I do agree that the Saudi Arabian numbers deserve some doubt.
When I say that the supply of oil is elastic, I am talking about https://en.wikipedia.org/wiki/Price_elasticity_of_supply
Elastic in this context means that an increase in the price will bring forth more supply. That's very much the same thing as your statement that we are running out of cheap oil.
In the short run, oil supply and demand are very inelastic. That means that even if oil prices were to double for a week, it wouldn't much change the amount of oil consumed nor the amount of oil produced.
It takes a while to explore and exploit new oilfields, and it takes a while to shift consumption to and from oil. Thus in the longer run, say over a few years, oil supply and demand are much more elastic.
Especially if you add in new technologies, like we saw with fracking.
The longer run being more elastic than the shorter run means that the longer running price is more stable than in the shorter run. (Of course, more stable doesn't mean constant. We still see the secular rise in real oil prices.)
That's all still totally in line with everything you say.
Now you correctly mention that renewables are getting cheaper. For most applications, you just want power say for electricity generation, so you can easily substitute renewables (or coal..) for oil. That further contributes to long running stability of the oil price.
For some applications like fueling cars, or even more so: planes, carbohydrates are harder to replace. So they get substituted later, or perhaps never; depending on how effective relative prices (including taxes and reputational effects) move.
(In principle, we don't need fancy electric batteries: you can use electricity from renewables to synthesize aviation fuel from scratch. It mostly just carbon and hydrogen. It's not just worth it at the moment, and might never become worthwhile.)
I'm all in favour of replacing fossil fuels with renewables. My point is just that the market driven replacement comes mostly from renewables becoming cheaper, less so from fossil fuel becoming more expensive.
> If you want to burn public money you can accelerate the process a bit with taxes and tech development (this is already being done and it could be done a bit more) but ultimately the future doesn't depend on that, just a bit of timing.
Yes. Though I do wish we had a carbon tax, even if just a low one. Not just for any of the effects of steering people away from fossil fuels, but to show that combating climate change should be a money-spinner for the government, not a money sink. That should make it easier to argue against government efforts of trying to pick winners like the pretty much useless German photovoltaic subsidies of the past: Germany is not known for its long days of blasting sun..
(And about competitive effects in regards to other countries: just treat the carbon tax like VAT when you adjust for products and services crossing borders.)
There is a lot of oil around to be extracted, it won't "run out" but it is absolutely not elastic, and not at arbitrary prices. The big reserves which remain are considerably more expensive to extract and convert to a usable state. The $100/bbl rate is somewhere around the floor price for the oil economy when those resources dominate. The price of fossil fuels has bounced around in the last decade or two for political reasons. OPEC was forcing prices above $100 because they're a cartel but then North America found an enormous quantity of tar sands and similar kinds of expensive-to-extract but in huge quantities, it was profitable to extract at those prices and OPECs cartel price highs were broken because they could not afford to cut production in order to raise prices (much of OPEC proping up their power with money that they couldn't do without).
OPEC is running out of cheap oil, the world is running out of cheap oil. There is an enormous amount of oil left in the ground which can be extracted, but at a price. A price which is easily beatable by renewables now and definitely in the future when scaling and technology factors further lower their prices.
Fossil fuels are over, it's done. There's little left to protest or try to change, the situation is forcing it and it can be seen by anybody in the energy business. If you want to burn public money you can accelerate the process a bit with taxes and tech development (this is already being done and it could be done a bit more) but ultimately the future doesn't depend on that, just a bit of timing.