A Quick Look at FuelEconomy.gov shows many modern cars for sale with highway efficiency of 25mpg or less. Some (many?) people may judge it unconscionable, but it’s clearly acceptable to the broader market and current regulations.
These models seem to be big (Volkswagen Atlas, Subaru Ascent, Ford F150) or fast (Audi RS5, Porche 911, Kia Stinger). If you can get similar mpg from an airplane that carries four people and their luggage at 100+ mph ground speed on a more direct (shorter) route… that’s very compelling to me.
So, reducing car emissions by a just 1% would be way better for the environment than entirely removing all piston engine aviation.
There are about 15m cars sold in the US every year, but around 1500 piston engine planes. That's a factor of 10,000. There are some 210m cars in use in the USA, but around 150k piston engine planes. That's a factor of 1400 (reflecting the fact that planes have a much longer life than cars, further contributing to their lower environmental impact).
Every day, cars burn more fuel than light airplanes burn in a year.
This project is a minuscule rounding error in climate change drivers.
