Chemtrails, why only in certain countries??

Question

why are chemtrails only observed in certain countries, mostly north america and parts of europe.

Answer 1

There is no such thing as a chemtrail. They are condensation trails or contrails and they occur everywhere where aircraft are flying in the upper troposphere if conditions are right.

There is a ridiculous conspiracy theory propounded by people who know nothing of atmospheric physics that these contrails are attempts by governments to poison the population. They are not. Contrails were first observed in the 1930s when aircraft started flying high. During World War II a method of forecasting their height and duration was devised using aerological diagrams from temperature soundings.

I have recently written a paper on the conspiracy theory which has been published in The Skeptic in Australia. See "Chemtrails: the sky's the limit" The Skeptic Vol 27 No 2 Winter 2007