According to these guys, industrial process heat accounts for larger emissions than electricity and transportation: https://www.absolicon.com/

The nice thing is that it's easy to make heat with higher efficiency than going through electricity.

Synthetic aviation fuels are effectively a fuel-air battery as long as you pull in CO2 from the air making it.

The altitude thing makes it a little more complicated than that, but… yes, essentially:

1. any flight that could be a train journey, make it so; if anything, luxury high-speed train is so much more enjoyable that whatever flying allows at the same cost; there will be electric short-distance planes soon, but we probably want to use those for over-seas journeys;

2. no matter what source of CO2 will remain after we address ICE cars, coal, red meat, dairy, cement and much more, we will need to go negative to restore sanity to the climate, so pulling CO2 will be essential.

The message is: all hands on deck, starting by the big stuff. Flying isn’t huge, but it needs addressing.

BTW, there are already quite a few electric planes in "production" use in the form of electric self-starting gliders:

https://en.wikipedia.org/wiki/Motor_glider#Electric

Basically, some gliders do have an auxiliary engine they can use to avoid ditching it the fields or possibly even to self launch from an airfield without the need for another place to tow them aloft or a glider winch.

Traditionally this engine used to be petrol powered and most still are, but electric ones are proliferating quickly as they have quite a few advantages.

For one they are much more likely to actually start if needed during flight, as there is much less moving pieces and oil/fuel that can go bad during prolonged periods of not being used. The startup is basically instant so you can keep lower margin before deciding you will not find that next thermal and engine power is needed.

The limited range is not much of an issue for a glider as its build to fly between thermals without an engine anyway, this being very efficient with insane glide ratios. The online just needs to compensate the few meters per second of height lost before you find the next upwards going column of air or to reach the next airport, so that your friends don't have to fetch your from the middle of the field + you can avoid the field disassembly of the plane to a the trailer.

For self-starting gliders electrical power also makes sense, as they really need a lot of power for just a few minutes to get to height and can then shut the engine down. A compact battery & electric motor provides just that.

I know, it’s awesome. The best part is that they are trialling the commercial options where I am (Northern Sweden) so I should be able to fly soon in one of those and go to Stockholm under one hour without polluting.

A lot more complicated than that in fact [0]. CO2 is only causing 1/3 of the radiative forcing. High atmosphere chemical interactions and contrails have a massive impact. [0] https://www.sciencedirect.com/science/article/pii/S135223102...

> Aviation contributes only 2% of global air pollution Whataboutism, one of the identified discourses of climate delay [0]. Besides, the proportion of radiative forcing (what actually matters) caused by aviation is more than twice that [1].

[0]https://www.cambridge.org/core/journals/global-sustainabilit... [1]https://www.sciencedirect.com/science/article/pii/S135223102...

0. It's not Whataboutism, though. I don't point to an entirely different problem and say, what about that. I say, if we want to tackle climate change, we ought to target the most effective and cost efficient reductions in order to get the most results with the least cost. And there I say that aviation is just a small part of the problem, so, say, even entirely dismantling aviation would not solve the problem.

1. Yes, as I said immediately following the part you quoted: > though maybe 5% of global greenhouse effect

From the article linked above: "(...) We call this whataboutism. Actors advancing this discourse often deploy statistics demonstrating their own small contribution to global emissions, or they point to large emitters such as China – “We are a nation that produces 1.8 per cent of global carbon dioxide, so I do not get closing down our aluminium smelters, most of our steel production, and now our refining industry …” "

Either we start giving get out of jail free cards to specific sectors and so on or we agree that everything needs to reduce its emissions by ~8%/year from now on, regardless of their share in total emissions, and of how hard it is technically to decarbonize.