I don’t agree. We already have alternatives to oil, they’re just more expensive in many cases.

In the 00s, we pursued biofuels (ethanol, biodiesel, bioplastics, etc… which has problems but does still replace some uses of oil) and on-shore wind aggressively.

In the 2010s, we developed battery electric vehicles, grid storage, solar, and off-shore wind.

I suspect this decade we’ll see hydrogen steel and ammonia production, battery electric flight, and chemical carbon capture. Another decade of this and expensive methods of oil extraction just aren’t very feasible, so if the price spikes, people will just switch to alternatives faster or even start synthesizing carbon neutral hydrocarbons (ie via electrolyzed hydrogen, direct air CO2 capture, and Fischer-Tropsch).

What replaces plastic currently?

PLA is a plastic made of corn (it is polymerized lactic acid). It's actually a pretty versatile thermoplastic as it's semi-crystalline and so although it can be formed at relatively low temperatures, if you heat treat it (which increases its crystallinity), it can withstand ~boiling temperatures like other common thermoplastics. It's also technically biodegradable, but usually won't actually break down unless thin and in proper industrial compost processes. (Which can be kind of good for many applications... you don't want your plastic breaking down while in use, although you definitely don't want to be littering PLA.)

It's pretty cheap, commonly used in one-time plastic items, and is the most common 3D printing plastic.

But also, you can make polypropylene and polyethylene pretty easily from methane (which can be from biological sources or synthesized from electrolyzed hydrogen and CO2) via methanol-to-olefins processes, common in China.

But you're missing the point. We can synthesize literally anything you can make from oil using hydrogen, direct air captured CO2, and the Fischer-Tropsch process. It's a complete replacement for crude oil. It's just more expensive than getting it from the ground.

With enough energy you can make plastic out of CO2 and water. So it's an economic question: What happens when oil is no longer useful as fuel? Will it be cheaper to just synthesize the hydrocarbons you need, or will it be cheaper to keep some of the oil infrastructure running?

I have no idea why you're being down-voted. You literally can make any hydrocarbons we get from crude using synthesis gas (from CO2 and water split into hydrogen) using the Fischer-Tropsch process: https://en.wikipedia.org/wiki/Fischer%E2%80%93Tropsch_proces...

Are folks just not aware of this, so they think people who say you can "make plastic out of CO2 and water" are talking hand-wavy nonsense?

The process is used commercially today in Qatar, Malaysia, and South Africa plus has had pilot plants in the US. But many of these US pilot plant efforts stopped when the price of oil cratered. So again, we absolutely do have alternatives to crude oil, it's just a function of economics.

We can also play with some alternatives such as artificial spider silk. This is an opportunity not just to ape current methods, but actually come with something completely new.

It would be a long time before we run out of oil. Given that solar is becoming super cheap, our reliance on oil will keep reducing.

What is likely to happen is change in political will to keep the ban - you know, the usual bribery and the talk of “jobs” etc. That is a bigger threat than oil shortage

Isn't political will just a function of external motivators such as the profitability of extracting oil? (Which will go up as supplies dwindle?) I don't think people will just decide differently with no change in circumstances.

Tapping oil reserves has a history of wrecking governments and economies. The economics of it quickly push out other forms of industry. Politicians quickly seize on the opportunity to claim they personally own the reserves - and become dictators. Then there's the horrible ecological costs.

The best option is to develop means of providing energy which disrupt the economics of even oil extraction/refinement. Nuclear could do this - uranium occurs at a pretty constant rate across the earth's crust. Nuclear could also be built out at a rate of choice to meet and pass the energy provided by fossil fuels. One thing that typified the industrial expansion to modernity is ever increasing utilization of greater amounts of energy. Energy storage even has suitable options to disrupt fossil fuels - vis a vi hydrogen fuel cells, lithium batteries, and plenty of other options. (Personally, I like that fuel cells output water since desert areas are seeing greater population characteristics.)

In short, the best option is to leave oil and fossil fuels in the ground and grow the world off its use through appropriate investments in tech and infrastructure.

Replying instead of editing

Even the term “fossil fuels” is an inappropriate framing of the chemicals involved since it restricts their use to burning. Consider the processes involved in their formations: organic material grew for eons millions of years ago. It then had to be buried in just the right conditions and later embedded into even further beneficial conditions. It took millions of years, high temperatures, and high pressures to go from plant material to these complex molecular forms. Then we dig them up or seep them out with fracking and further refine them. Then we burn them. Huge losses of energy all along the way. Using oil as fossil fuel is a huge waste of the energy it took to create those molecules.

We've changed many practices against pure profitability, including asbestos, marketing cigarettes to children, HCFCs, and slavery.

We may not have reached 100% on each, but we've changed a lot. We have other values than money.

Increasing solar and decreasing oil are largely independent. History shows that when we find new energy sources, we keep using the old and add the new.

Solar allows us to keep doing some things that oil powers, but we would stop using oil at some point, limited by pollution killing too many of us, running out, or choice.

Perhaps. I think the key question is how quickly the cost of alternatives goes down relative to oil.

But if Greenland is the last reserve of oil left on the planet, the value of that oil will be astronomical. Holding off on drilling during cheap oil is a good investment.

We'll need to cut about 50% of fossil fuel demand globally in the next 30 years (see eg https://www.iea.org/reports/net-zero-by-2050 ). It will probably happen by tax and emissions trading mechanisms (and elimintating subsisidies ) sufficiently to reduce demand to this level.