LTLFTcomposite wrote:From what I saw on the evening news, nobody there is yet concerned about declining population.
Just wait until they start having water outages!
Eh, what'll happen is that agriculture fed by the Colorado River will start getting pushed out of business. Farmers can't afford to pay nearly as much for water as people can pay for water for their homes. If it gets bad enough, you'll see desalination plants in California and an adjustment of the Colorado River Compact, with the upper states helping pay the cost in exchange for more of the river's water. Desalination water is generally too expensive for agriculture, but again, what's too expensive for agriculture isn't necessarily too expensive for homes.
Also, there's some interesting new desalination techs out there. My favorite -- although it'll require some massive-scale high-throughput ion-selective membranes or salt bridges to work -- is this really clever one involving evaporation ponds. So, basically, black-bottomed open-air evaporation ponds aren't very expensive. They're a *lot* cheaper than covered ones that try to collect condensation from the evaporation. So you can get very salty brine, many times saltier than seawater, really cheap. Now, that's the opposite of what you want, right? You want freshwater. So what they do is they link it up to two different ponds of normal concentration seawater with ion-selective channels -- one pond gets positive ions, like sodium, and the other pond negative ions, like chlorine. Now, obviously, the ions *really* want to travel out of this super-concentrated brine into these other ponds so they can all be equal saltiness... but they can't. If they did, they'd be mismatched! So, they bring into play a third pond of regular seawater. It also provides an ion channel to each of the other two seawater ponds, of the opposite type -- that is, the pond that has a positive ion channel to the brine gets a negative one, and the one that had a negative ion channel to the brine gets a positive one. So the brine gets to push ions down from its extreme concentration, so long as an opposite ion gets sucked out of the third seawater pond. Since the ions *really* want to leave the super-concentrated brine, that's no problem. And so what you end up with is all of the salt being sucked out of the third seawater pond in the process. Freshwater, with no electricity input! Again, though, the issue is making said membranes high enough throughput and low enough cost.