And according to these numbers, a plane is more efficient than a car with 2 occupants. Average vehicle occupancy varies around 1.5 people.
It doesn't make the plane a better way to travel, of course. It just shows that individual cars need to be proscribed just as much as airplanes.
Flying e.g. 6k miles is reasonably easy to do in a year. I think it is easy to not think about the impact as it all happens in a few gos.
Driving 6k miles takes a long time and would be felt more acutely. It is easier to switch to cleaner forms of energy for this travel and one may be more inclined to reduce this energy usage as it is also a huge time sink.
A commute of 40 miles per day is ~9600 miles per year.
I'd wager there are more people who commute 30 minutes each way by car than there are who go on an annual holiday to Europe :)
Of course, reducing either would be a good thing.
That's a somewhat short commute by modern American standards too.
Honestly, we'd all be better off if we stopped driving to work and made our cities denser and used trains to get around, had more/better train service between nearby cities, and then took annual holidays in Europe on Airbus A380 aircraft that were configured with only economy seating (700+ passengers per plane).
If we're making great efforts to even slow down the acceleration of greenhouse gas emissions, I find it odd to come up with ways to rationalize emitting 2-3x the result of a very long commute. Especially when the endpoint is a programming/software conference.