Another thing to consider is that aviation only accounts for around 2% of global carbon emissions. If SAF ends up being harder to make than expected, it might end up making sense to keep extracting + refining some fossil fuels and mitigate them using some other means (mineralization, perhaps).
Cheap carbon dioxide removal could end up leading to some rather unintuitive outcomes.
You mean: “aviation accounts for around 2% of global carbon emissions”.
There is no only about it. 2% is actually a meaningful and substantial number when you consider the pie-chart it's sliced out of represents a collossal problem.
Flying will cost at least 2x as much as it does today.
Fuel accounts 30-50% of the costs of air travel. A straight doubling of fuel costs would not double air travel costs (although it would hurt)
The CO2 emitted from air travel wouldn’t necessarily need to be converted back to a very high energy molecule like jet fuel. I’m not a chemist, but I’m pretty sure there are polymers that you can bind the carbon into and not be nearly as energy intensive as recreating petroleum molecules.
Finally, wind and solar electricity generation are already generally cheaper than any fossil fuel generation besides nat gas. The EIA (via Wikipedia) had that at around 2x cheaper solar versus diesel generation, and solar and wind continue to see cost improvement.
All that being said, any carbon elimination scheme is going to have a cost, but the theoretical cost efficiency can be much better than if you assume energy is 1-1 with cost.
Flying will cost more, but not necessarily 2x more.
Plus that's only if we can't synthesize jet fuel from all that CO2 we're extracting from the air.
PD: Yes, you could use a not electrified railway, but simply makes more sense to electrificate all railways
If only trains were traveling at predictable routes and you could supply them with electricity while traveling. Let's call it an electric locomotive.
Planes, at least passenger yets, will never use lithium ion batteries. Which is why the industry is pivoting to "green" aviation field.
Planes is another problem.