I think by now we should have cheap desalinization of oceans for fresh water supplies and we should have alternative sources of cheap energy.
For heaven's sake, all this talent and America can't get this done?
I don't know about that or decades more being needed.
Interesting you should mention desalinization. A few years ago My wife and I were on a cruise. One of the destinations was Aruba. There is no natural water supply on Aruba other than rain, and that apparently is sporadic althought enough to supply the population.
What they did was turn the roofs of their buildings, houses, etc, into drain systems ending up in large cisterns. That was the water supply until the government went into the desalinization business, building a large plant to supply the island.
In the process they required everyone to be on the system, destroy the previous water works, and make having one of the old ones illegal. Brilliant, now why didn't I think of that. I shoulda had a patent. NOT!
Speaking of technology, when one considers all involved in replacing the present energy source, and its manufacturing and distribution channels, one can quickly see there is not going to be a quick fix for the present source, unless the discovery is so cheap, and so available as to be instantly useable on a national scale.
On a list of things nearly impossible, this one shall remain very near the top. I'm sure all of us would welcome cheap, clean, and unlimited, but the laws of physics, science, economics and reality, cannot so easily be ignored.