You know, our pachiderm friend does illustrate though why such doomsday prophecies are so successful at fooling people, in spite of failing to actually deliver every single time for as long as we have a written history.
Basically I don't know what's WRONG with some people, but there seems to be this willingness -- nay, NEED -- to believe that their problems are the worst anyone ever faced. And that verily the times they live in must be the last days of civilization (or even the world), because surely these are the worst times and problems EVER, and surely it's SO bad that I don't get a lollipop that nature/economics/God/whatever can't allow such a wicked world to continue any more.
The quote that comes to mind is, "Tragedy is when I cut my finger. Comedy is when you fall into an open sewer and die" by Mel Brooks. And while most people will recognize the sarcasm when put like that, a lot then proceed to argue the same. Their problems are the worst the world has ever seen, while people in other times (e.g., during the middle ages, renaissance, whatever) or places (e.g., Tibet, India, whatever place they take as uber-enlightened) are so much happier. Why they practically never had any problems, if they don't have MY problems.
Basically the impression I'm invariably left with is, "look at me, I'm so unhappy because I read in the newspaper about a war and only got a raise on par with the inflation, surely these are worse and more trying times than when late medieval Spain went through an economic collapse, a century of continuous warfare, and lost a huge chunk of its population to bubonic plague, all at the same time. Why, those people only died of bubonic plague, screaming in agony, which is totally better than poor me having to pay back the mortgage!" Not an exact quote from anyone, but that seems to be the underlying stupidity.
And basically that kind of person is an easy mark if you want to sell a doomsday.
And there is an additional nearsightedness which lies behind such scenarios that can be summarized as "but <insert economic/industrial/etc thing> can't keep increasing any longer! Doom, gloom, collapse, bla, bla, bla." Well, so what? We've been there before, you know?
1. Technology moves on.
Once we needed wood to make steel (via charcoal), and sure enough at one point it looked like soon enough we'll run out of wood to make both that and ships. And, what do you know? In some places, e.g., England, they were even right. So what? Then we started using coal.
Once we used whale oil for lighting, and it sure looked like all the newfangled trend of literacy and having lamps to read by is an unsustainable trend. We'll run out of whale oil soon! Doom, gloom, bla, bla, bla. So what? We discovered that we can use different stuff for lighting.
Etc.
There is an inherent stupidity in any doomsday scenario whose implicit (and sometimes even explicit) assumption is that the current way of doing X is the only way people could EVER do X, and that society will crash and burn before it learns to do X differently.
2. Usually the solution actually already exists, it's just not economical to do it right now. The same applies to most of the current economic/energy/etc doomsday scenarios.
3. Nothing is for ever, and, again, knoweldge evolves, hence nothing has to be the perfect final solution. Humanity has been living on temporary solutions from day one.
Gathering berries was something that was worse than agriculture, but served to keep us going before we invented agriculture. Copying books by hand was worse than the printing press, but it served us well before we had a printing press. Etc.
The world isn't going to end because some current solution isn't perfect, any more than it ended 2000 years ago because their current solutions weren't perfect.
4. Not only that, but the more advanced solutions build on the less advanced ones, hence, we'd still be running naked through the jungle and sleeping in caves, if we didn't put up with imperfect and occasionally unsustainable partial solutions.
Before we could have a sailing boat, we had to have a raft. Before we had a bow and arrow, we had to have a dart. Before we had a writing system, we had to have inventory tags. And speaking of the economy, before having gold coins, we had to have barter. Etc.
A lot of those systems, yes, even in economics, were flawed, imperfect, and unsustainable in the long run. E.g., the Chinese idea to just use quantities of bronze as a common currency, and just let everyone "mint" their own bars of standard value if they have the bronze, worked well early in the bronze age when metal was scarce and quantities in circulation were modest, but fast forward a thousand years and there are millions of tons of bronze and often the "coins" to buy something are heavier than anything you can buy with them.
But we need such intermediate imperfect solutions before we can build better ones based on that experience.
5. People adapt.
We've had shortages before. Prices just went up and people learned to live with less of whatever there was a shortage of. I don't know what makes people think that if some problems (energy, economic, etc) crop up ahead, everyone would just ignore them and everything would continue on the road to destruction. It never worked that way before, and arguably it can't.
In fact, every example given for supposed societies which did continue, are manufactured BS. E.g., no, Easter Island inhabitants DIND'T continue just chopping trees until they collapsed for it, they were actually the victims of a combination of climate change (hence the later lack of trees), disease and some devastating raids by other people coming over the sea.