And if we simply slowed the world down a little bit I wonder if blimps could take over for a majority of ocean-crossing journeys. Not that it will ever happen.
Planes are not well suited to electrification. Trainers can reasonably be made electric, as might certain commercial purpose aircraft, but if there will be electric New York to LA passenger flights it won't happen any time soon.
Although the fuel in a Cessna would be AvGas which is basically leaded gasoline, essentially anything you'd pay to fly on has turbine engines running on JetA which is basically kerosene instead. Small local planes, especially in Europe might look like just the Cessna only bigger, but the propellers are spun by a jet turbine, they don't have internal combustion engines.
The traditional contrast to the I.C.E. is the external combustion of a steam engine, where the combustion occurs in a boiler, which then directs steam to the actual reciprocating engine (in a traditional steam engine).
Steam turbines actually could be a case of an external-combustion turbine, as these are powered by steam which is heated externally to the turbine itself (e.g., there is no internal combustion chamber).
Not all steam turbines are combustion engines, however. A nuclear power plant's steam turbines are fed by steam created from nuclear fission rather than chemical combustion. Some solar thermal power systems runs steam turbines based on solar power, and I believe that most geothermal power involves steam and turbines. Functionally, the steam turbine bits of these systems are identical to a coal-fired steam turbine, but the heat cycle differs.
An interesting thing about this is that there has been quite a lot of infrastructure built to create these fuels for road transport in the last decades. So if road transport is electrified but flight isn't, then all those resources could quite easily be redirected to make aircraft fuel instead. If I recall the interview correctly that I heard regarding the flight mentioned below, I think there are some countries that have enough biofuel production (currently for road transport) already, to replace all the aircraft fuel used domestically.
The first commercial transatlantic flight with this type of fuel was just two days ago:
https://apnews.com/article/transatlantic-flight-sustainable-...
> Is it snake oil?
While renewable, the worlds entire production of snake oil would only make a small dent in the fuel needs of the airline industry.
Planes don't run on the same fuel as trains and automobiles. The basic idea is pretty simple: it's all hydrocarbons. We traditionally use hydrocarbons grown as plants millions of years ago and stashed in the ground until we dig them up/pump out the ground. We don't put the carbon back in the ground -- it goes into the atmosphere mostly.
"Sustainable" fuels are the same thing except you grow the plants today. Since plants growing today use carbon from the atmosphere, even when the fuel is burned like traditional fuel, you're not adding much net carbon to the atmosphere.
Everything else is mere details, such as: growing plants today is much more costly than digging up plant material from the Cambrian; the fuel has to have the same energy density as traditional fuels; it has to not gunge up the engine; etc.
I'm not sure the fuel itself is that low carbon but the cycle of producing it may be. I'm sure a quick search would reveal they produce slightly less CO2 or something in a suitable engine.
Blimps are either too slow or can't carry enough cargo. Solving the use of heavy tanker fuel is quietly a massive priority, the naive answer is nuclear, the real world answer isn't clear.
IMO it's probably just a stand-in until hydrogen really works.
It's biofuel made from palm oil, algae, tallow, etc.
Don't get me started on the oil USED to produce this wonderful green fuel.
But it might be carbon-neutral... Which might not or might be part of sustainability...