JenCluse
I don't mean to sound smart-arsey or anything, but the fact that the temperature dropped and the skies cleared several days after the grounding of air traffic means absolutely nothing, at least in the UK! Whether the traffic was in the air or not, i can almost guarantee that the weather would have changed anyway!!!
As an aside, as a youngun, as many of us are, it isn't for me really a case of whether the environment is changing with or without input from human sources, I personally feel that people should do as much as they REASONABLY can to reduce this whole carbon footprint - use a bicycle where realistic, walk, etc when it isn't necessary to travel by any other method.
And while I'm not sure whether global warming is that heavily affected by humans, what I am sure of is that the things we do put into the atmosphere make the air we breathe less pleasant and more unhealthy with who knows what toxins. Up in the north west, the ICI paint plant produces an extremely unpleasant smell when you go past it and you know that the poor people that live around it have to breathe that air.
But then again, why am I on this forum? Because I'm just about to start training to fly airliners and burn masses of fuel over my (hopefully) 35 year career so who are we to give advice - no matter how little they contribute?!
cf