13 ms·

They will still use an enormous amount of fuel, carry fewer passengers, and heavily pollute the environment. I'm not too excited about the prospects.

Ericson2314 5y ago
All overland passenger transport should be rail. Over the oceans I suppose we should strive for ships and dirigibles. That said, I find it hard to believe that plane travel can be eradicated for e.g. diplomacy. And frankly, if frequent contract between the powerful different countries is needed to avoid e.g. world wars, it's is worth it. In the short term, any carbon we can capture needs to go in back in ground and stay there. But once we have good good greenhouse gas levels, much of carbon capture tech can be reused to make biofuels. I guess we can reward ourselves with lots of supersonic air travel then.
- t0mas88 5y ago
  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?
- harimau777 5y ago
  Unless we dramatically increase vacation time or dramatically increase rail speeds, that would mean that many people would not be able to see their families and friends or travel to events.
  - ClumsyPilot 5y ago
    If we had high-speed rail everywhere at 300km/h you can cross almost any country overnight, that radius of 3600km would give you 80% of all plane travel.
    - Ericson2314 5y ago
      Thank you, and great username for the clarification :).
    - beerandt 5y ago
      At energy and cost levels that exceed airline travel, per passenger-mile.
      - crazygringo 5y ago
        Do you have a citation for that? Quick Googling doesn't reveal any obvious authoritative answers (but a ton of guessing and unsubstantiated claims). The most authoritative/unbiased source seems to be this Wikipedia article: https://en.wikipedia.org/wiki/Energy_efficiency_in_transport https://en.wikipedia.org/wiki/Energy_efficiency_in_transport But the head-to-head comparisons are mostly gaps when it comes to trains, and the sections on trains and planes are in completely different families of units that makes comparison extremely non-trivial. :(
        redis_mlc 5y ago
        In the US, interstate and some other categories of rail require massive cars and locomotives to be used instead of light-rail cars. This affects efficiency in the US. An example is the Bay Area Caltrain, which shares track with a cargo train, so is required to use heavy-iron rolling stock. Considering that airliner jet engines increase efficiency 1% averaged per year since 1945, airliners could be more efficient than heavy trains used for passengers.
- deleted 5y ago
  [deleted]
- LargoLasskhyfv 5y ago
  One could imagine submerged floating rail tunnels for going over the oceans by rail. Say about 30 to 50 meters deep to be isolated from the weather, not disturbing the remaining shipping. Also usable as sensor platform, carrier for fiber optics. And enabler for floating cities, resorts, aqua-, wind-, and wave-farms out there.
dawnerd 5y ago
But are they that much worse than private jets and helicopters on a per person level?
- failwhaleshark 5y ago
  Flying, in-general, is inefficient unless it's a large, lifting body in ground effect.
  - nostromo 5y ago
    Flying on a full or almost-full plane is more carbon efficient than driving solo. And that's not taking into account the cost of the road networks we build and maintain to allow high volumes of vehicular traffic. https://yaleclimateconnections.org/2015/09/evolving-climate-math-of-flying-vs-driving/ https://yaleclimateconnections.org/2015/09/evolving-climate-...
    - perl4ever 5y ago
      >that's not taking into account the cost of the road networks we build and maintain Well, why would you? Then you'd have to take into account the airports and the transportation networks to get to them...
      - bluGill 5y ago
        Please do so. Airports are nothing compares to just I80 across the US. There are a lot of other roads as well that we could downgrade if more people flew.
        yurishimo 5y ago
        I think autonomous vehicles will help here eventually too. A lot of road maintenance is due to large semi-trucks. If those vehicles are operated autonomously, they can be programmed to drive more efficiently in regards to wear on the roads. Slower braking, slower speeds (since you don’t need stops for drivers to sleep to reach your destination in the same amount of time). We’d also see a closure of many roadside stops since there are no longer people around to use those facilities.
quotemstr 5y ago
If you think that we use too much fuel, increase the price of fuel. Don't just randomly oppose specific technologies that use fuel on the grounds that you, personally, yellow_led, don't feel those technologies are necessary.
- pessimizer 5y ago
  So it's alright to increase the price of fuel because yellow_led, personally, thinks too much fuel is being used, but not alright to randomly oppose specific technologies on the grounds that yellow_led, personally, thinks they use too much fuel? I'm not following your logic. Also I don't know how you randomly oppose specific things.
  - perl4ever 5y ago
    >yellow_led, personally, thinks too much fuel is being used >randomly oppose specific technologies on the grounds that yellow_led, personally, thinks they use too much fuel I think the assumption is that we mostly agree on the first item, but the second one is supposed to be a means to the first. Which yellow_led and others think is a big mistake. >I don't know how you randomly oppose specific things. Random means arbitrary here, I think. Without sound logical reasoning.
FreeSpeech 5y ago
Wait until you hear about SpaceX.
- fastball 5y ago
  Do you mean the methane-powered Starship, for which they plan to use the Sabatier process to get CH4 from the atmosphere?
  - iknowstuff 5y ago
    Is the process expensive compared to just buying CH4 otherwise? When Tesla announced superchargers, they were all about solar panels and cars powered by sunlight, but for the serious rollout they had to go with the more easily scalable, cheaper option, so very few superchargers have solar panels after all.
- jesseb 5y ago
  A Falcon 9 launch produces comparable carbon emissions to a trans-Atlantic 777 flight. There are considerably more trans-Atlantic 777 flights than there are Falcon 9 launches.
  - deleted 5y ago
    [deleted]

Ericson2314 5y ago

All overland passenger transport should be rail. Over the oceans I suppose we should strive for ships and dirigibles. That said, I find it hard to believe that plane travel can be eradicated for e.g. diplomacy. And frankly, if frequent contract between the powerful different countries is needed to avoid e.g. world wars, it's is worth it. In the short term, any carbon we can capture needs to go in back in ground and stay there. But once we have good good greenhouse gas levels, much of carbon capture tech can be reused to make biofuels. I guess we can reward ourselves with lots of supersonic air travel then.

t0mas88 5y ago
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?
harimau777 5y ago
Unless we dramatically increase vacation time or dramatically increase rail speeds, that would mean that many people would not be able to see their families and friends or travel to events.
- ClumsyPilot 5y ago
  If we had high-speed rail everywhere at 300km/h you can cross almost any country overnight, that radius of 3600km would give you 80% of all plane travel.
  - Ericson2314 5y ago
    Thank you, and great username for the clarification :).
  - beerandt 5y ago
    At energy and cost levels that exceed airline travel, per passenger-mile.
    - crazygringo 5y ago
      Do you have a citation for that? Quick Googling doesn't reveal any obvious authoritative answers (but a ton of guessing and unsubstantiated claims). The most authoritative/unbiased source seems to be this Wikipedia article: https://en.wikipedia.org/wiki/Energy_efficiency_in_transport https://en.wikipedia.org/wiki/Energy_efficiency_in_transport But the head-to-head comparisons are mostly gaps when it comes to trains, and the sections on trains and planes are in completely different families of units that makes comparison extremely non-trivial. :(
      - redis_mlc 5y ago
        In the US, interstate and some other categories of rail require massive cars and locomotives to be used instead of light-rail cars. This affects efficiency in the US. An example is the Bay Area Caltrain, which shares track with a cargo train, so is required to use heavy-iron rolling stock. Considering that airliner jet engines increase efficiency 1% averaged per year since 1945, airliners could be more efficient than heavy trains used for passengers.
deleted 5y ago
[deleted]
LargoLasskhyfv 5y ago
One could imagine submerged floating rail tunnels for going over the oceans by rail. Say about 30 to 50 meters deep to be isolated from the weather, not disturbing the remaining shipping. Also usable as sensor platform, carrier for fiber optics. And enabler for floating cities, resorts, aqua-, wind-, and wave-farms out there.

dawnerd 5y ago

But are they that much worse than private jets and helicopters on a per person level?

failwhaleshark 5y ago
Flying, in-general, is inefficient unless it's a large, lifting body in ground effect.
- nostromo 5y ago
  Flying on a full or almost-full plane is more carbon efficient than driving solo. And that's not taking into account the cost of the road networks we build and maintain to allow high volumes of vehicular traffic. https://yaleclimateconnections.org/2015/09/evolving-climate-math-of-flying-vs-driving/ https://yaleclimateconnections.org/2015/09/evolving-climate-...
  - perl4ever 5y ago
    >that's not taking into account the cost of the road networks we build and maintain Well, why would you? Then you'd have to take into account the airports and the transportation networks to get to them...
    - bluGill 5y ago
      Please do so. Airports are nothing compares to just I80 across the US. There are a lot of other roads as well that we could downgrade if more people flew.
      - yurishimo 5y ago
        I think autonomous vehicles will help here eventually too. A lot of road maintenance is due to large semi-trucks. If those vehicles are operated autonomously, they can be programmed to drive more efficiently in regards to wear on the roads. Slower braking, slower speeds (since you don’t need stops for drivers to sleep to reach your destination in the same amount of time). We’d also see a closure of many roadside stops since there are no longer people around to use those facilities.

quotemstr 5y ago

If you think that we use too much fuel, increase the price of fuel. Don't just randomly oppose specific technologies that use fuel on the grounds that you, personally, yellow_led, don't feel those technologies are necessary.

pessimizer 5y ago
So it's alright to increase the price of fuel because yellow_led, personally, thinks too much fuel is being used, but not alright to randomly oppose specific technologies on the grounds that yellow_led, personally, thinks they use too much fuel? I'm not following your logic. Also I don't know how you randomly oppose specific things.
- perl4ever 5y ago
  >yellow_led, personally, thinks too much fuel is being used >randomly oppose specific technologies on the grounds that yellow_led, personally, thinks they use too much fuel I think the assumption is that we mostly agree on the first item, but the second one is supposed to be a means to the first. Which yellow_led and others think is a big mistake. >I don't know how you randomly oppose specific things. Random means arbitrary here, I think. Without sound logical reasoning.

FreeSpeech 5y ago

Wait until you hear about SpaceX.

fastball 5y ago
Do you mean the methane-powered Starship, for which they plan to use the Sabatier process to get CH4 from the atmosphere?
- iknowstuff 5y ago
  Is the process expensive compared to just buying CH4 otherwise? When Tesla announced superchargers, they were all about solar panels and cars powered by sunlight, but for the serious rollout they had to go with the more easily scalable, cheaper option, so very few superchargers have solar panels after all.
jesseb 5y ago
A Falcon 9 launch produces comparable carbon emissions to a trans-Atlantic 777 flight. There are considerably more trans-Atlantic 777 flights than there are Falcon 9 launches.
- deleted 5y ago
  [deleted]