“Researchers believe dust particles trigger the formation of high-altitude cirrus clouds — although experts have no idea whether such clouds warm or cool the earth.”
http://www.reuters.com/article/newsOne/idUSTRE56J3YH20090720
It takes a year for the earth to complete an orbit around the Sun. That might help you on Cash Cab someday.
http://www.google.com/hostednews/ap/article/ALeqM5gRA3F_dIB5dkruSZ2Va3aka3zOwQD99B65U00
The Exeter Town Crier 