Re: Next steps towards a net zero IETF

[Hesham ElBakoury <[e-mail]>]

Companies are lookinto building electric flights. For example, hundreds of
them are building *eVTOLs*: electric vertical take-off and landing
vehicles. It’s a horrible acronym for small aircraft that take off and land
like a helicopter and fly like a plane.

I do not know when we will have an electric plane that travel from San
Francisco or Europe to Japan?

Hesham


On Thu, Mar 30, 2023, 10:31 PM Alexander Pelov <[e-mail]> wrote:

> Dear all,
>
> Indeed "proportional" doesn't exclude a constant (Ax+B) - and the size of
> that constant compared to the rest should also be taken into account.
>
> But I'm all for looking at the real world and see the real impact - don't
> care too much for abstract gains.
>
> I found an interesting paper dealing with the Marginal Fuel Burn per kg
> transported over 1000 km.
>
> "The opposite is also true: a reduction in weight
> by one kg saves ~ 0.02 to 0.03 kg of fuel per
> 1’000 km"
>
>    -
>    https://digitalcollection.zhaw.ch/bitstream/11475/1896/6/Steinegger_Fuel_Economy_as_a_Function_of_Weight_and_Distance_v1-1.pdf
>    <https://www.google.com/url?sa=i&source=web&cd=&ved=0CAMQw7AJahcKEwiQyoGCs4X-AhUAAAAAHQAAAAAQBg&url=https%3A%2F%2Fdigitalcollection.zhaw.ch%2Fbitstream%2F11475%2F1896%2F6%2FSteinegger_Fuel_Economy_as_a_Function_of_Weight_and_Distance_v1-1.pdf&psig=AOvVaw3mCu1q0ldGS6ji1maTqhKc&ust=1680325649308692>
>
>
>
> From what I found, a kg of kerosene is 1.22 liters and produces 3kg of CO2
> on average.
> https://www.engineeringtoolbox.com/co2-emission-fuels-d_1085.html
>
> Transporting a 100kg weight over 1000km then produces 60kg-90kg CO2
> emissions.
> For a round-trip Paris-Yokohama (9731km) that would be 1.2t-1.7t of CO2
> per person. (And use 0.95t-1.4t of kerosene)
>
>
>
> Worldwide, the average person produces about *four tons of carbon dioxide
> each year*.
> To have the best chance of avoiding a 2℃ rise in global temperatures, the
> average global carbon footprint per year needs to drop to under 2 tons by
> 2050.
>
>
>
> https://www.nature.org/en-us/get-involved/how-to-help/carbon-footprint-calculator/#:~:text=The%20average%20carbon%20footprint%20for,is%20closer%20to%204%20tons
> .
>
> So yeah, it turns out that the personal contribution - even if the planes
> are flying- is not negligible (at least for me).
>
> The IETF at the scale of the global population is of course not going to
> change much.
>
> But now I see the point that IETF's impact is NOT net zero if we do
> nothing about it (as I initially assumed).
>
> Cheers,
> Alexander
>
>
>
>
>
> Le mer. 29 mars 2023, 14:02, Andrew McConachie <[e-mail]> a
> écrit :
>
>>
>>
>> On 25 Mar 2023, at 16:37, Christian Huitema wrote:
>>
>> > On 3/25/2023 5:36 AM, Julian Reschke wrote:
>> >> On 25.03.2023 11:48, Andrew McConachie wrote:
>> >>> ...
>> >>> Trains and planes are fundamentally different in this regard,
>> >>> because
>> >>> planes calculate their weight at takeoff and only take as much fuel
>> >>> as
>> >>> they need. The amount of CO2 produced by a passenger plane is
>> >>> directly
>> >>> proportional to how many passengers it’s carrying.
>> >>> ...
>> >>
>> >> So a passenger plane not carrying any passengers is not producing any
>> >> CO2?
>> >
>> > I think Andrew erred when he said "directly proportional". As in many
>> > things, you can probably separate fixed costs and variable costs.
>> > There is a fixed cost to carrying the whole weight of the empty plane
>> > and the crew through the sky. There is also a variable cost based on
>> > the load of the plane, which for a passenger plane means the weight of
>> > passengers and their luggage. So yes, an additional passenger directly
>> > increases the fuel consumption of the plane -- but less so than if too
>> > few passengers lead the airline to fly fewer planes. And the "fewer
>> > plane" effect is entirely comparable to the "fewer trains" effect.
>> >
>>
>> Your first sentence is correct. I erred in claiming direct
>> proportionality. My point is that a plane carrying more people uses more
>> fuel and thus produces more CO2. This is much less true for trains.
>>
>> There are more direct consequences of individuals choosing to fly simply
>> because weight added to an airplane has a much greater effect on energy
>> consumption than weight added to a train. Things like luggage and
>> airplane meals add weight, which requires more fuel, which then requires
>> even more fuel. So there are direct consequences with actually boarding
>> an airplane more so than with trains.
>>
>> Whether or not reducing the number of overall passengers has the same
>> effect on planes as it does on trains is a really complicated and
>> difficult question to answer. You get into stuff like futures pricing of
>> jet fuel and regulations governing rescheduling practices, etc. I
>> don’t think anyone on this list is qualified enough to answer this
>> question.
>>
>> —Andrew
>>
>>