There's a bunch of other interesting flight path optimization work going on at <a href="https://contrails.org/" rel="nofollow">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.
<a href="https://www.transportenvironment.org/te-asia-pacific/topics/planes/contrails" rel="nofollow">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.
I don't see the claim you describe. That page discusses that daytime contrails have warming and cooling effects, but doesn't appear to take any stance regarding which effect is larger during the daytime.
Other sources claim that daytime contrails have a net cooling effect:
The daytime cooling effect is much smaller than the nighttime warming effect, a total elimination of contrails would be a big improvement, just not as optimal as possible.
thenobsta · · focus · HN ↗
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.
margalabargala · · focus · HN ↗
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.
tgsovlerkhgsel · · focus · HN ↗
margalabargala · · focus · HN ↗
Other sources claim that daytime contrails have a net cooling effect:
<a href="https://acp.copernicus.org/articles/24/6071/2024/" rel="nofollow">https://acp.copernicus.org/articles/24/6071/2024/
<a href="https://www.newscientist.com/article/2449212-jet-contrails-may-cool-the-planet-by-day-and-warm-it-by-night/" rel="nofollow">https://www.newscientist.com/article/2449212-jet-contrails-m...
<a href="https://www.carbon-direct.com/insights/contrails-major-climate-impact-major-opportunity" rel="nofollow">https://www.carbon-direct.com/insights/contrails-major-clima...
The daytime cooling effect is much smaller than the nighttime warming effect, a total elimination of contrails would be a big improvement, just not as optimal as possible.