[harmonics]

> Settlements used to be covered in smog due to coal fires for example.

Used to? Lots of them still are. Right now there's 150 µg/m³ of PM2.5 outside my window, and it's a "clean" day. Yesterday's concentrations were up to 900 µg (yes, that's correct), and the highest I've seen this winter were 2000 µg (yes, this is also correct). And it keeps getting worse, recently our so-called president mentioned that coal is our strategic reserve and we won't be phasing it out any time soon.

I'm relatively sure most of the "global south" has bad air quality, even if such extreme values are rare.

Here are some random photos of a typical winter day (winter is 8 months per year):

https://pasteboard.co/d2uZDyCd2gvt.jpg

https://pasteboard.co/F1zT2VPXFPKs.webp

https://pasteboard.co/r2S12bHXxzcI.jpg

https://pasteboard.co/w7CfK2Yfaz2l.webp

https://pasteboard.co/ceSDNcQuD4qL.jpg

https://pasteboard.co/z7XJcpoI6FCv.jpg

[ricardo81]

I was thinking more localised. When legislation changes happened (here in the UK) the problem disappeared quickly. The UK being an industrialised country in the context of the parent comments.