[superqwert]

You're claiming the argument is wrong, then supporting it again.

The person(s) who go over or under the threshold are the ones that make a difference. If thresholds aren't breached by the amount of people changing route, then there is not a very significant difference.

As you indeed state:

"but you can still very much say the climate footprint of each passenger is (total plane print/passengers)"

You can indeed say as much, but "this is oversimplified".

Just to be clear - I am not arguing that we should not pick routes responsibly, with the environment in mind. I am merely trying to ensure we are clearer about what impacts we are actually making and that we are considering all the impacts and not just doing a simple calculation that actually misses out the many complexities of transport.

[blackbrokkoli]

So, you're arguing that the straw that broke the camels back is the only straw that matters at all?

[superqwert]

In transport, we have learnt over the past century to not use aggregate models, as they do not provide the same detail and results as disaggregate models[p.18 Modelling Transport 4th Edition Ortuzar & Willumsen]. We should not lower our standards when discussing emissions and pollution.

This article above is a very worrying case - where the reader is encouraged to shame people for flying, without showing necessary statistics as to whether flying is indeed much worse than other transportation methods.

[superqwert]

No, I'm arguing that the calculations for emission per person are simplistic.