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Air travel has a big PR problem, because somehow a lot of people think it's the absolute worst for the environment. While on many routes a car is worse in terms

Air travel has a big PR problem, because somehow a lot of people think it's the absolute worst for the environment. While on many routes a car is worse in terms of CO2 emission per trip than a small to mid sized airliner if there are less than 3 people in the car. Similar for your suggestion that we should take ships over the ocean, because cruise ships are much more polluting per passenger mile than modern airliners.

eitland 5y ago
... and fast fashion is probably worse than both if what I read is correct. FTR: Years go by between everytime I travel by plane so I don't feel I have anything to defend, I just think it is good to keep the big picture in mind.
- t0mas88 5y ago
  Agree, and the airlines absolutely need to keep working to become more climate friendly just like we need to make road travel better. But climate-shaming specifically air travel while at the same time driving a non-electric car or using air conditioning without having solar panels is very hypocritical because both of those and many other things are a far bigger part of the total emissions.
  - tffgg 5y ago
    People insulting others as hypocritical for critizing something needs to stop.
    - t0mas88 5y ago
      It's not an insult. What you call criticising, climate shaming someone over one activity while engaging in other more polluting activities, is the exact definition of the word hypocrisy: > Hypocrisy is the practice of engaging in the same behavior or activity for which one criticizes another
Ericson2314 5y ago
> While on many routes a car is worse than a small to mid sized airliner if there are less than 3 people in the car. I never said cars. Cars are terrible. I would not complained if passenger-only cars were banned everywhere. > Similar for your suggestion that we should take ships over the ocean, because cruise ships are much more polluting per passenger mile than modern airliners. There are alternatives like wind power + giant batteries. The fact that weight doesn't matter for ships so much (container ships are more efficient than rail, scaling up is equivalent to shrinking the viscosity of water) opens a lot of doors.
- beerandt 5y ago
  Air travel is generally more energy efficient than trains, beyond a 300-400 mile range, depending on what you're traveling over/through. Track and right-of-way is a scarce resource with large amounts of embedded energy. The sky, not so much.
  - jltsiren 5y ago
    That depends on passenger volume. Trains require massive initial investments, but the marginal cost per passenger is very low. Air travel is mostly about marginal costs, and it requires massive infrastructure at endpoints. For example, an aiport serving 50 million passengers/year is two orders of magnitude larger than a railway station with a similar passenger volume. And while the airport would be one of the 30-40 busiest in the world, the railway station would not be particularly noteworthy.
    - beerandt 5y ago
      Yea, which is why trains costs are so sensitive to distance- it's massive up front cost is a function of that distance. It's not the stations, it's the rails and right-of-way. The problem most people ignore is that train marginal-increases max-out at some number of trains per day, before you need an additional set of tracks. And that happens at a much lower number than most people assume, especially if you're planning on sharing that track with other routes. And even worse if you have to use or cross a freight track. So not only does efficiency have a min bounds, but also a local-max bounds, where you need a large enough marginal increase to justify the additional rails. Whereas the airline equivalent is whether to schedule an additional flight. Which is easier to commit to than whether a new track is justified.
_Microft 5y ago
Air travel is not a problem because the emissions per kilometer are that bad but because one can easily travel one or two orders of magnitude farther than one usually would.
- onlyrealcuzzo 5y ago
  Exactly. It's not like if you couldn't fly from Los Angeles to New York once a month - you would just drive by yourself - and produce the same amount of carbon. You wouldn't produce any carbon, because you'd likely never make the trip!
  - Ericson2314 5y ago
    Yes, this is why dealing with air is so tricky in economic terms, because "uninducing demand" does have more intrinsic downsides. Car -> rail is a mere political problem, once you get there it "unlocks" more travel so it is clearly economically good. I guess thank god for 9/11 boosting security theater. Don't like all the other patriot act garbage, but the degree to which air travel is so awful really helps here.
    - jacobolus 5y ago
      After 9/11 air travel plateaued for 3–4 years, then afterward rebounded to the original trend line (i.e. massively expanded, and continues to expand). It doesn’t seem that all of the unpleasant security theater is enough to significantly deter people from flying.
      - Ericson2314 5y ago
        No one its own, but I think it would make a difference had we avoid hsr alternative.
- agent327 5y ago
  So your preferred solution is to restrict the allowed travel radius of people, a bit like with medieval serfs?
ClumsyPilot 5y ago
We coupd sctuallu fly even more efficiently, but slower, with turboprops
- sokoloff 5y ago
  There’s a practical maximum amount of thrust to get from a single turboprop engine; to meet performance requirements in the event of the failure of one engine, that puts a practical upper limit on the size of two engine turboprops. Four engine turboprops would likely not be competitive with modern two engine jets, except on the shortest of legs. Turboprops also fly lower, meaning they’re much more affected by en route weather that turbojets can often climb over. (Low and mid twenties [thousands of feet] is where much of the uncomfortable weather is. Storms that rise into the mid-30s are diverted around by most airplanes.) Turboprops have their place, but so do jets in air carrier ops.
- bronco21016 5y ago
  It looks like the future is a bit of a mashup of a turboprop and turbofan. Check out the efficiency of the Pratt and Whitney geared turbofans. On the A220-100 fuel burn (~3,800 pph) is comparable to a CRJ-900 with 35 more seats in a dual class configuration. That’s quite a leap. I’ll see if I can find someone to compare it to a B717 fuel burn, it’s the same number of seats.
wolverine876 5y ago
> While on many routes a car is worse in terms of CO2 emission per trip than a small to mid sized airliner if there are less than 3 people in the car. Wow. I read that one plane trip can increase your carbon footprint by a greater magnitude than all your typical actions to reduce it. Does anyone know where to find some data? EDIT: Here's some data https://www.bbc.com/news/science-environment-49349566 https://www.bbc.com/news/science-environment-49349566 https://theicct.org/blogs/staff/planes-trains-and-automobiles-counting-carbon https://theicct.org/blogs/staff/planes-trains-and-automobile... Also, planes have other problems: * cars can be powered by carbon-free energy. There's not much current prospect for planes. * planes also do great harm from non-CO2 emissions: "The climate effect of non-CO2 emissions from aviation is much greater than the equivalent from other modes of transport, as these non-CO2 greenhouse gases formed at higher altitudes persist for longer than at the surface and also have a stronger warming potential"
- sokoloff 5y ago
  Jet engines are pretty robust to fuel quality within broad ranges. Atmospheric CO2 to a carbon-neutral jet fuel is technically possible now. (I don’t think it competes economically with Jet-A/kerosene/diesel at the moment.)
publicola1990 5y ago
On the the other hand commercial air travel is one of the safest means of travel. If you wanted to optimize for safety you would take a scheduled flight to your destination than go by road.
- LargoLasskhyfv 5y ago
  Ah, well. You think so. But would that hold up if traveling by air so much more, for so many shorter trips? What could go wrong?

eitland 5y ago

... and fast fashion is probably worse than both if what I read is correct. FTR: Years go by between everytime I travel by plane so I don't feel I have anything to defend, I just think it is good to keep the big picture in mind.

t0mas88 5y ago
Agree, and the airlines absolutely need to keep working to become more climate friendly just like we need to make road travel better. But climate-shaming specifically air travel while at the same time driving a non-electric car or using air conditioning without having solar panels is very hypocritical because both of those and many other things are a far bigger part of the total emissions.
- tffgg 5y ago
  People insulting others as hypocritical for critizing something needs to stop.
  - t0mas88 5y ago
    It's not an insult. What you call criticising, climate shaming someone over one activity while engaging in other more polluting activities, is the exact definition of the word hypocrisy: > Hypocrisy is the practice of engaging in the same behavior or activity for which one criticizes another

Ericson2314 5y ago

> While on many routes a car is worse than a small to mid sized airliner if there are less than 3 people in the car. I never said cars. Cars are terrible. I would not complained if passenger-only cars were banned everywhere. > Similar for your suggestion that we should take ships over the ocean, because cruise ships are much more polluting per passenger mile than modern airliners. There are alternatives like wind power + giant batteries. The fact that weight doesn't matter for ships so much (container ships are more efficient than rail, scaling up is equivalent to shrinking the viscosity of water) opens a lot of doors.

beerandt 5y ago
Air travel is generally more energy efficient than trains, beyond a 300-400 mile range, depending on what you're traveling over/through. Track and right-of-way is a scarce resource with large amounts of embedded energy. The sky, not so much.
- jltsiren 5y ago
  That depends on passenger volume. Trains require massive initial investments, but the marginal cost per passenger is very low. Air travel is mostly about marginal costs, and it requires massive infrastructure at endpoints. For example, an aiport serving 50 million passengers/year is two orders of magnitude larger than a railway station with a similar passenger volume. And while the airport would be one of the 30-40 busiest in the world, the railway station would not be particularly noteworthy.
  - beerandt 5y ago
    Yea, which is why trains costs are so sensitive to distance- it's massive up front cost is a function of that distance. It's not the stations, it's the rails and right-of-way. The problem most people ignore is that train marginal-increases max-out at some number of trains per day, before you need an additional set of tracks. And that happens at a much lower number than most people assume, especially if you're planning on sharing that track with other routes. And even worse if you have to use or cross a freight track. So not only does efficiency have a min bounds, but also a local-max bounds, where you need a large enough marginal increase to justify the additional rails. Whereas the airline equivalent is whether to schedule an additional flight. Which is easier to commit to than whether a new track is justified.

_Microft 5y ago

Air travel is not a problem because the emissions per kilometer are that bad but because one can easily travel one or two orders of magnitude farther than one usually would.

onlyrealcuzzo 5y ago
Exactly. It's not like if you couldn't fly from Los Angeles to New York once a month - you would just drive by yourself - and produce the same amount of carbon. You wouldn't produce any carbon, because you'd likely never make the trip!
- Ericson2314 5y ago
  Yes, this is why dealing with air is so tricky in economic terms, because "uninducing demand" does have more intrinsic downsides. Car -> rail is a mere political problem, once you get there it "unlocks" more travel so it is clearly economically good. I guess thank god for 9/11 boosting security theater. Don't like all the other patriot act garbage, but the degree to which air travel is so awful really helps here.
  - jacobolus 5y ago
    After 9/11 air travel plateaued for 3–4 years, then afterward rebounded to the original trend line (i.e. massively expanded, and continues to expand). It doesn’t seem that all of the unpleasant security theater is enough to significantly deter people from flying.
    - Ericson2314 5y ago
      No one its own, but I think it would make a difference had we avoid hsr alternative.
agent327 5y ago
So your preferred solution is to restrict the allowed travel radius of people, a bit like with medieval serfs?

ClumsyPilot 5y ago

We coupd sctuallu fly even more efficiently, but slower, with turboprops

sokoloff 5y ago
There’s a practical maximum amount of thrust to get from a single turboprop engine; to meet performance requirements in the event of the failure of one engine, that puts a practical upper limit on the size of two engine turboprops. Four engine turboprops would likely not be competitive with modern two engine jets, except on the shortest of legs. Turboprops also fly lower, meaning they’re much more affected by en route weather that turbojets can often climb over. (Low and mid twenties [thousands of feet] is where much of the uncomfortable weather is. Storms that rise into the mid-30s are diverted around by most airplanes.) Turboprops have their place, but so do jets in air carrier ops.
bronco21016 5y ago
It looks like the future is a bit of a mashup of a turboprop and turbofan. Check out the efficiency of the Pratt and Whitney geared turbofans. On the A220-100 fuel burn (~3,800 pph) is comparable to a CRJ-900 with 35 more seats in a dual class configuration. That’s quite a leap. I’ll see if I can find someone to compare it to a B717 fuel burn, it’s the same number of seats.

wolverine876 5y ago

> While on many routes a car is worse in terms of CO2 emission per trip than a small to mid sized airliner if there are less than 3 people in the car. Wow. I read that one plane trip can increase your carbon footprint by a greater magnitude than all your typical actions to reduce it. Does anyone know where to find some data? EDIT: Here's some data https://www.bbc.com/news/science-environment-49349566 https://www.bbc.com/news/science-environment-49349566 https://theicct.org/blogs/staff/planes-trains-and-automobiles-counting-carbon https://theicct.org/blogs/staff/planes-trains-and-automobile... Also, planes have other problems: * cars can be powered by carbon-free energy. There's not much current prospect for planes. * planes also do great harm from non-CO2 emissions: "The climate effect of non-CO2 emissions from aviation is much greater than the equivalent from other modes of transport, as these non-CO2 greenhouse gases formed at higher altitudes persist for longer than at the surface and also have a stronger warming potential"

sokoloff 5y ago
Jet engines are pretty robust to fuel quality within broad ranges. Atmospheric CO2 to a carbon-neutral jet fuel is technically possible now. (I don’t think it competes economically with Jet-A/kerosene/diesel at the moment.)

publicola1990 5y ago

On the the other hand commercial air travel is one of the safest means of travel. If you wanted to optimize for safety you would take a scheduled flight to your destination than go by road.

LargoLasskhyfv 5y ago
Ah, well. You think so. But would that hold up if traveling by air so much more, for so many shorter trips? What could go wrong?