Limits

Five orders of magnitude between minimum and maximum emissions

We already saw that the average CO₂ emissions per passenger per flight in 2018 was 213 kg. Obviously there will be a huge range of different results within that average... Can we put some estimate on the lower and upper limits? Googling around led to the following story.

The shortest commercial passenger flight in the world is the Loganair Westray to Papa Westray route. The 2.7 km flight takes about 1 minute in a Britten-Norman BN-2 Islander. This aircraft can carry 10 passengers (all economy) and has two Lycoming O-540-E4C5 piston engines, each 190 kW. Burning gasoline releases 13 kWh/kg, so the Islander at maximum power uses 30 kg of fuel an hour, or 0.5 kg of fuel a minute. Let’s take that as the estimate for the Westray route - also one minute which won’t be all at maximum power but which also doesn’t include taxi-ing. 0.5 kg gasoline produces 1.5 kg CO₂. Assuming the plane was full, that’s 0.15 kg CO₂ per passenger.

The longest commercial passenger flight in the world is the Singapore Airlines Singapore to Newark route. The 16,000 km flight takes over 18h in an A350-900ULR. This aircraft can carry 161 passengers (67 business, 94 premium economy) and on the first flight, burned 101.4 t of fuel. 101.4 t jet fuel produces 319,410 kg CO₂. Let’s include an RF factor of 3 and say the plane was 50% full, that’s 12 t CO₂ per passenger.