"Why aren’t we doing more to eliminate contrails?"
I'm just having a hard time groking that contrails are really that impacting. TFA just quotes a bunch of numbers, but does not actually discuss how the numbers were derived. Maybe I've just been around too many people into Chemtrails, but this just reads to me as an offshoot of that type of thinking.
Real chemtrails are already invisible. When you see a contrail it's because the jet engines have been poorly maintained to cut costs and increase quarterly returns to the shareholders.
This is something the military, e.g. fighter jets worry about. The altitudes (in a given airspace) that form contrails are briefed as part of "tactical weather". You try to avoid them if able, because no matter how stealthy you are, you are lit up for all to see if you fly at those altitudes.
Given that the warming impacts of contrails are short-lived (roughly a day), I think it is a good idea to do research now on the weather forecasting needed to avoid producing contrails. But I don't really see a reason to actually start avoiding them now, with the associated costs in terms of fuel, CO2 emissions, and time. We can start avoiding them in a few decades when it might have become urgent to have cooling.
There was a really good section of the article that went into great detail of the math and how it would easily outweigh the CO2. How it would only require something like diverting 2% of all flights as it is only that percentage of flights that make the majority of the contrails and that the diversion of the average flight would be something small like an extra 2 minutes flight time for shorter flights and like 6 minutes on a longer flight which the article states is not much increase in fuel consumption as well as not such a time increase to dissatisfy customers. So if the article is accurate in their math then the associated costs in all three fuel, CO2, and time are not an issue.
The article mentions that some flights produce a net cooling effect. I wonder if it could be cost effective to divert flights toward contrail formation when it's predicted that they'll produce cooling (I also wonder what the actual circumstances are when they produce cooling--low surface temperatures, maybe?).
Did I miss the part of the article stating what percentage of all effects this would have? Like if it moves the needle 0.000001% is it worth the effort? Not to play whatabouttism, but the top 8 countries after China (US through Germany) together emit about the same amount of CO2 as China alone. Not saying we shouldn't improve where we can, as the sum of many small efforts helps the whole.
Somehow telling airlines to fly what might
be quite a bit longer, in order to avoid
all the different contrail potenial spot,
that will use even more fuel
migth nto be a popoular sell?
Due to the current war airplanes from Northern Europe to Asia are already re-routed, increasing travel time from Helsinki to Japan, for example, from previously some 9.5 hours to up to 13.5 hours.
N2O (laughing gas) is not combustible, but autodecomposes into a mixture composed of 1 part oxygen gas and 2 parts nitrogen gas, which happens to be the approximate composition of the atmosphere.
In theory we could design and use N2O engines and airplanes etc, and their exhaust could be a gas that is nearly equivalent to atmospheric composition.
One important issue is making sure all the N2O has decomposed because it is a very potent GHG.
Would N2 and O2 create contrails? in what sense is it distinct from atmosphere?
The claims they are making seem slightly at odds with the (I thought well-established) claims that jet emissions cause measurable global “dimming”: that is, that the pollutants reflect enough sunlight that it is accidentally retarding global warming, supporting the concern that necessarily cleaning up our air will briefly accelerate global warming itself. Are they? Or is it also a double whammy?
This was seen to be evident in global pan evaporation measurements after the essentially global flight travel bans in the few days after 9/11; I have often wondered whether the equivalent restrictions in the early days of the pandemic show it as clearly because the impacts on pollution were very striking.
There are a lot of comments here mocking “chemtrail” believers, but I think the confusion is understandable. There seems to be a mix-up between three terms: contrails, chemtrails, and cloud seeding.
Contrails are just condensation trails caused by jet exhaust and air pressure differences at high altitude.
Cloud seeding, on the other hand, is a real weather-modification technique that uses aircraft to disperse substances like silver iodide to encourage rainfall [1]
I completely empathize with people confused by this. They aren't all just a bunch of conspiracy nuts, many just don’t know how to identify what they’re seeing or how these technologies actually work. I don’t mock them, I try to educate.
I'm so confused. This article is explaining that eliminating contrails would have a significant effect on warming.
But contrails are just the tiniest, tiniest fraction of the sky somewhere and only last over a given area for a few minutes generally. Like, sure, if you live next to a busy airport maybe you see them more often, but that's balanced out by the 99.9% of sky not next to a busy airport. Plus the many days that they just don't show up at all, because they depend on certain weather conditions.
I mean, this just doesn't pass the smell test.
But Wikipedia has an entire section [1] full of citations. But then... it sounds like maybe a lot of them aren't credible or suggest that it's not a problem? E.g.:
> However, follow-up studies found that a natural change in cloud cover can more than explain these findings. The authors of a 2008 study wrote, "The variations in high cloud cover, including contrails and contrail-induced cirrus clouds, contribute weakly to the changes in the diurnal temperature range, which is governed primarily by lower altitude clouds, winds, and humidity."
> Then, the global response to the 2020 coronavirus pandemic led to a reduction in global air traffic of nearly 70% relative to 2019. Thus, it provided an extended opportunity to study the impact of contrails on regional and global temperature. Multiple studies found "no significant response of diurnal surface air temperature range" as the result of contrail changes, and either "no net significant global ERF" (effective radiative forcing) or a very small warming effect.
So it sounds like this theoretical contrail warming problem possibly doesn't exist? I find it strange the article doesn't even acknowledge any discussion over whether it's actually a problem in the first place.
So hard to get done though. Needs global cooperation. The overlap with chemtrails and climate change means Trump might hate it on vibes and ban this correction for US airlines.
Airlines are on wafer thin margins and for the longer turnaround times affecting schedules wont love it. The fact that it is a small % is worse: if you get hit you become less competitive!
Pilots workload is increased too.
Its a great technical idea but not sure how you'd get it off the ground.
In an alternative timeline with a carbon price it may work. You get x$ carbon credits for a detour. Let the planes decide if they want it.
Ah, yes, the solution is to pay someone to do something . An extra 3.50 euro pet flight/passenger to avoid extra contrails, genius money making machine.
34 comments
[ 2.9 ms ] story [ 73.3 ms ] threadI'm just having a hard time groking that contrails are really that impacting. TFA just quotes a bunch of numbers, but does not actually discuss how the numbers were derived. Maybe I've just been around too many people into Chemtrails, but this just reads to me as an offshoot of that type of thinking.
https://news.ycombinator.com/item?id=37060347
Furthermore https://duckduckgo.com/q=toxicologic+assessment+of+jet+fuel
and https://en.wikipedia.org/wiki/Fume_event
Are the fumes less bad, when they don't leak into the cabin by bleed air, just blown away backwards?
The solution to pollution is dilution (in the atmosphere)? With the current amount of global air traffic, no matter if civilian, or military?
In theory we could design and use N2O engines and airplanes etc, and their exhaust could be a gas that is nearly equivalent to atmospheric composition.
One important issue is making sure all the N2O has decomposed because it is a very potent GHG.
Would N2 and O2 create contrails? in what sense is it distinct from atmosphere?
This was seen to be evident in global pan evaporation measurements after the essentially global flight travel bans in the few days after 9/11; I have often wondered whether the equivalent restrictions in the early days of the pandemic show it as clearly because the impacts on pollution were very striking.
Contrails are just condensation trails caused by jet exhaust and air pressure differences at high altitude.
Cloud seeding, on the other hand, is a real weather-modification technique that uses aircraft to disperse substances like silver iodide to encourage rainfall [1]
I completely empathize with people confused by this. They aren't all just a bunch of conspiracy nuts, many just don’t know how to identify what they’re seeing or how these technologies actually work. I don’t mock them, I try to educate.
[1]: https://en.wikipedia.org/wiki/Cloud_seeding
But contrails are just the tiniest, tiniest fraction of the sky somewhere and only last over a given area for a few minutes generally. Like, sure, if you live next to a busy airport maybe you see them more often, but that's balanced out by the 99.9% of sky not next to a busy airport. Plus the many days that they just don't show up at all, because they depend on certain weather conditions.
I mean, this just doesn't pass the smell test.
But Wikipedia has an entire section [1] full of citations. But then... it sounds like maybe a lot of them aren't credible or suggest that it's not a problem? E.g.:
> However, follow-up studies found that a natural change in cloud cover can more than explain these findings. The authors of a 2008 study wrote, "The variations in high cloud cover, including contrails and contrail-induced cirrus clouds, contribute weakly to the changes in the diurnal temperature range, which is governed primarily by lower altitude clouds, winds, and humidity."
> Then, the global response to the 2020 coronavirus pandemic led to a reduction in global air traffic of nearly 70% relative to 2019. Thus, it provided an extended opportunity to study the impact of contrails on regional and global temperature. Multiple studies found "no significant response of diurnal surface air temperature range" as the result of contrail changes, and either "no net significant global ERF" (effective radiative forcing) or a very small warming effect.
So it sounds like this theoretical contrail warming problem possibly doesn't exist? I find it strange the article doesn't even acknowledge any discussion over whether it's actually a problem in the first place.
[1] https://en.wikipedia.org/wiki/Contrail#Impacts_on_climate
Then learned it’s just about rerouting a flight to climate zones that will less likely form a vapor trail.
Airlines are on wafer thin margins and for the longer turnaround times affecting schedules wont love it. The fact that it is a small % is worse: if you get hit you become less competitive!
Pilots workload is increased too.
Its a great technical idea but not sure how you'd get it off the ground.
In an alternative timeline with a carbon price it may work. You get x$ carbon credits for a detour. Let the planes decide if they want it.
I wonder if factoring in the contrail reduction of this tilts them towards financial breakeven.
edit: Googled it and an Airbus test last year suggested a 25% decrease in contrail formation:
https://www.airbus.com/en/newsroom/press-releases/2024-06-wo...