I am not into this interest... Yet the clarity of some skies in some regions of the world is beautiful. That has to be very humbling as well.

The winds prevail here from the west. Has had to have a haze effect on the atmosphere from the industrial areas. Personally I suspect the acid rain alone resulting has done some damage here. The population of trout in the brooks and streams is almost non existent now here for example. So the ph of the waters has probably been changed substantially.

The closest major pollution source is perhaps 600 miles away. The trout were abundant here sixty years ago. The population has remained static in numbers over that period so they were not fished out.

It also makes a good illustration of just how much influence man has on the planet with so many of his activities. Even the oil companies past warnings about the long term effects of airborne pollution go unheeded. The interest you fellows follow is perhaps one of the ones that make you aware of this. Where it seems lost on the general public. We on the east coast of Canada. Took a lot of fallout from the pollution generated from the smokestack industrial centers of north America. This I believe is also documented.