Aircraft vapour trails 'could cause global warming'

Breaking News ^ | 29/04/2004

[presidio9]

Cloud-like white trails left by aircraft may be playing a significant role in global warming, a scientist said today.

The exhaust plumes contain carbon dioxide and chemicals which can lead to the production of ozone – which creates smog.

At the same time, the vapour trails, in the right conditions, can form feathery cirrus clouds which warm the surface of the Earth’s by trapping heat.

Patrick Minnis, of the USA’s National Aeronautics and Space Administration’s Langley Research Center in Virginia, studied how the average temperature of the US increased by one degree from 1975 to 1994.

While acknowledging that it was difficult to tell exactly how much of the warming was due to vapour trails, he said their contribution was “significant”.

Dr Minnis found that as air traffic in the US rose by more than 500% from 1970 to 1995, the number of cirrus clouds in the sky also increased.

Until now scientists have been unable to say whether they increased for natural reasons or because of aircraft.

According to the Minnis study the conditions needed to create natural cirrus clouds did not become more common from the 1970s to the 1990s.

He concluded, therefore, that aeroplane vapour trails – also known as contrails – which are clouds of ice crystals mixed with exhaust gases, must be responsible.

Andrew Carleton, a climate expert at Pennsylvania State University, who was not involved in the study, said: “It suggests we may be having a double whammy here.

He told the USA Today newspaper: “It’s not good news for the Earth when you’ve got greenhouse gas increases and you’ve got ... contrails (that) seem to warm the surface of the Earth.”

[capt. norm]

How many jet aircraft contrails would it take to equal the output of one Mt Pinatubo eruption?

I don't think enough jet planes exist to match it.

I realize that they have to keep comingup with scary scenarios to dribble out to the media in order to keep their grant/funding from the liberal enviro-whackos, but they are really grasping at straws now.

[DustyMoment]

Aircraft vapour trails 'could cause global warming'

Oh give me a freakin' BREAK!!!! I thought it was caused by cows farting . . . or pork skins . . . or (fill in the blank).

More than 30 years since the Global Warming Theory was first proposed (and has since been recanted by the NASA scientist who initially suggested the GW Theory), alleged environmental "scientists" still don't know what causes it. Have they ever considered that it could be caused by the . . . um, SUN!!??

This is why you shouldn't let your kids fry their brains on drugs or put them on Ritalin. IDIOTS!!!!

[dfwgator]

Aircraft vapour trails 'could cause global warming'

And monkeys could fly out of my butt.

[capt. norm]

I hope you were joking.

First of all cirrus clouds are made up of ice crystals and they form at the edge of jet streams (the natural ones) when moisture (not carbon dioxide or ozone) freezes.

Carbon dioxide and ozone both freeze at temperatures sevral magnitudes colder than the temperature at the cirrus levels.

Cirrus forms where the air is cold enough for ice to form and not an inch lower.

[Arthalion]

Yup, I hate to agree with the environuts, but anyone who spends any time outside at all should be familiar with this. There have been days that I've walked outside and literally seen cirrus clouds stretching horizon to horizon as the contrails from passing jetliners have widened from the winds and run together (the area I live in lies beneath the flight paths of four international airports). If anyone here is going to tell me that man-made clouds up to a hundred miles wide DON'T affect the weather, I'm going to tell them they're nuts.

[Calvin Locke]

no no no not aluminum

I distinctly remember Bell commenting on the higher profits of the Alocoa.

Barium

Ugh. Strawberry flavored chalk....

[John H K]

You seem to be victim of the FR sydrome, common on science threads, of people babbling about things they know nothing about.

Contrails routinely form persistent cirrus clouds under the right atmospheric conditions.

There are atmospheric conditions, of course, where you don't even get a contrail, much less a persistent one that spreads out into a cirrus cloud.

At times you'll have waves where an aircraft flying level will have a "dashed line" contrail" as it moves into and out of areas favorable for forming one.

However, in many situations aircraft form persistent cirrus in areas that would otherwise be cloud free.

[Dr._Joseph_Warren]

[Petronski]

If I had my way, your collection of quotes would be added to ALL environ-Mental threads.

[Petronski]

If I had my way, your collection of quotes would be added to ALL environ-Mental threads.

[John H K]

Well, what people used to insist was that those persistent cirrus were CHEMtrails comprised of evil gubbmint experimental chemicals; I notice that idiocy seems to have died down, thankfully.

It's a simple matter of the combo of a variety of atmospheric conditions with jet aircraft exhaust.

[mindspy]

LOL, that was funny.

[Arthalion]

Here's an experiment for you. Next time the mercury drops below freezing, drag a big, forced air propane heater outside, fire it up, and watch the results. Unless the air is exceptionally dry, you should see a "cloud" form downwind of the heater as the frozen moisture in the air is vaporized by the heat and condenses into a local cloud.

Jet engines do the same thing, only on a greater scale.

The difference, or course, is that at cruising altitudes the temp is so low that these clouds quickly refreeze into ice clouds...which we typically call cirrus clouds (because that's what they look like), but which could just as easily be called "contrail clouds" if that term offends you. These "contrail clouds" can last for hours until they are finally dispersed by the wind, and in major flight corridors can actually combine to form a general overcast.

[PsyOp]

Can you believe this Nut Case!?! Everyone knows those aren't vapor trails! They're UN-piloted aircraft spraying the U.S. with experimental chemicals from high altitude...

It really irritates me when these junk-science wierdoes start start messing with perfectly sound conspiracy theories...

Ummmm... anyone see where I put my hat? It's the one with the foil insert...

[Salamander]

You're close.
It's caused by butterfly flatulence.
Everybody knows that.



;)

[INSENSITIVE GUY]

Vapor trails are great and hope to see more of them!

[Salamander]

"To Serve Man" is cookbook!!!!

[capt. norm]

To set the record straight, I am and have been a professional meteorologist for 34 years and operate the WeatherLab at Panama City (Florida) where we study such as that on a daily basis. It is you who have been fed a load of almost-fact.

Contrails form at a level where the dewpoint is below the freezing point of water. The dewpoint at upper levels of the atmosphere is cheked twice daily by weather balloons launched from NWS sites and is displayed on a plot known as a SKEW-T.

We study this day-in and day-out and you come along with something you have picked up somewhere that flies in the face of the actual facts.

[widgysoft]

its quite simple really.

them chemtrails are making a mess of our nice blue skys so lets blame global warming on them. That way planes will be banned and we can enjoy clear blue skys again. YAY!!

[Ditto]

They did a study of the days after 9/11, based on archived sat pics, and the cirrus cover was much, much lower than the current "normal."

And I bet that the month of September has the most number of cloudless days across the Notheast than any other time of the year with or witout contrails. Shut down all flights in January or February, and I bet the Northeast is still covered by clouds most days. How much you want to bet this wenie compared September of 2001 post 9-11 with February of 2002.

This stuff is bunk from the get go.