So you think "Chemtrails" are real huh? Here's some debunking for ya!

reply to post by Hally Burton

So does the water vapour of a wingtip contrail still form an ice crystal?

If the ambient temperature is low enough, otherwise it will form water droplets (like fog).

Are you saying that without the ice crystals a persistent contrail would still form with the right relative humidity levels?

No.
A contrail is ice crystals. The relative humidity determines how long the ice crystals (and thus the contrail) will last. If the air is not saturated the ice will sublimate back into vapor. If the air is saturated, the ice crystals can grow and multiply.

If you are asking about soot, yes, a persistent contrail could form without the additional nuclei provided by jet exhaust. Cirrus clouds are composed of ice crystals, they form without the aid of jet exhaust.

reply to post by Phage


Is it possible that contrails could be prolonged using a higher content of sulfur in the jet fuel?

reply to post by Hally Burton

I don't see what difference that would make.

I suppose the assumption is that there would be more soot produced by high sulfur fuel. That may be valid but are you assuming that if it is true it would lead to more condensation nuclei, resulting in more ice crystals? As pointed out, the number of ice crystals is not relevant to persistence. It is the lifetime of the ice crystals which matters and that is dependent upon the relative humidity.

reply to post by Phage


I think a higher sulphur content would probably be easily detected by basic analysis - sulphur in diesel, for example, is a big issue.

So if there was some sort of increased sulphur conent you shoudl be able to find some verifiable evidence of it....

I was wondering about the sufur content because of this video, watch at 50 seconds in.

reply to post by Hally Burton


Again.....that video demonstrates the fact that these ideas are being contemplated --- considered --- as possibilities.


The comparison to volcanic eruptions, and the effects on climate have been made for decades. BUT....take some time to study the amounts of material that Mother Nature can spew, just from one volcano. And do some math.....to be able to re-create that, in Human technology and on our scales? Would be daunting.


Another thing that people tend to not think about, RE: 'anything' in jet fuel is --- the jet's engines are running virtually the entire time, from the time of push-back from the departure gate, until parked at the destination. The same exhaust gases, actually a bit more sometimes, during takeoffs, due to the high power settings. Idling, too (I haven't checked the exact figures) likely the exhaust is "dirtier" due to lower internal heat of combustion, and lowered efficiency in burning the fuels.

(Ever been downwind of a jet that is taxiing by? Up close, to smell the exhaust?? I have, many times...since I flew them for a couple of decades. Sometimes, just sitting in line to takeoff, on those long delays..... if the wind is angled just right, and I stopped a bit too close to the guy ahead, his exhaust will be swept into our air intake, for the Air Conditioning.....very unpleasant, so you learn to avoid that situation).

Also, another thing to remember....(most) commercial jets have the Auxiliary Power Unit (APU) which is basically a jet turbine engine, designed just to provide electrics and pneumatics for times when main engines are shut down....that turbine burns the same fuel as the main engines.

Additionally, much of the ground equipment at every airport is diesel-powered.....and, guess what they use in the tanks? Yup.....jet fuel.


As to the viability of "adding" sulphur to the fuel? I have some doubts about that, and whether it would make it through the entire process, through filters and to combustion and exhaust, without having grave effects on engine performance and long-term mechanical reliability.....sulphur is in the "metals" family, on the Periodic Table of elements, I believe?

Have to check its melting point, and stuff like that. It might be the type of material that would melt, and then coat all the internal parts of the engine....the turbine blades, for example...and bearings, etc...effectively destroying an engine. This is what happens when jet engines encounter volcanic ash, in flight for example.......

Originally posted by weedwhacker

As to the viability of "adding" sulphur to the fuel? I have some doubts about that, and whether it would make it through the entire process, through filters and to combustion and exhaust, without having grave effects on engine performance and long-term mechanical reliability.....sulphur is in the "metals" family, on the Periodic Table of elements, I believe?

Have to check its melting point, and stuff like that. It might be the type of material that would melt, and then coat all the internal parts of the engine....the turbine blades, for example...and bearings, etc...effectively destroying an engine. This is what happens when jet engines encounter volcanic ash, in flight for example.......

Sulfur is already contained within the fuel, but there are lower and upper limits as to the amounts of sulfur that can be used in the fuel of a commercial fleet.
However, a paragraph from an IPCC report seems to show that the refininers shifted from using low sulfur fuels to higher sulfur fuel.

Aviation and the Global Atmosphere:

The impact of the trend to use low-sulfur diesel fuels is not clear. Many refineries worldwide do not have the hydro-treating capability to make low-sulfur fuels. The API/NPRA survey for 1996 reported that 46% of the jet fuel blendstock in the United States was straight-run material that was not hydro-treated (API/NPRA, 1997). For many of these refineries with limited hydro-treating capability, the most economical approach may be to shift blending stocks with higher sulfur content to jet fuel, saving streams with lower sulfur for diesel fuel.

www.ipcc.ch...

reply to post by Hally Burton


I was talking about amounts of sulfur above and beyond those that are simply a consequence of using fossil fuels, and their inherent impurities.

Not all the sulfides can be removed....is a problem and concern with all petroleum-based fuels. The actual quantity of sulfides that exist, in exhaust, are tiny compared to the concepts envisioned as a potential "geo-engineering" task.

The sulfurs contribute to the "acid rain" phenomenon, in the way they combine to produce the SO2 molecule:

www.policyalmanac.org...

Coal accounts for most US sulfur dioxide (SO2) emissions and a large portion of NOx emissions. Sulfur is present in coal as an impurity, and it reacts with air when the coal is burned to form SO2. In contrast, NOx is formed when any fossil fuel is burned.

Read the whole thing, to see just one piece of the puzzle of the sorts of contaminants, and their origins....that are usually MIS-attributed to the hoax of "chem"-trail "spraying"......majority, is GROUND-based!!

The role of soot is quite complicated, but it's really only a major factor in borderline conditions. This paper goes into it in some detail:

air.snu.ac.kr...

It would certainly be possible to manipulate the content of fuel and the operation of engines to make denser contrails, but given that this would decrease aircraft efficiency, and actually increase global warming (both via more cirrus clouds cover, and increase CO2 emissions), there seems very little incentive to do it. Plus there's no actual evidence that suggests any such manipulation has happened.

Originally posted by Uncinus
The role of soot is quite complicated, but it's really only a major factor in borderline conditions. This paper goes into it in some detail:

air.snu.ac.kr...

It would certainly be possible to manipulate the content of fuel and the operation of engines to make denser contrails, but given that this would decrease aircraft efficiency, and actually increase global warming (both via more cirrus clouds cover, and increase CO2 emissions), there seems very little incentive to do it. Plus there's no actual evidence that suggests any such manipulation has happened.

Thanks for this reply and the paper supplied Uncinus as it is closer to the answer that I am looking for, thanks to weedwacker too.
This is the part of your post that interests me the most: "It would certainly be possible to manipulate the content of fuel and the operation of engines to make denser contrails"

As we can see from my earlier post above concerning Aviation and the Global Atmosphere, it tells us that the refiners were considering shifting blending stocks with higher sulfur content to jet fuel, this was back in 1996 and from what I can find is that it was back in 1999, that people began to notice the trails to a large degree and that the chemtrail phenomena first began.
Of course we know that there has been an increase in air traffic and therefore an increase in contrail dispersion, but as you have noted "It would certainly be possible to manipulate the content of fuel and the operation of engines to make denser contrails"
So, it interests me that the refiners were considering this shifting of blending stocks with higher sulfur content to jet fuel for economical reasons.
So did the refiners actually get around to it and could the large amount of dense contrails we see today, given the right atmospheric conditions be the result of this?

As I have pointed out with the video presented earlier, they have been considering increasing sulfur in the jet fuel to mitigate global warming, here is another article that considers that idea.

Increasing Sulfur Content of Jet Fuel in Commercial Fleet

This option involves increasing the sulfur content of jet fuel for the commercial fleet of jet aircraft (around 20,000 planes today) from 0.04% to 0.6 and increasing to 0.9% by 2050. Sulfur dioxide gas is emitted in the turbine exhaust and ideally, nearly all of it converted to sulfuric acid gas and then to sulfuric acid aerosol. The sulfuric acid aerosol floats around in the stratosphere for 1-2 years and reflects sunlight. The level in jet fuel is raised each year to match increased greenhouse gas emissions.

As for the sulfur in fuel option, current jet fuel sulfur levels are around 400ppm, mostly due to the removal of sulfur by use of hydroprocessing to meet other parts of the jet fuel specification or the fact that low sulfur feedstock is available (27-29). Jet aircraft have a specification limit of 3000ppm in their fuel in the U.S. and similar elsewhere, so the level could be increased by a factor of almost 8 without any modification to the specifications (30). I don’t know the origin of the 3000ppm limit, i.e., whether it is set for environmental or performance reasons and whether or not increasing it is feasible. Inquiries as to this have been made and will be reported in a revision to this commentary. The refiners would have to reformulate the fuel, but ironically, since their recent problems have largely been how to remove sulfur, this would require modifying their refining process to add more, a job that might take 5 years or so to complete (31, 32) or reverse, locking in the strategy. Thus, if this strategy were to be adopted, it would have to be continued for some time, even if the results were unacceptable.

www.global-warming-geo-engineering.org...

But as you have pointed out and as was posted earlier, the increase in contrail created cirrus appears to increase global warming and has not resulted in cooling.
Could the reason for this be that the formation of contrails is scattered due to atmospheric conditions during high air traffic and is therefore trapping heat locally for several days or maybe even weeks at a time and not reflecting sunlight on a global scale?
As the article above seems to claim "The sulfuric acid aerosol floats around in the stratosphere for 1-2 years and reflects sunlight." does this mean that contrails do not even need to form to create a reflective barrier and only needs to be dispersed as a sulfuric acid aerosol to float around in the atmosphere for 1-2 years, and that it is only because of the atmospheric conditions that we see the result as denser contrails. (if indeed the jet fuel has a high sulfur content)
What I would really like to know is if the sulfuric acid aerosol accumulates and floats around in the stratosphere above the poles, the north pole in particular since most air traffic is concentrated in the northerm hemisphere.

Originally posted by Hally Burton

But as you have pointed out and as was posted earlier, the increase in contrail created cirrus appears to increase global warming and has not resulted in cooling.
Could the reason for this be that the formation of contrails is scattered due to atmospheric conditions during high air traffic and is therefore trapping heat locally for several days or maybe even weeks at a time and not reflecting sunlight on a global scale?
As the article above seems to claim "The sulfuric acid aerosol floats around in the stratosphere for 1-2 years and reflects sunlight." does this mean that contrails do not even need to form to create a reflective barrier and only needs to be dispersed as a sulfuric acid aerosol to float around in the atmosphere for 1-2 years, and that it is only because of the atmospheric conditions that we see the result as denser contrails. (if indeed the jet fuel has a high sulfur content)
What I would really like to know is if the sulfuric acid aerosol accumulates and floats around in the stratosphere above the poles, the north pole in particular since most air traffic is concentrated in the northerm hemisphere.

There's two separate things going on there. Contrails, and specifically contrail cirrus, have a net warming effect, and this is mostly because of night contrails reflecting longer wave heat radiation. Daytime contrails have little effect either way.
en.wikipedia.org...

The long term aerosols formed by sulfates have a net cooling effect because they scatter sunlight more than they reflect ground based heat radiation. The difference here is due to the particle size and the relative wavelengths of incoming and outgoing radiation.

So what you say is essentially correct, and is the most plausible form of the chemtrail conspiracy theory. Where it falls down is that the only evidence supporting it is the assertion that that "chemtrails" started to be noticed in 1999. The problem there is that they were ONLY noticed in the conspiracy community, and only after they were popularized by Art Bell. Tens of thousands of scientists and meteorologists saw no change. Billions of ordinary people also saw no change. I saw no change.

The biggest problem with the theory is that if it were true, they you would expect global dimming to increase. In fact global dimming has steadily been decreasing since 1993 (Mt Pinatubo eruption). Or really since the 1970s if you factor out volcanos. This has been mostly due to the clean air acts in most developed nations.

en.wikipedia.org...

Levels of black carbon (soot) and sulphate aerosol in the Arctic have also decreased steadily in the last 20 years:
www.atmos-chem-phys.net...

Originally posted by Uncinus

The biggest problem with the theory is that if it were true, they you would expect global dimming to increase. In fact global dimming has steadily been decreasing since 1993 (Mt Pinatubo eruption). Or really since the 1970s if you factor out volcanos. This has been mostly due to the clean air acts in most developed nations.

en.wikipedia.org...

Levels of black carbon (soot) and sulphate aerosol in the Arctic have also decreased steadily in the last 20 years:
www.atmos-chem-phys.net...

While it is true that global dimming has decreased, this is due largely to a reduction in industrial emissions, and anyone who has lived in say the 50's

60's and 70's will know that there has been a marked decrease in not only industrial air pollution but also water pollution etc.
So if you were to factor out volcanos, industrial emissisions and anything else for that matter that may induce dimming and you were left only with airline emissions, not only would you still have global dimming, although by a very small degree, but you would actually see an increase due to an increase in air traffic.
Airline emissions as you may know do not come under quite the same environmental scrutiny as that of industrial emissions, which brings us back to high content sulphur fuel and the shifting of blending stocks.

EU's airline emission goals under scrutiny "When the European Commission unveiled plans to slash transport CO2 emissions by 60% by 2050 last week, many assumed the figure would apply to road, rail and air travel in the same way. But EurActiv has learned that the cut for aviation is only 34%, a target both environmentalists and industry sources say is unrealistic."

"Sandro Santamato, head of the alternative fuel policy unit at the Commission's transport department, told EurActiv that "CO2 emissions from aviation will not decrease by 60% but by only 34% between 2005 and 2050". Other transport sectors will be measured against a 1990 baseline but in the 15 years to 2005, air emissions soared by some 81%. So the 2050 figure should be more easily achieved for airlines."

www.actmedia.eu...

So, taking into account that in the years from 1990 to 2005 there was an 81% increase in air emissions, (which begs the question of how much of a measurable percentage of that 81% occured after the mid 90's?) then there must have been a noticeable increase in persistent contrail formation, which as you claim Billions of the general public did not notice, while those in the chemtrail community did.
How the tens of thousands of scientists and meteorologists saw no change I have no idea, if indeed the figures are correct.

Could one of the reasons that the chemtrail community noticed persistent contrails in the first place be due to many of them also being ufo believers and therefore spend a lot of time checking the daytime sky?

I myself had read about chemtrails back in about 1999/2000 and kept my eye out for them, but as I did not notice anything odd at the time, apart from the odd sliver of the remnants of a contrail, I concluded that what was going on could only be happening in the USA and not happening here in the UK.
As it happens I live under a main UK to US atlantic flight path in the countryside, so the planes are already at cruising altitude by the time they reach my area, so if the conditions are right I should see trails.

It was not until around september 2002 while driving home just before dusk that in the distance, in the direction that I was traveling I noticed a huge X in the sky, it was not until I was almost under it that I realised that it was hanging above the local military firing range and practice ground.
I thought at the time that due to the build up with war with Iraq, that maybe it had something to do with the military, and it was only after that the trails became almost constant, so for a while I assumed that there must be a military defence explanation like bouncing radar signals over the horizon for instance.
As I mentioned the trails had been almost constant up until the iceland volcano when the skies cleared up during the period the planes were grounded, and even now they are not as frequent as they were, so does this mean that there is less air traffic than there was before the volcano, or has the fuel changed in some way that the trails are now rarely visible where I am, with the exception of the 4th of May when the trails were particulary heavy as a frontal weather system was on the way, although for a couple of days before that I noticed a lot of plane activity above but were not forming persistent contrails.
Now the plane activity appears to have tailed off again except for the Atlantic flight path of course, but even when I look to see if there are any trails now there are none, the sky is absolutely clear, almost of planes too except the odd plane heading towards the smaller airports, which is very different to all the planes coming from all directions like they did on May 4th and the couple of days previous.

As you have probaly gathered by now I do not go for the wilder chemtrail conspiracies like population reduction etc, but I do feel that the contrails are a lot denser than they used to be before when I noticed a change in 2002 and think that if it is happening, then there has to be a logical explanation for it, which has to be down to either economics, environmental, military use or even all three.

This is one of the most tricky ares of the chemtrail theory to discuss, because I feel that a very large part of the perception of an increase in persistent contrails is actually just that, a perception.

Contrail formation varies with the weather. The weather varies from year to year. Your focus varies from year to year.

You know how some years it snows a lot, some years it does not. Now if it had not been snowing much for a few year, and then it suddenly snowed a whole lot, would you not perhaps find some people who would say "oh, it's never snowed like this before, it must be geoengineering"? When really, it's just regular variation in the weather.

"Priming the pump" of your perceptions is also a big factor. I never really paid any attention to contrails before about 2004 when I started learning to fly, and then much more in 2007 when I started Contrail Science. I really can't say I remember huge persistent contrails in Los Angeles before 2007. But now I see them all the time, because I think about them a lot, with my hobby. Did then "chemtrails" only start in Southern California in 2007? No, that's just when I started paying attention.

It's a big red flag for the theory that the ONLY evidence is people's individual perceptions. Perceptions which I share, but with a different date. No scientists have noticed this change. No meteorologists have noticed it. Ask your local meteorology department at the nearest university if they noticed it. They study the sky a lot more than UFO watchers.

There's no evidence that a statistically significant change took place. Obviously you (and I) perceived a change, but that's all we can say.