Re: Next steps towards a net zero IETF

[Christian Huitema <[e-mail]>]

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.

-- Christian Huitema