I think civilization will survive...just not civilization as we know it. I think we're headed for a new mini-Dark Ages, where energy is scarce, life is very local, and luxuries are few. Hopefully there will be a government left, and energy will be rationed to the R&D facilities where, I believe, a new source of power will eventually be found to renew high-energy civilization. But the road will be long and hard.
Oh believe me, I'm completely open to the possibility that I'm wasting my time even finishing up in school for a degree in the arts. I've considered the possibility if push comes to shove, and shortages get bad enough, I'll have fight and even kill my fellow man to get what I need (or keep it). Not the prettiest thought that's ever gone through my head, but if the worst-case occurs, none of this will matter anyway.
Yes, we've all heard the stories: cars that run on water, perpetual motion machines, plasma generators, magnetic doo-dads, cold fusion, and whatnot. Problem is, none of it has ever been shown to work.
'Shown to work' being the crucial and operative phrase here.
If you're going to bury a new form of energy or propulsion so you can push your own brand, or secretly develop it, last thing you want is common knowledge that works. All, some, or none of the above might actually work, but we're not going to know until we know. Not when they can still sell Brand X, but that will change.
In 2000 I lost my father to cancer. Not just random cancer, but deliberate cancer. I knew next to nothing about mesothelioma prior to all that, but boy oh boy, did I get a crash course in the depths of human depravity and avarice. Not only did the asbestos industry conduct its own secret research in the dangers and health risks of that poison, but upon learning the truth, they buried the results, and countless people have paid the price. If there is a Hell, in my not-so-humble opinion they can't burn slowly or painfully enough in it.
I tell you the truth when I say big business will do anything to turn a profit...anything
Modern society is an illusion...a fabrication, at least in part. We can't say that we know until we know, because we don't.
As far as water-powered cars go, it's called fuel cell technology and space travel has been using it for decades. We know it works; it's just a matter of literally bringing it down to Earth for all.
Cold fusion might be a myth, but fusion we can do; just not in any form that's remotely energy efficient. But we're learning.
As for the rest; solar, hydroelectric, wind and geothermal, it all works it's just a matter of getting them to be the dominant energy sources, not the alternatives. We're surrounded by stupendous energies every second of our lives. It's just a matter of getting to them successfully, but nothing will push our innovation like the threat of civilization's collapse from lack of energy to drive it. Time will tell.