Re: Seawater Greenhouse
This is probably the best solution (one of anyway) the infrastructure can be built progressively and a modern reiteration of a simple and historical used form of condensation (http://science.the-environmentalist.org/2008/04/creating-drinking-water-from-air.html).
These projects however work on long term bases and only underlay the real problem.
This boils down ( :-) ) to how as a society we value collective welfare against individual interests. In other words: drought is not the point, it is only how society is able to accomplish the solutions to it that becomes the main hurdle.