There's a bunch of other interesting flight path optimization work going on at https://contrails.org/.
It turns out contrails contribute to 2% of global warming power and is relatively easily avoided. The cost might be a bit more fuel consumption though.
Fun fact, contrails contribute to global warming, but only at night.
During the day they have a cooling effect by reflecting/blocking some light.
The optimal is not to eliminate them entirely, but to create them only early in the day so that they dissipate by sunset.
https://www.transportenvironment.org/te-asia-pacific/topics/... acknowledges the difference between day and night but claims that the sum of the effects still results in net warming during the day.
The fuel consumption feels like the bigger problem since contrails last for hours vs co2 that lasts damn near forever.
They are roughly equal problems at the moment.
> Recent estimates show that contrails cause about the same amount of warming each year as all the CO₂ emitted by all flights from 1940 to 2018.
If we're measuring in terms of difficulty, CO2 is a much bigger problem than contrails.
Yes, contrails appears to be mostly solvable at a small cost in time and fuel and people have started to take action on that.
For most flights today though, if you only count the CO2 produced you're understanding the climate damage by about half.
It's one way to look at it I guess. CO2 is still the half of the damage that's way harder to fix.