Comment by entee | Hacker News Reader

Comment by entee | Hacker News Reader

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Keep in mind that as a fraction of emissions, air travel is actually quite small, about 2-3% [1] (and this is from a harsh article). There's some concern that as the industry grows (roughly 5% a year) and other sectors decarbonize, air travel will consume a larger fraction of remaining "carbon budget" (25-50% depending on where you look).

Clearly as the denominator shrinks, and the numerator grows even slowly, percentage increases. That said, it's probably not the main issue in in climate change or even close to it. Other sectors such as ground transport, industrial heat (cement, steel etc.), agriculture (primarily fertilizer) and other fixed sources (buildings/homes) are a bigger deal.

If we end up with airlines as the last carbon source, that's probably OK if we deal with the rest. 25% or even 50% of remaining budget is fine if the rest of the (easier) problems get solved. Air travel is uniquely hard, let's get the easier stuff first.

[1] https://www.nytimes.com/2019/09/19/climate/air-travel-emissi...

It's true that, overall, air travel isn't a large fraction of our carbon emissions. But that's entirely do to that fact that most people don't fly. Every trip you make across the Atlantic and back takes about 10% of a typical American's yearly carbon emissions. If you're a typical person who doesn't fly then indeed it's not worth worrying about the flying that other people are doing. But if you're someone who flies every year or especially multiple times a year then cutting down is probably one of the most significant things you can do for the environment.

How many of those trips are cuttable? Maybe one or two business trips. And businesses would already rather teleconference these days if the trip is really avoidable. Given how cumbersome and expensive flying is already, I'm not sure there's a huge amount of "waste" in the system to cut at the moment.

As for the occasional personal trip (I assume by # of people though maybe not # of miles flown, the far more common use case, only 12% of passengers are business travel[1]), should we be telling people, "no you're not going to see grandma for christmas"?

[1] https://www.investopedia.com/ask/answers/041315/how-much-rev...

"Environmental conservation by telling people to use less resources is like telling people not to sin.

The problem is that Christians have been telling people not to sin for 2000 years, and people have not stopped sinning..."

I'd imagine a lot of them are cuttable. I have a friend who regularly flies to the US (from the UK) to run conferences. Frankly it's ridiculous that they don't hire someone from the US to so it.

With modern video calling technology, how many business trips are really essential? Some sure, but a lot could be cut, or merged into fewer longer trips.

You're right I think some are overdone. One example is the consultants taking a plane 2x a week (leave early monday, come back thursday eve, often with unconstrained distances). Maybe a bunch of those could be cut, though in that case I think a lot of these business models offer a "premium" service. If you're paying $1M/quarter for a McKinsey contract or for an I-banker or a big 4 accountant you definitely want to see that person physically. Though keep in mind McKinsey is also probably less price sensitive than the average flyer.

Still even with that, I'd like to better understand the economics. If only 12% of trips are business vs pleasure, killing all business trips won't move the needle in the long run. There's some question of how long business trips are, you can be 12% of trips but if they're longer it's worse.

My overall point is that there are a lot of factors in how people chose to travel. It's far from clear that increasing the already quite high price is what's going to deter people unless you tax it massively. In which case we'll effectively return to a situation like the pre-deregulation days where only the rich flew, which may be fine, but should be directly considered.

In terms of impact there's a generally accepted ~2.7X multiplier applied to flight emissions:

"Among the reasons for this focus is that these emissions, because they are made at high altitude, have a climate impact that is commonly estimated to be 2.7 higher than the same emissions if made at ground-level." [0]

So you can look at 2-3% of co2, or you can look at impact and if we use the co2 proportion as a proxy of overall emissions, ~8% in terms of impact - and growing fast.

https://en.wikipedia.org/wiki/Hypermobility_(travel)

I wonder what the emissions from a methane powered suborbital BFR is compared with a 16 hour flight, especially if that methane was generated from CO2 extraction from the air using renewable sources of electricity.

3% of global emissions being due to air travel, when 4/5 of the world population has never set foot in an airplane, is incredibly huge, not quite small. This is an activity almost entirely engaged in by the very wealthy, that has a huge adverse effect on the planet.

Taxing air travel to reduce frivolous trips would be a great policy. Add fast trains between major US cities.

What you say isn't wrong, but when you're asking what the most impactful changes to the current system would be, the absolute climate impact of flying vs. other sources of greenhouse gases needs to be considered.

Which is to say, the world-wide policy priorities need to be on transportation (other than flying), electricity production and industrial emissions [0]. Giving up coal and petrol cars has potentially much greater impact than giving up flying.

That said, when you consider the CO2 emissions that you cause yourself directly, a good rule of thumb is that as soon as you fly at all, CO2 from flying dwarfs all your other CO2 emissions. On the individual level, not flying, flying less, or offsetting carbon emissions from flying has the biggest impact.

[0] https://www.epa.gov/ghgemissions/sources-greenhouse-gas-emis...

I think reducing CO2 emissions from a personal level is the wrong way to go about it. It needs to be addressed from a more higher level, because the majority of CO2 emissions cannot be attributed to a single person.

Take for example shipping, which uses 4.5% of global co2 emissions, yet most people haven't stepped on a ship in their lifetime, and never will!

Quote: "annual emissions from the world's merchant fleet have already reached 1.12bn tonnes of CO2, or nearly 4.5% of all global emissions" https://www.theguardian.com/environment/2008/feb/13/climatec...

Also, note that aircraft are not limited to carrying passengers... They also carry cargo.

Shipping also very often uses the dirtiest of fuels and is therefore much more polluting than airliners which burn quite high quality refined fuels. That's why, to get around recent laws limiting sulfur emissions, large container boats now first "scrub" their exhaust gasses with sea water, so all sulfur will now nicely pollute and acidify our oceans. [0] No emissions though, because emissions bad.

I agree with you wholeheartedly that this is not a problem that should be solved individually. I don't hold my breath for what the higher ups are coming up with though, their measures seem misguided at best, deliberately loop-holed at worst.

[0] http://www.imo.org/en/MediaCentre/HotTopics/Pages/Sulphur-20...

Yes, it's more efficient to concentrate on making one thing better. If you have a limited amount of people. But leaving the flying industry to play freely, the amount of saved environment will just move to the airplanes instead of taking the car. There is nothing that says we all can't do our part in lowering environment cost wherever we work.

Like every time this comes up, there are 7.5 billion humans on the planet and thus no need to only do X or only do Y. We can and must reduce every aspect of our global pollution problem, right now, or it will kill the majority of humanity. We aren't resource-constrained. This isn't a 5-person startup where you have 5 workers and that's it. You can put a million people (if needed) to work on fixing air travel at the same time as you put a million people (if needed) to work on any other aspect of climate change.

All arguments that we shouldn't fix X climate problem because it's less important than Y are just arguments that we shouldn't fix climate problems because the arguer doesn't want them fixed.

No individual actions have any effect at all, and people who argue about them are, again, just distracting from the important work of creating collective solutions.

I take your point, though I'm not sure taxes are the answer. Very rarely is air travel even close to the cheapest option (in the US here, Europe has low cost airlines that may shift the math). Although I'm pretty well off as compared to the average person, I don't know anyone personally who takes the plane purely on a whim, and I know nobody who prefers to fly when another comparable time option is available. If you were to tax air travel at say 10%, that would likely not change my travel, just make it more expensive. A $200 ticket now costing $220 isn't going to make me not take the flight. If you tax it more, sure I won't take the flight, but then you reduce quality of life given that in many places the alternatives don't exist.

In Europe I usually take the train places. If it's 2-3h away by train it's usually faster to take the train, and it's often (though not always) comparable or cheaper on price. In the US, I virtually never take the train, there simply aren't adequate options. The distances tend to be much larger, and we simply haven't built the infrastructure. We could build it, but that's proven quite hard (see CA high speed rail and efforts to modernize northeast corridor) for both political and practical reasons. NY<->DC I often take the bus, it's cheaper and only a slight time penalty vs. the train.

4/5 people sounds like a big number but those people are much more likely to start eating meat or buy a car at first than to fly. That's a way bigger problem environmentally.

In europe, jet fuel isn't taxed at all (but train/car fuel is) which often makes flying the cheaper option. From london, I can fly to several european cities cheaper than I can get a 2 hour train within the UK. Which is pretty ridiculous.

That's wild, agreed that is out of step. I usually book fairly last minute so I haven't seen those prices personally, but I know they exist. I surely don't believe we should favor air over train.

Train fuel is electricity.

A train with 500 seats running London to Manchester costs about £4/mile in electricity, of which 20p will be VAT (which I think is reclaimed) - so tax would be about £35, or 7p per passenger.

A flight of a 150 seat plane from London to Manchester attracts £3900 in tax.

> Train fuel is electricity.

Not in most of the USA (well, it is electric generated from a diesel hybrid). Electrification over large distances is expensive, the only country to have done that so far are the Chinese (and even then they don’t bother with way out Tibet...yet).

The USA is big but not that big. It's about twice as wide as Sweden is tall. Sweden is all electric rail. From the south of Sweden to Rome, is the same distance as Sweden is tall.

All of Sweden's rail is electric and most of Europe's too.

Sweden’s population is confined to a narrow corridor, so it’s not like they need many lines of coverage. Likewise, density in Europe is good enough to make electrification worthwhile, while America is way too spread out. An extreme case would be Australia, imagine electrifying the entire route from Melbourne to Darwin.

This is the quote:

> In europe, jet fuel isn't taxed at all (but train/car fuel is) which often makes flying the cheaper option. From london, I can fly to several european cities cheaper than I can get a 2 hour train within the UK. Which is pretty ridiculous.

Australia and America are irellevent. Almost all long distance trips in Europe is electricity

OP was comparing tax between Germany and the UK, especially on trips from London

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