“I never drink water; that is the stuff that rusts pipes” – W. C. Fields
The average human is about 70% water. The rest amounts to about $160 in trace elements and social media profiles. So, water is very nearly as important to us as Facebook likes. It’s too bad this ball of dirt we call home has so little of it. Hold on cowpoke, you’re probably saying, doesn’t water cover about 71% of the Earth? Why yes that’s true Skippy, but 96.5% of that is in the oceans, and ocean water is about as good at quenching thirst as Zima. When it comes to freshwater of the variety you can drink (not even accounting for when its laden with toxic chemicals that make your children grow tails and fail standardized tests, intestinal parasites that colonize your organs, or overzealous bacteria), 70% of the Earth’s freshwater is locked in the ice caps. Great you say, if push comes to shove let’s get busy with the global warming and melt those puppies – right into the salty ocean, where of course it becomes undrinkable. Bad plan.
Now, I don’t particularly like to think about the end of the world if I can avoid it as such speculations cater to my many neuroses, but the Bulletin of the Atomic Scientists, a nonprofit that sets the famous Doomsday Clock, just moved us to two-and-a-half minutes from midnight, the closest it’s been to midnight since 1953. Every year the big brains at the Atomic Bulletin consider the vast range of existential threats to humanity, and based on how close we are to nuclear holocaust, an anti-human singularity, runaway greenhouse effects or other ways in which we may murder ourselves, adjust our doom accordingly. Luckily we are a resilient species, like cockroaches, so at least a breeding population of us will probably survive most man-made, non-divinely inspired apocalypses through a combination of adaptability and moxy, but if you had to take odds on it, in all likelihood our species will just die thirsty.
We like to imagine all sorts of horrible ends for humanity, but the truth is we’ll probably just run out of stuff to drink (I mean let’s face it, you need at least a little water to make whiskey). Less than 1% of the world’s freshwater is readily accessible and only 6 countries (Brazil, Russia, Canada, Indonesia, China and Colombia) have 50 percent of the world’s freshwater reserves. I know Canada is looking a little nervous. There are of course lots of other problems that lack of freshwater entails, like famine, disease, and global conflict over one of the most precious resources, but mostly we’ll just dehydrate.
Already, twenty-one of the world’s 37 largest aquifers have passed the tipping point, in that we’ve steadily removed more water than can effectively be replaced through natural means. The Washington Post recently quoted Jay Famiglietti, senior water scientist at NASA’s Jet Propulsion Laboratory in California, a guy who is obviously trying to stay on top of the problem as saying, ““The water table is dropping all over the world…There’s not an infinite supply of water.”
We can live without a lot of things. Water isn’t one of them. While the odds of being immolated in an atomic fireball, succumbing to insidious biological or chemical terrorism, being hit by an asteroid, discombobulated by a gamma ray burst, or bumping up against the Four Horsemen of the Apocalypse are not zero, chances are unless we start looking for some nice water planets to harvest from, doomsday will simply be dry. Then again, we’re pretty efficient at inventing new ways to drive ourselves to extinction. As William Langewiesche said, “You should not see the desert simply as some faraway place of little rain. There are many forms of thirst”.
EsoterX 
But EsoterX, what about weather control? We do a smidgen even now, but with a few major advances we could specify where the rainfall actually falls rather than permitting it to automatically fall over the oceans.
Desalinization sounds good with cheap power, but after a while there will be no where to put the “salt” unless we invent some useful purpose for it. I wonder if aliens would like free salt along with all the other things they get into on this planet.
We know oil travels efficiently through pipelines. Providing water pumped from the poles through pipelines might appeal to the type of people interested in building the Hyperloop from Los Angeles to San Francisco.
But, I have to admit, the end of free fresh air and free clean water is just over the horizon, perhaps in the next century. Unless people are required to pay for things it is hard to truly appreciate them.
Overpopulation is the real culprit, and birth control is the solution. If human societies voluntarily reduce their numbers, the aquifers will recover. If the numbers keep growing, resources will be outstripped by consumption. Yes, we can get into a big argument about technological interventions that can stretch available resources farther, but the fact is still that no one will be able to afford these technological interventions if resources are already overstretched trying to take care of the immediate needs of a growing population. People like to bitch about the draconian measures taken by China to control their birth rate, but if they hadn’t taken these measures and the birth rate had continued to climb, people instead would be bitching about famine and disease (and water shortages) caused by overpopulation.
Simple, in my opinion.