Well I'm with dukof on this - I can see chemtrails in the whole sky from my window all day long ( well, the parts that aren't hidden by the bars).
We know it's over the entire planet, because we can see all the way to the edge of the world ( no pesky curvature to interfere with the view, y'see).
Elvis agrees with me, too, doncha? (he said 'Uh, Uh uh uh, yea, yea')