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.
Which is why work on fixing contrails is so important, it’d be insane to leave 50% improvement at a tiny cost unresolved whilst clawing back small percentage efficiency gains in co2 release from incremental and hideously expensive engine improvements.
We need to do both of course, but contrails should’ve been resolved the moment they were identified as so significant, it’s frustrating how slowly the industry responds to such an enormous opportunity (“we halved our climate impact last year” would be easy marketing)
As long as win there doesn't get used as an excuse to procrastinate on reducing co2. If you asked me I would favor a ban on all non-emergency flying which solves both problems.
<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.
hackernud3s · · focus · HN ↗
ZeroGravitas · · focus · HN ↗
> 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.
hackernud3s · · focus · HN ↗
ZeroGravitas · · focus · HN ↗
For most flights today though, if you only count the CO2 produced you're understanding the climate damage by about half.
hackernud3s · · focus · HN ↗
scratcheee · · focus · HN ↗
We need to do both of course, but contrails should’ve been resolved the moment they were identified as so significant, it’s frustrating how slowly the industry responds to such an enormous opportunity (“we halved our climate impact last year” would be easy marketing)
hackernud3s · · focus · HN ↗
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.