[samuelbalogh]

> With no corresponding change to the amount of fuel used to climb up to cruising altitude

Yes, but

1) a plane flying a larger distance has to lift a heavier load of fuel

2) emissions tend to do more damage at high altitude than they do at ground level

so I would not discount the benefits of reducing flight distance as much as possible.

Source: How Bad Are Bananas? by Mike Berners Lee

[conqueso]

>emissions tend to do more damage at high altitude than they do at ground level

I've always been a bit dismissive of aviation as a carbon emissions contributor because globally it only accounts for around 2%. Thanks for pointing this out, I was unaware of this fact. Is the relationship between altitude and warming effect known? Are we talking linear or something worse?

[geewee]

I think we're still puzzling it out, as there's both radiative forcing and contrails (the vapor, or condensation trails planes emit).

If you check out these two emission factors from the UK government, one taking radiative forcing and contrails into effect and one not:

https://www.climatiq.io/explorer/emission-factor/domestic-fl...

https://www.climatiq.io/explorer/emission-factor/domestic-fl...

You'll see a noticeable difference, (almost a doubling)

Full disclaimer: Work at Climatiq, but the emission factors are not from us directly.

[conqueso]

Appreciate the detailed answer - I was unaware that contrails were significant. TIL!

[geewee]

You're welcome!

[michaelgrafl]

2% is plenty anyway. I mean, we have to start somewhere.