10 ms·
Eliminating contrails from flying could be cheap
- pavel_lishin 1y agoI had no idea contrails actually caused that much warming, compared to the exhaust.
- Nzen 1y agoLikewise. In fact, I was under the opposite impression because of the benefit that sulfur enriched shipping exhaust had for our climate [0]. It looks like these clouds are thinner and don't have the same impact as that, though. While I felt that the featured article linked to their favorite site aggressively (four links to contrails.org), it looks like the google site is legitimate [1]. I couldn't find a recent [2] paper on NoAA about contrails, but presumably others have studied it. [0] https://cpo.noaa.gov/the-unintended-consequences-of-reducing-sulfur-emissions-from-ships/ https://cpo.noaa.gov/the-unintended-consequences-of-reducing... [1] https://sites.research.google/gr/contrails/ https://sites.research.google/gr/contrails/ [2] https://csl.noaa.gov/news/2011/101_0714.html https://csl.noaa.gov/news/2011/101_0714.html
- counters 1y ago> In fact, I was under the opposite impression because of the benefit that sulfur enriched shipping exhaust had for our climate. It isn't quite accurate to state that ship tracks have/had a "benefit" on our climate. Their existence creates a transient decrease in OLR and increase in albedo. If anything, they simply masked some GHG-induced warming that had a much longer half-time, and cleaning up ship emissions has "unmasked" some of that hidden warming. But, again, the warming was already committed.
- baggy_trough 1y agoThe benefit was that they cooled the climate.
- jagged-chisel 1y agoHow much will it cost in fuel (additional miles) and time (flyers’ lives) to reroute?
- deleted 1y ago[deleted]
- steanne 1y ago> The proposed detours typically result in a 1% shift (and again, this is only for a small percentage of flights). That means increasing fuel use and flight time by around 1%. So if your flight is three hours long, it’s only adding an extra two minutes. For a 10-hour flight, six minutes. This seems socially acceptable to me; most people would barely notice.
- SoftTalker 1y agoAirlines will certainly notice a 1% fuel cost increase however. But, they'll just add it to ticket prices.
- mulmen 1y agoIt’s not a 1% increase in fuel costs. It’s 1% of 3% (for 80% mitigation) to 17% (for total mitigation). That’s a 0.03% to 0.17% increase in fuel costs.
- andrewflnr 1y agoThey'll all need to do it at once though, or people will just pick the cheaper flight that doesn't go around the contrail-forming region, basically every time. Of course it's a coordination problem. It probably needs to be a regulation before it will actually happen.
- actionfromafar 1y ago1% less fuel will not be 1% less ticket cost, but something much less.
- dylan604 1y ago"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.
- burkaman 1y agoIt links to this post which has a little more technical explanation: https://notebook.contrails.org/comparing-contrails-and-co2/ https://notebook.contrails.org/comparing-contrails-and-co2/ And also this paper which is a very in-depth technical explanation: https://www.sciencedirect.com/science/article/pii/S1352231020305689 https://www.sciencedirect.com/science/article/pii/S135223102... I understand why you're reminded of chemtrails, but it is not crazy or conspiratorial to look at these giant lines in the sky and think "those things must be doing something". You can't then make the leap to "it's intentional and it's a biological weapon to control my mind and I don't need any evidence to believe this", but you can take the next step of looking into decades of research on the topic and deciding if the conclusions make sense to you.
- dylan604 1y agoWhere I'm from, contrails are so small and irrelevant compared to the giant cumulonimbus clouds that form in the high heat and humidity. It's like tears in the rain in comparison.
- burkaman 1y agoI don't know what to tell you, they are not irrelevant even if they visually look irrelevant from where you are. Small things can have a big impact, CO2 is only ~0.04% of the atmosphere (compared to the ideal level of ~0.03%) and it's causing us major problems.
- pixl97 1y agoRight there is local climate too that has different effects. Imagine a large city in an area that is always cloudy versus one in a sunny desert. They are both the same size, but the one in the desert is going to have an absolutely massive amount of evening heat release due to the urban heatsink effect.
- anigbrowl 1y agoIt'd be worth it just to shut the chemtrail nuts up.
- blipvert 1y agoYou don’t understand conspiracy loon logic. By the very act of hiding the chemtrails you are demonstrating that you are doing something nefarious.
- ryandrake 1y agoPlus, the invisibility of a thing does not stop the conspiracy loons from building conspiracies around it. 5G RF is invisible, yet still being used by the government to control our brains. For chemtrails, the conspiracy is just going to turn into: "They're spraying invisible chemicals all over us to turn us into communists." There's no end to it.
- cousinbryce 1y ago[flagged]
- tbrownaw 1y ago> 5G RF is invisible, yet still being used by the government to control our brains. Well it's one of the main last-mile mediums people use to doomscroll their propaganda feeds, so... yes?
- solid_fuel 1y agoIt's funny how often the conspiracy types are both right and wrong. We have precision targeted ~~propaganda~~ content streaming straight to the tracking device everyone willingly carries, but they land on 5G being some sci-fi form of mind control. It's some form of motivated reasoning. The same people who will tell you a secret cabal of billionaires controls the government will roll their eyes if you bring up the heritage foundation.
- huvarda 1y ago[flagged]
- pfannkuchen 1y agoIt’s funny to me that those people are all essentially a pessimistic flavor of homeopath (in the small quantities can have an effect sense).
- phoehne 1y agoNow they're hiding the chemtrails. It's even worse!
- xnx 1y agoVery briefly mentioned in the article, but Google worked on this years earlier: https://sites.research.google/gr/contrails/ https://sites.research.google/gr/contrails/ https://news.ycombinator.com/item?id=37060347 https://news.ycombinator.com/item?id=37060347
- imgabe 1y agoIf the incoming radiation can pass through, why can't it pass through on the way out?
- cvoss 1y agoThe radiation on the way in has a different frequency than on the way out. For example, there is UV included in sunlight. But black body heat at Earth's temperature radiates in infrared. Clouds are very opaque to infrared, and more (though not completely) transparent to UV.
- jcims 1y agoThis is the actual answer. The clouds aren't differentially reflecting sunlight into and out of the atmosphere, they are reflecting the black body radiation emitted by the earth.
- vamin 1y agoBecause it comes in at a different frequency versus when it goes out. Light, including UV and visible light, hits the ground, then the ground gets warm and radiates in the IR, which can be blocked by clouds.
- burkaman 1y agoGreenhouse gases only interact with specific wavelengths of light. A lot of sunlight comes in as visible or ultraviolet light, mostly passing through those gases. It hits the surface of the Earth and is absorbed and then re-emitted as infrared light, and a lot of that is just the right wavelength for greenhouse gases to interfere. Here's a good article about the physics of this: https://www.quantamagazine.org/the-quantum-mechanics-of-greenhouse-gases-20250915/ https://www.quantamagazine.org/the-quantum-mechanics-of-gree...
- justonceokay 1y agoSingle particles of radiation coming from the sun have higher energy than single particles radiating from the earth. Even though the total energy entering and leaving earth is at a near equilibrium. My mental model is that a bullet leaving the barrel of a gun has much more penetrative power than that same bullet once it has ricocheted off a concrete wall.
- squokko 1y agoI can't imagine that contrails are a significant percentage of cloud cover.
- infradig 1y agoLess than 1% globally, so you're right.
- deleted 1y ago[deleted]
- smakt 1y agoThis is bullshit. How can anyone pretend the radiation reflecting from it is significant? How wide are these things? 20 meters?
- stevage 1y agoThere are a lot of them.
- ceigey 1y agoThat’s narrower than a Boeing 737’s wingspan, and when you look at planes leaving a trail behind them, you can often see the trail fan out much wider than the plane. Not sure how wide that would be, but the length has to be factored in too, which begs the question, how wide and long is a piece of string/cloud? On the ground looking up the sense of scale falls apart a bit.
- stevage 1y agoThis is the terrible argument that leads so many countries to do nothing to reduce their emissions. Each country is a small portion of the total so they all do nothing.
- the__alchemist 1y agoThis 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.
- aerostable_slug 1y agoFun fact: the B-2 bomber has a LIDAR-based contrail detection sensor, called the Pilot Alert System. https://tridsys.com/our-divisions/optical-precision-sensors/ https://tridsys.com/our-divisions/optical-precision-sensors/
- Den_VR 1y agoThere’s always been something disturbing about public internet advertisements of military equipment. I suppose it’s dual use, but it seems like baiting a malicious actor to play with it in detail.
- Agree2468 1y agoIf you're ever in DC, you should check out the ads in the metro stops near the Pentagon. Seeing those kinds of ads in real life is even more shocking.
- Retric 1y agoWalked into a weapons show a few decades ago that had a full scale Abrams tank + demo camera providing good 360 degree visibility. It was odd because I was like yea this is obviously a good idea, but also I’m not the person you need to convince here so WTF.
- kiba 1y agoIt's designed to convince their customers which are other countries.
- DominikPeters 1y agoGiven 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.
- evnp 1y agoAren't the impacts perpetual if we're creating new contrails every single day? Taken from another comment, this seems pretty clear: > Contrail cirrus may be air traffic's largest radiative forcing component, larger than all CO2 accumulated from aviation, and could triple from a 2006 baseline to 160–180 mW/m2 by 2050 without intervention. [1] https://en.wikipedia.org/wiki/Contrail#Impacts_on_climate https://en.wikipedia.org/wiki/Contrail#Impacts_on_climate The original article describes associated costs in time and fuel usage in the realm of 1% increase.
- stevage 1y agoIt is already urgent.
- 1y ago
- SyzygyRhythm 1y agoThe 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?).
- stevage 1y agoPerhaps also early morning flights where most of the contrail's lifespan will be in sun.
- exabrial 1y agoDid 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.
- Oarch 1y agoI'm wondering if I missed this too. The percentage of the sky covered in contrails must be... absolutely minimal? If it was even 1% we'd surely be up in arms about how awful it looked.
- maltyr 1y ago> How, then, do contrails stack up in terms of total warming? They contribute roughly 2% to the world’s effective radiative forcing; tackling them would reduce that by a similar amount.
- exabrial 1y agoThanks, that is quite signficant
- deleted 1y ago[deleted]
- bitwize 1y agoBut then how would the government disperse mind-control chemicals over the public?
- NedF 1y ago[flagged]
- stevage 1y agoThe article addresses this and contradicts you, with scientific papers.
- sfink 1y agoThe article claims that the warming effect from bouncing heat back down is overall larger than the cooling effect from bouncing heat back up. If you disagree with this assertion, you'll need to say why, not just call someone a liar. The article does agree that 9% of contrails have an overall cooling effect, and perhaps that could be magnified by a larger or more persistent contrail.
- lmm 1y ago> The article claims that the warming effect from bouncing heat back down is overall larger than the cooling effect from bouncing heat back up. If you disagree with this assertion, you'll need to say why I'm not sure they do. It's an extremely counterintuitive claim that would need to be justified, and while the author does cite (their own) paper, it sounds like the model they came up with is highly parameterised and not particularly physically validated. If it's really the case that contrails reflect more heat down than up (unlike what the scientific consensus says is true for regular clouds), then there should be an explanation for what contrail-specific factor causes this, not just "here's a pile of math equations that say it doesn't, don't ask where we got the parameters to fill them out from".
- sfink 1y agoI'm not going to argue the point, I'm no climate scientist. But Wikipedia https://en.wikipedia.org/wiki/Contrail https://en.wikipedia.org/wiki/Contrail disagrees with you as well, so you'd need to argue with their sources too. "In general, aircraft contrails trap outgoing longwave radiation emitted by the Earth and atmosphere more than they reflect incoming solar radiation, resulting in a net increase in radiative forcing." Shiny bright light goes through or gets scattered. Dull red blackbody radiation gets absorbed. Doesn't sound too counterintuitive to me, but again I'm no expert.
- huflungdung 1y ago[dead]
- ThinkBeat 1y agoSomehow 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?
- fragmede 1y agofrom up thread, Google told American airlines exactly that https://sites.research.google/gr/contrails/ https://sites.research.google/gr/contrails/
- Tor3 1y agoDue 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.
- DoctorOetker 1y agoN2O (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?
- cyberax 1y agoN2O formation enthalpy is just 82kJ/mol. For comparison, water is 240kJ/mol. It doesn't sound so bad, but when translated into grams, it's 1.86kJ/g for N2O and 13.3kJ/g for water. In other words, when burning a gram of hydrogen, you get about 120kJ of energy. When decomposing a gram of N2O, you barely get 2kJ.
- klodolph 1y agoSomeone can break out their chemistry references, but I think N₂O is probably not workable as a fuel (or at best, not very good). It forms naturally in internal combustion engines, from air, at the temperature and pressures found in engines, given O₂ and N₂. If something has the habit of forming in an engine, I don’t think you could use it as fuel, but my thermodynamics is a bit too rusty to do any kind of ELI5 and I could just be wrong here. At the very least, it would be difficult to use or inefficient. It decomposes into N₂ and O₂ at normal atmospheric temperatures and pressures, outside an engine.
- deleted 1y ago[deleted]
- exasperaited 1y agoThe 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.
- dustfinger 1y agoThere 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. [1]: https://en.wikipedia.org/wiki/Cloud_seeding https://en.wikipedia.org/wiki/Cloud_seeding
- greekrich92 1y agoThe chemtrails conspiracy nuts aren't confused about cloud seeding. They believe contrails are visible evidence that airplanes are used to disperse mind control drugs over the populations below.
- dustfinger 1y agoThere are many people that believe the contrails, that they refer to as chemtrails, are about weather control. Those are the people that I think are confused. Just search "chemtrails weather control" or "manipulation". I have also spoken to many people that hold this belief. Also, read the wikipedia on chemtrails: https://en.wikipedia.org/wiki/Chemtrail_conspiracy_theory https://en.wikipedia.org/wiki/Chemtrail_conspiracy_theory
- crazygringo 1y agoI'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. [1] https://en.wikipedia.org/wiki/Contrail#Impacts_on_climate https://en.wikipedia.org/wiki/Contrail#Impacts_on_climate
- dingaling 1y ago> But contrails are just the tiniest > tiniest fraction of the sky somewhere Initially yes, but as a contrail diffuses it acts like a seed for wider cirrus cloud formation. During COVID lockdown, researchers at Universität Leipzig found that the reduction of air travel correspondingly reduced cirrus formation by 9% in the area studied.
- Theodores 1y agoCheck out satellite images and look at the clouds closely. Or, better still, try and predict rain just from the images. Chances are that you will be predicting a lot more rain or 'overcast days' than what you will get. I am based in the UK and there are clear flight paths, for example, the big airport is west of London (Heathrow) and a lot of planes fly west to the 'New World'. A typical route will be over the Bristol Channel, which is over water rather than land. If you look at the satellite imagery in the different wavelengths then you will see the whole Bristol Channel 'clouded' with what can only be contrails. If you are old enough then you might be able to remember 9/11 and the skies in the aftermath, when no planes were flying for quite a few days. The pandemic gave us a glimpse of this too, however, we were shutting down a lot else then. To summarise, we are pissing in the pool big time with this aviation lark. I appreciate that you can't see it, but I don't think anyone that is heavily car dependent actually will. It is a 'wood for the trees' thing, and, if you are always around cars, trucks and planes, you are in the pool of piss and just not seeing it or smelling it. You can see this filth if you get out of town, climb a hill and look back. If it is a clear day with a big sky and no wind, then you should be able to see the filthy air above the town, and that isn't from people riding bicycles. What we have done with cars is to make them more efficient. Nobody is rolling coal any more, well, maybe in South Carolina, but everything was 'rolling coal' with added lead until relatively recent times. There might not be clumps of soot the size of snowflakes in the air, what happens now is that the car dependent person has a vehicle that burns the same amount of fuel as before, but the particle sizes that come out the back are extremely small, so small that you can't see them. But you can see them if you happen to be using a satellite to do so, or if you do get ten miles out of town on a clear day, and look at it properly. I live in Scotland where we have had an interesting history with air quality. We have a network of paths that are made from former railway lines and canals that take you a long way from cars. There are stretches where you are riding through nothing but flowers for mile after mile. You can also unlock extra adventure levels to find networks of roads that don't exist on Google Maps that are closed to cars but definitely open to bicycles. However, eventually, some big road will need to be crossed or there will be a road running parallel to the trail. Then the magic ends. What amazes me is how you can get used to the wonderful smells of the truly clean air to then be utterly appalled at how toxic the air is anywhere within a mile of a car. But, inside a car,the air always smells good, right? It is not as if you get tired from carbon monoxide poisoning on longer journeys, is it? So, does any of this matter? Not if you are young with no health problems. Just suck in the air wherever there is an abundance of vehicles. You will never know what good air is or why it matters. Besides, we all need cars and trucks to get food on our tables, so there is no escaping and it would be hypocritical to do so. Or you can opt out, to never fly and never drive. I chose this as a challenge and, so far, no regrets. I haven't been on a plane for three decades yet I seem to know more about the world than most frequent fliers. As for not getting into a car, there are occasions such as funerals where I will get a lift, and yes, I do get the occasional item delivered to my door, but everything else? Bicycle, or electric train, powered by wind farms. It seems to me that you can only really assess the problem if you aren't part of it. Regarding contrails, they have been a conspiracy theorist talking point for as long as the internet has been around. What is pernicious about conspiracy stories is that there is always a small grain of truth in there. All of these hydrocarbons we burn - all of them - are toxic to life and cancer causing. Conspiracy theorists have egged the pudding on this, but who wins from this? Well, it means that anyone with a preference for genuinely clean air, buzzing with bees and wonderful smells from plants, can be branded a crazy person because they must be, right?
- alberth 1y agoI was hoping this was going to be about eliminating the heat trail of a plane. Then learned it’s just about rerouting a flight to climate zones that will less likely form a vapor trail.
- Tor3 1y agoBut there's no physics which can remove heat from a thermal engine, other than shifting the heat to the outside. (Science fiction books would use "heat sinks" in their war space ships to try to hide the heat for a short while, but would eventually have to dump the heat somewhere. As heat sinks are basically just a huge mass.. not an option for airplanes.)
- hshdhdhehd 1y agoSo 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.
- cosmin800 1y agoAh, 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.
- ZeroGravitas 1y agoOne of the touted benefits of e-fuel is the purity that after combustion reduces the exhaust soot. 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-worlds-first-in-flight-study-of-commercial-aircraft-using-100 https://www.airbus.com/en/newsroom/press-releases/2024-06-wo...
- gcanyon 1y agoRelated context: Sabine Hossenfelder's explanation of how the greenhouse effect works -- it's interesting and weird: https://www.youtube.com/watch?v=oqu5DjzOBF8 https://www.youtube.com/watch?v=oqu5DjzOBF8
- padjo 1y agoAs someone who lives near a flight path and has clear skies constantly ruined by contrails this would be fantastic from a purely aesthetic perspective.
- deleted 1y ago[deleted]
- rafa___ 1y agoI would be very skeptical of any "super cheap solutions" to anything in aviation... almost nothing in commercial aviation is "cheap"