Comment by 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