Some cities I k ow have smog:
Beijing, Hong Kong, Taiwan, Singapore, Jakartra, Mexico city, New York, Los Angeles, Houston, Atlanta. Flights get delayed in Northner Brazil because of clouds of ash from slash and burn smog from the rainforest. Similar shit happens in Singapore. Poland is part of the most polluted corridor in Europe, and pollution which knows no borders fucks over multiple countries.
150 years ago wasn’t necessarily better either. When we burned coal we had London Fog, which is pretty much what you see today in a lot of China. Ships burn the cheapest and most polluting grade of fuel, and so all major crowded port cities are among the most polluted whenever there are sufficient crowds of cargo ships lined up.
Most cities and subburbs near major cities now have a tinge of brown or even grey smog depending on the day, which doesn’t exist in a lot of Southern hemisphere cities. Much of Japan has it to a degree, even in more rural outskirts. After a literally surprised when I didn’t see it in the capital of Western Australia, or most of New Zealand, but then again it’s right by the coast, and Melbourne, Sydney and definitely have it. The skies are generally a darker blue like if you climbed a mountain. Most people have lived with desaturated skies for so long they have forgotten what it normally looks like, and a single farm can fuck it up for several km by a highway just from the dust of a few tractors.