flybywire wrote:
http://earthobservatory.nasa.gov/New...3?img_id=17474

Somewhat troubling logic he

"They might seem to be too transient to have a significant effect on
the atmosphere, but can influence the climate by increasing the cloud
cover in heavy air-traffic regions.

Clouds can have contradictory influences on the climate, depending on
their extent, thickness, and altitude, among many factors.

Clouds can cool the climate by blocking incoming sunlight, and they can
also warm the climate by absorbing energy radiated from the Earth's
surface.

Thin cirrus clouds have more of a warming influence; their thinness
makes them not very good at intercepting incoming solar radiation, but
they do absorb outgoing radiation that would otherwise escape to
space."

But:

"In 2004, NASA scientists discovered that contrail-generated cirrus
clouds could be responsible for much of the warming of surface
temperatures over the United States from 1975-1994.

The streaky clouds were not found to be the culprit in other parts of
the globe where temperatures also warmed.

The scientists said that the discrepancy indicates that warming from
contrails is in addition to warming produced by increasing
concentrations of greenhouse gases."

Yeah, right.

We are talking about a cyclical range of less than 1.3 degrees
Centigrade -max., in something like 14 years:
http://www.john-daly.com/index.htm#nasa

Note:
"However, after looking closely, there is evidence that both satellites
have calibration drifts."