One thing that's clear about those and other studies is that there's a lot of uncertainty as to both radiative forcing effects of contrails (how much they trap and reflect heat) and the effects of the various mitigation methods (like increase CO2 emissions, crowded skies, increased travel time, costs). This uncertainly is probably why nobody is really pushing to do something.
Mitigating contrails by adjusting cruise altitudes may also be impractical simply because of the huge volume of air space that can be conducive to persistent contrail formation.Several issues were encountered during the study, putting a damper on results from this
study. In particular, the sheer size of the high contrails-risk airspace volumes to be avoided
was so large on occasions that most of the avoidance algorithms were not applicable.
-- ATM Contrail Mitigation Options - Environmental Study
No matter what..they are STILL contrails...and not some nefarious "aerosol spray program".
Then why after all the studies and discussion not one single superficial or practical mitigation effort has been implemented?????Originally Posted by Trigger Hippie
The only thing guaranteed in life is deception. . . everything else is optional . . . George B
I don't necessarily think that is true. . .
http://www.mendeley.com/research/a-n...ntrail-cirrus/
Transportation Research Part D: Transport and Environment (2005)
Volume: 10, Issue: 5, Pages: 421-426
ISSN: 13619209
DOI: 10.1016/j.trd.2005.04.012
Available from linkinghub.elsevier.com
or Find this paper at:
Abstract
Aircraft induced cirrus clouds have a major effect on climate. Here we use operational radiosonde data with high vertical resolution to estimate the effect of a small change in flight altitudes on the contrail and cirrus formation. It is shown that a substantial fraction of contrails and contrail induced cirrus can be avoided by relatively small changes in flight level, due to the shallowness of ice-super-saturation layers.
The only thing guaranteed in life is deception. . . everything else is optional . . . George B
lee h oswald (March 10th, 2012)
What is true . . . is . . . if flight times were managed properly the resulting contrails and induced cirrus cloud banks could be beneficial instead of only ugly. . . See.Solutions
http://www-pm.larc.nasa.gov/sass/pub...troller.09.pdf
Last edited by George B; March 9th, 2012 at 05:36 PM.
The only thing guaranteed in life is deception. . . everything else is optional . . . George B
Studies regarding persistent contrail mitigation are showing conflicting results and you're wondering why there is no government policy to mitigate persistent contrail formation.
Maybe because the studies are producing conflicting results.
There is no confusion on how to mitigate persistent contrails. . . They have just not done it. . . They chose lower greenhouse gases and less fuel per passenger mile. . . They knew all along more efficient engines would result in more persistent contrails. . .
The only thing guaranteed in life is deception. . . everything else is optional . . . George B
Looks like you've answered your own question.
That is my point . . . It was a conscious policy decision. . . Thank You for recognizing that fact!!!!!!!
The only thing guaranteed in life is deception. . . everything else is optional . . . George B
Belief does not equal reality.
For example it's easy to prove that the strong beliefs of billions of people is totally wrong -
There's about 1.5 billion Muslims in the world.
There's about 2 billion Christians in the world.
They can't both be right, and they are almost certainly both wrong.
True - More fuel efficient jets have higher exhaust gas temperatures going into the turbine section, the higher they can stand the better. The turbine section extracts energy from the gas stream but there's still quite a lot of residual heat energy expelled out the back of the engine. If the turbines were 100% thermally efficient they'd exhaust the gasses at ambient temperature but with the laws of thermodynamics being what they are we can only extract a fraction of the energy.
While that is true of the interior . . . the exhaust that is expelled into the atmosphere has a lower temperature than the exhausts of lower efficient engines and the exhaust has also higher relative humidity because of the more complete combustion than the lower efficient engines . . . thus a greater likelihood to form visible and persistent contrails in less optimal air than earlier engines . . .
The only thing guaranteed in life is deception. . . everything else is optional . . . George B
I never said it did . . . the point was being made that complaining about chemtrails was in essence complaining about persistent contrails and contrails induced cirrus cloud banks . . .
The only thing guaranteed in life is deception. . . everything else is optional . . . George B
Many months ago, I referred Lee to Robert Van Waning's site. Robert started his crusade against contrails over the Netherlands when his sunny beach resort there was shunned by tourists who really found more suitable conditions in Ibiza.
Another more common sense pressure group against contrails is the ETC group.
They both reject all belief in chemtrails, and maintain a distance from the chemtrails hoax advocates like Lee and George, for obvious reasons.
Neither George nor Lee will ever have any effect in the real world, their chief purpose seems to be creation of mobius gigo loops.
"A lie can travel halfway around the world while the truth is putting on its shoes." ...Mark Twain
Technically true, it is essentially what you said.
More people are complaining about 'chemtrails' because of the very poor dis-information being spread about them.
I'm gonna need a reference for that. In any case if what you say is correct then the better the engine runs the more contrails we should see. So greener engines make their mark!
The interior, or core to give it its correct name, is the only section we're interested in as the outer section, or cold stream duct, does not have any combustion going on.
I never said I agreed with you, just that you answered your own question. It could also be explained by inaction on their part.
Aren't people currently trying to determine the effects of persistent contrails on the environment? There does not seem to be agreement. Why force airlines to fly expensive and wasteful routes when the climate impact of persistent contrails is not well understood? Is there something you know that the German Institute of Atmospheric Physics doesn't?
This study by the DoE makes it clear that reducing or altering the Cirrus Cloud Banks could result in mitigating global warming . . .
6. Recapitulation
Recent GCM studies (Sanderson et al2008, Mitchell et al2008) suggest that climate sensitivity is very sensitive to upper tropospheric cloud cover and humidity, making cirrus clouds a logical candidate for climate modification efforts. Cirrus clouds also affect OLR more than other cloud types, with their modification directly addressing the radiation imbalance imposed by greenhouse gases. Due to the expected dominance of homogeneous freezing nucleation at temperatures below−40 ◦C, it may be possible to decrease cirrus cloud coverage by introducing efficient heterogeneous ice nuclei at these temperatures where the cirrus greenhouse effect is strongest.
http://www.agriculturedefensecoaliti...References.pdf
The only thing guaranteed in life is deception. . . everything else is optional . . . George B
That's right. It "could result" in mitigating global warming. Like I said, the studies are not very conclusive.
http://ozone-uv.defra.gov.uk/reports...ertainties.pdf
Paragraph 3.3.2
The only thing guaranteed in life is deception. . . everything else is optional . . . George B
Ah okay - You haven't interpreted that correctly sorry.
All it says is as the bypass ratio (the ratio of air going around the cold section compared to the hot section) increases, so does propulsion efficiency and this also reduces the exhaust gas temperatures.
It does reduce the hot section temperatures directly, it does reduce the overall temps due the larger proportion of cold air around the hot core exhaust gasses.
So like I said earlier, the more efficient the engine the more likely it is to make contrails.
LoL . . . I never met a scientist, politician, physician or any professional that did not disagree with someone's theory not their own . . . theirs the only one that has any chance to be correct . . . the question is . . . is there sufficient consensus about something to form a policy and act or not act . . . what is the threshold . . .I think the threshold has been met and you don't . . .
The only thing guaranteed in life is deception. . . everything else is optional . . . George B
That's not actually true, and I shamefully take some responsibility for spreading this urban legend. When I was starting out in the chemtrail debunking hobby, I though that efficiency referred to the efficiency of combustion. It does not. It refers to the ratio of energy propulsion to waste heat energy. Combustion is basically complete in any engine in the last 50+ years.
If anything, the exhaust is much LESS humid, as the volume of air is greater, and there is much less fuel burnt, as it's more efficient. Of course this is somewhat counteracted by the engine and plane being bigger.
A better measure is the contrail factor, not the efficiency.
And how did you determine this? Did you take a poll of climate scientists?
What? Sounds like some sort of "post-normal science" or something.LoL . . . I never met a scientist, politician, physician or any professional that did not disagree with someone's theory not their own . . . theirs the only one that has any chance to be correct
Pretty much everyone I've met in the above professions are mostly the opposite of what you describe. Did you spend your career in a bunker full of paranoid schizophrenic egomaniacs or what?
As arrogant as Isaac Newton was said to be, one of his most famous quotes states:
If I have seen farther it is by standing on the shoulders of giants.
Right. Like I said before, the increase in efficiency is a product of the bypass fan. The rate of increase in fan diameter, hence efficiency, is driven by the ability to design and manufacture gear assemblies to withstand the harsh conditions, that keep the fanblade tips below supersonic speeds.It refers to the ratio of energy propulsion to waste heat energy. Combustion is basically complete in any engine in the last 50+ years.
Isn't the humidity of the air being used for combustion a factor? I don't get it...doesn't the exhaust have to push the saturation, in respect to ice, past the supersaturation point in order for the contrail to persist?
Last edited by Noble1965; March 10th, 2012 at 02:44 AM.
You are all making my point. . . You are all trying to state your position on engine efficiency and what causes persistent contrails. . . Please fined me the one definitive, scientifically validated explanation that all those scientists will agree with. . .
The only thing guaranteed in life is deception. . . everything else is optional . . . George B
thanks for clarifying: but maybe you put the emphasis in the wrong place - I think I demonstrated quite clearly that 'global coordination of any sort' (Your exact words)is the norm. This would be in direct contradiction of your statement. It shows where your bias is; it is easy to see that your position is not correct, but you prefer to believe this to be the case rather than knowing it to be so - as it so clearly is not so.
You also said:
Global commerce is easy.
global regulation? ...not so much.
Again, your assertion is easily taken apart. Are you saying there is no regulation in global commerce? Come now - I think you really need to check your logic, judgement etc. Statements like these are bordering on disingenuous. But they do provide opportunity to expose your cognitive bias.
Good morning lee . . . welcome to the Thread Wars . . .
The only thing guaranteed in life is deception. . . everything else is optional . . . George B
The humidity of the air going in is a factor. But the point here is that a high bypass engine does not create wetter air through more complete combustion. The exhaust gas is wetter than the air going in, but not wetter than the exhaust gas of a less efficient engine.
When a certain mass of fuel is burned it creates a certain mass of water which is added to the air. High bypass engines create basically the same amount of water per gram of fuel as low bypass, but they burn less fuel per pound of thrust, as they make more efficient use of the energy of combustion. They also mix that smaller amount of fuel with more air before it is expelled. Then the thing that tips the balance is that that exhaust air is a lot cooler, as more of the energy goes to thrust, not direct heat.
And the exhaust has to push the saturation, with respect to WATER (not ice), past the saturation point for contrails to form. The ambient air needs to already be supersaturated with respect to ice for the contrail to persist.
Please find me the one definitive, scientifically validated explanation that says the trails aren't just contrails...and they are intentional.
Last edited by Mick; March 10th, 2012 at 06:10 AM. Reason: typo edit for clarity
Oh the scientists agree on these basic matters. It's just us yahoos on the internet
And what is your point? I though your point was that the science was all worked out decades ago, which is why they decided to not do anything about contrails.
Because MY point was that the science of contrail's interaction with climate is not well understood, which is why they have not decided anything, and are still studying it.
So what is your point?
You are going deep into the world of philosophy with this - and what exactly do you believe? That you are almost certainly right? I think you'll find that's a bit harder to answer than your previous general assertions, if you're honest and take time to properly think through what you've said here. To be so sure of others' 'wrongness' and one's own 'rightness' is not necessarily helpful in any respect.
Belief does not equal reality. It's easy to prove that the strong belief of billions of people is totally wrong
Can't you see what a can of worms this statement is? Either that or - go ahead and prove it.
Last edited by lee h oswald; March 10th, 2012 at 06:21 AM.
Yes, the one thing they did agree upon is that high efficiency engines have a higher chance to produce persistent contrails . . . so they considered it something to study with multiple research efforts and to do nothing to mitigate them . . .Oh the scientists agree on these basic matters. It's just us yahoos on the internet
And what is your point? I though your point was that the science was all worked out decades ago, which is why they decided to not do anything about contrails.
Because MY point was that the science of contrail's interaction with climate is not well understood, which is why they have not decided anything, and are still studying it.
So what is your point?
The only thing guaranteed in life is deception. . . everything else is optional . . . George B
Because they don't know what the quantitative effect of that slight increase in contrails is across all domains, nor do they know the costs or effects of mitigation attempts.
And scientists research, they don't legislate. Since mitigation would cost the airlines money, it requires legislation. Since the scientists don't know much about it, they can't yet present a good argument either way.
But you think someone figured it out 20 years ago?
Last edited by Mick; March 10th, 2012 at 06:56 AM. Reason: of -> or
Noble1965 (March 10th, 2012)
And this from the man who is proud of his country's (US) position as '...the foremost defender of freedom in the entire world.'
Hmmm...the 'real' world, eh?
Ok, then we ARE in agreement.
And a very good morning to you, sir. (Actually, it's mid afternoon round my way!)
Yet, he did exactly that with that one post.
Either 1.5 (I read somewhere that the number is actually 2.2 billion) Muslims are wrong, or 2 billion Christians are wrong. Either way, billions of people are wrong. Or to be technical, anywhere between 1.5 billion and 3 billion people related to this one argument, are wrong. Both Christians and Muslims can't be right...according to their own religions.
Add all the other religions to the mix and there are many billions of people who must be wrong. Then again, we could ALL be wrong as far as "god" goes. And that includes anyone who has ever lived, which is many more billions.
Again, this is based on their OWN beliefs, not my personal beliefs about their religions.
Last edited by Noble1965; March 10th, 2012 at 06:58 AM.
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