Contrails - friend or foe?

[degrub]

link #3 is not functional  and the ftp server just times out. Perhaps a different link ?
Frank

[Justan]

The LL site insists on adding “http://” to the beginning of the link. The link I posed is repeated below with quotation marks added:

“ftp://ftp.rta.nato.int/PubFullText/RTO/EN/RTO-EN-AVT-150/EN-AVT-150-15.pdf”


When I tried the site a moment ago, the ftp site appears to be down when using an FTP program. There are other sites that address the topic. I used Mr. Google for the following:

“gaseous and particulate emissions with jet engine exhaust”

without the quotation marks and the first 2 results reference the NATO site I found.

[cybis]

...
But it’s hard for me to look at them without thinking about the toxic crap they dump into the air. While contrails admittedly occur only during certain conditions, those conditions are commonplace for commercial aircraft.

Unfortunately, we would have to radically change not only how air traffic is done but also how any internal combustion engine works, to significantly alter the overall volume of chemicals that are dumped into the atmosphere, from the ground and at any distance above that. That is not likely to happen any time soon.

At least in my life federal and state legislation has served to remove lead from fuels and newer diesel fuels now have ultra-low sulfur content. Those are both huge positive steps.
...

Just to be sure we are on the same page, the contrails (condensation trails) are simply made of water. The main environmental impact of air travel are a massive release of the non toxic invisible CO2, a greenhouse gas.

[Justan]

> The main environmental impact of air travel are a massive release of the non toxic invisible CO2, a greenhouse gas.

I believe you are mistaken. CO2 is part of the issue, while jet fuel exhaust is another part.

[cybis]

> The main environmental impact of air travel are a massive release of the non toxic invisible CO2, a greenhouse gas.

I believe you are mistaken. CO2 is part of the issue, while jet fuel exhaust is another part.

CO2 is part of the 'jet fuel exhaust'. You are correct that air travel also causes the release of other toxic substances similar to all other combustion engines. But the release of those substances is mostly away from populated area (i.e. high altitude). A far greater concern is the release of the same chemicals in cities by cars and trucks.

And contrails are made of water, just like all other clouds.

[Rob C]

Great juxtaposition of pelicans and jet!

Yes, it's a lovely image that would lose a helluva lot without the hand of man... And in this case, blue cloudless is best.

But Jumbo Jets! I hate them; fly in anything other than a Jumbo. Haven't you noticed how they shake themselves almost to destruction as they take off? Oh - something you might care to know for next time you fly: the worst area for materials disintegrating in aircraft is around the toilets. Stop pissing, folks, take it home with you!

Rob C

[bjammin]

This maybe slightly off topic, though I dislike contrails in my pictures, contrails do have a major effect on the environment: global dimming.  In a nutshell, scientists have discovered that contrails act as cloud actuators.  That is, they lead to more clouds and reduced sunlight to the earth.  The American Public Broadcasting program NOVA had a piece on the phenomemon a while back and the program was quite compelling. It appears that global dimming may reduce global warming, but that is an entirely different topic.

If you would like more information on this, here is the NOVA website on the topic: http://www.pbs.org/wgbh/nova/sun/

Additionally, Wikipedia has a web page as well: http://en.wikipedia.org/wiki/Global_dimming

bjammin

[dreed]

In a nutshell, scientists have discovered that contrails act as cloud actuators.  That is, they lead to more clouds and reduced sunlight to the earth.

And aren't clouds something that most photographers covet in order to break up that barren blue sky?