Also, farming is how we produce our food, and if we have the overhead to produce fuel instead, then we have overhead to lower our output to healthier levels to avoid overtaxing our farmland.

Currently we have no viable sustainable aeroplane fuel. Theoretically we could design planes that work well with hydrogen, but hydrogen is expensive as heck already and we'd need to not only replace the planes, but also all our refueling infrastructure. Also it wouldn't be ready for a decade or two anyway, so in the mean time there's literally sustainable option.

Ideally, we'd find a way to make synthfuel somewhat viable, but in the mean time our best option is reducing plane usage and reducing emissions elsewhere in the economy.

Brazil is insanely wasteful with their sugar/biofuel scheme. Japan will also be inefficient going to hydrogen.