Earlier quoted context omitted.
I recently did some calculations on car vs plane travel. For commuter flights, it surprised me to find out that for gasoline cars, car travel isn't better than a flight until you get to a carpool of four passengers. For electric cars, a solo driver is about the same as air travel (in an average airport flight) - a second passenger makes it better than air travel. (This was for a flight halfway across the country.) So…
Care to reproduce your calculations here? I'm certain you're off by a factor of 10 (at least). Flying is probably the worst thing you will do in your entire life as far as the environment is concerned.
FAA Office of Environment and Energy
January 2015
Aviation stands out among transportation modes, however, in terms of improving fuel efficiency over the past decade. As shown in Figure 1: Comparison of Vehicle Fuel Efficiency, in 2004, automobiles and airlines operating in the U.S. had very similar energy intensities, with automobiles at 3,496 BTU/passenger mile versus airlines at 3,505 BTU/passenger mile. Between 2004 and 2012, auto energy intensity fell to 3,193 BTU/passenger mile, for an 8.8% improvement. For the same period, aviation energy intensity fell to 2,654 BTU/passenger mile, a 24.3% improvement and is now significantly lower than automobiles.
https://www.faa.gov/regulations_policies/policy_guidance/env...
In addition to being more efficient flying is wildly safer. You have a 750x better chance of surviving a commercial flight than a car trip the same distance. (2000-2010)