Hi jjjnettie thanks, that's right it was an SBS doco where I saw that stuff on contrails
Hi Ron, what Argonavis says below has also pricked my memory a bit that the issue reported in that particular doco - i think - wasn't global warming rather the opposite where these contrails and various other airborne wastes were reflecting incident sunlight and reducing the amount of evaporation significantly at different locations around the globe, in some places by as much as 20-30% in the last 50 years - with consequences for rainfall etc etc..
cheers,