7 ms·

You need to divide that 3.4 tons of carbon by the ~270 people on each flight

dehrmann 7y ago
It might be slightly better if there's cargo. Or worse if there's a lot of first class passengers. Someone I know got denied boarding a flight on employee standby (~free ticket, family member works for the airline) because they needed the weight for cargo.
- acchow 7y ago
  I had no idea weight limits on planes were actually so tight. You'd think with this limit a leaner airline would come out with per-kg passenger surcharges?
  - Symmetry 7y ago
    I'd expect the time delay in weighing every passenger and dealing with any who are above weight would be enough to sink the idea, quite apart from PR concerns.
  - sm4rk0 7y ago
    https://theweek.com/articles/466035/should-airlines-charge-passengers-by-weight https://theweek.com/articles/466035/should-airlines-charge-p...
usaar333 7y ago
GP wrote the per passenger stat
dredmorbius 7y ago
Aircraft use a lot of fuel. Roughly half the takeoff weight of an airliner is fuel. The fuel burned on a continental-distance (3000+ km / 2000+ mile) flight is roughly equal to the passenger's weight. CO2 emissions by mass exceed the mass of the fuel by a factor of three, as you're adding the mass of the oxygen that's added, far more than the hydrogen that's split off. https://www.engineeringtoolbox.com/co2-emission-fuels-d_1085.html https://www.engineeringtoolbox.com/co2-emission-fuels-d_1085... For a 747, roughly, takeoff, climb and descent require a fixed share of fuel, 7840 kg, and take about 250km (30.1 kg/km), cruise, another 10.1 kg/km. Shorter flights are comparatively worse, but what gets you in long-haul flights is simply the total distance: about 12,000 km for each leg of that Shanghai-NYC trip. And that's allocated across about 420 passengers. https://www.sciencefocus.com/future-technology/how-many-cars-equal-the-co2-emissions-of-one-plane/ https://www.sciencefocus.com/future-technology/how-many-cars... Back-of-the-envelope estimates: At Shanghai-NYC distances, that's 34,300 kg of fuel vs. about 420 * 100 kg/passenger total allowance (rough numbers), or roughly 3x the fuel mass per passenger, per leg, or 9x the CO2 emissions mass. That works out to about 1.8 tonnes based on my figures and maths, which is lower than your parent, but probably assumes too large a plane and too many passengers for a long-distance flight. But yes: tonnes of CO2 emissions per passenger for round-trip international travel is about right.
- vonmoltke 7y ago
  > At Shanghai-NYC distances, that's 34,300 kg of fuel That's sounds very low for fuel burn at that distance for a 747. The 747-8 carries over 191,000kg of fuel, yet has a maximum range of only 14,320km. As an aside, I wonder if using "carbon" as shorthand for "carbon dioxide" does more harm than good.
  - dredmorbius 7y ago
    I've updated my comment to make clear that's a back-of-the-envelope calculation, and not based on actual performance data. Generally, if you're within a few powers of two with the approach, it's a good start, and empirical data trump rough estimates any day. The "carbon" vs. "fuel" vs. "CO2 emissions" terminology is legitimate -- these are all different real aspects of the phenomenon. Playing fast and loose between these, or simply confusing the terms (see also kW vs. kWh confusion in energy discussions) is far too common. I specifically called which of these I was using and how they're related. Much of this would benefit by more use of tables and graphs and sensible comparisons, so that people are at least familiar with appearances. Understanding might or might not follow, but the journalistic practice of "tell a story around numbers without using numbers or pictures" seems to me actively harmful.

It might be slightly better if there's cargo. Or worse if there's a lot of first class passengers. Someone I know got denied boarding a flight on employee standby (~free ticket, family member works for the airline) because they needed the weight for cargo.

acchow 7y ago
I had no idea weight limits on planes were actually so tight. You'd think with this limit a leaner airline would come out with per-kg passenger surcharges?
- Symmetry 7y ago
  I'd expect the time delay in weighing every passenger and dealing with any who are above weight would be enough to sink the idea, quite apart from PR concerns.
- sm4rk0 7y ago
  https://theweek.com/articles/466035/should-airlines-charge-passengers-by-weight https://theweek.com/articles/466035/should-airlines-charge-p...

usaar333 7y ago

GP wrote the per passenger stat

dredmorbius 7y ago

Aircraft use a lot of fuel. Roughly half the takeoff weight of an airliner is fuel. The fuel burned on a continental-distance (3000+ km / 2000+ mile) flight is roughly equal to the passenger's weight. CO2 emissions by mass exceed the mass of the fuel by a factor of three, as you're adding the mass of the oxygen that's added, far more than the hydrogen that's split off. https://www.engineeringtoolbox.com/co2-emission-fuels-d_1085.html https://www.engineeringtoolbox.com/co2-emission-fuels-d_1085... For a 747, roughly, takeoff, climb and descent require a fixed share of fuel, 7840 kg, and take about 250km (30.1 kg/km), cruise, another 10.1 kg/km. Shorter flights are comparatively worse, but what gets you in long-haul flights is simply the total distance: about 12,000 km for each leg of that Shanghai-NYC trip. And that's allocated across about 420 passengers. https://www.sciencefocus.com/future-technology/how-many-cars-equal-the-co2-emissions-of-one-plane/ https://www.sciencefocus.com/future-technology/how-many-cars... Back-of-the-envelope estimates: At Shanghai-NYC distances, that's 34,300 kg of fuel vs. about 420 * 100 kg/passenger total allowance (rough numbers), or roughly 3x the fuel mass per passenger, per leg, or 9x the CO2 emissions mass. That works out to about 1.8 tonnes based on my figures and maths, which is lower than your parent, but probably assumes too large a plane and too many passengers for a long-distance flight. But yes: tonnes of CO2 emissions per passenger for round-trip international travel is about right.

vonmoltke 7y ago
> At Shanghai-NYC distances, that's 34,300 kg of fuel That's sounds very low for fuel burn at that distance for a 747. The 747-8 carries over 191,000kg of fuel, yet has a maximum range of only 14,320km. As an aside, I wonder if using "carbon" as shorthand for "carbon dioxide" does more harm than good.
- dredmorbius 7y ago
  I've updated my comment to make clear that's a back-of-the-envelope calculation, and not based on actual performance data. Generally, if you're within a few powers of two with the approach, it's a good start, and empirical data trump rough estimates any day. The "carbon" vs. "fuel" vs. "CO2 emissions" terminology is legitimate -- these are all different real aspects of the phenomenon. Playing fast and loose between these, or simply confusing the terms (see also kW vs. kWh confusion in energy discussions) is far too common. I specifically called which of these I was using and how they're related. Much of this would benefit by more use of tables and graphs and sensible comparisons, so that people are at least familiar with appearances. Understanding might or might not follow, but the journalistic practice of "tell a story around numbers without using numbers or pictures" seems to me actively harmful.