Hacker News

Contrails Map

• 43 Comments
• Two links about "stratospheric aerosol injection" from mainstream sources.
  "The Advanced Research and Innovation Agency (ARIA) - a government backed body - is funding nearly £60m that could allow real-world experiments, including in the UK.
  "As part of the Exploring Climate Cooling programme, projects in Solar Radiation Modification (SRM) will involve trying to thicken Arctic sea ice and make clouds more reflective." https://www.bbc.co.uk/weather/articles/c5ygydeqq08o
  Paper on how "Low-Altitude High-Latitude Stratospheric Aerosol Injection Is Feasible With Existing Aircraft" https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024EF00...

  By nephihaha 4 hours ago

• So there are papers. There are studies on tons and tons of things. One of the things you learn really studying science is that there are always papers, and you really have to immerse yourself in a field to see what’s actually happening.
  People who believe in chemtrails need to prove that the it’s being done, is being done at industrial scale (not just a few one off experiments), and that this is harmful to human health or the environment.
  Ocean fertilization to soak up CO2 has been extensively studied and in that case there are documented experiments, but we are not doing it at scale… mostly because nobody wants to pay for it and because we are not 100% sure the CO2 will actually be sequestered. There’s also some concern about side effects on ocean ecosystems.
  A lot of things get studied.
  Of course the real conspiracy I keep hearing is that this is some kind of mind control thing. Why? Even if that were possible, why bother when you can mesmerize humans at scale with mindless slop scrollers like TikTok and program them like a zombie army. Much cheaper and done 100% in the open.

  By api an hour ago

• It states that half of aircraft pollution is from contrails made of aircraft soot.
  I’d like to see the literature and discovery of aircraft soot.
  As an engineer who has built aircraft, I find this fascinating. I would like to measure my amount of soot. How does one go about measuring how much soot I have?
  Obviously if my exhaust ports are black that’s bad but I’m genuinely curious about this as I’ve always assumed “black smoke bad, white smoke ok”. As for contrails, disturbing the atmosphere is going to cause some freezing (clouds) at that altitude, at that temperature. How do you suggest we mitigate that? Fly lower and burn more fuel? Fly less and tell people to take the train or that their package will arrive next week?

  By reactordev 6 hours ago

• It does not state that half of aircraft pollution is from contrails. It says half of the climate impact of aviation is from contrails. Soot can have other effects and cause pollution in other ways such as reducing air quality but I suspect that is very minimal compared to other industries.
  The guide presented by the map gives a very good explanation on how contrail formation can be mitigating by altering the course of flights to reduce the formation in areas where it will have the most impact. This is based on a recent study that showed contrail avoidance could be one of the most cost-effective methods of reducing warming that we know of.
  https://iopscience.iop.org/article/10.1088/2634-4505/ad310c
  Simon Clark did a good video on this recently:
  https://www.youtube.com/watch?v=QoOVqQ5sa08

  By spuz 5 hours ago

• >The CO2 emitted by aircraft only causes about half the climate impact of aviation. The other half comes from contrails— artificial clouds that are created by soot in the engine exhaust.
  Then what does that mean?
  I find it strange. Clouds happen naturally. Contrails are mini clouds (literally a cloud chamber), are we saying that all those “chemtrails” are pollution?
  Or are we saying the unspent fuel particulate inside that they formed around is?
  This is where this bizarro science is going off the deep end for me. As any object traveling through the atmosphere at that altitude, disrupting air, is going to form condensation and cloud trails. The more moisture in the atmosphere, the more trails. Sure there’s a little bit of unspent kerosene particles but hardly enough to even be a glycerin on a well working engine.
  Are we suggesting changing flight routes and wasting more fuel (which pollutes more) to protect the ground from these 0.0000001% reduction in light cloud trails? Seriously. I want to know the science behind how this plays out.
  I’m all for shutting down the black exhaust engines and cleaning up how we produce thrust. I’m all for that. This argument that clouds cause pollution is just wacky.
  What about wingtips. Those cause trails (though not as pronounced as the engines turning at 12,000rpm), those contain no particulates and yet, they exist. Atmospheric science can explain a lot of what you see at 30,000ft (10,000m). This all sounds like NIMBY science posturing and pseudo-science to me.

  By reactordev 26 minutes ago

• > I find it strange. Clouds happen naturally. Contrails are mini clouds (literally a cloud chamber), are we saying that all those “chemtrails” are pollution?
  Estimating radiative forcing is about measuring relative to a baseline. Here, the baseline is a world with no contrails. When you introduce contrails, you're introducing cloudy volumes predominantly made of ice crystals and occurring very high in the atmosphere. On the balance, these clouds re-emit more long-wave radiation (e.g. what' emitted by the Earth's surface) than they allow to escape the atmosphere.
  Hence, these clouds have a small but positive net radiative forcing - meaning that aviation, by the way it leads to contrail formation, has at least this small radiative forcing on climate.
  > As any object traveling through the atmosphere at that altitude, disrupting air, is going to form condensation and cloud trails. The more moisture in the atmosphere, the more trails.
  Actually - it won't. We rigorously started studying contrail formation back in WWII when meteorologists tried to anticipate when bomber flights returning from mainland Europe might induce contrails and leave a path for intercept fighters to follow and shoot them down. As the science and understanding of vertical atmosphere thermodynamic structure and cloud microphysical structure has advanced in the ensuing 80 years, we have a much better understanding of when contrails are likely to form, versus when they aren't.
  But don't take my word for it. Look up at the sky any time you hear an aircraft - sometimes you'll see a contrail, sometimes you won't. Contrails aren't a given when a jet flies high in the atmosphere.
  (that's actually the entire basis for the Contrails/DeepMind team's work - avoid areas where contrails _are_ likely to form, to avoid that radiative forcing from the first part of this comment)
  > Are we suggesting changing flight routes and wasting more fuel (which pollutes more) to protect the ground from these 0.0000001% reduction in light cloud trails? Seriously. I want to know the science behind how this plays out.
  The science is pretty well developed at this point. You'd probably hit it in an undergraduate-level physical meteorology class. The missing detail that the Contrails team helped solve was improving forecasts of the key parameters involved here from weather models.
  The whole point is that this is _another_ lever that flight planners could use to optimize their route planning. It's just one factor. It has trade-offs - although those trade-offs aren't always net negative (e.g. it's not a given that the "less contrail-y" route is also the "more fuel burn-y" one).

  By counters 10 minutes ago

• Fly less. Is waiting a week for a package really that big of a deal? Is traveling less really that much to ask?
  It’s totally ok to be skeptical of the claims. I can’t make a judgement on them as I know even less than you might. But that’s not a reason to doubt that human’s environment impact matters and that maybe part of the solution is for those of us with access to 2day delivery for everything and cheap flights live a teeny bit more like those who don’t.

  By roxolotl 5 hours ago

• The general point here is that your individual behavior as a consumer likely doesn't impact this mechanism. An aircraft doesn't skip a flight just because you waited a week to go on vacation. Aviation infrastructure is something of a fixed-cost which would likely only respond to systemic changes in travel demand, economic impacts on maintenance or fueling, or possibly some other form of regulation (e.g. a penalty for inducing contrails).

  By counters 7 minutes ago

• It is easy to suggest to fly less but it is going to be impossible to convince society where core values include agressive "extra" consumption, which in turn is the backbone of the world's current economy. Flying is one of top "extra" consumption types out there. I know many people are trying to convince people of that, but the society is moving in the opposite direction - bigger cars (both us and eu), more travel. Maybe arguments used currently are not convincing enough? I mean, sure, keep trying and you will obviously reach a certain 0.00x% of the population, but that's not really going to make any difference

  By harddrivereque 5 hours ago

• The general way to affect public habits (whether it works or not) is to apply a "sin tax" to that activity.

  By JKCalhoun 4 hours ago

• Just tax everything the amount it costs to clean up the pollution it causes, then use that money to clean up the pollution, now everything will have the correct price including externalities

  By mavhc 3 hours ago

• There is a big anti-tourism movement being built up across the world which is also being pushed by mass media. In Barcelona and Venice this has turned physical in a few instances. Flying is going to be made more expensive in the near future, I've no doubt of it. The environmental lobby will call for it.
  By the way, I have not flown for over a decade. I can't stand airports...

  By nephihaha 4 hours ago

• Night trains

  By ant6n 5 hours ago

• What would make you say such a thing?

  By baobun 5 hours ago

• but contrails are not made of soot, where I define soot as dark unburned carbon, contrails actual are made of water. There is also a highly likely chance I am being to literal and the word choice of soot was a bit of poetic license on the part of the author.
  As a bonus consideration it might be better if they were made of soot, it would be ugly but water vapor is a tremendous greenhouse gas, several times as potent as CO2, soot blocking the sun might have more of a neutral effect, And related, we worked hard to get sulfur out of our fuels but sulfur dioxide turns out to be a negative greenhouse gas, it has a net cooling effect, I am not saying we should deliberately add sulfur back in, the downsides are too great, but it is an interesting bit of irony.

  By somat 5 hours ago

• The water is actually ice crystals and the ice crystals form around the soot.

  By bird0861 3 hours ago

• There is also an immense amount of water vapour being produced by the combustion of a hydrocarbon.

  By wolttam an hour ago

• Sure, but water vapor doesn't spontaneously transition to a liquid and accrete onto surfaces - there needs to be a super-saturation of water vapor, and given the temperatures of jet exhaust, that's not trivial to achieve. However, the super-saturation needed for water vapor to deposit onto surfaces as ice is much lower, hence the preference for ice crystal nucleation.

  By counters 6 minutes ago

• Hi all - very grateful to see this posted here. I'm the director of this project and would be happy to answer questions.
  We are seeking a high level full stack engineer to join the team to work on infrastructure for this and other efforts. Please reach out if interested - info@contrails.org

  By mlshapiro an hour ago

• Where are the rocket launches? Surely those are worth measuring as they are a daily occurrence on Earth.

  By 1970-01-01 an hour ago

• I found this extremely interesting and enjoyable.
  I would however recommend testing it on a slower internet connection and a lower end device. Because I was spending 90% of my time in the "loading data" phases, and once the intro was done, the thing ran at one frame per second and I was not able to use it. (I have 5G and I bought my phone last year.)

  By andai 4 hours ago

• Thanks for the feedback! We have done all the performance optimization we can in its current manifestation.
  We're in the process of refactoring the models that support these visualizations, so we hope to make it more performant in the near future. Hopefully end of this year.

  By mlshapiro an hour ago

• It literally (and repeatably) crashes Chrome on my android phone that has 6 GB of RAM. As in the entire browser closes.
  EDIT: Though it's pretty cool on a powerful desktop. Maybe could benefit from performance optimization.

  By HPsquared 4 hours ago

• Amazing visualisation, an excellent tool.
  Are there other sites that can suggest how much of an issue it is, and how much flight plan tweaking could improve this.
  Remember kids a 1° C rise in temperature can mean 7% more water vapour in the air, and with water vapour being a greenhouse gas itself this can cause heating and holding yet more water.

  By zeristor 10 hours ago

• The site itself has more information. https://contrails.org/
  I guess the map is posted today due to this recent video (worth a watch): https://youtu.be/QoOVqQ5sa08?si=sGK9Q9tUoFOW1QZg

  By victorbjorklund 9 hours ago

• The team behind this is world-class. Among other things, they have developed a python library that could be used to model contrails in your own projects.
  https://py.contrails.org

  By p-a_58213 6 hours ago

• I was expecting this to be a gag about chemtrails. I am glad I was wrong.

  By Sieyk 9 hours ago

• They definitely increase the cloud cover where I live. Very noticeable, you can often see which clouds were created by them... And that's without the conspiratorial stuff.

  By nephihaha 6 hours ago

• This group is funded by Orca Sciences, which is also behind Standard Thermal.
  https://www.orcasciences.com/

  By pfdietz 3 hours ago

• That's right! The project started at Orca Sciences back in 2021. We moved to Breakthrough Energy in 2023, and will be spinning out into our own standalone non-profit soon.

  By mlshapiro an hour ago

• I'm not following the logic why contrails cause net warming.
  Why nuclear blasts - that also introduce lots of particles in atmosphere cause a cooling effect - "nuclear winter"?

  By extropy 9 hours ago

• Water vapour absorbs the thermal radiation (heat trying to escape earth) better than it absorbs sunlight (heat trying to enter earth). Therefore, the more water vapour in the atmosphere, the stronger the greenhouse effect.
  https://en.wikipedia.org/wiki/Electromagnetic_absorption_by_...
  https://en.wikipedia.org/wiki/Greenhouse_effect

  By maltelau 8 hours ago

• In this case I believe it's not water vapor, but rather reflection of IR from ice crystals.

  By pfdietz 2 hours ago

• They don’t cause net warming, it’s transient. If we stopped flying tomorrow it would go away quickly. But we keep flying.
  But even with that the amount of warming this continuous effect creates is quite small and negligible compared to greenhouse gas warming and isn’t really worth talking about.

  By rottencupcakes 8 hours ago

• I think this link hit HN in part due to the new Simon Clark video on contrails which mentioned it. Simon discusses the claim that contrails can be avoided for a small fuel penalty, reducing the overall effect on climate change a given flight would have. Apparently some airlines are already exploring this and Google includes contrail impact estimates on their flight search. So maybe it is worth talking about.
  https://youtu.be/QoOVqQ5sa08

  By SequoiaHope 8 hours ago

• The difference is that water vapour is a greenhouse gas. IIRC the net warming effect of clouds is a function of altitude.

  By ekunazanu 8 hours ago

• Yes, also a mushroom cloud from a nuclear blast blocks light from passing through which reduces heating on the ground whereas contrails are thin which lets light through but still retains heat below them.

  By ejago53 8 hours ago

• I have no doubt that nuclear testing has affected the environment far more than is being let on. These experiments by their nature were classified. Who's to say they weren't a factor in helping create the ozone hole?

  By nephihaha 4 hours ago

• It's not specifically about logic. It is possible to model and measure the radiative effect of contrails.

  By complex_pi 7 hours ago

• Preserving the aesthetics of the sky is reason enough to stop artificial clouds. Why would we accept such a mess?

  By janpmz 5 hours ago

• Would be great for shiptracks, too— which used to mitigate 1/3 of the warming impact of maritime shipping — until the 2022 clean fuel standards were implemented.

  By dr_dshiv 9 hours ago

• All I really learned from this is that European skies have a much higher density of flights than the rest of the world.
  If the future of aviation is similar flight densities everywhere then people might actually begin to care about this topic.

  By sublinear 2 hours ago

• Remember that there are more flights during the day than during the night. When you posted this it was late afternoon in Europe, noon on the East Coast US and early morning on the West Coast. And of course it was night in Asia.

  By prennert 38 minutes ago