Well if it's only two passengers then a Corolla with two passengers is better for the environment than an airplane.

I'm using the Suburban as an example to show what it's like for a family taking a vehicle that isn't efficient vs taking an airplane. The SUV wins.

Getting a rental car once you reach your destination is the same as driving your own car from an environmental perspective, the only difference is that you polluted more to reach your destination than if you had just taken your car from the beginning.

It's also possible to use ride sharing apps to fill up your car if you were otherwise going to travel alone.

The real solution is for people to stop traveling all over the world like they're doing right now, but if they want to continue traveling long distances then airplanes are the least efficient way to do it in most cases, cars, bus, trains are all much better for the environment but the best is to just not travel long distances at all.

Also, I'm just talking about fuel economy, emissions released by airplanes cause twice as much damage AND cars have catalytic converters to at least reduce other emissions, airplanes don't have that and if we look at smaller aircrafts with piston engines they even use leaded fuel!