4 ms·

It depends on who you are. The median person doesn't fly. But a round trip flight from Shanghai to New York is 3.4 tons of carbon, pretty close to the average

It depends on who you are. The median person doesn't fly. But a round trip flight from Shanghai to New York is 3.4 tons of carbon, pretty close to the average global anual per capita emissions of 4.0 tons.

csallen 7y ago
Seems implausible to me that this is a problem that's going to be solved by asking people to make personal sacrifices. The numbers don't add up. When the op says, "we should focus on…" I assume he's talking about policy, technology, etc., not individual concessions. The best argument I can imagine for encouraging individual concessions is that, if the campaign to do so is massively successful, it might create a new norm, which will increase public awareness, which will increase public support for new policies and participation in the development of new technologies. But imo that's an unnecessarily roundabout course to chart.
- TheSpiceIsLife 7y ago
  There are people who believe that is an essential course to chart because with out the will to change we are nothing. I’m not saying that is or isn’t my perspective, just pointing out that it is a perspective that may hold some validity.
  - csallen 7y ago
    Totally, and this is the perspective I'm responding to. I don't think it's necessarily invalid. But I do think it's very easy to get sucked into a mindset of, "Let's shame individuals into making sacrifices," without actually doing the math on whether or not that's an effective approach.
    - TheSpiceIsLife 7y ago
      Yep, that’s it, shifting the Overton window to better practices.
- bennofs 7y ago
  On the other hand, it also seems implausible to me that the problem can be solved if everyone on the world would produce a few tones of carbon emissions each year by flying. So either flights need to become so expensive that they remain a privilege for the rich or they need to be limited in some other way. I agree that flights are perhaps not the most urgent issue. But encouraging people to fly more is still wrong. When possible, we should avoid flights.
taylortrusty 7y ago
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.

csallen 7y ago

Seems implausible to me that this is a problem that's going to be solved by asking people to make personal sacrifices. The numbers don't add up. When the op says, "we should focus on…" I assume he's talking about policy, technology, etc., not individual concessions. The best argument I can imagine for encouraging individual concessions is that, if the campaign to do so is massively successful, it might create a new norm, which will increase public awareness, which will increase public support for new policies and participation in the development of new technologies. But imo that's an unnecessarily roundabout course to chart.

TheSpiceIsLife 7y ago
There are people who believe that is an essential course to chart because with out the will to change we are nothing. I’m not saying that is or isn’t my perspective, just pointing out that it is a perspective that may hold some validity.
- csallen 7y ago
  Totally, and this is the perspective I'm responding to. I don't think it's necessarily invalid. But I do think it's very easy to get sucked into a mindset of, "Let's shame individuals into making sacrifices," without actually doing the math on whether or not that's an effective approach.
  - TheSpiceIsLife 7y ago
    Yep, that’s it, shifting the Overton window to better practices.
bennofs 7y ago
On the other hand, it also seems implausible to me that the problem can be solved if everyone on the world would produce a few tones of carbon emissions each year by flying. So either flights need to become so expensive that they remain a privilege for the rich or they need to be limited in some other way. I agree that flights are perhaps not the most urgent issue. But encouraging people to fly more is still wrong. When possible, we should avoid flights.

taylortrusty 7y ago

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.