Airplane Contrails Will Do Triple the Damage They Do Today By 2050, Study Finds (newscientist.com) 399
An anonymous reader quotes a report from New Scientist: The contrails left by airplanes last only hours. But they are now so widespread that their warming effect is greater than that of all the carbon dioxide emitted by airplanes that has accumulated in the atmosphere since the first flight of the Wright brothers. Worse still, this non-CO2 warming effect is set to triple by 2050, according to a study by Ulrike Burkhardt and colleagues at the Institute of Atmospheric Physics in Germany. Altogether, flying is responsible for around 5 percent of global warming, the team say, so this figure will soar even higher -- and no meaningful actions are being taken to prevent this.
The researchers used a computer model of the atmosphere to estimate how much warming contrails caused in 2006 -- the latest year for which a detailed air traffic inventory is available -- and how much they will cause by 2050, when air traffic is expected to be four times higher. The model takes account of not only of the change in air traffic volume, but also the location and altitude of flights, along with the changing climate. The team conclude that the warming effect of contrails will rise from 50 milliwatts per square meter of the earth's surface in 2006 to 160 mW/m^2 by 2050. In comparison, the warming due to CO2 from aviation will rise from 24 mW/m^2 to 84 mW/m^2 by 2050. If the airline industry improves fuel efficiency and reduces the number of soot particles by improving fuels and engines, the researchers say the warming from contrails by 2050 will be limited to 140 mW/m^2 and the warming from CO2 to 60 mW/m^2.
The study has been published in the journal Atmospheric Chemistry and Physics.
The researchers used a computer model of the atmosphere to estimate how much warming contrails caused in 2006 -- the latest year for which a detailed air traffic inventory is available -- and how much they will cause by 2050, when air traffic is expected to be four times higher. The model takes account of not only of the change in air traffic volume, but also the location and altitude of flights, along with the changing climate. The team conclude that the warming effect of contrails will rise from 50 milliwatts per square meter of the earth's surface in 2006 to 160 mW/m^2 by 2050. In comparison, the warming due to CO2 from aviation will rise from 24 mW/m^2 to 84 mW/m^2 by 2050. If the airline industry improves fuel efficiency and reduces the number of soot particles by improving fuels and engines, the researchers say the warming from contrails by 2050 will be limited to 140 mW/m^2 and the warming from CO2 to 60 mW/m^2.
The study has been published in the journal Atmospheric Chemistry and Physics.
Chem Trails (Score:5, Funny)
Re: (Score:2, Informative)
A contrail is created by the speed and angle that the plane's wing hits the air. At certain altitudes and atmospheric properties it makes a little cloud of water vapor. If you've ever played Ace Combat and turned your jet really hard it will make contrails on the wings (only on the PS2 or better due to graphics!).
A CHEMtrail is thought to be a mixture of chemicals deliberately dumped from a plane for a specific purpose. The purpose is up for debate:
Some people think chemtrails contain metal particles for ja
Re: Chem Trails (Score:5, Informative)
Contrails are usually not caused by the wings.
Yes, wings can in certain circumstances create contrails all by themselves if the air is oversaturated in moisture. Usually, though, any condensation caused by the wings (due to the pressure drop above the wing cooling the air) evaporates again immediately afterwards.
The vast majority of contrails is caused by the extra water vapor that's added by the engine exhausts. You can clearly see four engined airplanes producing four contrails that then merge into one.
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Like I said, they can, but usually it's the engines rather than the wings. The wings by themselves often do cause condensation, but this usually evaporates again immediately afterwards except in conditions where the air is already more than 100% saturated with moisture and is just waiting for something to condense around. This does happen, but not quite as often.
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Contrails aren't just caused by water vapor, they're nucleated around the soot produced, just like a real cloud, which is why they form so readily and also why they persist.
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Contrails aren't just caused by water vapor, they're nucleated around the soot produced, just like a real cloud, which is why they form so readily and also why they persist.
I was listening to a shortwave broadcast some years ago. The dood explained that Contrails were actually particles put in the jet fuel that would turn the atmosphere into a big projector screen, then the government was going to project flying saucers on it to panic Americans and have us allow the government total subjugation of the populous.
I think it was a skeeze named Brother Stair. He's not on the air any more because he's been caught kiddie diddling.
The more you know!
Re: Chem Trails (Score:4, Interesting)
I was listening to a shortwave broadcast some years ago. The dood explained that Contrails were actually particles put in the jet fuel that would turn the atmosphere into a big projector screen, then the government was going to project flying saucers on it
When someone is talking about what gay martians are doing the soil, you know they're a nutter. However, the government has done experiments by spraying things on people from airplanes before, so enough elements of the overall theory make sense for it to have staying power. That is, the government has done things similar to "chemtrails" in the past, so it's easy for many people to believe that they're doing it now. There's a plausible conspiracy therory somewhere in the middle of the bag of bullshit, which keeps it alive.
Re: Chem Trails (Score:5, Funny)
A chemtrail post got modded 'Informative' ?
You might want to try putting in some references to Putin or evil spirits to get modded up.
At the end of the pizzagate tunnels, in Area 51, when they aren't banging little kids, Hellery and O'Blama are mixing up the poisons they put into Jet fuel to weaken American's. The orgy room is the converted studio where Stanley Kubrick filmed the faked moon landings. Next to it is chemlab where they mix up the autism creating chemicals (democrat's tears) that they have replaced real vaccines with. And the HAARP combination mind control and chemical injection by way of riding on radio waves is just making the whole thing worse.
I almost forgot to add - it's a long way from Pizzagate HQ to their area 51 complex - why do you think that Elon Musk has been working on the hyperloop - that's right - he's part of the whole conspiracy. Need Proof? https://www.youtube.com/watch?... [youtube.com]
Wake up...... sorry..... WAKE UP AMERICA!
re: Chem Trails (Score:3)
A chemtrail post got modded 'Informative' ?
Just where do they get these crazy ideas?
From: [wikipedia.org]
The existence of Project 112 (along with the related Project SHAD) was categorically denied by the military until May 2000, when a CBS Evening News investigative report produced dramatic revelations about the tests. This report caused the Department of Defense and the Department of Veterans Affairs to launch an extensive investigation of the experiments, and reveal to the affected personnel their exposure to toxins.
Revelations concerning Project SHAD were first
Re: Chem Trails (Score:5, Funny)
What's the difference between chemtrails and contrails?
Contrails are water vapor. Chemtrails are mind control vapors, disbursed by the UN, that turn patriotic God-fearing Americans into mindless liberals.
TFA only addresses the water vapor, because NewScientist is part of the MSM and thus already under the spell of the chemtrails.
Wouldn't that make contrails be chemtrails too?
That's what they want you to think.
Factoid: If you see a contrail stretch all the way across the sky, rather than dissipating quickly, it will most likely rain within 12 hours.
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Contrails are water vapor. Chemtrails are mind control vapors, disbursed by the UN, that turn patriotic God-fearing Americans into mindless liberals.
OK, I am going to assume that you are trolling, but please don't.
There are voters out there who actually reason like this. (Just look at how many followers Alex Jones have, and he pretty much preaches like this.)
When you post like that they feel like their beliefs have been validated.
Re: Chem Trails (Score:5, Insightful)
Any idiot without an even rudimentary sarcasm detector will find a way to validate their braindamage. We should not lose our sense of humour for this.
Re: Chem Trails (Score:5, Funny)
We used to think that, but then homeopathy showed us that water has memory. No need to distribute actual chemicals, when they can instead use undetectable homeopathic chemicals to brainwash everyone.
Re: Chem Trails (Score:5, Funny)
One time I forgot to take my homeopathic medicine and I overdosed.
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Factoid: If you see a contrail stretch all the way across the sky, rather than dissipating quickly, it will most likely rain within 12 hours.
That's because we get long-lasting contrails when the stratosphere is unusually cold, causing the vapor to freeze into ice crystals rather than dissipating in a short time.
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Factoid: If you see a contrail stretch all the way across the sky, rather than dissipating quickly, it will most likely rain within 12 hours.
Factoid? So it's not true then?
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Contrails are water vapor. Chemtrails are mind control vapors, disbursed by the UN, that turn patriotic God-fearing Americans into mindless liberals.
You must go deeper. Chemtrails are mind control vapors, disbursed by the UN, that turn patriotic God-fearing Americans into mindless liberals who believe that contrails will make the oceans boil
Re: Chem Trails (Score:4, Informative)
https://youtu.be/e20vaAtncsM [youtu.be]
Here you go, all the information you will ever need on chemtrails.
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High speed rails (Score:5, Interesting)
If you look outside of US, in the rest of the world, high speed rails is very practical and feasible approach to long distance travel across land. It is already fully electric and do not burn any fossil fuels, its carbon footprint will be reduce as power sources switch to greener options. Avoiding security check lines is an extra bonus.
If any "environmental" groups is serious about the environment, they would be pushing for high speed rails for continental travel and condemning private jets.
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It is already fully electric and do not burn any fossil fuels, its carbon footprint will be reduce as power sources switch to greener options.
Those trains burn fossil fuels. The rate they release CO2 will increase unless these nations can get a viable energy storage system for all those green options or find a green energy option that is reliable enough to keep the trains running on time. Wind, water, and sun will not do without storage, and lots of it.
Here's just one example of people realizing that getting to zero carbon by 2050 is just a fantasy. ->
https://business.financialpost... [financialpost.com]
Growth in "green energy" isn't even keeping pace with grow
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It is already fully electric and do not burn any fossil fuels, its carbon footprint will be reduce as power sources switch to greener options.
Those trains burn fossil fuels.
Do you even read before you reply? Lots of HSR are fully electric.
Take, for example, Japan's Shinkansen:
https://en.wikipedia.org/wiki/Shinkansen#Electrical_systems
"Shinkansen uses a 25 kV AC overhead power supply..."
"Shinkansen trains are electric multiple units..."
Here's just one example of people realizing that getting to zero carbon by 2050 is just a fantasy.
Nice strawman, who said anything about zero carbon?
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Do you even read before you reply? Lots of HSR are fully electric.
The power plants producing the electricity are burning carbon. That electricity comes from somewhere, no?
Nice strawman, who said anything about zero carbon?
The article did. The planes produce warming from CO2 and contrails, both need to be addressed and they implied 2050 as a deadline. Electric planes (assuming they prove practical) will still leave contrails. Electric planes and trains still produce CO2 if the power plants producing the electricity are burning coal, oil, and gas. Maybe the application of synthesized fuel can address the CO2 problem, t
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Many short haul flights would be better done as train journeys, but the problem with trains is building the line. Lots of land that needs to be bought up, and high speed lines need separation (i.e. no crossings).
Some countries have been quite successful at building such things. It really seems to depend on how willing the government is to straighten the legal situation out.
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The power plants producing the electricity are burning carbon. That electricity comes from somewhere, no?
Nuclear power plants burn carbon?
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Nuclear power plants burn carbon?
Nuclear power plants do not burn carbon. I have yet to see any rail system that does not get any of it's electricity from some fossil fuel, therefore these trains are burning carbon to run. It's certainly possible to run a train system with a zero CO2 emissions, but only with some nuclear power on the grid, and to my knowledge nobody is operating one today.
Lots of smart people are saying it's impossible to have a zero carbon electrical grid without some nuclear. Here's a sample of them...
https://www.theg [theguardian.com]
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Do you even read before you reply? Lots of HSR are fully electric.
I actually think all of the HSRs are fully electric. Maybe I am wrong.
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two energy sources that those same left wingers absolutely hate: nuclear and fossil fuels!
So basically you're saying that right wingers hate solar, wind and geothermal?
I'm not surprised left wingers are essentially good at creating things and right wingers are good at running things.
When it comes to solving the issues we face as a species if we don't get over this petty political pandering then it is hardly likely that will we will be fit enough as a species to survive.
Re: High speed rails (Score:4, Insightful)
Hating things is the bastion of the Left. On the Right, we
Seems to me that you're doing a pretty good job of it.
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I don't hate anything that's a practical and economical solution. What I hate is fear mongering and irrational change. If solar works, can cost about the same and be reliable all without causing other unintended environmental issues, I'm all for it. .
In terms of cost and working (sun permitting) solar is there, in term of PV, even more so for domestic thermal. There are some infrastructure and raw material production issues, but then there are for any power generation system, including nuclear, hydro, wind, coal, gas, etc. and I haven't seen evidence that solar is particularly any worse overall, just different waste outputs.
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Removing the global warming threat will require some solutions that many will not yet consider. But they will, in time.
Fortunately most people have a capacity for coming up with solutions that some people cannot see. They can look at things that just don't work and based on those experiences come up with something completely new and radically alter society.
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If any "environmental" groups is serious about the environment, they would be pushing for high speed rails for continental travel and condemning private jets.
There's plenty of other things they'd also be doing if they were serious.
Like maybe the members of Congress not flying back and forth from DC to their districts several times per year. Congress doesn't need to be in session year round. Have a winter session at the beginning of the year, so they don't have to run energy intensive air conditioning. Then go home for the summer. Then maybe go into a short fall session to finish up business before breaking for Thanksgiving, and not come back until the new ye
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Avoiding security check lines is an extra bonus.
You make me laugh - you think the US could put a high-profile, long distance Hi-Speed rail line in that won't have TSA checking bags and screening passengers? Not likely.
Imagine the PR coup if a terrorist organization got a bomb on a US "bullet train"...
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Imagine the PR coup if a terrorist organization got a bomb on a US "bullet train"...
Imagine a PR of such a bomb on a US subway train. Yep, I don't see any difference between a bullet train or the existing subway. Usually the subway will be much more crowded during peak hours than any HSR train (HSR usually required you to buy tickets for seats, so no standing passengers==no fully packed trains), which makes the subway a much more attractive target for terrorist.
Worrying about terrorist for HSR is even more of a security theatre than the TSA.
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If you look outside of US, in the rest of the world, high speed rails is very practical and feasible approach to long distance travel across land. It is already fully electric and do not burn any fossil fuels, its carbon footprint will be reduce as power sources switch to greener options. Avoiding security check lines is an extra bonus.
If any "environmental" groups is serious about the environment, they would be pushing for high speed rails for continental travel and condemning private jets.
*cough* nuclear *cough*
Re:High speed rails (Score:4, Interesting)
To be fair, most of the rest of the world that can afford and cares about speedy travel is FAR smaller than the US in size. Basically the places where such high speed trains are replacing flights are Japan and Europe. Japan, a VERY small country compared to the US and Europe with its fairly small scale structures where a trip of 500 miles is already considered "long distance" and a commute of more than 20 miles is considered unreasonable.
Personally, I have replaced most flights with overnight trains. Needn't even be "bullet" trains, there's plenty of time while I sleep. The benefits are clear, first, they're by no means more expensive (the price is roughly equal with frequent traveler bonuses), and it's WAY more comfortable. Instead of getting up at 5am to catch a plane at 7 (because it takes about an hour to get through rush hour traffic to the airport and another hour to get stripped of the last shreds of remaining dignity you might still have), flying for two hours and being dumped out of a plane, completely crumpled and squished, you check in around 6pm, have ample time to get comfy in your cabin, work 'til about 10pm (free WiFi included) while you're already traveling towards your destination, get a wake up visit at 6am (or whenever you want), with the morning paper and fresh bread for breakfast, have ample time to suit up for a meeting and as a bonus get to smell like you just showered (because you did) instead of that fat ass you were wedged against who showered last time when GWB was still in office.
Sadly, this of course only makes sense for trips shorter than 1000 miles. Which is fine in Europe, but probably not really that feasible in the US.
Re:High speed rails (Score:4, Interesting)
To be fair, most of the rest of the world that can afford and cares about speedy travel is FAR smaller than the US in size.
Have you seen how big China is? And whilst a typical long journey in Europe might be no more than 500 miles, that happens a lot, and the last time I did so I took the train and it was just as fast door-to-door and no more expensive, and much more convenient for taking pets.
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Over here in Europe, the environmental groups do this very much.
A challenge in a densely populated area, is that high-speed trains require tracks that are very straight -- and that land has to be acquired which proper concession. Planning can therefore take decades.
For extending the range of existing trains, there is a challenge in that different European countries have incompati
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About time they think of the most important GHG (Score:4, Interesting)
Despite some advances in the understanding of the physical processes that control the cloud response to climate change and in the evaluation of some components of cloud feedbacks in current models, it is not yet possible to assess which of the model estimates of cloud feedback is the most reliable
So, it is by far the dominant factor in the climate, but we don't have any clue how good the models are - so we'll fiddle with the CO2 knob in the meantime. Reminds me of this story:
A police officer sees a drunken man intently searching the ground near a lamppost and asks him the goal of his quest. The inebriate replies that he is looking for his car keys, and the officer helps for a few minutes without success then he asks whether the man is certain that he dropped the keys near the lamppost.
“No,” is the reply, “I lost the keys somewhere across the street.” “Why look here?” asks the surprised and irritated officer. “The light is much better here,” the intoxicated man responds with aplomb.
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Water vapor. It dominates the entire thing.
Water vapor concentration is in a steady state condition, set by temperature. It's CO2 that drives the temperature rise, which then leads to increased water vapor.
So, it is by far the dominant factor in the climate, but we don't have any clue how good the models are
You're confused. Water vapor is an important contributor, but isn't particularly hard to model. Clouds, not vapor, are much harder to model, but they are only a small factor in climate change, because they block both IR as well as visible light.
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Water vapor is the dominant greenhouse gas [wikipedia.org]. The IPCC (as I linked above) says it's too hard to model how clouds form or what they do to the climate - and thus the impact on the models is unknown. CO2 doesn't drive it - water vapor does.
Oh, and water vapor also varies with pressure - not just temperature - meaning it becomes doubly difficult to model as weather patterns will create high and low pressure zones and different levels of water in the air. You know, that whole "pV=nRT" thing...
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Clouds are not water vapor. Clouds consist of ice crystals and water droplets, neither of which are gases, let alone greenhouse gases.
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Actual greenhouses are made from solids, and trap heat just fine. Who says only gases can cause a greenhouse effect?
So we need to drink less water? (Score:2)
And exercise less, all that sweat cannot be good for the environment.
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Not to mention that you exhale a lot more CO2 when working out!
Re:So we need to drink less water? (Score:4, Funny)
I identify as a plant, you insensitive clod!
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Yes, and we're very proud of you.
Especially in Spring when you're in bloom.
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The thing you need to know in order to understand this chart is that diff
Re:About time they think of the most important GHG (Score:4, Informative)
Re:About time they think of the most important GHG (Score:4, Interesting)
Most of the water vapour is stuff we can't do anything about, that's why it doesn't get as much attention. Compared to CO2, relatively small amounts of it are emitted by humans. The thought is that water vapour is mostly a natural process and will balance out if we fix the CO2 problem.
Aircraft are the exception, as they deposit water vapour directly into the place where it does maximum harm.
Bull (Score:3, Insightful)
The contrails left by airplanes last only hours. But they are now so widespread that their warming effect is greater than that of all the carbon dioxide emitted by airplanes that has accumulated in the atmosphere since the first flight of the Wright brothers.
Prove it. Don't just assert it, prove it - contrails are fleeting blips on environment, the argument that they are more detrimental than the sum total of every bit of carbon dioxide ever emitted by every plane that has ever flown.
Get serious.
Re:Bull (Score:5, Insightful)
Prove it. Don't just assert it, prove it
Didn't you read the summary? They proved it, with a model.
Electric Planes (Score:3, Interesting)
No contrails. Maybe this is an incentive to develop the technology.
Re:Electric Planes (Score:5, Informative)
Even gliders produce contrails. The wings on jetliner produce contrails too, not just the engines.
Here's an image of a space shuttle producing contrails as it glides to a landing.
https://www.metabunk.org/sk/sk... [metabunk.org]
That's just one image I could find with a minute or two of searching.
The fuel burning in the engines produce plenty of moisture to condense in the right conditions, but the moisture in the air being disturbed by a wing will produce them too.
Electric planes are quite likely to reduce the effect but it won't eliminate it.
Oh, and there's already plenty of incentive to produce electric airplanes, I doubt this new info on contrails changes that by much.
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Jet engines are really hot and when they hit moisture laden air they produce the steam that produces contrails.
If you look closely the Space Shuttle [metabunk.org] is creating steam from the hot friction surfaces after doing mach 25+ during reentry. I find you have to look closely at things like that so that you challenge your assumptions and are not misled by oversimplifications.
There are dozens of scale model electric planes of conventional aircraft that don't produce contrails so I think your theory fails the tes
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There are dozens of scale model electric planes of conventional aircraft that don't produce contrails so I think your theory fails the test of experimentation because we don't see scaled contrails on electric model aircraft but we do see them on jet powered model aircraft (which are really cool btw).
Scale model planes are rarely powerful enough to produce the effect. The soot from a model rocket engine is not a contrail. I was going to give other photos of contrails from gliders but I suspected many of them were actually smoke generators. Here's a photo of a contrail coming from the tips of a propeller. This rules out smoke generators, engine exhaust, and whatever you think was happening from the space shuttle photo.
https://upload.wikimedia.org/w... [wikimedia.org]
A full scale electric airplane will produce contra
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Scale model planes are rarely powerful enough to produce the effect. The soot from a model rocket engine is not a contrail. I was going to give other photos of contrails from gliders but I suspected many of them were actually smoke generators.
Is it possible that the contrails you've seen from gliders are actually from smoke generators?
Here's a photo of a contrail coming from the tips of a propeller.
This is a different mechanism called "prop tip vortices". When air is reaching saturation point of humidity, pressure and temperature changes create them. I think they're also called "cloud streamers". This video shows them happening on one side of the aircraft but not the other. [youtube.com]
Encyclopedia Britannica has an explanation of the contrails [britannica.com] and how they occur.
This rules out smoke generators, engine exhaust, and whatever you think was happening from the space shuttle photo.
This is also a different mechanism. Consider that th
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I'm done trying to educate you. It appears that your arguments are being torn apart by others. I'll let them do the educating.
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Oh, for fuck's sake.
I don't understand why people need to emote if they disagree with something.
Jet engines emit water vapor.
True, however they don't produce contrails all the time when they are at altitude, mainly in cold humid air as opposed to cold dry air. Encyclopedia Britannica has an explanation of the mechanism. [britannica.com]
The heat is why it doesn't condense immediately, it's not the cause of the contrail.
Yes it doesn't condense immediately, whilst it is still a vapor, you can't see it because IIRC a jet engine has an internal temperature of around 1500C, which is more than enough energy to heat the water in the air. Once it starts to cool
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There simply isn't enough water in jet fuel to produce that much vapor
Skipped basic chemistry, did you? It's not water IN the fuel, it's water PRODUCED BY the fuel that makes the contrails.
Which doesn't explain why jet engines don't produce contrails all the time at altitude.
All of the hydrogen in those hydrocarbons combines with atmospheric oxygen, producing water.
I didn't dispute that. What I dispute that it is the sole source of contrails because you don't see jet engines producing contrails all the time.
Is it possible that you slept through your high school science classes?
-jcr
I don't mind being wrong but is it possible for you to explain to me why I am wrong without being an asshole about it? Is it possible for you to explain why jet engines don't produce contrails all the time? If you are right, why is that so?
Well I did, and it turns out we're b
Re:Electric Plains (Score:2)
plane - not plain.
Mr Grandma Nazi
You're Grandma was a Nazi?
No, he was a faux "netic"
What's a "netic" and how can it be faked?
It's like when you go to smell something and it's not really what you wrote but the computer corrected it to what you didn't really mean.
Gee, that must be annoying
Not half as annoying as the one who try to correct the computer!
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Fuel burning also produces particulates that act as long term condensation nuclei. Pressure induced condensation is a much shorter lived effect.
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No contrails. Maybe this is an incentive to develop the technology.
The contrails are not made by the engine. They are made by the body of a plane moving through certain states of air at high speed. A plane with any other engine flying at the same speeds would produce them.
What About Global Dimming? (Score:2)
It... (Score:2)
Can't we all just use an 'It' instead of waiting in airline queues and paying the hefty prices?
Oh boy (Score:2)
The conspiracy nuts will have a field day.
Warp 5 (Score:2)
Reminds me of ST:TNG episode "The Force of Nature [stackexchange.com]", where Picard is not very happy about the speed limit.
If we're told to slow down, the whole world will have that reaction, but it may be necessary until we figure out better options.
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Re: i hate to sound like a republican (Score:2)
Ever notice how when it's cloudy out during the day (when the majority of flights occur), it's cooler out as the clouds reflect the sunlight back?
Re: i hate to sound like a republican (Score:4, Informative)
https://skepticalscience.com/c... [skepticalscience.com]
The current understanding suggests that clouds insulate the planet more than they shield it from sunlight, on the whole.
A cloudy day is not necessarily cooler just because it's blocking the sun; Clouds accumulate in low pressure systems, which tend to be made of cooler air to begin with. But at the same time, that cloud cover is preventing heat radiating from ground level from escaping... a cloudy day is unlikely to be cooler than a clear night, all else equal.
=Smidge=
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So it's actually warmer on cloudy days, we just don't realize it? Got it. And to think I foolishly put on my Members Only jacket on cloudy days - what was I thinking? (And yes, "Get off my lawn!")
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The presence 0f a cloud layer is an indication of a temperature inversion.
Such inversions act as a heat trap, holding heat created during the day in.
It’s well known that cloudless nights are colder than those with cloud.
https://en.m.wikipedia.org/wik... [wikipedia.org]
Re:i hate to sound like a republican (Score:4, Informative)
Clouds (and contrails are a form of artificial cloud) reflect light hand heat BOTH ways. So they cool the Earth during the day, by reflecting sunlight back into space, and they warm the Earth slightly by reflecting radiated heat back to the Earth.
On balance, the net effect is cooling, because reflected sunlight (back into space) is a WHOLE lot more energetic than reflected terrestrial heat.
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Citation needed. The Earth radiates infrared at night. The contrails might be more opaque to that than full spectrum sunlight. Contrails might linger longer at night. There could be a number of other factors leading to the consensus of net warming from them that you haven't considered.
Re:i hate to sound like a republican (Score:4, Informative)
That's what they used to think back in 1995. However, the situation is much more complex than that; the net effect of clouds depends on their altitude, type, thickness, albedo of the surface below and several other factors. For contrails, it also depends on what type of clouds, if any, are found below them and at what time of the day planes fly etc. etc. Net cloud effect remains one of the more uncertain aspects of climate science. However, "evidence is building that the net cloud feedback is likely positive, and unlikely to be strongly negative."
https://skepticalscience.com/c... [skepticalscience.com]
Re:Aren't contrails a right wing conspiracy theory (Score:5, Funny)
You can see contrails, so clearly they were denied by the right, not the left. Science is a Democrat thing, remember?
Re:Aren't contrails a right wing conspiracy theory (Score:4, Interesting)
Science is a Democrat thing, remember?
Not really. It depends on the issue. Conservatives are anti-science when it comes to evolutionary biology, geology, and climatology. But liberals are often anti-science when it comes to GMO, nukes, and (especially) the heritability of intelligence.
Anti-vaxxers and homeopathics are evenly split, supported by idiots on both left and right.
Re: (Score:2, Informative)
I don't think liberals are anti-science so much as pro-safety and anti-greed, particularly when that greed puts safety at risk.
For example, it's not that they think GMO foods are necessarily bad, so much as that they might be bad, and so they should be thoroughly tested, and they should be labeled so that people can at least ostensibly make informed decisions about whether to buy them or not.
Re: (Score:2)
it's not that they think GMO foods are necessarily bad, so much as that they might be bad, and so they should be thoroughly tested
So wholesale genetic modification with radiation or harsh mutagenic chemicals (not GMO) are fine, but a precise targeted genetic change (GMO) needs to be tested and labeled? Do you really think that is "scientific"? Oh, and the precise changes are not GMO if they are induced with CRISPR/Cas9, because that is considered a "natural" method, even though the resulting DNA is exactly the same? No rational person should believe that.
These CRISPR modified crops don't count as GMOs [theconversation.com]
Re: (Score:2)
Genetic intelligence is a right wing anti-science theory because it has to discard a lot of contradictory evidence to prove the point they want it to make.
Re: (Score:3)
Genetic intelligence is a right wing anti-science theory
If there is not a genetic component to intelligence, why are you smarter that your dog? Wait, wait, AmiMoJo was a bad example. Why is the typical Slashdot poster smarter than his dog?
You gotta pick either "genetics" or "souls".
So, if we believe in genetics, the question is only "how strong is the correlation, after adjusting for everything else", because questions about genetics are statistical questions.
it has to discard a lot of contradictory evidence to prove the point they want it to make.
Uh, huh. Sure. It's the right that's doing that. Because they're bad people, you see.
Re: (Score:3)
Contrails are real. Chemtrails are what the conspiracy theory is about.
Re:Aren't contrails a right wing conspiracy theory (Score:5, Funny)
Aren't contrails a right wing conspiracy theory?
yes a conspiracy between the right wing, the left wing, and the engines of the aircraft.
Re:Balderdash! (Score:5, Informative)
Given that we're moving into an extended Solar Minimum, and the global temperatures are more likely to FALL than rise,
Solar activity has decreased since the 80's, while temperature has only shot up. Variance in solar activity is very small, only 0.1%, and easily overwhelmed by CO2.
Re: (Score:2)
yet anyone who has been outside on a sunny day knows the significant temperature differential that exists when in the shade versus being in the sun. It's a lot more than 0.1% or whatever nonsensical number you gave.
http://lasp.colorado.edu/home/... [colorado.edu]
Oh, and there's no shade in space. You may be cool in the shade of a tree, but that only means that the tree itself is getting warmer.
Re: (Score:2)
I don't remember the last time I saw clear skies.
I do...
September 12, 2001
Re: (Score:2)
Ever hear of cloud seeding? Small particles like soot trigger the formation of water droplets, from water vapour in certain atmospheric conditions. The reason contrails start and stop, and sometimes persist for longer is the changes in humidity in different air masses,
Re: (Score:2)
Each ice crystal forms around a speck of soot.
Re: (Score:2)
You know, I was always wondering... With the advances in telepresence (quite frankly, I have replaced virtually all personal meetings with telcos), wouldn't it be a strong message to send if they did not travel around the globe to meet for negotiations?
I guess it doesn't make for good press pics, I give you that, but I'm sure some solution can be found for that, too.
Re: (Score:2)
We use video conferencing at work (I'm not a climate scientist) and it's still problematic, unfortunately, with people randomly vanishing from meetings, people with noisy connections, poor microphones, noisy colleagues in a shared office as the meeting room wasn't available, someone decides to dig up the road right outside, etc. So it's certainly a useful adjunct to in-person meetings but we have face-to-face ones as well. Sure, we could spend a ton and have dedicated links set up, but that's not what most
Re: (Score:2)
I have no actual figures, but I would be surprised if that was true. I am sure most of our trains are electric by number of trains and by number of passengers are electric. There are few diesel passenger trains, but possibly the majority of freight trains are diesel. I have just returned from Switzerland and the mix appeared similar there.
When comparing trains with planes, remember, most trains carry about 1,200 passengers, with engines
Re: (Score:2)
No. Britain today has not yet reached the level of railway electrification of Switzerland an hundred years ago.
Here are some statistics from 2016: https://www.statista.com/stati... [statista.com] (only lines in service are counted) showing Switzerland at 100%, Eu average at 54%, UK at 34%.
However, the traffic share of electric railways tends to be substantially higher, as most traffic runs on electrified lines. An EU document from 2017 ("Electrification of the Transport System") states that 60% of main lines in Europe are
Re: (Score:2)
The lines may be electrified, but they still use diesel engines in both countries. I was on Zug (name of town, but means "train" in Swiss German) Station on Monday - almost all the freight trains were diesel (some going between Germany and Italy).
Here in London, the majority of trains are electric both by number of trains, and number of passengers. The Underground and Overground have trains every 2
Re: (Score:2)
There are different types of clouds. The contrails are cirrus clouds, which consist of ice crystals and have been shown to contribute to warming.
Clouds reflect some light, let some through. Those effects also depend on the wavelength of the light.
Cirrus clouds let though most wavelengths in sunlight. But they tend to block infrared. So they keep the heat radiated from the earth in, while at the same time letting in nearly all of the heat from the sun.