IF this whole contrails thing is real, wouldn’t you need to do it over a significant percentage of the planet for it have any effect?

I don’t live in the US and I have not seen any evidence of some attempt to blanket the sky with artificial clouds where I live or in any of the many countries I have visited in the last year.

On top of that, even if it was every country was doing it that is only 1/3 of the earth’s surface, who’s doing the other 2/3?