, but isn't the earth a relatively closed system? If water evaporates it doesn't leave earth's gravitational pull. It doesn't magically teleport to Mars. It becomes water vapor. Ultimately, only so much of the planet's ice can become water and so much of the water can become vapor before the atmosphere is so humid that it has to rain. So-called man-made global warming is not costing us water.  Water does not leave the system.

Desert regions can change. Ice levels can rise and drop.  This is all normal change.  The opposite of climate change would be climate stagnation. I imagine that and picture fetid swamps and permanent deserts. No wind, no rain, no seasons.  That would be a natural disaster.