Contrails are mostly water vapour that’s condensed due to the hot exhaust of airplane engines.
They are certainly not completely avoidable, they are likely inescapable without sacrificing significant fuel efficiencies (eg: all methods stealth fighters use to suppress or mask their exhaust heat signature)… which would negate any benefits to global warming.
P. s. I’m not going to watch a YouTube video that could be a few paragraphs of textual explanation, because it’ll no doubt be eight times longer than it needs to be for the benefit of more ad money or promotion in the almighty algorithm.
And maybe people dismiss comments that dont get liked and assume the answer that gets liked is “more correct”. Yes I wish it would work without the likes systemy but in reality 90% of the internet is AI slop and misinformation.
Its not a huge breakthrough in research, mate - its a feasibility study. Its claims are promising, but until its tested in the real world it’s just interesting, not a breakthrough.
Upvotes don’t mean much, they don’t change the ranking of comments like on worse social media like Facebook or Reddit. Don’t worry about them. I’ve seen very useful and valuable comments downvoted to heck and vice-versa.
Its been tested by now, Ive looked into it a little. Seems like 90% of the time contrails form inside clouds and there is no benefit in avoiding them there. So simply avoiding contrails altogether is not recommended, but avoiding the ones forming in a clear sky would be pretty easy and extremely efficient warming-wise.
Upvotes matter in the sense that comments with negative upvotes get dismissed more easily without thinking about them. Less people would watch a video from a comment with -5 votes than one with +100.
I’m not going to watch a YouTube video that could be a few paragraphs of textual explanation, because it’ll no doubt be eight times longer than it needs to be for the benefit of more ad money or promotion in the almighty algorithm.
The linked one is a short video with a duration of 02:37. There’s no padding in this one. Naturally, you can’t actually get all of the nuances of the full-duration video, which also can’t cover the full nuances of the study itself that it’s based on (https://iopscience.iop.org/article/10.1088/2634-4505/ad310c).
Pop science videos making studies accessible to the general public are good, actually. I recommend that you stop being dismissive of them. Had you actually put in the time, you wouldn’t have posted things that are in direct contradiction with the latest science on the subject, spreading misinformation in the process.
I’ve got no interest in watching even 2.5 minute YouTube videos when I can read the text of the same content in 45 seconds. Instructional videos can be great and valuable, but that’s not what we’re talking about here. There are a wealth of crap pop science videos on YouTube that misrepresent studies.
The study is interesting, but it’s a feasibility study data utilizing a theoretical models - there are a lot of assumptions here. If they or other researchers go on to perform trials using their proposed flight adjustments to the autopilot software and validate it works, great! Until then, it’s very far from settled science. Here is another recent study that proposes the main problem is incompletely-burned fuel which causes soot particles that sustain the contrails in the atmosphere for much longer than contrails from low-soot contrails, which quickly diaperse. This is an emerging field of study with few published studies and varying ideas on how to resolve issues.
Maybe if people want to share emerging scientific information that’s important to them on a written forum they should put in the time to look to more valuable text sources, instead of dropping YouTube links with overconfident assertions that will put off people from watching them, eg, “contrails are completely avoidable”.
That YouTube Short seems to be a valid one. It’s by someone who (according to his own words) has a PhD in atmospheric physics. Basically, he says that contrails causes global warming by preventing heat from escaping from Earth, and that contrails are mostly only formed when a plane flies through a cold humid patch. By simply re-routing planes around these cold patches, the contrails could be reduced.
By simply re-routing planes around these cold patches, the contrails could be reduced.
And routes now are generally chosen to be the most fuel-efficient, subject to regulatory constraints such as avoiding overflight of areas of high population density. So any alternate path will be longer and burn more fuel.
According to this one study [1] that focused on Japanese airspace, 2.2% of the flights causes 80% of all contrail energy forcing (EF).
A small-scale strategy of selectively diverting 1.7% of the fleet could reduce the contrail EF by up to 59.3% [52.4, 65.6%], with only a 0.014% [0.010, 0.017%] increase in total fuel consumption and CO2 emissions. A low-risk strategy of diverting flights only if there is no fuel penalty, thereby avoiding additional long-lived CO2 emissions, would reduce contrail EF by 20.0% [17.4, 23.0%].
The re-routing can simply be achieved by changing the flight elevation by 2000 feet one or the other direction.
[1] Teoh, Roger et al. “Mitigating the Climate Forcing of Aircraft Contrails by Small-Scale Diversions and Technology Adoption.” Environmental science & technology vol. 54,5 (2020): 2941-2950. doi:10.1021/acs.est.9b05608
My legit question is then, is the impact on the average temperature by reducing the visible trails greater or less than the impact of adding the emissions from the extra fuel spent.
My gut tells me no, those number seem small, but small numbers often lie, and impacts to the chemical makeup of the atmosphere is an ongoing change whereas a trail of condensation is a short lived phenomenon.
This is not an argument either way, it seems like a legitimate question to me. It’s also not the question that “chemtrails” conspiracy theorists would ask.
Here’s a short answer: For a hundred-year time span, “diverting up to 1.7% of the flights could reduce the total EF by 35.6%. The reduction in total EF is contributed almost entirely by the reduction in contrail EF, while the change in the CO2 EF as a result of a diversion appears to be negligible.”
Long answer:
In that study, they created an algorithm that would divert flights vertically if they are going to create a large contrail, and if diversion is possible (the new airspace isn’t already in use). The algorithm chooses a flight path that has the best total energy forcing (EF). They then applied that algorithm for 6 one-week periods of recorded data. Those weeks were spread around the year.
From “Supporting Information” of that research report (the main text isn’t freely available):
To compare the climate forcing of contrails and CO2 emissions, the absolute global warming potential (AGWP), the time integral of the [radiative forcing] of CO2 over time, is used as a first-order approximation to quantify the CO2 EF and total EF (contrails plus CO2)
Although approximately 25% of the emitted CO2 remains in the atmosphere after a millennium, we applied the 100-year [time horizon] to be in line with the Kyoto Protocol, and assumed that the AGWP is normally distributed in the Monte Carlo simulation
For the six weeks of data, diverting up to 1.7% of the flights could reduce the total EF by 35.6% […]. The reduction in total EF is contributed almost entirely by the reduction in contrail EF, while the change in the CO2 EF as a result of a diversion appears to be negligible.
If an AGWP of a longer [time horizon] of 1000 years […] is used to quantify the EF of CO2, this sensitivity analysis suggest that the overall reduction in the total EF will be significantly smaller at 12.2% […]. In contrast, the total EF could be reduced by up to 50.1% […] if a shorter [time horizon] of 20-years […] is used.
While the potential changes in the global mean surface temperature, quantified using the Absolute Global Temperature Potential (AGTP) are also important, we have refrained from quantifying it because the current level of scientific understanding remains low.
Even when considering a thousand-year time span, diverting the flights still has a positive effect. And we can always play with the idea that mankind figures out a way to remove CO2 from the atmosphere, which would make those numbers for shorter time spans more meaningful.
That’s great info, thanks for the reply, seriously. It’s why I ask the questions and give you my reasons for them.
The part about the chemtrail types is because I have heard all kinds of arguments against them for tinfoil hat reasons. I’m very grateful to get some actual science.
According to him, the contrails have very potent effect on global warming. Apparently, contrails from just one year’s flights has almost the same effect as all the CO2 emitted by all flights ever. Re-routing extends the flight by only so much, so the added CO2 emission has negligible effect.
I’m not saying this is wrong because I don’t know shit but when ships crossing the Atlantic were forced to switch to low sulfur fuel a few years ago the North Atlantic rose in temp a few degrees. Turned out the sulfur in the exhaust was causes clouds to form in the atmosphere and was shading the ocean and masking global warming in that region. Pretty much the opposite effect of what you’re saying this dude is claiming.
Speaking with my limited knowledge, there apparently are cooling contrails and warming contrails, but the warming ones are more common. I don’t know why or when the contrails are cooling or warming.
Contrails are mostly water vapour that’s condensed due to the hot exhaust of airplane engines.
They are certainly not completely avoidable, they are likely inescapable without sacrificing significant fuel efficiencies (eg: all methods stealth fighters use to suppress or mask their exhaust heat signature)… which would negate any benefits to global warming.
P. s. I’m not going to watch a YouTube video that could be a few paragraphs of textual explanation, because it’ll no doubt be eight times longer than it needs to be for the benefit of more ad money or promotion in the almighty algorithm.
Pretty sad that your comment gets so much attention while dismissing a huge breakthrough in research.
Maybe we shouldn’t have to SMASH THAT LIKE BUTTON to have a discussion on the internet, or sit through an ad read for Brilliant or whatever
And maybe people dismiss comments that dont get liked and assume the answer that gets liked is “more correct”. Yes I wish it would work without the likes systemy but in reality 90% of the internet is AI slop and misinformation.
In his defense, the comment didn’t say shit about breakthrough research, it said “watch this”.
Say what you want to say and people won’t dismiss it. Link to something random and who knows.
Well yes, thats why I said “pretty sad” and didnt blame the commenter for it.
You understand Smash that Like button is referring to the video, yeah?
Its not a huge breakthrough in research, mate - its a feasibility study. Its claims are promising, but until its tested in the real world it’s just interesting, not a breakthrough.
Upvotes don’t mean much, they don’t change the ranking of comments like on worse social media like Facebook or Reddit. Don’t worry about them. I’ve seen very useful and valuable comments downvoted to heck and vice-versa.
Its been tested by now, Ive looked into it a little. Seems like 90% of the time contrails form inside clouds and there is no benefit in avoiding them there. So simply avoiding contrails altogether is not recommended, but avoiding the ones forming in a clear sky would be pretty easy and extremely efficient warming-wise.
Upvotes matter in the sense that comments with negative upvotes get dismissed more easily without thinking about them. Less people would watch a video from a comment with -5 votes than one with +100.
The linked one is a short video with a duration of 02:37. There’s no padding in this one. Naturally, you can’t actually get all of the nuances of the full-duration video, which also can’t cover the full nuances of the study itself that it’s based on (https://iopscience.iop.org/article/10.1088/2634-4505/ad310c).
Pop science videos making studies accessible to the general public are good, actually. I recommend that you stop being dismissive of them. Had you actually put in the time, you wouldn’t have posted things that are in direct contradiction with the latest science on the subject, spreading misinformation in the process.
I’ve got no interest in watching even 2.5 minute YouTube videos when I can read the text of the same content in 45 seconds. Instructional videos can be great and valuable, but that’s not what we’re talking about here. There are a wealth of crap pop science videos on YouTube that misrepresent studies.
The study is interesting, but it’s a feasibility study data utilizing a theoretical models - there are a lot of assumptions here. If they or other researchers go on to perform trials using their proposed flight adjustments to the autopilot software and validate it works, great! Until then, it’s very far from settled science. Here is another recent study that proposes the main problem is incompletely-burned fuel which causes soot particles that sustain the contrails in the atmosphere for much longer than contrails from low-soot contrails, which quickly diaperse. This is an emerging field of study with few published studies and varying ideas on how to resolve issues.
Maybe if people want to share emerging scientific information that’s important to them on a written forum they should put in the time to look to more valuable text sources, instead of dropping YouTube links with overconfident assertions that will put off people from watching them, eg, “contrails are completely avoidable”.
Well said
That YouTube Short seems to be a valid one. It’s by someone who (according to his own words) has a PhD in atmospheric physics. Basically, he says that contrails causes global warming by preventing heat from escaping from Earth, and that contrails are mostly only formed when a plane flies through a cold humid patch. By simply re-routing planes around these cold patches, the contrails could be reduced.
And routes now are generally chosen to be the most fuel-efficient, subject to regulatory constraints such as avoiding overflight of areas of high population density. So any alternate path will be longer and burn more fuel.
According to this one study [1] that focused on Japanese airspace, 2.2% of the flights causes 80% of all contrail energy forcing (EF).
The re-routing can simply be achieved by changing the flight elevation by 2000 feet one or the other direction.
[1] Teoh, Roger et al. “Mitigating the Climate Forcing of Aircraft Contrails by Small-Scale Diversions and Technology Adoption.” Environmental science & technology vol. 54,5 (2020): 2941-2950. doi:10.1021/acs.est.9b05608
My legit question is then, is the impact on the average temperature by reducing the visible trails greater or less than the impact of adding the emissions from the extra fuel spent.
My gut tells me no, those number seem small, but small numbers often lie, and impacts to the chemical makeup of the atmosphere is an ongoing change whereas a trail of condensation is a short lived phenomenon.
This is not an argument either way, it seems like a legitimate question to me. It’s also not the question that “chemtrails” conspiracy theorists would ask.
Here’s a short answer: For a hundred-year time span, “diverting up to 1.7% of the flights could reduce the total EF by 35.6%. The reduction in total EF is contributed almost entirely by the reduction in contrail EF, while the change in the CO2 EF as a result of a diversion appears to be negligible.”
Long answer:
In that study, they created an algorithm that would divert flights vertically if they are going to create a large contrail, and if diversion is possible (the new airspace isn’t already in use). The algorithm chooses a flight path that has the best total energy forcing (EF). They then applied that algorithm for 6 one-week periods of recorded data. Those weeks were spread around the year.
From “Supporting Information” of that research report (the main text isn’t freely available):
Even when considering a thousand-year time span, diverting the flights still has a positive effect. And we can always play with the idea that mankind figures out a way to remove CO2 from the atmosphere, which would make those numbers for shorter time spans more meaningful.
That’s great info, thanks for the reply, seriously. It’s why I ask the questions and give you my reasons for them.
The part about the chemtrail types is because I have heard all kinds of arguments against them for tinfoil hat reasons. I’m very grateful to get some actual science.
Wouldn’t rerouting be more fuel-intensive in most scenarios, though? I feel like burning more fuel to make fewer clouds isn’t the right play.
It would require a slight increase in fuel consumption, traded off with a large decrease in heating caused by the water vapour.
Seriously, you should watch the video, it covers all of this stuff.
According to him, the contrails have very potent effect on global warming. Apparently, contrails from just one year’s flights has almost the same effect as all the CO2 emitted by all flights ever. Re-routing extends the flight by only so much, so the added CO2 emission has negligible effect.
Good luck with the Florida and California flights.
I’m not saying this is wrong because I don’t know shit but when ships crossing the Atlantic were forced to switch to low sulfur fuel a few years ago the North Atlantic rose in temp a few degrees. Turned out the sulfur in the exhaust was causes clouds to form in the atmosphere and was shading the ocean and masking global warming in that region. Pretty much the opposite effect of what you’re saying this dude is claiming.
Speaking with my limited knowledge, there apparently are cooling contrails and warming contrails, but the warming ones are more common. I don’t know why or when the contrails are cooling or warming.