I noticed that the Airbus A320N burns around 5000 lbs/hr of jet fuel fully loaded, plus or minus a few hundred. For fun, I decided to calculate how that fuel usage and carbon footprint compares to driving – and to running the simulator. 
At full capacity 180 passengers, 5000 lbs/hour is about 28 lbs/hr/passenger. If we convert pounds to gallons, and gallons of jet fuel to carbon dioxide emissions, then back to gallons of automotive gasoline, that’s roughly equivalent to 4.5 gallons/hr/passenger of mogas in terms of co2 output.
Cruising FL350 at Mach 0.78 gives us 517 mph, so we’re getting the equivalent of 115 mpg/passenger – this compares reasonably well with a 3- or 4-passenger automobile on the highway, and a full plane will beat a driver-only car almost every time.
To complete the cycle, I calculated the equivalent emissions for running Flight Simulator.
An RTX 2070 Super is rated at 215 watts, but the recommended power supply for the whole computer is 650 watts – let’s calculate for the whole system, assuming it’s pumping the GPU and CPU full steam. Plug 0.65 kWh into Greenhouse Gas Equivalencies Calculator | Energy and the Environment | US EPA and it comes up as equivalent to 0.052 gallons of gasoline based on some average energy generation. (Actual electricity generation may be relatively dirty, like coal, or clean, like hydroelectric or wind or solar, so there’s a lot of wiggle room here.)
Going with that figure, that gives us a miles-per-gallon equivalent of like 10,000 mpg for the simulator, nearly 100x as efficient as driving or flying for real. 
[If I got any of the math wrong, please give a shout! I’m happy to correct it.]