On Sun, 12 Dec 2004 13:07:18 +0100, Stefan
wrote in ::

Larry Dighera wrote:

If I recall correctly, as a result of the ban on flight over the US
following the 9/11 terrorist attack, there was a measurable
temperature rise attributed to the reduction in airliner contrails.

The source you menion says quite the opposite:

"Locally, contrails are equally as significant as greenhouse gases."


Would that "opposite" be during the day or night? It also says: "...
nights warmer by trapping the Earth's heat."

So while my 3 year old memory may have been incomplete, it was about
as accurate as your interpretation of the article I posted yesterday.

What seems infinitely more significant is the awesome magnitude of
exhaust spewing from airliners as a result of burning 18,536,000,000
(that's 18-1/2 trillion) gallons of kerosene annually*; one would
expect some environmental impact.

* http://www.aopa.org/whatsnew/factcard.pdf